naitate MUSEUM Novitates PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY CENTRAL PARK WEST AT 79TH STREET NEW YORK, N.Y. 10024 U.S.A. NUMBER 2714 JUNE 24, 1981 MARY LECROY The Genus Paradisaea Display and Evolution a es a is a ‘ ary Wg iad ee eee Spe ae No AMERICAN MUSEUM vitates PUBLISHED BY THE AMERICAN CENTRAL PARK WEST AT MUSEUM OF NATURAL HISTORY 79TH STREET, NEW YORK, N.Y. Number 2714, pp. 1-52, figs. 1-20, table 1 10024 June 24, 1981 The Genus Paradisaea—Display and Evolution MARY LECROY’ ABSTRACT The 42 species of birds of paradise are herein divided into three groups based on breeding be- havior: one group of 12 species for which monog- amy is known or assumed, one of 13 species which may either be territorial with a pair bond or polygynous with an ‘‘exploded’”’ display arena, and one of 17 species presumed to be polygynous arena-displaying species without a pair bond. An attempt is made to list characteristics that are shared by arena birds but not necessarily restrict- ed to them: (1) loud calls; (2) extreme sexual di- morphism in plumage; (3) males considerably larger than females; (4) few males in adult plum- age seen in comparison to numbers of females and unplumed males; (5) groups of males displaying throughout much of the year whether or not fe- males are present, and (6) frequently members of speciose genera. The seven species of the genus Paradisaea are treated in greater detail. Six (P. rubra, P. apoda, P. raggiana, P. minor, P. decora, and P. guiliel- mi) are considered polygynous arena birds with no pair bond. Reasons are given for thinking that P. rudolphi may have secondarily acquired pair bond behavior. The known displays of the six polygynous arena species are analyzed and the importance of dis- tinguishing between male-male displays which set up and maintain the male hierarchy and the fe- male-male displays which lead to mating is stressed. I have recognized eight display postures in the genus: (1) Wing Pose; (2) Charging; (3) Zig- zagging; (4) Male-male Duetting; (5) Flower Dis- play; (6) Inverted Display; (7) Hopping; and (8) Copulation. The first four are male-male displays; the last four are female-male displays. Other display components are discussed: Bill- wiping, Pecking-at-Perch, Ritualized Preening, Leaf-plucking, Butterfiy Dance, Sun-bathing, and Seed Regurgitation. Display of unplumed males is discussed, and a brief summary of calls is given. Evolution of polygyny and evolutionary relation- ships within the genus Paradisaea are discussed. INTRODUCTION Within the family Paradisaeidae, Paradi- saea is the best-known genus. The seven. species are birds of the lowlands and middle altitudes on New Guinea and nearby islands and may be found in close proximity to hu- man settlement. Despite extensive collecting by local residents dating to long before Eu- ropean contact and a period of over-collect- ing for the European millinery trade in the late nineteenth and early twentieth centuries, 1 Scientific Assistant, Department of Ornithology, American Museum of Natural History. Copyright © American Museum of Natural History 1981 ISSN 0003-0082 / Price $3.55 2 AMERICAN MUSEUM NOVITATES the birds are numerous in areas where their habitat remains intact. Gilliard (1969) has discussed the reasons for this ability to with- stand strong collecting pressures and has re- lated them to the birds’ mating system—an arena system in which males gather to dis- play in groups, whether or not a female is present. Usually there is no pair bond formed, and females visit these assemblages of males only for copulation. Nesting and raising the young are carried out by the fe- male alone. My observations of P. decora (LeCroy, Kulupi, and Peckover, 1980), P. minor, P. raggiana, P. guilielmi, and P. rudolphi in the field, and a careful rereading of Gilliard’s un- published field journals and an unpublished manuscript on the birds of paradise and bow- erbirds have led me to attempt the following analysis. My debt to Gilliard (1969, and other papers), Dinsmore (1969, 1970a, 1970b), and Cooper and Forshaw (1977) is obvious; and I have tried to consult as many original pub- lications on these birds as possible. Before beginning an analysis of mating be- havior in the genus Paradisaea, I will at- tempt to place this genus within the wider context of mating behavior as it is currently known within the family. The following sum- mary is based mainly on Gilliard (1969), Peckover (1973), and Cooper and Forshaw (1977). BIRDS OF PARADISE KNOWN OR PRESUMED TO BE MONOGAMOUS Of the 42 species of birds of paradise, 12 are either known to be or are suspected of being monogamous either due to lack of ex- treme sexual dimorphism or, in one case at least, because a domed nest is built and a brightly colored male would be concealed on the nest. These 12 species include the five species of Manucodia (including keraudren- ii). Manucodia ater and M. keraudrenii males are known to assist with nesting (Rand, 1938; Cooper and Forshaw, 1977), and it is presumed that the other species do also. Of the mating of the Paradigalla su- perspecies (two species) nothing is known, but a pair bond is assumed because the sexes NO. 2714 are very similar and without bright colors or obvious displays. Nothing is known of Ly- cocorax pyrrhopterus, which is included here because of its dull coloration. Rand (1940) reported a male Macgregoria pulchra accompanying a female as she built a nest and when she left to feed while incubating, and helping to feed the young, thus indicat- ing a pair bond. The three species in the subfamily Cne- mophilinae are little known and the infor- mation available is inconclusive. Gilliard (in Mayr and Gilliard, 1954) reported a male Loria loriae singing daily during July from a favorite perch; this possibly indicates ter- ritoriality. There is only moderate plumage dimorphism, both sexes being dull colored. In Loboparadisea sericea the male and fe- male are similar and are brightly colored, but the yellow rump and underparts would not be visible in either sex if the bird were sitting on the nest. There is no further information on display or nesting. Cnemophilus macere- goriae shows extreme sexual dimorphism in plumage, with the male exhibiting an unusual ‘“‘upside down’’ plumage pattern, red-orange on the upperparts and very dark brown be- low. However, it is included here because the species is known to travel in small parties of which one or two individuals are adult males, and these may be family parties. The observation that it builds a domed nest is usually given as a reason for considering that this species may have a pair bond, the con- spicuous male thereby being effectively con- cealed if he visits the nest, but Loke (in Sims, 1956, p. 426, erroneously recorded un- der Loria loriae; see Gilliard, 1969, p. 89) saw only the female at the nest and feeding the young. This may indicate that there is no pair bond or only one of short duration. This nest was photographed by Loke (1957, and in Gyldenstolpe, 1955, pl. XI, erroneous- ly identified as Loria loriae), and as W. S. Peckover (in litt.) has pointed out to me, the nest appears to be a hole in a living clump of moss and is thus not dissimilar to the nest reported for Diphyllodes (=Cicinnurus) re- gius in a cavity in a small tree (Gilliard, 1969, p. 199) and not truly a ‘‘domed’’ nest. Other birds of paradise may also nest in clumps of 1981 LECROY: PARADISAEA 3 vegetation. Local residents of Nade, Fergus- son Island, said that Paradisaea decora put its nests in clumps of arboreal ferns. The nest of this species has not been collected, per- haps partly because collectors have not looked in such an ‘‘unusual’’ place for a Par- adisaea nest. SEXUALLY DIMORPHIC BIRDS OF PARADISE WITH UNDOCUMENTED BREEDING SYSTEMS Thirteen of the dimorphic species are too poorly known for one to be able to decide whether the males are displaying territorial- ly, in which case there may be a pair bond of greater or lesser duration and the female may nest within the male’s territory; or whether an extreme form of arena behavior is involved and there is no pair bond, i.e., the ‘‘exploded’’ arena (Gilliard, 1963, pp. 41-42) where each male on his court is in auditory contact with other males but the arena Is too large and the courts too far apart for males to be in visual contact. Presumably all 13 have either one or the other of these breeding systems, and there is potentially a thin line between a small territory and the courts of an exploded arena, in the latter case with the female not nesting within the territory and no pair bond formed. A ‘*court’” may be thought of as a very com- pressed territory. Details of these 13 species follow. . All three species of rifle birds are known for their loud calls and it may be that there is an exploded arena. The females are barred and cryptically colored, and the males are ornate with iridescent plumage and short flank plumes. Males of the three species are usually reported displaying alone in the tops of tall trees, but Sharland (1977) has reported a male Ptiloris victoriae displaying only 18 feet up on a broken off dead tree under the forest canopy and Coates (1973, p. 3) has reported a display between two males of P. magnificus in the forest understory. It is not known whether this was a territorial display nor is it known whether other males ever display within auditory range of solitary males displaying in tree tops. In Seleucidis melanoleuca the male has elongated, brightly colored plumes and a loud call; the females are barred and crypti- cally colored. Males may be territorial as they are recorded displaying alone. At Kan- ganaman (Gilliard and LeCroy, 1966, p. 271) Gilliard found that the female alone incubat- ed, but there is no information on whether this was within a male territory. Bergman (1957a, p. 19) records two female-plumaged birds visiting a male at his display tree, but later when he observed copulation only a sin- gle female was present. The four species of sicklebills (Epima- chus, including Drepanornis) are very poor- ly known. When displays have been seen they have been by males alone and loud call- ing by the males is noted in the four species. That females alone rear the young is possible as Gilliard (ms) and Cooper and Forshaw (1977, p. 107) independently saw a nesting female Epimachus meyeri chase a male As- trapia mayeri away from the nest vicinity and in neither case did a male E. meyeri ap- pear. Diamond (1972, p. 331) found altitudinal differences in distribution between males and females of Lophorina superba with both sexes occurring between 1550 and 1727 m., adult males only between 1727 and 2121 m., and females and immatures only between 1060 and 1550 m. Thane Pratt (personal com- mun.) found that female-plumaged birds oc- curred above and below, as well as through- out, the range of plumed males in his study area on Mt. Misim. The males were highly territorial, as was a male I observed near Ubaigubi, in the Eastern Highlands at ap- proximately 1700 m., in October 1980. Dia- mond found that adult males were invariably solitary. However, in November 1978, Mary Stringer and I saw a male and a female-plum- aged bird together flying in an open garden area just below undisturbed forest in the Kratke Mountains at about 1660 m., and in October 1980 near Ubaigubi I frequently saw a male and a female-plumaged bird of this species feeding together in second-growth and garden areas. In captivity a male fed and displayed to a nesting female but killed the young bird when it hatched. A second nest- 4 AMERICAN MUSEUM NOVITATES ing was successful as the male was removed (Timmis, 1968). Other observations indicat- ing at least a short pair bond are allopreening by a captive pair (Crandall, 1932, p. 85) and a male coming to the aid of a female being chased out of a feeding tree by Melipotes fumigatus (Meliphagidae, Weston, 1977, p. 17). Pteridophora alberti is apparently territo- rial with a male patrolling a territory and sing- ing from various exposed perches (Gilliard, 1969, p. 188; Beach, 1975, p. 2), but males may clump in certain areas and there is thus the possibility that the territories serve as an exploded arena. The display with a female is a joint display in the substage of the forest canopy, and there is apparently no special display perch (Gilliard, 1969, p. 190; Beach, 1975, p. 2; Healey, 1975, pp. 6—7). There is no information on nest location and incuba- tion. The display of Diphyllodes (=Cicinnurus) regius in the wild is poorly known. Two males have been heard calling from the crowns of display trees 100 m. apart (Cooper and Forshaw, 1977, p. 162) and the display may have an aerial component (Goodfellow, in Ogilvie-Grant, 1915, p. 21). Whether this is arena display or territorial display is un- known. W. S. Peckover (in litt.) informs me that various members of the Papua New Guinea Bird Society, including himself, have observed a solitary male D. regius displaying in several localities near Port Moresby. In all of these cases there is “‘little doubt the dis- playing bird was in auditory contact with other ‘nearby’ displaying males.’’ In captiv- ity only the female tended the young and the male did not feed her (Bergman, 1957b). Coates (in Cooper and Forshaw, 1977, p. 169) found that a male of Diphyllodes mag- nificus stationed himself on his main display perch and called loudly when another male was heard, but it is not known whether the other male was at a display area. However, Cooper and Mackay (in Cooper and For- shaw, 1977, p. 168) observed three female- plumaged birds at a display area; but when Mackay observed copulation there was only one female present. Also Thair and Thair (1977, p. 13) reported the presence of two NO. 2714 adult males at a display area. This may in- dicate that Diphyllodes magnificus has no pair bond and displays in an exploded arena and should be included in the following group. More information is needed. Diphyl- lodes respublica is little known in the wild but will presumably prove similar to D. mag- nificus. SEXUALLY DIMORPHIC BIRDS OF PARADISE WITH ARENA BREEDING SYSTEMS The remaining 17 species, except perhaps Paradisaea rudolphi, are probably arena- displaying birds without a pair bond and with a polygynous social system. There are a number of characteristics shared by arena birds but not necessarily restricted to them, and it is useful to list these before discussing the non-pair-bond-forming birds of paradise. 1. Loud calls: The ringing calls of males are frequently noted not only for arena-dis- playing birds of paradise but also for arena birds such as various species of manakins (Pipridae) and the Cock of the Rock (Rupi- cola) in South America. These calls probably serve the dual purpose of assembling males at a display arena and of informing females of display in progress. They may also serve to notify other groups of males of display activities of their neighbors. What little in- formation we have on dispersal of arenas in a particular area indicates that activities at one arena are audible to birds at other arenas nearby (Peckover, personal commun., and LeCroy, personal observ.). 2. Extreme sexual dimorphism in plumage: As Gilliard (1969, p. 57) has stated, the re- lease of males from nesting duties has ap- parently relaxed natural selection for cryptic coloration and allowed rapid selection for bright plumage coloration (presumably in re- sponse to agonistic displays among males). The unusually large number of hybrids be- tween morphologically very distinct arena- displaying species argues for this, as genetic isolating mechanisms have not kept pace with the morphological changes in males. In these cases female plumage is usually cryptic and presumably conservative, although con- 1981 LECROY: PARADISAEA » vergence cannot be ruled out. The rapid and extreme development of sexual dimorphism of males is aided by the apparent fact that only a small percentage of the adult males in any clan are responsible for most of the mat- ings. Thus changes occurring in the domi- nant male(s) are potentially passed on very quickly to most of the males in the popula- tion, assuming that these changes are advan- tageous in the setting up of a male dominance hierarchy. These easily recognized species- specific signals are also important to females, who rapidly mate and form no pair bond, for fast recognition of the correct male. Hybrid- ization probably occurs when a female ready to mate is attracted to a display area of another species by the noise and movement of display among males. If the sort of alti- tudinal differences in distribution of the sexes that Diamond (1972) found in several species of bird of paradise is common, then it is easy to imagine a situation where males of one species are rare, but males of another species are more abundant. If a female ready to mate has difficulty finding a male of her own species, her threshold for discrimination may be lowered and mating with the wrong species might occur quickly upon her arrival at the arena. 3. Males considerably larger than females: This frequently occurs in arena birds and is presumably due to the same sort of selection pressures that allow for elaborate plume de- velopment in males. Upper limits of size dif- ferences in the sexes are presumably set by genetic constraints of mating compatibility, egg size, development of the embryo, and the ability of the female to raise the young. The size differences are apparent even in un- plumed males (see table 1). - 4, Few males in adult plumage compared with the number of unplumed males and fe- males seen: This, along with the possibility of a different altitudinal distribution of the sexes at certain times of the year, leads to an apparent skewed sex ratio; many ac- counts of arena birds stress the scarcity of males. This has been proposed as an expla- nation for the development of arena display by Darwin and others, but it seems clear now that this apparent scarcity of males is a result of the arena system, not its cause. There is the possibility (discussed below) that plume development in subordinate males may be inhibited. 5. Groups of males display for long periods during the year in arenas or exploded arenas, with or without females present: This has to do with the setting up and maintenance of the male-male hierarchy and is discussed more fully below. 6. Frequently associated with speciose genera: This may be assumed to have come about as an extension of the rapid acquisition of sexual dimorphism. Isolation of popula- tions would lead to rapid differentiation. In birds of paradise the arena birds are the gen- era that have speciated most. The 17 arena-displaying species of Paradi- saeidae are in only four genera. Semioptera wallacei is a monotypic genus and is con- fined to Halmahera and Batjan, with a sub- species on each island. It is very little known, but Gilliard (1969) gives evidence that it is an arena bird with groups of males displaying in low slender trees close togeth- er, that unplumed males and females out- number plumed males, that it has a harsh call, and that there is some sexual dimor- phism in size. The remaining species are in three genera: Astrapia, Parotia, and Paradisaea. Healey (1978b) has recently described the communal display of Astrapia stephaniae. He gives dis- tribution of display arenas, description of arenas (exploded arenas composed of sev- eral nearby trees), differing altitudinal distri- bution of males and female-plumaged birds (2050-2250 m. for all plumages but female- plumaged birds down to 1630 m. on occa- sion), reports virtually year-long period of display by males, and mentions loud calls and whistles by males at the display site but virtually silent displays to females. In all of these traits A. stephaniae agrees with other arena species. The other species of Astrapia, except per- haps A. splendidissima, will probably also prove to have communal displays. All five species are sexually dimorphic in plumage and all except splendidissima have pro- nounced sexual dimorphism in size. Differ- Paradisaea apoda apoda Plumed males Unplumed males Females novaeguineae Plumed males Unplumed males Females Paradisaea raggiana salvadorii Plumed males Unplumed males Females raggiana Plumed males Unplumed males Females intermedia Plumed males Unplumed males Females augustaevictoriae Plumed males Unplumed males Females TABLE 1 Measurements (in Millimeters) of the Genus Paradisaea Wing Tail Exposed Bill Tarsus Range Range Range Range ‘(mean + SD) N (mean + SD) N (mean + SD) N (mean + SD) N 222.0-232.0 5 156.5-171.0 6 34.0-36.0 4 53.0-57.0 6 (227.6 + 3.8) (162.2 + 4.8) (35.3 + 1.0) (55.2 + 1.5) 196.0-231.0 7 141.0-162.0 7 35.0-39.0 7 52.5-56.0 7 (213.9 + 12.9) (153.3 + 6.9) (36.6 + 1.4) (54.3 + 1.3) 178.0-190.0 4 132.0-137.0 4 33.5-360 4 47.0-49.0 4 (183.3 + 5.4) (134.5 + 2.4) (34.9 + 1.3) (47.9 + 1.0) 195.0—209.0 9 133.0-153.0 13 31.0-34.0 12 46.0-51.5 5 (199.4 + 5.1) (141.0 + 5.3) (32.3 + 0.8) (48.3 + 2.2) 180.0-197.0 5 131.0-141.5 5 32.0-340 4 49.0-50.0 5 (186.8 + 7.5) (136.5 + 4.5) (32.6 + 1.0) (49.7 + 0.5) 169.0-175.0 3 126.0-133.0 3 320-340 3 41.0440 3 (171.0 + 3.5) (128.7 + 3.8) (32.7 + 1.2) (42.0 + 1.7) 183.0-194.0 8 129.0-142.0 8 31.0-33.5 8 42.0-47.0 7 (187.3 + 4.1) (132.9 + 4.2) (32.1 + 0.9) (45:2 + 1.7) 173.0-191.0 21 120.0-140.0 20 31.0-35.0 19 43.0-49.0 20 (181.1 + 4.8) (129.7 + 5.7) (32.4 + 1.1) (45.6 + 1.6) 149.0-169.0 13 112.0-125.0 13 30.0-33.0 13 38.0-44.0 12 (160.0 + 5.8) (118.0 + 4.5) = (31.5 + 0.9) (40.0 + 1.9) 178.0-199.0 24 127.0-144.0 23 30.0-33.5 20 44.0-48.0 22 (188.4 + 5.4) (135.6 + 4.7) (31.9 + 0.9) (46.4 + 1.0) 187.0, 190.0 2 135.0,142.0 2 32.0,32.0 2 47.0 1 156.0-164.0 5 116.0-121.55 5 30.0-33.0 5 39.0-41.0 5 (159.0 + 3.1) (118.9 + 2.3) (31.5 + 1.2) (40.4 + 0.9) 177.0-188.0 12 127.0-140.0 11 31.0-35.0 11 42.0-47.0 11 (183.1 + 4.0) (131.7 + 3.9) (32.4 + 1.1) (45.3 + 1.6) 166.0-186.0 11 122.0-134.0 10 32.0-340 9 42.0-46.0 11 (177.5 + 6.7) (128.5 + 4.0) (33.2 + 1.0) (44.9 + 1.3) 151.0-159.0 7 113.0-128.0 7 32.0-33.5 7 38.0-41.0 7 (157.9 + 3.4) (119.0 + 5.3) (32.6 + 0.6) (39.0 + 1.2) 184.0-192.0 18 127.0-138.0 17 31.0-35.5 16 44.5-49.0 18 (188.4 + 2.0) (133.3 + 3.3) (32.8 + 1.2) (46.8 + 1.2) 175.0—187.0 5 122.0-138.0 5 33.0-34.0 5 45.0-48.0 5 (183.2 + 4.8) (130.6 + 6.0) (33.4 + 0.6) (47.0 + 1.2) 150.0-168.0 12 111.0-123.0 12 31.0-34.0 10 39.0-42.0 12 (159.2 + 4.6) (32.5 + 0.9) (40.2 + 1.0) AMERICAN MUSEUM NOVITATES (115.8 + 3.5) NO. 2714 Weights Range (mean + SD) 170.0, 173.02 2 168.0—203.0 3 (187.3 + 17.8) 1981 Paradisaea minor finschi Plumed males Unplumed males Females jobiensis Plumed males Unplumed males Females minor Plumed males Unplumed males Females “‘pulchra”’ Plumed males Unplumed males Females Paradisaea decora Plumed males Unplumed males Females Paradisaea rubra Plumed males Unplumed males Females Range (mean + SD) N 185.0-197.0 12 (192.5 + 2.9) 175.0-191.0 5 (184.3 + 5.9) 156.0-167.0 6 (161.2 + 5.1) 198.0-204.0 5 (201.6 + 2.5) 181.0-192.0 3 (186.3 + 5.5) 161.0-179.0 6 (169.2 + 6.2) 178.0-195.0 19 (185.7 + 4.8) 172.0-186.0 16 (177.7 + 4.0) 155.0-165.0 14 (159.3 + 3.1) 190.0-192.0 3 (190.7 + 1.15) 176.0-194.0 3 (184 + 9.2) 161.0-168.0 4 (164.3 + 2.9) 176.0-182.0 9 (180.0 + 2.0) 174.0-182.0 9 (177.1 + 2.5) 156.0-165.0 4 (159.2 + 4.0) 171.0-178.0 (174.1 + 2.1) 166.0-174.0 (170.8 + 3.2) 150.0-160.0 9 (154.0 + 4.2) LECROY: PARADISAEA TABLE 1—(Continued) Range (mean + SD) N 127.0-141.0 (134.8 + 4.0) 124.5-134.0 (131.3 + 3.9) 113.0-121.0 (116.0 + 3.5) 137.0-143.0 (140.3 + 2.7) 130.0-139.0 (133.7 + 4.7) 119.0-129.0 (122.8 + 5.2) 120.0-137.0 (128.6 + 4.5) 119.0-130.0 (124.6 + 3.5) 110.0-119.0 (114.4 + 3.1) 130.0-132.0 (131.0 + 1.0) 120.0-134.0 (129.0 + 7.8) 106.0-116.0 (109.5 + 4.5) 134.0-144.0 (138.5 + 2.9) 136.0-145.5 (139.9 + 3.4) 124.0-130.0 (128.3 + 2.9) 115.5-126.0 (120.3 + 3.3) 113.0-127.0 (120.1 + 3.6) 107.5-114.0 (110.8 + 2.7) 12 an 19 18 Exposed Bill Range (mean + SD) N 32.0-34.0 (32.9 + 0.7) 32.0-34.0 (33.0 + 0.6) 31.0-34.0 (32.2 + 1.0) 33.5-36.0 (34.3 + 1.2) 33.0-34.0 (33.7 + 0.6) 31.0-33.5 (33.3 + 0.9) 30.0-35.5 (33.1 + 1.6) 32.0-34.0 (33.3 + 0.7) 31.0-36.0 (32.4 + 1.3) 32.5-33.0 (32.8 + 0.3) 33.0-34.5 (33.8 + 0.8) 32.0-34.0 (33.0 + 0.8) 33.5-35.0 (33.9 + 0.5) 33.0-34.5 (33.4 + 0.6) 32.0-34.0 (32.9 + 1.0) 27.0-29.0 (28.4 + 0.8) 25.0-30.0 (28.1 + 1.4) 28.5-32.0 (30.9 + 1.1) 10 14 Tarsus rr Sn Range (mean + SD) 47.0-50.0 (48.0 + 0.9) 48.0-50.0 (49.2 + 0.7) 40.0-43.0 (42.0 + 1.0) 50.0-53.0 (51.4 + 1.5) 49.0-53.0 (51.3 + 2.1) 43.0-45.0 (44.3 + 0.8) 45.0-51.5 (47.2 + 1.4) 44.0-50.0 (46.8 + 1.6) 38.5-44.0 (41.6 + 1.2) 46.5-48.0 (47.2 + 0.8) 44.0-48.0 (46.5 + 2.2) 40.0-42.0 (41.4 + 0.9) 42.0-46.0 (43.7 + 1.2) 42.0-44.5 (43.1 + 0.6) 38.0-39.0 (38.5 + 0.6) 43.0—45.0 (44.1 + 0.6) 42.0-45.0 (43.8 + 1.0) 39.0-42.5 (40.5 + 1.3) Weights Range N_ (mean + SD) 12 264.0-291.0 (278.6 + 10.7) 6 256.0, 268.0 6 185.0 5 293.0, 300.0 3 210.0, 250.0 6 152.0, 185.0 19 225.0-285.0 (250.0 + 22.9) 19 205.0 165.0, 170.0 9 237.0 15 158.0-224.0 (203.7 + 20.3) 156.0-212.0 (194.9 + 19.2) 8 137.0-182.0 (156.8 + 17.0) i°) ea) Paradisaea guilielmi Range (mean + SD) N (mean + SD) N (mean + SD) N (mean + SD) N (mean+ SD) N TABLE 1—(Continued) Range Plumed males 169.0-181.0 16 109.0-120.0 (174.8 + 3.1) (115.4 + 3.6) Unplumed 161.0-183.0 10 111.0-120.0 males (171.6 + 6.0) (115.0 + 2.8) Females 150.0—157.0 7 101.0-110.0 (153.8 + 2.7) (104.2 + 3.0) Paradisaea rudolphi rudolphi Plumed males 152.0-160.0 6 76.0-80.0 (157.2 + 3.1) (78.6 + 2.6) Unplumed 153.0-156.0 3 92.0-93.0 males (154.7 + 1.5) (92.3 + 0.6) Females 141.0-146.0 4 91.0-100.0 (143.0 + 2.2) (94.6 + 3.6) margaretae Unplumed male 153.0 1 98.5 Females 141.0, 147.0 2 94.0, 97.0 ampla Plumed male 152.0 1 76.0 ences between the displays of A. stephaniae seen by Healey and those reported by Cran- dall (1932) for captive A. rothschildi may prove to be at least partly the difference be- tween male-male and female-male displays within the genus (see below for Paradisaea). In the geographically peripheral species (A. nigra and A. rothschildi) there has been no subspeciation but there is a cluster of popu- lations on the main trunk of New Guinea that is similar to Paradisaea in distribution. As- trapia mayeri and A. stephaniae are broadly sympatric, and hybrids between these pop- ulations are known. It remains to be seen whether A. stephaniae and A. splendidissi- ma meet. The genus Parotia is composed of four species (five if one recognizes helenae, see Schodde and McKean, 1973). Parotia wah- nesi, P. sefilata, and P. lawesii appear to have groups of courts in which groups of males display, and I would interpret this as an exploded arena system. However, I have watched a single male clear and display on three courts during a single display bout. During several days of observation there was never more than a single male present at the trio of courts. Very little is recorded con- 16 11 7 aod No — Exposed Bill Range Tarsus Range Weigh Range ts 34.5-38.0 16 45.0-48.0 17 — (36.7 + 1.2) (46.6 + 0.9) 36.0-40.0 11 44.5-49.0 11 _— (37.4 + 1.2) (46.5 + 1.4) 34.5-36.0 7 40.0-42.0 7 — (35.5 + 0.7) (41.4 + 0.9) 31.0-34.0 6 40.5-43.0 6 178.0 (32.3 + 1.0) (42.3 + 1.0) 33.0-34.0 3 40.0-43.5 3 165.0 (33.3 + 0.6) (42.2 + 1.9) 35.5-37.0 5 37.0-41.0 5 — (36.3 + 0.7) (39.5 + 2.0) 34.0 1 40.0 1 = = 34.0,34.0 2 39.0,40.00 2 — — 30.0 1 43.0 1 — — cerning calls. Displays are silent or virtually so, but calling occurs in the trees over a court. The sexes are very different in ap- pearance and there is pronounced sexual di- morphism in size. In P. carolae and P. se- filata, adult males have been found to occur at higher altitudes than unplumed males and females. An apparent scarcity of males in adult plumage has been reported. While there are no known hybrids among the species, P. lawesii and P. carolae are at least locally sympatric and there is a recent report of a female-plumaged P. lawesii hav- ing been seen on a P. carolae court (Healey, 1976). The species occurring on the Vogel- kop and on the Huon Peninsula have not sub- speciated, but the central complex of popu- lations has been considered to comprise two or three species with numerous subspecies. Again this is similar to the situation in Par- adisaea. The seven currently recognized species of Paradisaea are discussed in detail below. THE GENUS PARADISAEA Paradisaea rubra and P. decora are island species and have not subspeciated. P. apoda 1981 occurs on the Aru Islands and the adjacent mainland of New Guinea. The two subspe- cies of this species along with populations of P. raggiana and P. minor form a ring of in- tergrading subspecies circling New Guinea. Of the remaining two species P. guilielmi is monotypic and occurs on the Huon Penin- sula, generally at higher elevations than P. minor finschi and P. raggiana augustaevic- toriae. The details of its overlap with those two species are still unclear. It has been known to hybridize with both, and P. gui- lielmi and P. raggiana occur together in the Saruwaged Mts. (personal observ.). Parad- isaea rudolphi is also generally confined to higher elevations in southeastern New Guinea; it has three subspecies. Little is known about its display, but it has hybrid- ized with P. raggiana. The zones of inter- gradation involving these four species are narrow and limited in extent.’ Both P. gui- lielmi and P. rudolphi have a fully inverted display as a main component of their court- ship, and this has presumably developed as an isolating mechanism in these species (Gil- liard, 1969, p. 248). Group displays by males are known in all species except P. rudolphi. All the other species have loud calls, extreme sexual di- morphism in plumage, pronounced sexual dimorphism in size (see table 1), and appar- ent paucity of plumed males with unplumed males and females being much more numer- ous, males displaying for most of the year, group displays by males in arenas or explod- ed arenas, no pair bond, and females nesting and raising the young entirely alone. Par- adisaea rudolphi is poorly known but appar- ently its display differs so radically from the displays of the other six species that it will be discussed separately. DISPLAY SYSTEMS As each new description of a display is published it becomes more and more appar- ent that it is extremely important to distin- guish between male-male encounters (includ- ing unplumed males, which can usually be identified on the basis of their large size and behavior) and female-male encounters. Gil- LECROY: PARADISAEA liard (1969, p. 221) pointed out the impor- tance of the distinction but had few descrip- tions of female-male encounters. The fact that sometimes one and sometimes the other has been described for a particular species or that unplumed males have been identified as females has led to what I believe is a false impression of species differences in displays. MALE-MALE ENCOUNTERS: In male-male encounters the hierarchy within the clan is set up and maintained. Males display in groups, often, or perhaps usually, with un- plumed males present. Paradisaea apoda display has been very thoroughly studied by Gilliard (1958; 1969, pp. 399-414; and unpublished notes) and by Dinsmore (1970a, 1970b, and 1969) in a small, introduced population on Little To- bago in the West Indies. These birds appar- ently have an exploded arena composed of three or four trees. In Dinsmore’s study, the three main trees were within 64 m. of each other; the fourth was less used and was far- ther away. There was usually one adult male per tree and one main display limb in that tree. But early in the season males came to- gether and had a communal display, and this is presumably when the male-male hierarchy is set up. The small numbers of males in this introduced population would account for the differences between Gilliard’s and Dins- more’s observations and those of Wallace (1869) in the Aru Islands. But Wallace ob- viously observed the communal display by males. He described a tree where both adult and unplumed males assembled ‘‘high up in the thickest of the foliage, and flying and jumping about so continually that I could get no good view of them.’’ The display trees had ‘‘an immense head of spreading branch- es and large but scattered leaves, giving a clear space for the birds to play and exhibit their plumes. On one of these trees a dozen or twenty full-plumaged males assemble to- gether... .’’ (Wallace, 1869). Paradisaea decora also displays in an ex- ploded arena of four (or five) trees 50 to 100 m. apart. Communal displays by males occur and up to four plumed and five unplumed males were present in one tree. During these group displays there was much activity in the 10 AMERICAN MUSEUM NOVITATES tree, with both plumed and unplumed birds actively displaying. Plumed males often chased unplumed males out of the tree but did not chase each other. Frequently the males were distributed two plumed males per tree and these often duet- ted, and duetting could be heard simulta- neously in other trees as well. Often there was loud calling back and forth between arena trees. The displays were noisy and rang through the forest (LeCroy, Kulupi, and Peckover, 1980). Paradisaea raggiana salvadorii has an ex- ploded arena in which three to six males dis- play, usually one to a tree but sometimes several in a large tree. The arenas were 100 to approximately 400 feet in diameter. Each male appeared to own a display perch, gen- erally a gently sloping limb under the canopy in tall slender trees 35-60 feet up, and these perches were from 20 to 50 or more feet apart (Gilliard, 1969). The individual display limbs are within auditory and visual range and when the owner of a limb is killed, that limb is deserted. In the one case Gilliard ob- served, an unplumed male came to the de- serted limb after several days and displayed. No attack by plumed males was noted (Gil- lard, MS). . But male-male encounters may bring sev- eral plumed and unplumed males into the area of a single male’s display limb. When ‘‘a male with elaborate plumes, or even a male with long wires and no plumes, begins his deep calling, the drone of birds in female plumage [probably unplumed males] be- comes excited and [converges] on the male making the best auditory rendition. . . . The drone moves from tree to tree, and a male which has won the attention of the drone one day may not necessarily win it again for sev- eral days to come.’’ The male displays ac- tively when these birds are around. “‘But he is most apt to be badgered by other males which select this critical time to leave their perches nearby and to investigate the com- motion. They are probably stimulated by the performance, and they fly in close to the dis- playing male. This always causes a fight. The owner of the dance limb attacks the other males, especially those which land for a few NO. 2714 seconds at the edge of the dance limb. In attacking the intruding males the dance limb owner charges them from the center of the [display limb] and at such times his orna- mental plumage is extended to its fullest . so that the position of the head of the charging bird is hard to determine.’’ He chases first one and then another plumed male in this manner. This is accompanied by loud calling (Gilliard, Ms). Paradisaea minor finschi males display in five or six trees and then shift to other sets of trees nearby. There may be 5—15 males moving through the upper limbs, calling and displaying and there is no apparent defense of individual limbs by males. Loud calling was usually a sign of beginning display (Gil- liard, Ms). Bergman (in Gyldenstolpe, 1955) mentions a similar arrangement for P. minor minor, and Gilliard (1969, p. 235) says that the species ‘‘often performs its arena dis- plays in the top of a single tree with the males dancing close together.”’ Gilliard (Ms) noted that ‘‘the birds in fe- male plumage [probably unplumed males] are all about in the crown and in the limbs close to the displaying males which perform together at the height of the ceremony with- out apparent competition. I have not seen copulation .... All I have seen is a group of males displaying together and I have seen this very well about five times, each time for a matter of hours. Some of these periods of observation began before daybreak, some were during the middle of the morning, some during the mid-afternoon and some termi- nated at dusk. Many times ... I passed through the display area which bordered a main trail, or was within earshot of it, and during April and May, it was rare indeed when the display trees were not occupied by at least two birds.”’ Paradisaea guilielmi apparently displays in an exploded arena. Draffan (1978) found three areas where display took place, each consisting of three to four trees. Males moved from one group of trees to another, within sight and sound of each other. They finally settled in one or two trees to display in groups. He saw up to four males inverted simultaneously, with others in upright dis- 1981 LECROY: PARADISAEA 11 play nearby. Female plumaged birds (prob- ably unplumed males) were watching them and hopping about the canopy. He also saw pairs or trios of plumed males displaying to- gether. Paradisaea rubra is little known in the wild. The description by Bergman (in Gyl- denstolpe, 1955) is the most complete. He reports a single giant display tree in a clear- ing with up to 10 males displaying on dead limbs high in the canopy. The birds were continually on the move from branch to branch ‘‘quivering with their ornamental plumes and rapidly beating the wings. While displaying they not only uttered their usual calls but also a number of. other noises.” There is no indication of whether there is limb ownership by a single male, nor did Bergman report the presence of unplumed males. Gilliard, in his unpublished field notes from Batanta Island, says, ‘‘During after- noon, as during morning, tried to observe Paradisaea rubra in its display tree. I have now concluded that each adult male occupies a single tree at this season [June]. In morning I got under display tree but failed to see male. Tree is very tall and thickly leaved. In afternoon male was heard in same tree for more than one hour.”’ This observation may indicate that after the group displays by males and the setting up of a male-male hi- erarchy, males may display singly, one to a tree. It seems from the foregoing summaries that each species has communal male-male displays, differing in detail, in which the clan hierarchy is set up. It is not apparent, given the state of our knowledge at present, how males are incorporated into the hierarchy— i,e., whether subdominant males move up or males are recruited from unplumed males. Nor is it possible to know, in the absence of marked birds, how stable the hierarchy is or what percentage of copulations go to the dominant male(s), although Dinsmore (1970a, p. 318) reports that all copulations he ob- served in P. apoda on Little Tobago Island were by the same male, a bird identifiable in the field. FEMALE-MALE ENCOUNTERS: Only in the last few years have copulations been ob- served in Paradisaea. Gilliard (1969) and particularly Dinsmore (1970a) have both called attention to the basic differences be- tween the female-male encounters and the male-male encounters. Copulation has been observed in the field in four species and these can be augmented with accounts of copula- tions in captivity. Male-male encounters are virtually. never observed in captivity due to the fact that usually only single birds or a pair are acquired. : A common theme in the reports of male to female displays in Paradisaea is their static quality; whereas, there is much activity dur- ing male-male display. The position of the plumes may not change so that attention to details of plumage position without noting level of activity may fail to convey the ex- treme difference in effect between the two types of display. Paradisaea apoda apoda: Dinsmore (1970a) described a male displaying in the ‘presence of a female. There was only one male displaying and his movements included a Static display (the ‘‘Flower Display’’ of Gilliard [1958, 1969]) and also a bouncing display. The female landed at the opposite end of the display limb and stood quietly and usually crouched. The male came toward her and extended his wing over her body while continuing to dance. The male rubbed his bill against the female’s bill and the far side of her head and stretched his head and neck beneath hers. After about 20 seconds of dancing in contact, the male mounted. After copulation the female always flew out from under the male. Paradisaea decora: Arrival of a female is announced by the male ‘“‘growling.’’ The male’s movements are very slow and almost Static and there are no vocalizations. A bouncing display may also be given. The male’s plumes are raised until the shafts are vertical but the plumes do not fall forward over the head. The female stood quietly near the displaying male and then began soliciting by opening her wings slightly and quivering them. The male hopped stiffly up and down near the female, moved over to her and rubbed his chin and breast on her back and 12 AMERICAN MUSEUM NOVITATES put his wing over her briefly before mount- ing. He brought his wings down around her body while they copulated. Copulation last- ed from 15 to 30 seconds (LeCroy, Kulupi, and Peckover, 1980). Males frequently duetted in the presence of females, but one moved off to the side and sat quietly while the other courted and cop- ulated with the female. More than one female may be present but additional females were not chased by the soliciting female, and once a male copulated with two females in quick succession. Unplumed males may be present and displaying and may copulate with the fe- male (LeCroy, Kulupi, and Peckover, 1980). Paradisaea raggiana: Female-male dis- play may take several forms in this species, perhaps partly depending on whether the main display perch is vertical or horizontal. On a horizontal perch Gilliard (1969, p. 226) noted that the male is ‘‘silent and motionless except for the short upstrokes of the wings and the thudding sound of the wing-clapping, which is audible seventy feet away,’’ and Crandall (1936, p. 98) saw a captive male tilt- ing forward until the body was almost per- pendicular to the perch. The wings were over the head and were brought together in the front, and the plumes were raised. Cooper (in Cooper and Forshaw, 1977, p. 184) saw both of these displays with a female present and ending in copulation. ‘‘The fe- male would sit beside or in front of the dis- playing male and reach in under the open wings to peck at his bill.’ The male mounted and they copulated repeatedly for four min- utes. Cooper also noted that at least two plumed males were displaying on one perch but that one was dominant and chased away the other when a female was present. And once a female stopped soliciting to chase away another female. David Gillison (personal commun.) has ob- served female-male display on a near vertical perch and in this situation the female perches above the male and they move together slow- ly up the perch with a ritualized bowing first to one side of the perch and then to the other. After about 30 seconds the male mounts the female while she is parallel to the limb. She turns crosswise of the limb and they copu- NO. 2714 late. The female then flies away. Prior to the female’s arrival, two males had been duet- ting. The second male did not interfere with the female-male display, and several males crowded around the copulating couple again without interfering. Paradisaea minor finschi: Gilliard (1969, p. 235) notes: ‘‘When [the female] was clos- est to him he was quite motionless, with the head held far down, much like the males of Paradisaea apoda of the Aru Islands in their ‘flower’ display.’’ Gilliard also noted that the female arrived quietly. She pulled several times at the male’s neck feathers but no cop- ulation was attempted. Peckover (1973, p. 11) and Cooper and Forshaw (1977, p. 190) report that the wings of the male are over the female and display continues for a short while before the birds copulate. Paradisaea guilielmi: Female-male display and copulation have not been observed. Paradisaea rubra: Female-male display and copulation have not been observed. It seems evident from the above brief sum- maries that female-male encounters are ba- sically similar for the species for which we have information. The quiet behavior of the female, the static displays and lack of vocal- izations by the male, the wing over the fe- male and perhaps around her during copu- lation, and the billing or neck rubbing seem to be components of the displays in each species known. DISPLAY POSTURES Dinsmore (1970a) names five phases or display postures in P. apoda display. This is a convenient way to analyze the postures of the various species, and I have adopted some of his terminology but have subdivided one of his categories and added two others. I have also indicated male-male and female- male displays. Various earlier writers have also attempted to categorize display postures for different species, and I have tried to equate their categories with Dinsmore’s whenever possible. Actual bouts of display often have certain postures repeated or omit- ted, particularly during bouts of male-male display with no female present, and the se- 1981 LECROY: PARADISAEA 13 - we Fic. 1. Wing Pose in Paradisaea apoda. New York Zoological Society Photo. quence of postures given in any one bout is not necessarily in the order listed. In the following account I include descrip- tions of display postures of both wild and captive birds. The postures in captive birds seem similar to those of wild birds. (Compare Gilliard’s description of a wild P. raggiana Wing Pose given below to the pho- tograph of a captive individual in figure 4.) However, the conditions under which the displays are given are highly artificial and therefore the sequences of display, the con- text in which a display is given (male-male or female-male), and the orientation (posi- tion and height of display perch) may not be those normal to the species. Also we have almost no information on the range of normal display behavior in wild birds. Frith (Ms) is convinced of the normality of sequences giv- en by captive birds and discusses sequences AMERICAN MUSEUM NOVITATES NO. 2714 Fic. 2. Upright component of Wing Pose in Paradisaea apoda. Photograph by Frederick Kent Truslow, © National Geographic Society. 1981 LECROY: PARADISAEA 15 Pe TY) Fic. 3. Wing Pose in Paradisaea decora. Drawing by Juan Barbaris from a photograph by M. LeCroy. 16 AMERICAN MUSEUM NOVITATES NO. 2714 Fic. 4. Wing Pose in Paradisaea raggiana, with wings over back. New York Zoological Society Photo. of display in several species. This is another line of evidence and while some of our con- clusions differ, we have independently reached similar conclusions in some cases. WING Pose: This is essentially a male- male display although a female or females may be present. In P. apoda apada the plumes are raised and the wings are to the front and down and held rigid (fig. 1); or the male alternately drops the wings to his side and flaps them. The tail is tucked under the perch. This display is accompanied by loud ‘‘wauk’’ and ‘‘eee-ah’’ calls and may go on for 30 minutes or more. This corresponds to Crandall’s (1936, pp. 90-91) first stage. There is also an upright component to the Wing Pose in P. apoda apoda, not men- tioned, but photographed (fig. 2). 1981 LECROY: PARADISAEA 17 Fic. 5. Greenewalt. This is essentially the same pose adopted by P. decora when several males are dis- playing together or two males are duetting. One male may also display alone in this man- ner. The wings are not brought so far for- ward; they are held more straight down to the sides of the body and moved with ‘‘row- ing’’ motions. The tail and body remain more horizontal (fig. 3). This display may last for Upright component of Wing Pose in Paradisaea raggiana. Photograph by Crawford H. 30 minutes. Loud ‘‘wark’’ calls are given, or duetting males may give their ringing calls ending in ‘‘gargling.’’ We did not observe an upright component of this posture in P. dec- ora (LeCroy, Kulupi, and Peckover, 1980). Gilliard (ms) describes this pose in P. rag- giana salvadorii (fig. 4): ‘‘The dance begins when the male who has been sitting some- what slouched on his perch suddenly deliv- AMERICAN MUSEUM NOVITATES NO. 2714 Fic. 6. Upright component of Wing Pose in Paradisaea guilielmi. Photograph by Crawford H. Greenewalt. ers a loud bugled Waa hee who whit. This is preening and bill wiping .... With body punctuated with occasional kees, much erect, he pulls the neck down silently in a 1981 LECROY: PARADISAEA 19 Fic. 7. Wing Pose in Paradisaea raggiana with wings down. Photograph by Crawford H. Greene- walt. frontal crook with the bill straight ahead and a little elevated. Now he shuffles the wings a little and pulls them forward in such a way that they seem to become shortened. They are drawn high on the body with the shoul- ders pointed inward and hidden in the plum- age of the neck. The primaries are opened and extended outward, the first primary ex- tending forward almost to the eyes and stand- ing free of the others in a peculiar manner. Ih this position the wings appear ridiculously short and assume the shape of fans framing the neck and head on the sides. Display be- gins silently with short waving of the wings. As this progresses the shoulders come close together on the back. When excitement mounts a little further they come together with audible thumps over the upper back .... The upward movement of the shoul- ders is a snapping movement and the thump- ing of the wrists can be heard at a distance of fifty feet or more .... During this wing flapping the plumes are only partially spread and the plumes of the upper series are not much elevated over the level of the back.”’ There is also an upright component in the Wing Pose of this species rather similar to that of P. guilielmi (figs. 5 and 6), and there is a position in which the wings are spread and down similar to the Wing Pose in P. 20 AMERICAN MUSEUM NOVITATES see SN ‘ y ys 4 “SSSR Sos NO. 2714 Fic. 8. Upright component of Wing Pose in Paradisaea minor. Drawing by Juan Barbaris after Ogilvie-Grant, 1905. apoda apoda (fig. 7). Paradisaea raggiana is the only species so far reported to clap the wings together over the head, although the wings may be foreshortened in a similar way in P. guilielmi Wing Pose (fig. 6). Paradisaea. minor finschi: Gilliard (Ms) noted that ‘“The usual sign of beginning ex- citement was a clear series of rich notes, a ringing gah haa haa waaaaaaah, notes au- dible at least a quarter of a mile. Another preliminary call is a sharp ringing gig gig and a sharp, plaintive quee. This is followed by much shaking of plumes in a kind of dusting motion and by side hopping. The head is held low and the body is moved in a near hori- zontal position with the neck crooked. As this is executed a low grrrr is emitted.’’ Both Ogilvie-Grant (1905, p. 436) and Crandall (1936, p. 92) note that a captive bird was at first upright with the tail curved under the 198] LECROY: PARADISAEA 21 c*8 AS | 4 @ ids * a & »~ oe ‘Sy wa ‘ Fic. 9. Charging in Paradisaea apoda. Photograph by E. T. Gilliard. horizontal limb, wings open and held slightly above the level of the body, and the plumes arching upward (fig. 8). In both cases these birds were probably P. m. minor. Paradisaea guilielmi: Stonor (1936, p. 1180) observed a captive bird displaying and described the beginning display as follows (fig. 6): ‘“‘bird starts hopping up and down with head and neck stretched upwards; it then opens its wings and, jerking the head into the air, calls loudly several times with a clear and not unpleasing and very charac- teristic note. ‘‘Next the wings are fluttered, with the head kept down, and during this part of the performance they are kept open for a few seconds and are then closed suddenly with a snap, this being repeated five or six times; according to my own observations the plumes play no part in the performance.”’ Crandall (1932, p. 79) described the first part of the display in which the bird is bob- bing slowly up and down from the hips with wings spread horizontally and vibrated rap- idly and has plumes slightly raised. This dis- play continued for about 10 minutes. Then the body became rigid and horizontal, the head and neck held forward and slightly down, and the flank plumes slightly raised. The wings were ‘‘suddenly spread and flicked forward, so that the upper surfaces were toward the bird’s head.’’ This position was held for about five seconds and then the wings were snapped back to their normal po- sition for about five seconds. This was re- peated seven times. These two accounts de AMERICAN MUSEUM NOVITATES NO. 2714 Fic. 10. Charging in Paradisaea raggiana. Photograph by Crawford H. Greenewalt. probably correspond to Group 1 of Wagner’s (1938, p. 550) three groups of dances. Draffan (1978, p. 158) ‘‘saw a couple [of males] displaying (not upside down) but with wings outstretched and quivering. They faced each other almost touching and then turned away from each other.”’ This display may or may not prove homologous to the Wing Pose display. Paradisaea rubra: Frith (1976, p. 70) stat- ed that the male usually began by perching on a branch on or near the upper part of the vertical display limb. It ‘‘gives Bill-click-call frequently, flicks the outer primaries rapidly forward and back and occasionally performs Bill-wiping. Once on the vertical branch, he perches diagonally with bill pointing upward and continues to flick the primaries. As he - becomes more excited the wings are slightly spread and quivered; again he wipes his bill and sways gently from side to side.”’ CHARGING DISPLAY: (The Pump Display of Dinsmore): In P. a. apoda this posture is assumed most often in male-male displays. The body is almost parallel to the display branch, the plumes are erected vertically and the head and bill are pointed down (fig. 9). The bird hops rapidly along the limb giving the “‘pump’’ call—a series of rapid wa-wa- wa-wa notes—and bounding up and down. The movements are rapid and jerky (Dins- more, 1970a, pp. 308-309). | Gilliard (1969, p. 219) noted: ‘‘Such jumps, charges, and cries are often synchronized between a number of males all calling and moving in a spasm of displays.”’ Paradisaea decora male or males perform this display on a horizontal branch, moving LECROY: PARADISAEA 23 1981 Juan Barbaris after Ogilvie-Grant, 1905. Charging in Paradisaea minor. Drawing by Fic. 11. move along adjacent limbs together (Le- Croy, Kulupi, and Peckover, 1980). rapidly along the limb for several feet and then returning. The rowing motions of the In P. raggiana salvadorii, Gilliard (Ms) also noted an active display of the same sort. wings may go below the level of the limb. Duetting birds may also adopt this pose and 24 AMERICAN MUSEUM NOVITATES ‘The quee, quee, quees began which were repeated again and again in a rising crescen- do. Later it took place again indicating that at least two males were dancing with their wings overhead and sort of charging each other slowly back and forth across the dance limb.”’ This display probably corresponds to the first stage of display given by Crandall (1936, pp. 95-98). The bird (fig. 10) calls loudly and runs on the horizontal perch with plumes whirling over the back and the body held horizontal. It may be given by a single indi- vidual or by two or more plumed males to- gether. Paradisaea minor: Bergman (in Gylden- stolpe, 1955, pp. 309-310) described this dis- play: ‘‘After a few minutes they started to leap on the limbs uttering their harsh and — rather penetrating guttural cries ....’’ The plumes were raised and the wings were jerked forward and quivered. There were ‘‘mock attacks’’ toward other displaying males. One tossed the head downwards, opened the bill and hopped to and fro on the branch. Ogilvie-Grant (1905, p. 438) also de- scribes Charging in a captive male, in what he calls the second stage of display (fig. 11). Paradisaea guilielmi: Crandall (1932, p. 79) spoke of a captive individual ‘‘moving about his perches’’ after having given the wing pose display. And Stonor (1936, p. 1181) said, ‘‘It may be noted that the dance is not at all unlike the typical Paradisea (sic.) display except that the plumes play no part.” But it is not clear whether there is a Charging component in the display of this species. Paradisaea rubra: 1 have not found a dis- play reported in this species which seems homologous to Charging unless it is what Frith (1976, p. 73) called the Butterfly Dance. In this, males ‘‘hopped quickly from branch to branch with fluttering, flicking and ex- tended wings like a butterfly and, suddenly landing on a vertical display-perch, went di- rectly into the sequence with the inverted posture without preliminaries.”’ ZIGZAGGING: This component of display appears to be a part of male-male display. For P. a. apoda, Gilliard (unpublished notes, 1958) noted: On a perch at a 45 degree NO. 2714 angle a male became ‘‘very agitated, lower- ing the neck and head, and elevating the plumes. This male then ‘switch-jumped’ to a high perch and then pranced some more.”’ Paradisaea decora: The male performs this display on a nearly vertical branch. His body is parallel to the steeply sloping branch, and the rowing motions of his wings may go below the level of the limb. Changing the position of his feet as he moves up or down causes his body to appear to zigzag back and forth across the limb (personal observ.). Duetting birds may adopt this pose (see be- low). Paradisaea raggiana salvadorii: Gilliard (Ms) described this display thus: ‘‘The male danced in an area covering approximately six lineal feet of a steeply sloping limb. It walked up the limb and hopped down it sideways. [As it] walked up it moved lengthwise with the limb, placing one foot in front of the oth- er, and walking very slowly, its wings par- tially opened and its plumes partially ar- ranged to the side. This walk was slow and deliberate, and every foot or so the bird paused to posture by elevating the plumes somewhat and to ... peck at the bark. At the top of the march the bird turned to the right and sat across the steeply pitched limb, then, in short hops it let itself down, as though jumping from stair to stair until it had again reached the bottom.”’ Again he (Ms) noted: ‘“‘Then suddenly [af- ter the Wing Pose display] the bird delivers sharp kei kei notes, crooks the head deeply, leans low sometimes below the level of the feet and may hop several times switching the now erected, spread flank plumes from side to side of the perch as it switch-jumps along the perch or up a steep limb beside it. This serves to display the flank plumes. David Gillison (personal commun.) has re- cently observed this rapid zigzagging display in P. raggiana salvadorii where three or four males may participate. It is to be distin- guished from the slow, ritualized female- male display described below. Paradisaea minor: | have not found Zig- zagging described for this species. Paradisaea guilielmi: No Zigzagging has been described for this species nor has any 1981 vertical limb component, which may be nec- essary for this display to occur. Paradisaea rubra: Frith (1976, p. 73) has noted that after the inverted display the plumage returns to normal and the plumed male hops down the nearly vertical perch, sometimes directly and sometimes in a spi- ral, and then back up, usually in a zigzag pattern. Crandall (1937, p. 194) noted that a bird of this species hopping up the slanting branch ‘‘leaped clear of the perch at each jump, alternating the feet in the forward po- sition. This action caused the body to jerk violently from side to side, bringing the red plumes into greater prominence... .”’ MALE-MALE DUETTING: Thorpe et al. (1972) have referred all cases of male-male dual song to ‘‘countersinging in defence of a territory or at a boundary.”’ The synchro- nized calling of two Paradisaea males does not fit into this category. In these non-pair- bonding arena birds there is no territorial de- fense in the usual sense of the term, even if one accepts the hypothesis that display perches represent shrunken territories and that group calling may have evolved from male-male countersinging. Group calling is a feature of the Paradi- saea arena and two males’ calling synchro- nously is probably only a special case of the more inclusive activity. Group calling prob- ably helps in setting up and maintaining a hierarchy among males within the arena, par- ticularly in exploded arenas, as well as in informing other males and females of the arena’s location. Payne (1971) reports groups of males of parasitic cuckoos (Cuculus soli- tarius) calling together in a tree where fe- males come when ready to mate. And many arena birds are well known for the loud calls of males on the display ground. Foster (1977) discusses the synchronous calls of a pair of male Chiroxiphia linearis (Pipridae) that occupy a court and remain to- gether, often for several years. These syn- chronous calls are not related to territory defense and Foster believes they serve to notify a female of an active court. I think the synchronized calling of two Paradisaea males is of this type. While there is as yet no evidence for or against a male-male bond in LECROY: PARADISAEA 25 Paradisaea, | think it is safe to say that the synchronized calling probably serves to maintain a dominance relationship between the two males and to attract females to an active display perch. Duetting is a useful term that accurately describes this activity and needs only to be designated Male-male Duetting to distinguish it from the male-fe- male duetting discussed by Thorpe et al. (1972). Male-male Duetting was first mentioned in Paradisaea by Dinsmore (1969, pp. 139-140) in P. apoda. In this species there were vari- ations in the pattern of calls given by the two males and they did not seem to be a part of the courtship display although occasionally displays did follow duets. The duets that he heard involved two recognizable males on display limbs 46 m. apart, and he thinks that the dual calling may have evolved as a means of individual recognition between adjacent males. A slightly different form of duetting in P. apoda, more like that in P. decora, was re- corded by Gilliard (unpublished field notes, 1958): ‘“The two began preening and flipping their wings and in a short time they were dancing together with their wings being ex- panded in the [rowing] position .. . . At one point I was particularly struck with the ‘dual- ness’ of the display. That was when both males burst forth in a series of bugled notes that so perfectly overlapped that they could be mistaken for a series of notes from one bird and not two.”’ Paradisaea decora has the most elaborate Male-male Duetting so far reported (LeCroy, Kulupi, and Peckover, 1980). Pairs of males apparently share a display tree and the duet- ting probably serves to set up a dominance hierarchy between them. This seems espe- cially likely in the light of the fact that one male of the pair sits quietly when the other is displaying to, and copulating with, a fe- male. Male-male Duetting has become an im- portant display component in this species and the loud, ringing metallic calls and ‘“‘gar- gling’’ are characteristic sounds of displaying birds in the forests of Fergusson Island. There is no published record of Male-male Duetting in P. raggiana, but W. S. Peckover 26 AMERICAN MUSEUM NOVITATES NO. 2714 Fic. 12. Two male Paradisaea raggiana displaying together. Photograph by David Gillison. 1981 LECROY: PARADISAEA 27 Fic. 13. Geographic Society. has recorded what is undoubtedly such duet- ting at Varirata National Park near Port Moresby and Peckover and I observed it in October 1980. Also David Gillison (personal commun.) tells me that two or more males frequently display and call together. Cooper (in Cooper and Forshaw, 1977, p. 184) re- ported: “‘There were at least two fully plumed males using the display perch, one obviously dominant because it always chased off the second male whenever a fe- male appeared.’’ And I have seen photo- Flower Display in Paradisaea apoda. Photograph by Frederick Kent Truslow, © National graphs by David Gillison (fig. 12) and David Parer showing two males displaying togeth- er. I find no record of possible Male-male Duetting behavior in P. minor. Both Wagner (1938) and Draffan (1978) give evidence of pairs of captive and wild males of P. guilielmi displaying together. Draffan ‘‘saw [two males] displaying (not upside down) but with wings outstretched and quivering. They faced each other almost touching and then turned away from each 28 AMERICAN MUSEUM NOVITATES other.’ Wagner describes a similar display but neither author comments on any vocal- izations. In November 1979, I watched two males give a bubbling duet in the Saruwaged Mts. However, this was an isolated occur- rence and it remains to be seen how it fits into the species’ display sequence. Frith (1976) does not mention Male-male Duetting in P. rubra. FLOWER DispLaAy: Dinsmore (1970a, p. 309) calls this the Bow and describes it for P. apoda, and it is illustrated by Truslow (in Gilliard, 1958, see also fig. 13). In this display the body is humped with both head and tail low, the wings are out and cupped around the limb and the plumes are erect over the back and extend forward over the head as well in a golden spray. A female may or may not be present and a baa note may be given as the bird tips its body down. If the female is present the display may be held for over a minute. This is the display described by Crandall (1936, p. 91) as ‘‘Full Display,’ by Wallace (1869), and by Gilliard (1958) as the Flower Display. Paradisaea decora: In this species this static display is less extreme. The body re- mains virtually horizontal and while the plumes are erected vertically, they were nev- er seen to fall forward over the head. The bird was usually silent, although loud whick- whick calls were occasionally given. The rowing motion of the wings continued spas- modically. The Flower Display may occur when no female is present but is more pro- longed when the female is there. Paradisaea raggiana salvadorii: Gilliard (1969, p. 98) described this display, in which the male crouched forward, elevated and ex- panded the plumes and clapped the wings to- gether over the head. The display was silent and motionless except for the upstrokes of the wings and the sound of the wing clap- ping. This is also the ‘‘Full Display’’ of Cran- dall (1936, p. 98). Paradisaea minor minor: Crandall (1936, pp. 92-94) describes the ‘‘Full Display’’ in which the male holds the wings horizontal or curves them downward as does P. apoda. The body is arched downward but not so low NO. 2714 as in P. apoda and the plumes are up. The display of P. minor finschi reminded Gilliard (1969, p. 235) of the Flower Display of P. apoda. He described the peculiar manner in which the wings are held (Gilliard, Ms): ‘“The shoulders are drawn close to the body and the primaries are extended outward, almost straight out like an oarsman holding oars out of the water. They are held still for a while, and the bird makes no noise except the oc- casional low graaa. Then the wings begin to move up and down, moving up slowly about three inches at their tips, then downward snappily to a point just below the shoulders . . . as the performance continues, [the flank plumes] begin to rise up behind in a splendid cascade. But the distinctive thing is that cer- tain of the shorter yellow flank plumes are lofted through the opening normally covered by the scapulars, and they stick up in random places like separate little golden fountains.”’ Ogilvie-Grant (1905, p. 438) mentions a static phase following Charging: ‘“‘For some seconds he remains in a sort of ecstasy, rub- bing his bill on the perch, and occasionally glancing backwards below his feet with the back fully arched’’ (fig. 14). A female may or may not be present. Paradisaea guilielmi and P. rubra: I have found no description of a static Flower Dis- play in these species. INVERTED DispLAy: As Paradisaea is studied more, it becomes increasingly likely that an Inverted Display occurs in all species. It is only in P. guilielmi (and P. ru- dolphi) that it is developed to its fullest ex- tent. In these two species it is a static display and probably serves as an isolating mecha- nism. In all species of Paradisaea the static displays are the most obvious component of female-male displays and probably ‘serve as species specific signals. The two species of Paradisaea that have developed the Invert- ed Display most fully overlap in distribution other Paradisaea species and would thus most need an isolating mechanism to prevent the hybridization known to occur occasion- ally. Paradisaea apoda apoda: Dinsmore (1970a, p. 312) noted a male hanging briefly upside 1981 LECROY: PARADISAEA 29 SS ; ve y ys Ly oo on § x << ae LTA SS SAAS 5 =~, Fic. 14. Flower Display in Paradisaea minor. Drawing by Juan Barbaris after Ogilvie-Grant, 1905. 30 AMERICAN MUSEUM NOVITATES NO. 2714 Fic. 15. Inverted posture in Paradisaea raggiana. New York Zoological Society Photo. down on five different occasions, shortly af- | side down while another male was displaying ter a bout of display. This was accompanied _ nearby. He considered that it was not a reg- by nasal calls. Once a male briefly hung up- —_ ular component of display in this species. 1981 LECROY: PARADISAEA 31 Fic. 16. Paradisaea decora: This species has not been observed in an inverted posture. Paradisaea raggiana salvadorii: Crandall (1936, p. 98) noted and gave a photo of this species in full display with head forward and down below the level of the branch (fig. 15). It is apparently common during most intense display. Opit (1975), Hadden (1976), and Cooper (in Cooper and Forshaw, 1977, p. 184) also saw a male display in an inverted position. Gilliard (Ms) noted: ‘‘An excited male hap- pened to fall over and hang upside down, his head pointing toward the ground and waving like a slow-moving pendulum, as though trying to gauge its drop if it fell. After sev- Inverted posture in Paradisaea minor. New York Zoological Society Photo. eral seconds of this with the plumes fanned out, a bird in female plumage dove in and landed on the center of the display perch di- rectly over the feet of the hanging male, so close that their feet must have touched. This brought on an instantaneous fencing match as the suspended male attempted to fight his way to an upright position. This was seen only once....”’ Another time (Gilliard, Ms) an unplumed bird was charged by a plumed male, fell backward and hung upside down for about 30 seconds with the male standing almost directly over the inverted bird. Paradisaea minor: The only mention of an inverted display that I have found is in Elliot 32 AMERICAN MUSEUM NOVITATES (1873). He quotes Mr. A. D. Bartlett, Super- intendent of Zoological Gardens, Regents Park: ‘‘During this display the bird would become greatly excited, and sometimes turn almost under the perch or branch, the head and neck being bent so low down.’’ Also Crandall photographed a male in inverted position (fig. 16) but did not mention this in his paper. Paradisaea guilielmi: Crandall (1932, p. 80) has described this phase of the display in greatest detail in a captive bird (fig. 17). The male turned head first under the perch and held the body nearly horizontal with the wings spread and turned well up. The tail was spread and turned up with the tail wires vertical; the head and neck were extended and turned upward. The plumes were erect- ed at an angle of 45 degrees and extended around on each side so that they formed a circle when they met anteriorly and poste- riorly. Each plume was well separated from the others and stood out as a separate entity. The body movement was a slight rotary mo- tion from side to side, making the plumes wave. This display was silent and lasted about five minutes, after which the bird re- turned head first to normal position. Draffan (1978), Wagner (1938), and Cran- dall (1932) have recorded this species as in- verting head first. Stonor (1936), Detzner (in Stresemann, 1924), Gilliard (Ms), and Le- Croy (personal observ.) have recorded it in- verting tail first. Obviously there is variation. In either event the bird faces in the opposite direction to what it did before inverting and the position taken by the female observing the display will be of interest. The bird I ob- served inverting tail first came back up to the limb head first. Paradisaea rubra: Frith (1976) described an Inverted Display in this species. The cap- tive bird gradually leaned over a vertical branch on which it was perching diagonally with bill pointing upward, spreading and shaking his wings as he did so. When com- pletely inverted, he spread the wings wide, vibrating them and swaying the body from side to side. This made the plumes conspic- uous although they were neither spread nor NO. 2714 raised. He may give a soft, high-pitched meew or a Single snap of the mandibles. At the peak of display the bird was momentarily motionless with wings fully extended on either side level with the body and vibrated very slightly and rapidly. The flank plumes were very slightly raised, but not spread and the tail was slightly depressed, both motions accenting the plumes. The male may give an occasional mandible-snap. Crandall (1937, p. 193) also described this display in captiv- ity. Hoppinc: This is Dinsmore’s (1970a) Dancing Display. I believe Hopping (or Hop- ping-on-the-Spot as used by Frith, 1976) bet- ter describes this posture as Dancing implies a more active display and has been used in the literature to describe the entire display sequence and various parts thereof. In P. apoda this display is performed in a crouched position. The bird “‘slowly and rhythmically bounces and shuffles back and forth along the court with leg flexion exag- gerating the vertical motion’’ (Dinsmore, 1970a, p. 310). The movements are slow and rhythmic and both feet are off the limb at the same time. The displaying bird gives a click call and sometimes a bonk note. This is a display given by the male with the female present. In P. decora the male bounces slowly up and down in the period just before copula- tion. Both feet were seen to leave the pérch. Occasionally the male gives loud whick- whick calls at this time, but he is generally silent (LeCroy, Kulupi, and Peckover, 1980). Paradisaea raggiana salvadorii: David Gillison (personal commun.) has observed Hopping in this species. As two males duet- ted at the bottom of a steeply sloping display limb, a female landed on the upper part and moved down near the males. One male began to ‘‘rock.’’ The female turned and started slowly up the limb. As the male approached ‘trocking’’ slowly, the female began to rock and they hopped slowly and in a very ritu- alized manner up the limb, bowing from side to side in unison as they went (fig. 18). This lasted about 30 seconds. Another display reported by Cooper (in ‘OJOY AI9IDOG [edIBOJOOZ YIOX MON “WuJayINs vavsipoavg ul Aeldsiq powoaauy “LT “Ol 34 AMERICAN MUSEUM NOVITATES NO. 2714 Fic. 18. Hopping in Paradisaea raggiana with female leading. Photograph by David Gillison. 1981 | LECROY: PARADISAEA 35 Cooper and Forshaw, 1977) was seen only once, when a male was displaying to a female on a horizontal branch. ‘‘After displaying in the usual manner the bird relaxed the plumes, but, with wings raised above the back, turned to face along the perch toward a female sitting about 25 cm. away. The feathers of the throat and breast he puffed out to form a round ‘ball’ and the head was withdrawn into this ‘ball’ so that only his crown and protruding bill were visible. Hold- ing this posture he then rocked back and forth, coming toward the female so that he almost touched her with his bill.’’ This dis- play lasted about six seconds; then the fe- male left. Cooper did not state whether the feet left the perch as the male rocked back and forth, and it may be that this rocking by the male alone precedes the joint hopping and bowing, as in the display above. The po- sition of the perch, whether it is horizontal or vertical, may also influence the exact form of the display. Clifford Frith (Ms) has also described both of these components of display of captive P. raggiana and from the film by David Parer. Paradisaea minor: 1 have been unable to find any indication of a Hopping display in this species. Paradisaea guilielmi: Female-male en- counters have not been observed in this species. Paradisaea rubra: Frith (1976, p. 73) de- scribes the Hopping (=Hopping-on-the-Spot) display as mechanical and slow, sometimes interspersed with ‘‘Head-peering’’ in which the head is rotated and its green plumage conspicuously erected. This is associated with bill-tapping, which produces an audible tick, an occasional bill click, and rapid wing vibration with slight swaying of the body. There was no female present when this dis- play was given but it came at the end of a sequence of high intensity displays. Female- male encounters have not been observed in this species. COPULATION: Dinsmore (1970a, p. 311) de- scribes one mating in P. apoda apoda in de- tail: ‘‘On this occasion I saw that the male’s wing next to the female was extended over her body and as he flapped his wings he held her close alongside his body. The male also repeatedly rubbed his bill against her bill, bit at her bill, and stretched his head and neck beneath hers and rubbed his bill on the far side of her head, all as he continued to dance.’’ This lasted for about 20 seconds be- fore the male mounted and copulated with the female. Paradisaea decora: Just prior to copula- tion the male rubs his chin and breast on the back of the female. When he mounts her his wings come down around her body and they copulate (LeCroy, Kulupi, and Peckover, 1980). Paradisaea raggiana: | find no published description of copulation in this species. Da- vid Gillison (personal commun.) reports that after the 30 seconds of Hopping reported above, the male mounted and the pair con- tinued to bow back and forth for another 30 seconds. Then the female turned across the limb with the male still on her back and cop- ulation followed. The male’s duetting partner and two other plumed males watched the Hopping sequence with plumes raised and crowded around the copulating birds but did not try to interfere. After copulation the fe- male flew away and the male flew to the top of the tree and began plucking leaves. Photos by David Gillison and a film se- quence by David Parer of this species cop- ulating show the wings around the female; in addition the film sequence shows rather aggressive bill sparring between the two birds during copulation. Paradisaea minor: Peckover (1973, p. 11) reports that “‘the female is attracted to the dominant male, moves on to his display branch and then under his wing; display con- tinues for a time, he then ceases and mounts the female.’’ Cooper (in Cooper and For- shaw, 1977, p. 190) noted that “‘the male beat his wings over and about [the female] for some twenty seconds and then mounted her twice.”’ Paradisaea guilielmi and P. rubra: Copu- lation has not been observed. Paradisaea rudolphi Paradisaea rudolphi has been omitted from the above characterization of display 36 AMERICAN MUSEUM NOVITATES postures because it is poorly known and some of its behavior is anomalous. After much consideration I have come to the con- clusion that it is probably not a polygynous arena displaying species but has secondarily become territorial. My reasons for this con- clusion are several. In the first place no loud calls of groups of males on arenas have been recorded, nor have several males been seen displaying together. When the display has been seen in the wild (Smyth, 1970, p. 70) the male has been displaying alone in the understory with no other plumed or un- plumed birds nearby. The male makes a characteristic growling noise at this time. In November 1979, W. S. Peckover and I observed a male P. rudolphi near the Aiyura Agricultural Station that seemed quite terri- torial. The bird moved about in a complete circle perhaps 300 ft. in diameter and called in the characteristic two-toned calls of this species from high in the trees or gave loud kow-kow-kow calls and low growling calls from midway up in the trees. There was nev- er any sign of another bird, either male or female, and the male moved about regularly from one spot to another within what I in- terpret as his territorial boundary. On five days in October 1980, near Ubai- gubi in the Eastern Highlands at approxi- mately 1700 m., I watched and listened to a male P. rudolphi visit in succession five or six trees located in a rough circle about a quarter mile in diameter. He called and growled from high in these trees for approx- imately three hours, from about six o’clock each morning. Other males could be heard at a distance. Only once was a female-plum- aged bird seen. It was feeding in one of the sentinel trees at a time when the male was at a distant tree, and the visit of several min- utes’ duration elicited no response from him. The male was also observed feeding within the territory. Mary Stringer (personal commun. and 1979, p. 26) saw three males spaced out through a small area of remnant forest in a gorge. Apparently these territories did not include feeding areas as she and other ob- servers have seen numbers of plumed males and unplumed birds feeding together in a NO. 2714 fruiting tree. Nearby a lone male was seen perching and calling in two trees about 15 m. apart. There are several reports in the older lit- erature of several P. rudolphi being seen to- gether, and Mary Stringer (personal com- mun.) was told by a local man that two plumed males dance together but that when a female comes one is chased away and the other courts the female. Perhaps this latter case refers to a territorial encounter, and as several individuals of this species are known to feed together these older accounts need Verification. The female is more nearly male plumaged than in any other of the species of Paradi- saea and may jointly defend a territory with the male, or as Thane Pratt (personal com- mun.) has suggested to me, may defend a territory of her own. The female (confirmed by dissection) has been shown by Crandall (1932, p. 77) to have a display in captivity in which she assumed a posture similar to that of the male but was silent. No other species of Paradisaea has been reported to have a female display. Also there is no great sexual dimorphism in size between males and fe- males as there is in all of the arena displaying species of Paradisaea (table 1). While there are the usual reports of un- plumed birds moving through the forest to- gether, Cooper (in Cooper and Forshaw, 1977, p. 204) reports what is unique for this species—a plumed male and a female (how identified?) feeding and moving together in the forest. Thus, there may be a period in which there is a pair bond in this species. But virtually nothing is known of incubation and feeding of the young. The two or three observations of nests record the female in- cubating and feeding young. The unplumed male is similar in plumage to the adult fe- male; the adult male has a much shorter tail (table 1). The static display that has been observed is rather like the static display of P. guilielmi and like it may be homologous to the Flower Display of other species. Crandall (1921, p. 113 and 1936, p. 102) describes this display in captivity. The male lowers himself back- ward and hangs head downward for several 1981 LECROY: PARADISAEA 37 C3 . 3 + sre — “BASS 5 ie 4 WEES YN fF Lis) oe SS. a WS Rat ots Waa 4 Ny 4 y i f ¢ ; \ eg 7 Hie “x WIEN Sea | - y J; Nf. TD < ”e a 4 ‘ " M GE a Vid : i EY LS a Fic. 19. Inverted Display in Paradisaea rudolphi. Drawing by Juan Barbaris after a New York Zoological Society Photo. minutes without moving the feet (fig. 19). The wings are closed and the head points upward; the plumes and the abdomen feath- ers are spread. The tail wires rise above the plumes and then droop down on either side and the broken white eye-ring is conspicu- ous. The bird sways gently back and forth with the hips as a fulcrum, causing the plumes to move. According to Crandall, this display is accompanied by a low grating noise. The female display mentioned above and described by Crandall (1932, pp. 77-78) is very similar to the above but there were of course no plumes, the tail was pressed for- ward between the legs and there was a rapid up and down motion, effected by bending the legs, which was never seen in males. Both Frith (in Cooper and Forshaw, 1977, p. 206) and Gilliard (Ms) mention that P. ru- dolphi assumes its inverted position by drop- ping backward from the perch into the in- verted position. The male is then facing in the opposite direction from that in which he was facing before inverting. No observers have yet commented on this fact or on the position of a female before the male inverts. Frith (in Cooper and Forshaw, 1977, p. 206) reports seeing a captive female P. ru- dolphi fly to and perch above an inverted displaying male, looking down at him. This is very much like the cases reported by Draf- fan (1978, p. 159) for P. guilielmi and for P. raggiana by Gilliard (Ms), where in each case the bird was an unplumed male. Frith does not say how the sex of the bird he observed was known. When the displaying male that Frith saw returned to its normal position, head-first, he displaced the unplumed bird from the perch above him. There is no in- formation on copulation or precopulatory display. If this bird does prove to be terri- 38 AMERICAN MUSEUM NOVITATES ‘torial with a pair bond, copulation may not occur at the display limb. OTHER DISPLAY COMPONENTS BILL-WIPING: This is not a display posture but apparently occurs as a component of dis- play in several (and perhaps all) species of Paradisaea. Dinsmore (1970a, pp. 312-313) found bill-wiping to occur in P. apoda. We did not notice it in P. decora. Gilliard (Ms) said there was much preening and bill-wiping in conjunction with beginning display in P. raggiana. ‘‘In executing the latter the bird will walk along a limb audibly pecking and wiping first one side of the bill and then the other. He does this for some time and then, back on his perch, he begins to assume the dance position.’’ Gilliard (Ms) also noted that in displaying groups of male P. minor ‘‘the body was held down much of the time, the bill was wiped, first one side, then the oth- er.”’ Ogilvie-Grant (1905, p. 438) observed bill-wiping in a displaying captive male P. minor. I saw an unplumed male of P. gui- lielmi bill-wiping several times just before it gave an inverted display. Frith (1976, pp. 70, 73) noted that at the beginning of display a male P. rubra “‘occasionally performs Bill- wiping,’’ and ‘‘ritualized Bill-wiping’’ occurs sporadically throughout display. I have not found reference to P. rudolphi bill-wiping. From the observations noted above, it seems obvious that bill-wiping is probably a regular and ritualized part of display in Par- adisaea and it needs to be specifically looked for so that its role can be determined. PECKING-AT-PERCH: This appears to be another ritualized display component which has been mentioned by several authors. Dinsmore (1970a, p. 312) said it occurred in P. apoda during a break in the display. Gil- liard (Ms) noted ‘‘symbolic pecking”’ in a P. raggiana male as it moved up a ladder-like vertical series of limbs ‘‘pausing here and there to peck at the hard wood of the perch with such strength that I could hear it 50 feet away. Also it pecked and pinched with its bill little knobs of wood which protruded like nail heads from the vertical limb, always wrestling rather viciously with these before NO. 2714 moving on.’’ He also mentioned that on another occasion, after chasing away an un- plumed bird, an unplumed bird that was in possession of a display limb, ‘‘gave a vigor- ous display of pecking at knobs of wood, shaking body violently and climbing up and hopping sideways down vertical part of dis- play stage.’’ Frith (1976, p. 73) said that near the end of the Hopping Display, a P. rubra male taps ‘‘the sides of the bill at its very tip sharply on the perch every few seconds while the head is rotated (Hear-peering) with its green plumage conspicuously erected. The bill tapping produces a clear tick, which is quite audible at ten metres.’’ This is not necessarily homologous to pecking-at-perch in the other species. I found no mention of pecking-at-perch in the other species, but I suspect that it is easily overlooked. RITUALIZED PREENING: Ritualized preen- ing is documented by Dinsmore (1970a, p. 312) for P. apoda and by Gilliard (ms) for P. minor at the beginning of the Flower Display and for P. raggiana at the beginning of dis- play, but apparently has not been noted for the other species. This ritualized preening as a part of display is not to be confused with post-display preening which has been noted for several species. A kind of ritualized body-shaking has been noted by Gilliard (Ms) for P. minor and P. raggiana but not for other species. LEAF-PLUCKING: Leaf-plucking is an im- portant component of display in Diphyl- lodes, clearing the vegetation from above their low display courts. It also seems to be an important component in the genus Par- adisaea. Dinsmore (1970a, p. 312) mentioned leaf-tearing in P. apoda in or near the display area. These were large palm leaves and the flora on Little Tobago Island in the West In- dies was one to which the bird was intro- duced. Perhaps the bird was unable to pluck the entire leaf. On one occasion the bird car- ried a piece of leaf to his display limb and dropped it there; Dinsmore did not see birds eating leaves (see Frith and Frith, 1979). This activity appeared to Dinsmore to be associ- ated with display but not an integral part of it; it most often occurred after a brief visit by a female prompted a partial display. Lu- 1981 LECROY: PARADISAEA 39 ban (in Baker, 1923, p. 297) had earlier re- ported that on Little Tobago ‘‘A queer action of the males. . . is their snapping off of tiny twigs of leaves. This is usually from their ‘dancing’ trees.”’ We observed leaf-plucking by a male P. decora on several occasions (LeCroy, Ku- lupi, and Peckover, 1980). This most often occurred during lulls in display and with only one male present but did occur once during a brief display. The birds always plucked the leaves from above a main display limb. Frith and Frith (1979) have recently re- ported leaf-plucking and leaf eating by cap- tive P. raggiana, and in Varirata National Park near Port Moresby I have seen that the area above a display limb was almost entirely bare of leaves. Gilliard (1969, pp. 233, 234) noted two in- stances of leaf-plucking by P. minor. Once a male displaying with a number of other males interrupted display and moved away 6 feet to violently rip off large leaves and drop them. On another occasion a single male, after landing in a display tree, violently ripped off leaves and held them a few sec- onds before dropping them. Frith (1976, p. 73) saw a male P. rubra clearing a new display perch by plucking and dropping leaves. He believes that the activity may have originated as displacement activity but now serves to create display perches and keep the area around them clear. I agree that this seems a likely origin of the habit. There are several references in the literature to the morning sun hitting display limbs, and it may be that leaf-clearing facilitates this, although we saw no correlation between sun and dis- play activity in P. decora. BUTTERFLY DANCE: Stonor (1936, p. 1181) in writing of P. guilielmi in captivity noted: ‘‘Next follows the third and last part of the display, during which [the male] hops from perch to perch, performing a sort of dance, fluttering the wings and occasionally spinning round in small circles; as in the first stage, no use is made of the plumes.’’ This display followed the inverted display and there was no female (or other male) present. I have not found anything comparable in oth- er species. I consider the preliminary display observed by Frith (1976, p. 73) in P. rubra, and called a Butterfly Dance by him, more likely to be a Charging Display. SUN-BATHING: Frith (1976, p. 74) first called attention to this phenomenon in his article on P. rubra. He said that captive males of this species sunned for long periods in direct sunlight in a “‘peculiar pose with one wing drooping, the body leaning away from the sun and the head held high with bill pointing upward or tilted to one side.’’ Gil- liard (Ms) noted a similar display in a captive individual (fig. 20): ‘‘The tufts on the fore- head and the green shielding on the sides of the lower head were elevated and flexed as the bird struck one pose or posture after the other. Such posturing was executed after the male had scaled the thin trunk of a heavily leafed tree. At the top of the climb with the head protruding into the sun above the low crown, it would suddenly stiffen into the oddest sorts of positions. Often the head was thrust off to one side and this unnatural po- sition was held for seconds. At other times it leaned uncommonly far back and lofted the head and neck still farther as though drawn by a cruel check rein... .” Gilliard (Ms) noted in P. raggiana that: ‘*Sometimes during the quiet part of the day silent males assumed rather grotesque posi- tions, partially hanging over the limbs with the chest and head held downward and fairly motionless for long seconds.’’ This may not correspond to the above and could conceiv- ably be a sleep posture. I have seen a young Red-footed Booby sleeping in this position. However, on another occasion (1969, p. 226) he noted: ‘‘As a general rule males sat on their private courts or on semi-hidden perch- es nearby for many hours per day. They sat quietly except for occasional calling and not infrequently as they sat they would lean backward or to the side so far out of balance that they appeared to be dying.”’ SEED REGURGITATION: Several species of Paradisaea have been seen to regurgitate seeds while on the display limb. It has been reported for P. apoda; Gilliard (unpublished notes, 1958) and Fred Truslow saw birds reg- ularly regurgitate seeds as they sat on the main display limb between bouts of display. 40 AMERICAN MUSEUM NOVITATES NO. 2714 Fic. 20. Sun-bathing in Paradisaea rubra. Photograph by E. T. Gilliard. The bird drew back its head and kept the posture for about three seconds, then began working open mandibles. After a few sec- onds, a seed came flying out in a gentle arc. Dinsmore (personal commun.) saw this species regurgitate seeds of Gumbo Limbo, Bursera sinaruba. Fred Shaw Mayer told Gilliard (unpub- lished notes, 1959) that captive Paradisaea raggiana were fed on oily pandanus seeds, which they swallowed whole. They later re- gurgitated the seeds. W.S. Peckover discovered that P. decora on the display limb regurgitates seeds of 1981 LECROY: PARADISAEA 41 Medusanthera laxiflora, a food plant. On in- vestigation we found that there were numer- ous other seeds of that species beneath the display tree. Most display trees we saw had food trees of this species and others growing beneath them, doubtless a result of seed re- gurgitation. There is no evidence that seed regurgitation is an element in actual display, but it may-function to cut time spent search- ing for food, thus allowing more time for dis- play. And W. S. Peckover (in litt.) suggested that it may serve as an added attraction to females. CALLS Calls are extremely difficult to analyze as no two workers record them in the same way. Therefore, the following is only a brief attempt to group calls. All species of Paradisaea have had one or two types of crowlike calls recorded. In ad- dition, there are shrill kii or quee calls re- corded for P. apoda, P. raggiana, and P. minor. Paradisaea guilielmi is reported also to make a popping call ‘‘like Chinese fire- crackers’’ (Draffan, 1978, p. 58). A growling call has been reported for P. minor (Gilliard, unpublished notes, 1958), P. decora, P. rag- giana, P. rudolphi, and P. guilielmi (person- al observ.). A whiplike call has been report- ed for P. decora, P. minor, and P. guilielmi (personal observ.); a mewing call for P. rag- giana and P. rubra; and a click call for P. rubra and P. apoda. The duetting calls of P. decora are probably homologous to the bu- gle-like calls of P. raggiana and P. apoda mentioned by Gilliard (Ms) and to the bub- bling duet I heard given by P. guilielmi, Frith (1976) mentioned a ‘‘weep,’’ a mandible snap, and Bill-click-call for P. rubra and Dinsmore (1970a) a ‘‘Cugich’’ call for P. apoda which do not seem to have counter- parts in other species. DISPLAY BY UNPLUMED MALES Display by unplumed males has been re- ported for most species of Paradisaea and probably occurs regularly. There is the pos- sibility that on occasion these are molting males, but molting birds in captivity do not display. Also these birds frequently lack yel- low or green on the head and have no tail wires. They seem to move about regularly in bands or ‘‘drones’’ as Gilliard (Ms) called them. The unplumed males may display in the absence of plumed males and may reoccupy traditional trees when plumed males are shot as suggested by Healey (1978a, p. 154): ‘*‘Some. subadult males [of Paradisaea minor] may mate at display-trees abandoned by adult males: at Tabibuga I observed two subadult males displaying in early June with no adult males but several female-plumaged birds nearby. This indicates that display trees are not necessarily abandoned if all mature males are shot. Though females may not mate with subadult males when mature males are present, they may do so where dis- play trees are widely spaced and mature males locally rare.”’ Gilliard (1969, p. 226) saw that an un- plumed male of P. raggiana may obtain a display limb after the owner was shot: “‘Not knowing of the shooting, I sat under its dis- play space—a sloping limb—for three morn- ings waiting for the distinctively-plumed owner to return. Other adult males in the arena did not visit this limb, but three days after the shooting a young male still in female dress investigated it. It flew in quietly and perched at one end of the limb, then after a few seconds it jumped onto the main display space, crouched, and began thumping its wings overhead, exactly as in the adult male.”’ Gilliard (ms) spoke of ‘‘drones’’ of dis- playing unplumed male P. minor around dis- playing plumed males, and we (LeCroy, Ku- lupi, and Peckover, 1980) several times saw groups of unplumed P. decora males dis- playing to, and mating with, females in the presence of a displaying plumed male. Wal- lace (1869) noted unplumed male P. apoda displaying. Probably unplumed males of all species (except P. rudolphi?) do so regular- ly. It is probable that the brightly colored plumes serve as a signal to males to gather and display. D’Albertis (1876) has reported that people in the Fly River area and on the 42 AMERICAN MUSEUM NOVITATES Aru Islands suspend plumes of Paradisaea in a tree to which they wish to attract males, and Goodfellow (1910) mentions a similar practice on the Mimika River. Unplumed males may be allowed around the arena be- cause they have no plumes, and it may be that only a small percentage of the males in the population is plumed at any one time. Inhibition of plume development in sub- ordinate males cannot be ruled out. (Stein- bacher, 1938, mentions that dominated birds may lose their sexual plumage.) The estimate of the number of years required for a male Paradisaea to acquire plumes is based either on stages of plumage in museum specimens (which may reflect hormone levels more closely than age) or on the age at which cap- tive birds acquire plumes (which may be a minimum age as they are usually alone in the captive situation and therefore without a dominance framework). Recruitment into the dominance framework in the wild may permit plume development and give the bird an opportunity to become the dominant male. EVOLUTION WITHIN THE GENUS PARADISAEA Most recent authors (Bock, 1963; Gilliard, 1969; Diamond, 1972; Frith, 1976) have considered the genus Paradisaea to be closely related to Diphyllodes (including Ci- cinnurus, see Diamond, 1972). I agree and believe that various elements in the display of Paradisaea support its close relationship to Diphyllodes. The use of a vertical or near vertical limb in displays of P. rubra, P. rag- giana, P. decora, and perhaps other conge- ners, and leaf-plucking over the display limb are similar to elements of display in species of Diphyllodes. Paradisaea and ‘‘Cicinnu- rus’? have several display postures in com- mon; see especially the ‘‘first stage of dis- play’’ figured by Ingram (1907, p. 226), the inverted display described by Bergman (1957b), and the zigzagging display described by Gilliard (1969, p. 197). The crowlike call of Paradisaea is very similar to that of D. regius and fairly similar to that of D. mag- nificus (Diamond, in litt.). Also Paradisaea NO. 2714 and Diphyllodes are the only two genera in the family that have the central tail feathers of males modified into wirelike (ribbon-like in P. rubra and P. rudolphi) structures (Diamond, 1972). Gilliard (1969) proposed that the ancestors of birds of paradise were arboreal and mo- nogamous and that polygynous arena species evolved and were different morphologically but behaved like semispecies in that they ex- cluded each other geographically and ecolog- ically. A result of this exclusion was that some of the arena birds were displaced downward to display on the forest floor. Di- phyllodes was one such line and as such would be more recent and highly evolved than arboreally displaying Paradisaea. _ Frith (1976) accepts this direction of evo- lution and further believes P. rubra to rep- resent a possible intermediate stage between communal display and individual display. However, his reasons are based partly on observations of captive birds whose displays likely were affected by the presence of a hu- man observer. It seems to me that increased dispersal during display when an observer is in the cage and indications that the bird is descending toward forest floor are both ar- tifacts of captivity. Gilliard (ms) noted that a male P. raggiana displaying in the wild moved from the main to a peripheral display limb when disturbed by an observer—the logical reaction to disturbance. And both Gilliard (in Greenway, 1969) and Bergman (in Gyldenstolpe, 1955) only saw P. rubra in the exposed tops of trees in the wild. I do not think we are yet in a position to make a statement as to the direction of evo- lution. We are not certain, for example, that there is no pair bond in Diphyllodes. And it could be argued that because barring is pres- ent in most female birds of paradise, this is the primitive condition and Diphyllodes is thus primitive. Paradisaea could then be de- rived from ancestors in which females are barred through intermediates, such as P. ru- dolphi, in which females are barred on the abdomen. But barring in females may be in- dependently evolved and convergent, and as P. rudolphi seems anomalous in many facets of its display, it seems premature to propose 1981] LECROY: PARADISAEA . 43 that species as the primitive species in the genus. Among the remaining species of Paradi- saea, P. rubra appears to be the least spe- cialized in terms of plume development. It has probably also been isolated the longest on the islands of Waigeu and Batanta. Frith (1976) has pointed out that posturing on a vertical limb was the most developed part of the display he observed, and movement of the highly developed feathers on the head was an integral part of display. In each of these respects P. rubra is more similar to Diphyllodes than to other species of Par- adisaea. The iris of P. rubra is brown, as in Diphyllodes. On the other hand, the display repertoire of P. rubra has most if not all of the elements present in displays of the other arena species of Paradisaea. The three similar species, P. apoda, P. minor, and P. raggiana, hybridize rather freely whenever they are in contact; and the static Flower Display, which I believe to be the species-recognition signal in these non- pair-forming birds, is similar in these three taxa. I believe they should be considered a superspecies, P. [apoda], as Diamond (1972, p. 316) has suggested. [I am defining super- species as ‘‘a group of entirely or essentially allopatric taxa that were once races of a sin- gle species but which now have achieved species status’” (Amadon, 1966; Short, 1969) and semispecies as populations that are es- sentially allopatric but that show some hy- bridization in areas of overlap. ‘‘Semispecies are one type of allospecies comprising a su- perspecies’’ (Amadon, 1966; Short, 1969, p. 90). The use of brackets to designate a superspecies follows Amadon, 1966.] The male-male displays of P. apoda, P. minor, and P. raggiana differ only in detail, and I believe these differences are more apparent than real and that as our knowledge in- creases so will our understanding of the sim- ilarities. The plumed males and adult females have a yellow iris in all three taxa. These three semispecies probably evolved on the Aru Islands, in northern New Guinea (or on the Vogelkop), and in southeastern New Guinea, respectively, and have subsequently spread until they encircle New Guinea from sea level to slightly over 1500 m. where suit- able forest occurs. Paradisaea decora is morphologically sim- ilar to P. [apoda] and should be included in the superspecies. Plumed males and adult fe- males have a yellow iris, and the Flower Dis- play is similar to that of P. [apoda] but not quite so highly developed. Paradisaea dec- ora display differs mainly in the importance of Male-male Duetting in setting up the male hierarchy, but Male-male Duetting occurs in other species and may prove to be common. The females have faint barring or speckling on the abdomen. Paradisaea guilielmi undoubtedly evolved in isolation on the Huon Peninsula at a time when it was separated from the central mountains by a water barrier. Reinvasion of the area by minor from the northwest. and raggiana from the southeast has perhaps driven this species to higher elevations. However, both P. guilielmi and P. raggiana occur together in the Saruwaged Mts. at about 450 m. (personal observ.). Paradisaea guilielmi is known to hybridize in the wild with both P. minor and P. raggiana. The inverted display of P. guilielmi is undoubt- edly an isolating mechanism. Gilliard (1969, p. 256) believed that inverted display was probably derived separately in P. guilielmi and P. rudolphi, and I agree. As there is some evidence of inverted display in most speices, it is not hard to imagine its enhance- ment in these two species independently. Crandall (1932, p. 80) mentions that the plumes of P. guilielmi were ‘‘erected at an angle of about 45°”’ on the ventral side of the bird and spread anteriorly and posteriorly to form two semicircles which met to form a complete circle around the breast and ab- domen of the inverted bird. Stonor (1936, p. 1181) said that during display in P. rudolphi, ‘‘the plumes are spread out in the form of a fan, but are not pointed forward to the same extent as in Trichoparadisea |[=P. guilielmi].’’ It would be interesting to study the musculature of the display plumes to see how birds giving an inverted display differ from those in which the plumes are raised above the back, and whether P. rudolphi and P. guilielmi differ in this respect. Plumed 44 AMERICAN MUSEUM NOVITATES males and females of both species have the iris dark as in P. rubra, but the plumed male of P. rudolphi apparently has a navy blue iris. As Gilliard (1969) has pointed out, the number of intergeneric and interspecific hy- brids known from the wild in the Paradisaei- dae indicates that these birds are much more closely related genetically than the morphol- ogy of the males would imply and that arena behavior allows selection to act very rapidly on the species, particularly on the males. Thus the display postures that serve as iso- lating mechanisms assume great importance in the non-pair-bonding species. It is espe- cially in these that we find the most diversity within Paradisaea, and where two species meet the displays that serve to prevent inter- breeding are most different. But even so, in- verted versus noninverted display has not served completely to prevent hybridization, as wild hybrids between P. guilielmi and P. ragegiana, P. guilielmi and P. minor, and P. raggiana and P. rudolphi are known. It would be of great interest to know exactly where these hybrids were found and which species provided the male and which the female parent. If males tend to occur at higher alti- tudes than females within a species’ range, as they do in some species (Diamond, 1972), then it seems likely that the male parent was a member of the P. [apoda] superspecies and the female a member of the species with in- verted display. Thus a female at the lower altitudes of her species’ range and ready to mate might occasionally respond to the dis- play of P. [apoda] males in the absence of males of her own species. Stonor (1936) has discussed evolution within the genus Paradisaea and decided on the basis of captive displays and feather structure that Uranornis (=P. rubra) branched off from the ancestral stock earliest followed by Paradisornis (=P. rudolphi) and Trichoparadisea (=P. guilielmi) stock which later gave rise to the two species with in- verted display. Paradisaea decora next branched off earlier than the remaining species. My interpretation based on the analysis given in this paper is that within the genus NO. 2714 Paradisaea, P. rubra is closer to the ances- tral stock, has the most generalized display, and does not spread its plumes. I envision development in two directions from a rubra- like ancestor (which may have been wide- spread in New Guinea). In one direction P. guilielmi may have evolved. Some of its pos- tures are similar to those of P. rubra, partic- ularly the Wing Pose; and display of the green head feathers is pronounced in both species. Paradisaea rubra also has a well- developed Inverted Display although it is given on a near-vertical limb and is not as highly developed as that in P. guilielmi. Spreading of plumes ventrally would have developed independently of plume spreading in the other species. Along another line, P. [apoda] probably developed by accenting the upright poses in display and raising the plumes over the back in a cascade. As mentioned by Frith (1976, p. 75) the wing position of P. rubra most closely resembles that in P. minor. The depression of the tail (Frith, 1976, p. 75) seems to me to function strictly as a coun- terbalance in those species which raise the plumes over the head. Thus, it would not be expected to occur in P. rubra, P. guilielmi, and P. rudolphi, nor does it occur in P. dec- ora, where the plumes are not thrown so far forward. Paradisaea rudolphi may either be the most primitive member of the genus (its pos- sible pair bond behavior having been re- tained from an ancestral form), or it may have diverged from the Paradisaea line more recently (its probable territoriality and ‘the barred plumage of the female being de- rived characters). Most authors agree to a close relationship between Diphyllodes and Paradisaea, and Diamond (1972) has pointed out that the red and yellow pigments present in Diphyllodes have counterparts in most species of Paradisaea. P. rudolphi is unique in having blue and black plumage. The bird’s inverted display is also different from that of P. guilielmi, the flank plumes being spread fanlike across the lower abdomen and not angled at all. These may all be secondary adaptations evolved in response to compe- tition with P. raggiana across its range. Dia- 1981 mond (in litt.) has suggested that perhaps **P. rudolphi is the old eastern member of the Paradisaea superspecies, and diverged rapidly as well as was displaced altitudinally when its range was overrun by the western population that became the minor-raggiana line.’’ I agree that this may be the case. The short plumes of P. rudolphi may not be a primitive condition. The species is not known to have a Wing Pose, Charging Dis- play, or Zigzag Display, all of which are male-male displays at the arena. If, as I have hypothesized, the plumes in Paradisaea have developed in response to male-male in- teractions, they are perhaps being lost in this species. Furthermore, if character displace- ment is involved as Gilliard (1969) thought, then shorter plumes would be at a selective advantage in this species (as well as in P. guilielmi) because the two species are com- peting with the sympatric long-plumed P. minor and P. raggiana. Paradisaea rubra is smaller than members of the P. apoda superspecies but is not smaller than P. guilielmi and P. rudolphi (see table 1). I believe that small size may prove to be a primitive character in P. rubra. Diphyllodes certainly is small, and Bock (1963, p. 122) found that the group of genera including Diphyllodes had the least special- ized skull within the Paradisaeinae. How- ever, he stresses that with the evidence at hand it is impossible to tell whether this un- specialized skull is truly primitive. Character displacement may be involved in the smaller size of P. guilielmi and P. rudolphi. Frith’s (1976) statements deserve com- ment. He said that the small size of P. rubra occurs despite the fact that it is confined to small islands ‘‘where individuals tend to be larger in size of body (Mayr, 1963)’ and that ‘‘the larger size of other members of the ge- nus could be because they extend higher al- titudinally than P. rubra, birds at higher al- titudes having been proven to be larger in New Guinea (Rand, 1936).’’ Mayr (1963, p. 319) said: ‘‘In view of occasional misunder- standings in the literature, it is important to emphasize ‘that the validity of the ecological rules .. . is restricted to intraspecific varia- tion...’ (Mayr, 1956).’’ Altitudinal varia- LECROY: PARADISAEA 45 tion in body size is also intraspecific (Rand, 1936). Thus these general ecological rules cannot be applied interspecifically in Par- adisaea where gene exchange is minimal or nonexistent and evolutionary pressures dif- fer. EVOLUTION OF NON-PAIR-BOND POLYGYNY The similarities are striking between non- pair-bonding polygynous arena-displaying birds of paradise and birds in totally unrelat- ed families but with a similar social struc- ture. The studies by Chapman (1935), Gil- liard (1959), Sick (1967), and especially Snow (1976 and earlier papers listed therein) and Foster (1977 and personal commun.) on New World manakins (Pipridae); the studies by Gilliard (1962) and Snow (1976 and earlier papers) on cotingas (Cotingidae); the studies by Shepard (1976) on Ruffs (Scolopacidae); the studies by Kruijt and Hogan (1967) on Black Grouse (Tetraonidae); and others too numerous to mention all show that these di- verse species have evolved basically very similar solutions to the problems associated with maximum reproductive output. The six characteristics of arena birds which I dis- cussed earlier apply to the above: loud calls by males on the arena (mechanical noises sometimes substituted), extreme sexual di- morphism in plumage, males considerably larger than females, few males in adult plum- age compared with the number of unplumed males and females seen, groups of males dis- playing for long periods of the year whether or not females are present, and the species frequently but not always belonging to spe- ciose genera. Male-male displays differ from female-male displays and many of the above authors have commented on these differ- ences. In one species, at least, there is a proven male-male bond between two or more males on one display perch or court (see Foster, 1977). These similar develop- ments related to the social systems in unre- lated birds raise many questions. A number of theories have been put for- ward to explain extreme sexual dimorphism and polygyny in birds. The earliest was Dar- 46 AMERICAN MUSEUM NOVITATES win’s (1871, p. 916) theory of sexual selec- tion about which he said, ‘“The sexual strug- gle is of two kinds; in the one it is between individuals of the same sex, generally the males, in order to drive away or kill their rivals, the females remaining passive; whilst in the other, the struggle is likewise between individuals of the same sex, in order to excite or charm those of the opposite sex, generally the females, which no longer remain passive, but select the more agreeable partners.”’ With few exceptions, bird of paradise be- havior (and that of other arena-displaying species) has been interpreted in terms of Darwin’s second kind of sexual selection— females choosing the most ‘‘attractive’’ male. Crandall (1936, p. 88) approached a different interpretation when he questioned the term ‘‘courtship’’ before ‘‘display’’ and implied that he felt that courtship displays were primarily for the female but had spread into male rivalry situations, albeit still relat- ed to reproductive processes. “‘So now we come again to Darwin’s theory of Sexual Se- lection—with a twist. For instead of careful- ly selecting the male that strikes her as the handsomest, it seems to me that the female acts from an irresistible impulse to accept the one that approaches most nearly the highest standard of her race. Thus would the chief principal of Darwin’s thought be supported: the finest, as well as the most vigorous, would be certain of finding mates, and the species would continue in all its glory.”’ In Paradisaea decora we saw no evidence that the female made any kind of mate selec- tion (LeCroy, Kulupi, and Peckover, 1980). The plumed males spent many hours dis- playing among themselves, with and without unplumed males being present. In so doing they presumably set up and maintained a mating hierarchy among themselves—chas- ing unplumed males away, or at least to the periphery. That this dominance hierarchy worked was shown by the disappearance of all but one other plumed male (the Male-male Duetting partner) when a female appeared, and by this male’s acquiescence to the dom- inant male in the later stages of display to the female. This also occurs in P. raggiana (see above) as well as in Chiroxiphia linearis NO. 2714 (Foster, 1977) and will probably prove to be widespread in arena-displaying species. In P. decora the female appeared to come to a particular limb near the main display limb— a locality of high stimulation presumably, and which male was displaying seemed un- important to her as she mated with unplumed males as well as with the displaying plumed male. In the literature most displays of Par- adisaea in the wild are of both plumed and unplumed males; but the few observations of copulations in the wild do not conflict with this interpretation. | I think that the importance of setting up the male-male dominance hierarchy in arena- displaying birds has not been sufficiently stressed previously and that the plumes have primarily evolved in response to male-male pressures. Secondarily the plumes have be- come involved in the display to a female. The female ready to mate may be drawn to the arena area by the vocalizations and move- ments of the displaying males. But it seems likely that she is not attracted to any partic- ular male but to a locality (or localities) with- in the arena, which may or may not be tra- ditional, there to mate with whichever male has acquired that display space. A number of the authors cited above who have worked with marked birds have commented that most of the copulations go to the male(s) on the central court(s). If the female is indeed attracted by the vocalizations and move- ments of the males then it seems logical that this attraction would be greatest at the cen- ter, and that the dominant male or males would hold this position. If one accepts the hypothesis that the dom- inant male is also superior in fitness, and if it proves to be generally true in arena-dis- playing birds that most copulations go to the dominant male, then essentially only his genes would be passed on to the next gen- eration, allowing for rapid evolution in the male line. Selection on females would not occur in the display situation, the males mat- ing with any female in breeding condition. Natural selection would act on the females in the context of their ability to raise young that reproduce. How can a polygynous system such as this 1981 LECROY: PARADISAEA 47 develop? There are many theories concern- ing the development of polygyny, most hav- ing to do with territorial birds that have more than one mate, either simultaneously or se- quentially, but within the territory held by the male and with the development of a pair bond of greater or lesser duration. Trivers (1972) believes that the develop- ment of polygyny has to do with the invest- ment each sex has in its offspring. As female investment becomes more and male invest- ment less there will be an increased selection among males for more frequent matings; 1.e., females will tend to be in short supply and will be competed for, and ecological factors will contribute to the amount of parental in- vestment. This also implies some choice by the female to protect her investment and avoid mating with an inferior male. But this theory only applies in situations where a large proportion of the population of males and females is breeding and there is some sort of pair bond. In a situation such as that in Paradisaea where there is polygyny with- out a pair bond and males do not defend in- dividual territories in which a female rears the young, it is not necessary to have female choice to produce the extreme sexual dimor- phism and elaborate displays seen, as dis- cussed above. If this sort of system develops only in non- territorial birds we might ask what the ad- vantages of such a non-territorial polygynous system would be. Verner and Willson (1966) propose that the ‘*polygyny threshold’’ occurs when there is a sufficient difference in quality between male territories that a female could rear more offspring on a better territory without the help of the male than she could on a poorer territory with the resident male’s help. This may be as much or more a result of popula- tion density as of food availability, forcing males into marginal territories. But these au- thors say that the adaptive basis of non-pair- bonded polygyny eludes them. Emlen and Oring (1977) introduce the ‘‘operational sex ratio’’ and define it as ‘‘the average ratio of fertilizable females to sex- ually active males at any given time,’’ and they discuss the degree to which environ- mental tactors control access to and defense of mates. Under their category of male dom- inance polygyny they include cases in which males do not directly defend females, or re- sources necessary to them, but the males sort out among themselves their relative po- sitions of dominance. Females choose males primarily on the basis of male status. Emlen and Oring (op. cit.) state that ‘communal displaying is frequent among species in which the male is totally emanci- pated from parental care and the environ- ment provides little potential for resource or mate control.’ In such cases direct male- male encounters may occur and a dominance hierarchy be set up among the males. Under such a system a high-ranking male should benefit by joining a communally displaying group, but they ask why a subordinate male should join such a group. Presumably the strength of the stimulus is enhanced by con- centration of displaying males—the larger the aggregation the more attractive it be- comes to females—and ‘‘low-ranking males will be expected to adopt alternative, cryp- tic, or satellite strategies for obtaining fe- males within the communal display areas rather than avoiding male aggregations alto- gether.’’ This seems to be exactly what has happened in P. decora, where subordinate, unplumed males are usually chased by the plumed males, but during the height of dis- play by the dominant male, in which the dominance is sufficiently strong to cause oth- er plumed males to leave the tree or sit in silence, unplumed males slip in and copulate with the female. Whether these copulations are successful or not is another question. Presumably they could not often be or the hierarchy would break down. It is perhaps also significant in this regard that the un- plumed males mated only with the female in the central position near the displaying plumed male. Several times a second female was present and occasionally solicited from another limb. The unplumed males did not attempt copulation with her although on one occasion the plumed male did copulate brief- ly with the second female on the other limb immediately after copulating with the central female. 48 AMERICAN MUSEUM NOVITATES It is interesting to speculate on the possi- bility that all of the males in a clan are relat- ed. If this were true then occasional suc- cessful matings by unplumed males, or by plumed males lower in the hierarchy, might be tolerated by the dominant male(s) as a kind of kin selection. But Foster (1977) pro- vides strong arguments against kin selection in such cases. Proximity of the unplumed males to the display arena provides them with a better opportunity of being incorpo- rated into the hierarchy when a dominant bird disappears. The time spent in what Gil- liard (Ms) called a “‘drone of males’’ might serve as a kind of apprenticeship, and Foster (1977), Snow (1976), and others have dis- cussed the potential advantage, in evolution- ary terms, to an individual serving such an apprenticeship. Emlen and Oring (1977) further maintain that if the females are asynchronous in their sexual receptivity, the operant sex ratio be- comes skewed and then lek systems develop where males remain sexually active over long periods of time and set up a relatively stable hierarchy. Display areas develop for the sole purpose of attracting females for mating and after mating they leave the area and nest and rear the young alone. To this extent Paradisaea exactly fits their descrip- tion of a lek bird. But I see no evidence in Paradisaea that sexually receptive females ‘**sample’ numerous males before selecting a mate.’’ In other words, the evidence sug- gests that the sexual selection involved is Darwin’s first kind—male-male selection with the female remaining passive in terms of choosing a male. Females would benefit from the long period of male display, and ’ presumably of sexual readiness, as re-nest- ing by females might be attempted over a much greater period of the year as long as food supplies are adequate. That males could not control resources within a territory to support a female and young is indicated by the fact that Paradi- saea is largely frugivorous (as is also the case with most, if not all, of the cotingas and man- akins referred to above), and fruit ripening on any one tree at any one time would cause a superabundance of food in that locality. NO. 2714 But fruit trees may be scattered in the forests and females and/or young males are often seen feeding in groups moving through the forest. Defense of such an ephemeral food supply by males would not appear feasible, and there is no indication that females defend a territory either. Emlen and Oring (1977) hypothesize that *‘all cases [of lek mating systems] will be typ- ified by a fairly long breeding season, a heavily skewed operational sex ratio, and by the inability of individual males to econom- ically control or monopolize the resources essential for female acquisition.” Paradi- saea fulfills all of these requirements. I have not discussed the possibility that females of Paradisaea are polyandrous; i.e., that they have a succession of male partners in any one breeding season. Certainly they are in the sense that unplumed males mated with females in the arena of P. decora, fol- lowed by a plumed male mating with the same female. If these matings produce off- spring, if females mate with more than one male in the dominance hierarchy, or if that hierarchy shifts, then these birds might be considered polygamous (males are polygy- nous and females are polyandrous) as sug- gested by Peckover (1973). Even so, it would be a facultative polyandry on the part of the female, dictated by the dominance system of the males. Given our present state of knowl- edge—we do not know, for example, wheth- er a female mates more than once to produce a clutch—such a possibility can only be men- tioned. Two additional interesting ideas are rele- vant here. One, brought to my attention by Bertram Murray (personal commun.), is that there is some evidence in chickens (Compton et al., 1978) that sperm from the last rooster to mate with a hen fertilize the eggs. I have been unable to find any information concern- ing whether a sperm storage vesicle such as occurs in chickens might also occur in birds of paradise. If it does, then the copulations by unplumed male P. decora would not be likely to fertilize the egg(s). Smith (1979) has proposed another hy- pothesis in relation to the polygynous mating system of Fallow Deer (Dama dama). He 1981 LECROY: PARADISAEA 49 states that inbreeding may be selected for in this species, in which the dominant male does all the mating, even over a period of several years, and females bring their daugh- ters to the mating area where their father is dominant. This might occur, he hypothesiz- es, if the initial deleterious effects of in- creased homozygosity do not become exces- sive and if these deleterious alleles are eliminated and a new balance struck at a low level genetic load. Even so, he states that this would require altruistic behavior by the female in producing fawns with a somewhat greater genetic load than outbreeding would produce, but that this would be offset by an increase in inclusive fitness in the closely re- lated population. Such ideas cannot be dis- cussed in relation to Paradisaea until we have some information on behavior of indi- vidual birds and on relatedness of birds in the arena. ACKNOWLEDGMENTS I dedicate this paper to the memory of E. T. Gilliard, who enthusiastically introduced me to birds of paradise and bowerbirds and whose enthusiasm was contagious! I had the great privilege of working with him for five and a half years and his papers, journals, notes, and insights remain a constant source of inspiration to me. There are many others to whom I am grateful for assistance with one or another aspect of this study. Special thanks are due W. S. Peckover with whom I have worked in the field on four trips to New Guinea, and with whom I have had many discussions on birds of paradise, and who has made many helpful comments on various drafts of this paper. For help in the field I thank Harry Crouch, Gill and Dick Doyle, Kilion Ephraim, Graeme and Barbara George, Alfred Kulupi, Roy and Margaret Mackay, Joseph Mansei- ma, Mick Raga, Chris and Don Sanderson, Geoff Smith, Mary Stringer, the late Hobart M. Van Deusen, Tom and Inez Weston, the Papua New Guinea Bird Society, residents of Nade (Fergusson Island) and Kelologea (Normanby Island), and the Wildlife Divi- sion of the Department of Lands and Envi- ronment. I have benefited from discussions with or comments from Charles W. Myers, Jared Diamond, James Dinsmore, Mercedes Foster, Clifford Frith, David Gillison, Helen Hays, Scott Lanyon, Wesley Lanyon, Helen Lapham, Bertram Murray, Thane Pratt, Les- ter Short, and Francois Vuilleumier. Gerlof Mees made available to me weights of Para- disaea apoda novae-guineae and measured for me the specimens of P. minor “‘pulchra’’ at Leiden. Photographs have been kindly made avail- able to me by Donald Bruning and William Meng at the New York Zoological Park, by David Gillison, and by the National Geo- graphic Society. Juan Barbaris of the Amer- ican Museum’s Department of Exhibitions and Graphics made drawings of several Par- adisaea poses from photographs or old pub- lished illustrations, and I am much indebted to him. I also thank Arthur Singer and Har- old Walters of the American Museum’s Di- vision of Photography, who made black and white conversions from slides, and Florence Brauner for her expert editing. My thanks also to the Frank M. Chapman Memorial Fund for support of my fieldwork in 1974. LITERATURE CITED Amadon, D. 1966. The superspecies concept. Syst. Zool., vol. 15, pp. 245-249. Baker, H. D. 1923. Birds-of-Paradise at Little Tobago Is- land. Bird-Lore, vol. 25, pp. 295-302. Beach, J. 1975. Display and mating of the King of Sax- ony Bird of Paradise. New Guinea Bird Soc. 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