Biological Exuberance: Animal Homosexuality and Natural Diversity

and mount females in lesbian pairs, while the latter may mate with males to fertilize their eggs. Most females in homosexual pairs, however, show no interest in males. Pairs of female Scarlet Ibises (Eudocimus ruber) have also been observed in captive flocks, nesting together and sometimes laying fertile eggs.

Sources

*asterisked references discuss homosexuality/transgender

Allen, R. P. (1956) The Flamingos: Their Life History and Survival. National Audubon Society Research Report no. 5. New York: National Audubon Society.

*Alraun, R., and N. Hewston (1997) “Breeding the Lesser Flamingo Phoeniconaias minor,” Avicultural Magazine 103:175—81.

Bildstein, K. L., C. B. Golden, and B. J. McCraith (1993) “Feeding Behavior, Aggression, and the Conservation Biology of Flamingos: Integrating Studies of Captive and Free-Ranging Birds.” American Zoologist 33:117—25.

Cezilly, F. (1993) “Nest Desertion in the Greater Flamingo, Phoenicopterus ruber roseus.” Animal Behavior 45:1038—40.

Cezilly, F., and A. R. Johnson (1995) “Re-Mating Between and Within Breeding Seasons in the Greater Flamingo Phoenicopterus ruber roseus.” Ibis 137:543-46.

*Elbin, S. B., and A. M. Lyles (1994) “Managing Colonial Waterbirds: the Scarlet Ibis Eudocimus ruber as a Model Species.” International Zoo Yearbook 33:85-94.

Kahl, M. P. (1974) “Ritualized Displays.” In J. Kear and N. Duplaix-Hall, eds., Flamingos, pp. 142-49. Berkhamsted, UK: T. and A. D. Poyser.

*King, C. E. (1996) Personal communication.

*———(1994) “Management and Research Implications of Selected Behaviors in a Mixed Colony of Flamingos at Rotterdam Zoo.” International Zoo Yearbook 33:103-13.

*———(1993a) “Ondergeschoven Kinderen [Supposititious Children].” Dieren 10 (4):116—19.

*———(1993b) “Ongelukkige Flamingo Liefdes [Tales of Flamingo-Love Gone Awry].” Dieren 10(2):36—39.

Ogilvie, M., and C. Ogilvie (1989) Flamingos. Wolfeboro, N.H.: Alan Sutton.

*Shannon, P. (1985) “Flamingo Management at Audubon Park Zoo and the Benefits of Long-Term Research.” In AAZPA Regional Conference Proceedings, pp. 226—36. Wheeling, W.Va.: AAZPA.

*Stevens, E. F. (1996) Personal communication.

———(1991) “Flamingo Breeding: The Role of Group Displays.” Zoo Biology 10:53—63.

*Studer-Thiersch, A. (1975) “Basle Zoo.” In Kear and Duplaix-Hall, Flamingos, pp. 121—30.

Tourenq, C., A. R. Johnson, and A. Gallo (1995) “Adult Aggressiveness and Creching Behavior in the Greater Flamingo, Phoenicopterus ruber roseus.” Colonial Waterbirds 18:216—21.

*Wilkinson, R. (1989) “Breeding and Management of Flamingos at Chester Zoo.” Avicultural Magazine 95:51-61.

Shore Birds

SANDPIPERS AND THEIR RELATIVES

RUFF

IDENTIFICATION: A large (12 inch) sandpiper with gray or brownish plumage and, in some males, spectacular ruffs and feather tufts on the head that vary widely in color and pattern (see below). DISTRIBUTION: Northern Europe and Asia; winters in Mediterranean, sub-Saharan Africa, Middle East, India. HABITAT: Tundra, lakes, swampy meadows, farms, floodlands. STUDY AREAS: Texel, Schiermonnikoog, Roderwolde, and several other locations in the Netherlands; Oie and Kirr Islands, Germany.

BUFF-BREASTED SANDPIPER

IDENTIFICATION: A medium-sized (7—8 inch) wading bird with a small head and short beak, buff- colored face and underparts, and regular dark brown patterning on the back and crown. DISTRIBUTION: Arctic Canada, Alaska, extreme northeast Siberia; winters in south-central South America. HABITAT: Tundra, grass- lands,mudflats. STUDY AREA: Meade River, Alaska.

Social Organization

Ruffs and Buff-breasted Sandpipers are both LEKKING species, which means that males gather together to perform elaborate courtship displays on communal grounds known as LEKS (some Buff-breasts also display solitarily). The mating system is polygamous or promiscuous: males (and sometimes females) mate with multiple partners, and females raise any resulting offspring on their own. Outside of the breeding season these sandpipers tend to associate in flocks, which can number in the thousands among Ruffs.

Description

Behavioral Expression: There are four distinct types or “classes” of male Ruffs, differing in their appearance, social behavior, and sexuality. RESIDENT males generally have dark plumage (with a wide variety of different feather patterns) and defend their own territories on the lek. MARGINAL males look similar to residents but do not have their own territories; they stay on the periphery of the lek and are often attacked by residents. SATELLITE males usually have white or light-colored plumage; they do not own territories, but often visit the lek and associate with particular residents. Finally, NAKED-NAPE males lack the nuptial plumage—ruff and head tufts—of other males, giving them the superficial appearance of females. They are not territorial either, but occasionally visit leks for short periods. Naked-napes may include younger males and/or adults passing through on their migratory journeys prior to developing their breeding plumage. Resident and satellite males also differ genetically from one another.

Homosexual behavior occurs among males of all types and is especially prominent between residents and satellites. While a resident male is displaying on his territory, one or more satellites may approach him and engage in courtship behaviors. Most notable of these is SQUATTING, in which the males lie with their bellies to the ground and expand their ruffs, crouching together while the resident places his bill on top of the satellite’s head. This may lead to homosexual copulation, in which either the resident or the satellite mounts the other male and attempts to make genital contact—he lowers himself and spreads his wings while holding the other male’s head feathers in his bill. The mounted bird reacts by either remaining crouched or by trying to shake the other male off his back. If more than one satellite male is present on the lek, they sometimes also mount each other. Many satellites have “preferred” resident males with whom they spend most of their time, and residents may also actively entice satellite males onto their display courts.

Females are often drawn to the activities between resident and satellite males, and heterosexual courtship and copulation (involving either residents or satellites) may occur at the same time as homosexual activities (or shortly thereafter). Occasionally, a satellite male will mount a resident male who is in the act of mating with a female; residents and satellites may also try to prevent each other from mating with females. Naked-nape males also engage in homosexual mounting with each other and with residents. When a naked-nape arrives on the lek, the resident male may respond by squatting; the naked-nape approaches him in a horizontal posture or may himself squat. The naked-nape may then try to mount the resident, although he does not usually lower his body to “complete” the copulation; he may also mount in a backwards position with his head facing the resident’s tail. Residents also sometimes mount naked-napes, and naked-napes also mount each other. Naked-nape males are sometimes courted by other males during stopovers on the spring migration as well (i.e., outside of the mating