Homosexual group copulation in Sage Grouse: a female crouching with outstretched wings (left) is being mounted by another female (center, upright bird), who is simultaneously being mounted by a third female (right, with its neck extended over the back of the second female). A fourth female (foreground, facing front), is not part of this “pile-up.”
Frequency: Approximately 2-3 percent of Sage Grouse females participate in homosexual courtships and copulations, which occur in perhaps one out of five female visits to the lek (on average); the prevalence of homosexual behavior in wild Ruffed Grouse is not known.
Orientation: Some female Sage Grouse that mate with females do not apparently engage in heterosexual copulation; others alternate between homosexual and heterosexual activity (sometimes within a few hours or minutes). As described above, bisexual “pile-ups” involving birds of the same and opposite sexes mounting each other simultaneously also occur. In Ruffed Grouse, little is known about homosexual activity in the wild, but it is likely that there is a similar combination of bisexuality with occasional exclusive homosexuality. Displaying males that mount other males probably also court and mate with females, while those males who approach displaying males are most likely nondrumming “alternate” males (see below) that do not mate heterosexually.
Nonreproductive and Alternative Heterosexualities
In both of these species, significant portions of the population are nonbreeding. As many as 30 percent of male Ruffed Grouse are nondrummers who do not mate heterosexually, and some birds never breed during their entire lives. In fact, one researcher found that nonbreeders live longer and have a better survival rate than breeders. Many nonbreeders are younger males who have yet to acquire a drumming log; others are ALTERNATE males that tend to associate with another male on his display site without themselves drumming. Still others give up or “abdicate” their display territories and become nonbreeders. Up to 25 percent of female Ruffed Grouse may not nest in any given year, as is true for 20-32 percent of female Sage Grouse in some populations. Moreover, 14-16 percent of female Sage Grouse abandon their nests (especially if they have been disturbed), which means that any eggs or chicks they have will not survive; this also occasionally occurs in Ruffed Grouse. The majority of Sage Grouse copulations are performed by only a small fraction of the male population, and one-half to two-thirds of males never mate at all; during each breeding season, 3-6 percent of females do not ovulate either.
Even among birds that do mate, heterosexual copulation is often complicated by a host of factors: female Sage Grouse may refuse to be mounted, males often ignore females’ solicitations to mate (especially later in the breeding season), and 10–18 percent of copulations are disrupted by neighboring males who attack mating birds. In addition, males and females are often physically separated from each other: in both species, typically the only contact the two sexes have with each other during the breeding season is mating. Since each female usually copulates only once, hers is a largely male-free existence. Even on the display grounds, Sage Grouse are typically sex-segregated when not actually mating. Several types of alternative sexual behavior also occur in these species. Male Sage Grouse often “masturbate” by mounting a pile of dirt or a dunghill and performing all the motions of a full copulation. Both male Ruffed and Sage Grouse occasionally court and mate with females of other grouse species. And male Sage Grouse sometimes mount females without attempting to inseminate them (no genital contact). Moreover, even though most females mate only once (that is, the minimum required to fertilize their eggs), multiple copulations also occasionally occur: one female, for example, was mounted more than 22 times in one hour. Female Sage Grouse sometimes combine their youngsters into what is known as a GANG BROOD, a communal “nursery flock” of sorts.
Other Species
Homosexual activity occurs in several species of pigeons. Feral Rock Doves (Columba livia), for example, form both male and female same-sex pairs that engage in a full suite of courtship, pair-bonding, sexual, and nesting activities. Homosexual pairs of female Ring Doves (Streptopelia risoria) in captivity are generally more devoted incubators than heterosexual pairs, being less likely to abandon their eggs.
Sources
*asterisked references discuss homosexuality/transgender
*Allen, A. A. (1934) “Sex Rhythm in the Ruffed Grouse (Bonasa umbellus Linn.) and Other Birds.” Auk 51:180-99.
*Allen, T. O., and C. J. Erickson (1982) “Social Aspects of the Termination of Incubation Behavior in the Ring Dove (Streptopelia risoria).” Animal Behavior 30:345-51.
Bergerud, A. T., and M. W. Gratson (1988) “Survival and Breeding Strategies of Grouse.” In A. T. Bergerud and M. W. Gratson, eds., Adaptive Strategies and Population Ecology of Northern Grouse, pp. 473-577. Minneapolis: University of Minnesota Press.
*Brackbill, H. (1941) “Possible Homosexual Mating of the Rock Dove.” Auk 58:581.
*Gibson, R. M., and J. W. Bradbury (1986) “Male and Female Mating Strategies on Sage Grouse Leks.” In D. 1. Rubenstein and R. W. Wrangham, eds., Ecological Aspects of Social Evolution, pp. 379-98. Princeton: Princeton University Press.
Gullion, G. W. (1981) “Non-Drumming Males in a Ruffed Grouse Population.” Wilson Bulletin 93:372-82.
———(1967) “Selection and Use of Drumming Sites by Male Ruffed Grouse.” Auk 84:87-112.
Hartzler, J. E. (1972) “An Analysis of Sage Grouse Lek Behavior.” Ph.D. thesis, University of Montana.
Hartzler, J. E., and D. A. Jenni (1988) “Mate Choice by Female Sage Grouse.” In A. T. Bergerud and M. W. Gratson, eds., Adaptive Strategies and Population Ecology of Northern Grouse, pp. 240-69. Minneapolis: University of Minnesota Press.
Johnsgard, P. A. (1989) “Courtship and Mating.” In S. Atwater and J. Schnell, eds., Ruffed Grouse, pp. 112–17. Harrisburg, Pa.: Stackpole Books.
*Johnston, R. F., and M. Janiga (1995) Feral Pigeons. New York: Oxford University Press.
Lumsden, H. G. (1968) “The Displays of the Sage Grouse.” Ontario Department of Lands and Forests Research Report (Wildlife) 83:1-94.
*Patterson, R. L. (1952) The Sage Grouse in Wyoming. Denver: Sage Books.
Schroeder, M. A. (1997) “Unusually High Reproductive Effort by Sage Grouse in a Fragmented Habitat in North-Central Washington.” Condor 99:933-41.
*Scott, J. W. (1942) “Mating Behavior of the Sage Grouse.” Auk 59:477-98.
Simon, J. R. (1940) “Mating Performance of the Sage Grouse.” Auk 57:467-71.
Wallestad, R. (1975) Life History and Habitat Requirements of Sage Grouse in Central Montana. Helena: Montana Department of Fish and Game.
*Wiley, R. H. (1973) “Territoriality and Non-Random Mating in Sage Grouse, Centrocercus urophasianus.” Animal Behavior Monographs 6:87-169.
HUMMINGBIRDS, WOODPECKERS, AND OTHERS
LONG-TAILED HERMIT HUMMINGBIRD
IDENTIFICATION: A medium-sized hummingbird with purplish or greenish bronze upperparts, a striped face, a long, downward-curving bill, and elongated tail feathers. DISTRIBUTION: Southwestern Mexico, Central America, northwestern South America. HABITAT: Tropical forest undergrowth. STUDY AREA: La Selva Biological Reserve, Sarapiqui, Costa Rica.
ANNA’S HUMMINGBIRD
IDENTIFICATION: A medium-sized hummingbird (up to 4 inches long) with an iridescent, rose-colored throat and crown (in males), and a bronze-green back. DISTRIBUTION: Western United States to northwestern Mexico. HABITAT: Woodland, chaparral, scrub, meadows. STUDY AREA: Franklin Canyon, Santa Monica Mountains, California.
Social Organization
Long-tailed Hermit Hummingbirds form singing assemblies or LEKS composed of about a dozen males and have a polygamous or promiscuous mating system (in which birds mate with multiple partners). Anna’s Hummingbirds are not particularly social: each bird defends its own territory and does not generally associate with others. No pair formation occurs as part of the mating system; instead, males and probably also females mate with several different partners.
Description
Behavioral Expression: Male Long-tailed Hermit Hummingbirds gather on their leks or courtship display territories in dense, stream-side thickets, singing to advertise their presence and attract birds to mate with. Their monotonous songs consist of single notes of various types—sometimes transliterated as kaching, churk, shree, or chrrik—repeated for up to 30 minutes at a time. Females and males visit the leks, and both sexes may be courted and mounted by the territorial males. In a typical homosexual encounter, a male approaches another male that has landed on his territory and performs an aerial maneuver known as the FLOAT. In this display, he slowly flies back and forth in front of the perched male, pivoting his body from side to side. Often he holds his bill wide open, exposing his bright orange mouth lining and striking facial stripes, which combine to produce an arresting visual pattern. The perched bird may respond by gaping his own bill and “tracking” the movements of the swiveling and hovering male in front of him, always keeping his bill pointed toward him. The courting male then circles behind the other male and copulates with him: he alights on the other male’s back, quivering his wings while twisting and vibrating his tail to achieve cloacal (genital) contact. Homosexual copulations are generally somewhat briefer than the three-to-five-second duration of heterosexual matings, and the mountee may fail to cooperate (for example by not twisting his own tail to facilitate genital contact).
Male Anna’s Hummingbirds also court and mount both females and males (including juvenile males). These birds usually visit the male’s territory to feed on his supply of nectar-rich currant and gooseberry blossoms. If a visiting male lands on a perch, the territorial male usually performs a spectacular DIVE DISPLAY toward him. He first hovers above the other male and utters a few bzz notes, then climbs nearly vertically in a wavering path of 150 feet or more, peering down at the other male. At the top of his climb, he suddenly dives downward at immense speed, making a shrill, metallic popping or squeaking sound just as he swoops over the other male. He then repeats the entire performance several more times. The startlingly loud sound at the end of his dives is produced by air rushing through his tail feathers and is often preceded by vocalizations such as various trilled or buzzing notes. A dive-bombing male actually orients his acrobatic display precisely to face the sun, dazzling the object of his attentions with the shimmering, iridescent, rose-colored feathers of his crown and throat. On cloudy days, he rarely performs such dives since the mesmerizing visual effect cannot be achieved. After a dive display the other male usually flies off—with the territorial male in close pursuit—and seeks refuge by perching in a low clump of vegetation away from the territory. The pursuing male sings intensely at him, uttering a loud and complex sequence of notes that sounds like bzz-bzz-bzz chur-zwEE dzi! dzi! bzz-bzz-bzz. He may also perform a SHUTTLE DISPLAY (similar to the Long-tailed Hermit’s float), flying back and forth above the other male, tracing a series of arcs with his body. A homosexual copulation attempt may then follow, with the male landing on the other’s back as in a heterosexual mount. If the mounted male tries to get away, the pursuing male may knock him down, grappling and tumbling with him while emitting low-pitched, gurgling brrrt notes (similar aggressive interactions are also characteristic of heterosexual mating attempts; see below).
A male Long-tailed Hermit Hummingbird (right) courting another male with the “float” display
Frequency: Although homosexual copulations are not frequent in these species, neither are heterosexual ones, and a relatively high proportion of sexual activity—up to 25 percent—actually occurs between males. During several extensive studies, two out of eight observed copulations in Long-tailed Hermits were between males, while one out of four sexual encounters in Anna’s Hummingbirds (where the sexes of the birds could reliably be determined) was homosexual. Moreover, when male Anna’s Hummingbirds are presented with stuffed birds of both sexes, they court and mount the males as frequently as they do the females.
Orientation: In Long-tailed Hermit Hummingbirds, approximately 7 percent of territorial males and 11 percent of all males participate in homosexual activity. Territorial males in both of these hummingbird species are probably bisexual, pursuing, courting, and mounting both females and males. Some of the male Long-tailed Hermits who visit other males’ territories are nonbreeders (they do not have their own territories), which means they probably do not participate in any heterosexual activity (at least for the duration of that breeding season). Male Anna’s Hummingbirds usually strongly resist being mounted by other males, perhaps indicating a more heterosexual orientation on their part (although females also sometimes resist heterosexual mating attempts).
Nonreproductive and Alternative Heterosexualities
Heterosexual mating in Anna’s Hummingbirds can have all of the aggressive and even violent characteristics described above for homosexual matings—males pursue females in high-speed chases and sometimes even strike them in midair, forcing them down in order to copulate. Some matings are also nonreproductive since they take place outside of the breeding season. Males in this species have their own distinct seasonal sexual cycle, with their sperm production and hormone levels greatly reduced from July through November. Male Anna’s Hummingbirds also frequently court females of other species such as the Allen hummingbird (Selas-phorus sasin) and Costa’s hummingbird (Calypte costae). Among Long-tailed Hermit Hummingbirds (as well as other species of hermit hummingbirds), males often “masturbate” by mounting and copulating with small, inanimate objects (including leaves suspended in spiderwebs).
Other than when mating, however, males and females in both of these species rarely meet. In Anna’s Hummingbirds, the two sexes occupy distinct habitats during the breeding season—males frequent open areas such as hill slopes or the sides of canyons, females occupy more covered, forested areas. Each female Long-tailed Hermit usually encounters males only once every two to four weeks when she visits the lekking areas prior to nesting. Males of both species take no part in nesting or raising of young. In addition, a significant number of birds are nonbreeders: nearly a quarter of all Long-tailed Hermit males are nonterritorial and therefore do not participate in heterosexual courtship or copulation, while of those who hold territories, only some get to mate with females.
Sources
*asterisked references discuss homosexuality/transgender
Gohier, F., and N. Simmons-Christie (1986) “Portrait of Anna’s Hummingbird.” Animal Kingdom 89:30–33.
Hamilton, W. J., III (1965) “Sun-Oriented Display of the Anna’s Hummingbird.” Wilson Bulletin 77:38–44.
*Johnsgard, P. A. (1997) “Long-tailed Hermit” and “Anna Hummingbird.” In The Hummingbirds of North America, 2nd ed., pp. 65–69, 195–99. Washington, D.C.: Smithsonian Institution Press.
Ortiz-Crespo, F. I. (1972) “A New Method to Separate Immature and Adult Hummingbirds.” Auk 89:851–57.
Russell, S. M. (1996) “Anna’s Hummingbird (Calypte anna).” In A. Poole and F. Gill, eds., The Birds of North America: Life Histories for the 21st Century, no. 226. Philadelphia: Academy of Natural Sciences; Washington, D.C.: American Ornithologists’ Union.
Snow, B. K. (1974) “Lek Behavior and Breeding of Guy’s Hermit Hummingbird Phaethornis guy.” Ibis 116:278–97.
———(1973) “The Behavior and Ecology of Hermit Hummingbirds in the Kanaku Mountains, Guyana.” Wilson Bulletin 85:163–77.
Stiles, F. G. (1983) “Phaethornis superciliosus.” In D. H. Janzen, ed., Costa Rican Natural History, pp. 597–599. Chicago: University of Chicago Press.
*———(1982) “Aggressive and Courtship Displays of the Male Anna’s Hummingbird.” Condor 84:208–25.
*Stiles, E G., and L. L. Wolf (1979) Ecology and Evolution of Lek Mating Behavior in the Long-tailed Hermit Hummingbird. Ornithological Monographs no. 27. Washington, D.C.: American Ornithologists’ Union.
Tyrell, E. Q., and R. A. Tyrell (1985) Hummingbirds: Their Life and Behavior. New York: Crown Publishers.
Wells, S., and L. F. Baptista (1979) “Displays and Morphology of an Anna X Allen Hummingbird Hybrid.” Wilson Bulletin 91:524–32.
Wells, S., L. E Baptista, S. F. Bailey, and H. M. Horblit (1996) “Age and Sex Determination in Anna’s Hummingbird by Means of Tail Pattern.” Western Birds 27:204–6.
Wells, S., R. A. Bradley, and L. E Baptista (1978) “Hybridization in Calypte Hummingbirds.” Auk 95:537–49.
Williamson, E S. L. (1956) “The Molt and Testis Cycle of the Anna Hummingbird.” Condor 58:342–66.
BLACK-RUMPED FLAMEBACK
IDENTIFICATION: A medium-sized, red-crested woodpecker with a golden back, black rump, and black-and-white patterning on the face and neck. DISTRIBUTION: India, Pakistan, Sri Lanka. HABITAT: Woodland, scrub, gardens. STUDY AREA: Near Chittur, India; subspecies D.b. puncticolle.
ACORN WOODPECKER
IDENTIFICATION: A red-capped woodpecker with a striking black-and-white face, black upperparts, white underparts, and a black breast band. DISTRIBUTION: Pacific and southwest United States, Mexico through Colombia. HABITAT: Oak and pine woodland. STUDY AREAS: Hastings Natural History Reservation (Monterey) and near Los Altos, California.
Social Organization
Acorn Woodpeckers have an extraordinarily varied and complex social organization. In many populations, birds live in communal family groups containing up to 15 individuals—typically there are as many as 4 breeding males and 3 breeding females in such groups (though nonbreeding groups also occur—see below). The remaining birds in a group are nonbreeding “helpers” that may share in the parenting duties. Within groups, the mating system is known as POLYGYNANDRY, that is, each male mates and bonds with several females and vice versa. In other populations, monogamous pairs as well as other variations on polygamy occur. Little is known about the social organization of Black-rumped Flamebacks, although it is thought that they form monogamous mated pairs.
Description
Behavioral Expression: Male Black-rumped Flamebacks sometimes copulate with each other. One male mounts the back of the other (as in heterosexual mating), bending his tail down and thrusting it under the belly of the other male to make cloacal (genital) contact. Reciprocal mounting may occur, in which a male copulates with a male that has just mounted him. A bird involved in same-sex mounting activity may adopt a distinctive posture, in which his body is perpendicular to the branch he is perching on and his wing tips are arched toward the ground and hanging below his feet. Males also sometimes drum against a tree trunk prior to homosexual mounting.
Acorn Woodpeckers participate in a fascinating group display that involves ritualized sexual and courtship behavior, including homosexual mounting. At dusk, the members of a group gather together prior to roosting in their tree holes. As more and more birds arrive, they begin mounting each other in all combinations—males mount females and other males, females mount males and other females, young Woodpeckers mount older ones and vice versa. The mounting behavior resembles heterosexual mating, except it is usually briefer and cloacal contact is generally not involved (although genital contact does sometimes occur). Reciprocal mountings are common, and sometimes two Woodpeckers will try to mount the same bird simultaneously. Following the display, group members fly off to their roost holes to sleep. Ritualized mounting may also occur at dawn when the birds emerge from their roost holes. Because many group members are related to each other, at least some of this mounting is incestuous. Female Acorn Woodpeckers often coparent together, both laying eggs in the same nest cavity. Such “joint nesters” are often related (mother and daughter, or sisters), but sometimes two unrelated females nest and parent together as well. Joint-nesting females may continue to associate even if they happen not to breed in a particular year.
Frequency: Homosexual behavior in Black-rumped Flamebacks probably occurs only occasionally; however, heterosexual mating has never been observed in this species in the wild, so much remains to be learned about the behavior of this Woodpecker. The mounting display of Acorn Woodpeckers—including homosexual mounting—is a regular feature of the social life of this species at all times of the year, occurring daily in most groups. More than a third of all female Acorn Woodpeckers nest jointly, and about a quarter of all groups have joint-nesting females; 14 percent of these joint nests involve unrelated females as coparents.
Orientation: To the extent that they mount both males and females in the group display, Acorn Woodpeckers are bisexual (although it must be remembered that such mounting is often ritualized, i.e., it may not always involve genital contact). Not enough is known about the life histories of individual Black-rumped Flamebacks to make any generalizations about their sexual orientation.
Nonreproductive and Alternative Heterosexualities
As described above, Acorn Woodpeckers have an unusual communal family organization that can involve different forms of polygamy. In addition, many birds are nonbreeding: more than a third of all groups may not reproduce in a given year, and one-quarter to one-half of all adult birds do not procreate. In some populations the proportion of nonbreeders may be as high as 85 percent. Many of these are birds who remain with their family group for several years after they become sexually mature, helping their parents raise young; some delay reproducing for three or four years. Other nonbreeders (as many as one-quarter) do not in any way help to raise young. Some groups are nonreproductive because all their adult members are of the same sex: nearly 15 percent of nonbreeding groups have no adult females and nearly 4 percent have no adult males. In addition to the nonprocreative heterosexual behaviors mentioned above (REVERSE mounting, group sexual activity, mounting without genital contact), female Acorn Woodpeckers also sometimes copulate with more than one male in quick succession. About 3 percent of families contain offspring that result from promiscuous matings with males outside the group. Incestuous heterosexual matings occasionally occur as well, although they seem to be avoided—in fact, incest avoidance may lead to a group’s forgoing breeding for an extended time. Parenting in this species is notable for a variety of counterreproductive and violent behaviors. Egg destruction is common—particularly among joint-nesting females, who often break (and eat) each other’s and their own eggs until they begin laying synchronously. Males also sometimes destroy eggs of their own group. In addition, infanticide and cannibalism occur regularly in Acorn Woodpeckers. A common pattern seems to be for a new bird in a group—often a female—to peck the nestlings to death and eat some of them in order to breed with the other adults in the group. Parents also regularly starve any chicks that hatch later than a day after the others do.
Sources
*asterisked references discuss homosexuality/transgender
*Koenig, W. D. (1995–96) Personal communication.
Koenig, W. D., and R. L. Mumme (1987) Population Ecology of the Cooperatively Breeding Acorn Woodpecker. Princeton, N.J.: Princeton University Press.
Koenig, W. D., R. L. Mumme, M. T. Stanback, and F. A. Pitelka (1995) “Patterns and Consequences of Egg Destruction Among Joint-Nesting Acorn Woodpeckers.” Animal Behavior 50:607–21.
Koenig, W. D., and P. B. Stacey (1990) “Acorn Woodpeckers: Group-Living and Food Storage Under Contrasting Ecological Conditions.” In P. B. Stacey and W. D. Koenig, eds., Cooperative Breeding in Birds: Long-Term Studies of Ecology and Behavior, pp. 415–53. Cambridge: Cambridge University Press.
Koenig, W. D., and F. A. Pitelka (1979) “Relatedness and Inbreeding Avoidance: Counterploys in the Communally Nesting Acorn Woodpecker.” Science 206:1103–5.
*MacRoberts, M. H., and B. R. MacRoberts (1976) Social Organization and Behavior of the Acorn Woodpecker in Central Coastal California. Ornithological Monographs no. 21. Washington, D.C.: American Ornithologists’ Union.
Mumme, R. L., W. D. Koenig, and F. A. Pitelka (1988) “Costs and Benefits of Joint Nesting in the Acorn Woodpecker.” American Naturalist 131:654–77.
———(1983) “Reproductive Competition in the Communal Acorn Woodpecker: Sisters Destroy Each Other’s Eggs.” Nature 306:583–84.
Mumme, R. L., W. D. Koenig, R. M. Zink, and J.A. Marten (1985) “Genetic Variation and Parentage in a California Population of Acorn Woodpeckers.” Auk 102:305–12.
*Neelakantan, K. K. (1962) “Drumming by, and an Instance of Homo-sexual Behavior in, the Lesser Gold-enbacked Woodpecker (Dinopium benghalense).” Journal of the Bombay Natural History Society 59:288–90.
Short, L.L. (1982) Woodpeckers of the World. Delaware Museum of Natural History Monograph Series no. 4. Greenville, Del.: Delaware Museum of Natural History.
———(1973) “Habits of Some Asian Woodpeckers (Aves, Pisidae).” Bulletin of the American Museum of Natural History 152:253–364.
Stacey, P. B. (1979) “Kinship, Promiscuity, and Communal Breeding in the Acorn Woodpecker.” Behavioral Ecology and Sociobiology 6:53–66.
Stacey, P. B., and T. C. Edwards, Jr. (1983) “Possible Cases of Infanticide by Immigrant Females in a Group-breeding Bird.” Auk 100:731–33.
Stacey, P. B., and W. D. Koenig (1984) “Cooperative Breeding in the Acorn Woodpecker.” Scientific American 251:114–21.
Stanback, M. T. (1994) “Dominance Within Broods of the Cooperatively Breeding Acorn Woodpecker.” Animal Behavior 47:1121–26.
*Troetschler, R. G. (1976) “Acorn Woodpecker Breeding Strategy as Affected by Starling Nest-Hole Competition.” Condor 78:151–65.
Winkler, H., D. A. Christie, and D. Nurney (1995) “Black-rumped Flameback (Dinopium benghalense).” In Woodpeckers: A Guide to the Woodpeckers of the World, pp. 375–77. Boston: Houghton Mifflin.
PIED KINGFISHER
IDENTIFICATION: A robin-sized, crested bird with speckled black-and-white plumage and a long bill. DISTRIBUTION: Sub-Saharan Africa, the Middle East, India, Southeast Asia. HABITAT: Lakes and rivers. STUDY AREA: Basse Casamance region of Senegal; subspecies C.r. rudis.
BLUE-BELLIED ROLLER
IDENTIFICATION: A stocky, 14-inch bird with dark blue plumage, a long, turquoise, forked tail, and a creamy white head and breast DISTRIBUTION: West Africa. HABITAT: Savanna woodland. STUDY AREA: Basse Casamance region of Senegal.
Social Organization
Pied Kingfishers sometimes gather in flocks of 80 or more birds, and outside of the mating season they associate in small groups. Breeding birds form monogamous pairs, but there is a large population of nonbreeding males as well, many of whom help heterosexual pairs raise their young. Blue-bellied Rollers live in pairs or small groups of 3-13 birds, which are probably extended families or clans; mating may occur promiscuously among several group members.
Description
Behavioral Expression: In Pied Kingfishers, two males sometimes develop a pair-bond and may engage in homosexual mounting and copulation attempts. Homosexual mounting can also occur among males that are not bonded to each other. In all cases, homosexual activity is found among nonbreeding males, of which there are several distinct categories. Some males are HELPERS, who assist heterosexual pairs in raising their young. There are two types of such helpers: PRIMARY helpers, adult birds who help their parents; and SECONDARY helpers, who are unrelated to the pairs they help. In addition, some nonbreeding birds are nonhelpers, who do not assist heterosexual pairs at all. Homosexual pairing probably occurs mostly in the latter group, since primary helpers are devoted to assisting their parents and are also often hostile toward secondary helpers, openly attacking and fighting with them. Some homosexual behavior may also take place among secondary helpers, although this is less likely, since such males are usually preoccupied with feeding females in the pairs they assist (though their parenting duties are usually less extensive than those of primary helpers).
A remarkable form of ritualized sexual behavior occurs among Blue-bellied Rollers, and in some cases the participating birds are of the same sex. One bird mounts the other as in regular copulation, beating its wings and sometimes grabbing in its bill the neck or head feathers of its partner. The mounter lowers its tail while the mountee droops its wings and raises its tail, in some cases achieving cloacal (genital) contact. In almost three-quarters of the cases, mounting is reciprocal (the mountee becoming the mounter and vice versa); reciprocal mounting may be more common between birds of the opposite sex, however. Sometimes, mounting with exchange of positions is performed repeatedly, with as many as 28 mounts alternating between the partners in succession. This mounting behavior is often a ritualized display performed for other birds, and sometimes the tail movements and other gestures characteristic of full sexual behavior are more stylized or attenuated. Mounting may be accompanied by a number of dramatic aerial displays (often considered signs of aggression), including acrobatic chases, SOARS (rapid ascents with wings angled in a V-shape, just prior to being “caught” by a pursuing bird), and swoops (breathtaking plummets with folded wings). Birds may also utter loud, mechanical-sounding RATTLES as well as screaming RASP notes during mounting or the associated aerial displays.
Frequency: Homosexual bonding and mounting probably occur only occasionally among Pied Kingfishers. Ritual mounting behavior is common among Blue-bellied Rollers, occurring throughout the year; the exact proportion of mounting that is same-sex, however, is not known.
Orientation: In some populations of Pied Kingfishers, about 30 percent of the birds are neither breeders nor helpers, while about 18 percent are secondary helpers—these are the segments in which male homosexual activity is found, although probably only a fraction of these birds are involved. Although secondary helpers often go on to mate heterosexually, it is not known whether the same is true of nonhelpers or birds that participate in homosexual activity. However, because of the relatively short life span (one to three years) and high mortality rate of this species, it is likely that at least some males are involved in homosexual activity for most of their lives without ever mating heterosexually.
Nonreproductive and Alternative Heterosexualities
As discussed above, there is a large segment of nonbreeders in the Pied Kingfisher population: as many as 45-60 percent of males do not mate heterosexually. Remarkably, studies have shown that the reproductive systems of primary helpers are actually physiologically suppressed, since they have reduced male hormone levels, small testes, and no sperm production. Only one in three primary helpers goes on to mate after being a helper, and it is likely that some never breed for their entire lives. In contrast, secondary helpers do not have dormant reproductive systems, but are in most cases simply unable to find female mates due to the greater proportion of males in most populations. Because secondary helpers are not genetically related to the birds they assist, a large number of Pied Kingfishers are involved in “foster-parenting.”
Sexual activity between male and female Blue-bellied Rollers is notable for its nonreproductive components: it occurs at all times of the year (not just during the breeding season), and it often involves nonprocreative REVERSE mounts or mounting without genital contact. In addition, multiple copulations—far in excess of what is required for fertilization—are common. Not only do birds mount each other repeatedly in a single session (dozens of times, as mentioned above), but both males and females may copulate with many partners, sometimes several times each with up to three birds in a row.
Sources
*asterisked references discuss homosexuality/transgender
Douthwaite, R. J. (1978) “Breeding Biology of the Pied Kingfisher Ceryle rudis in Lake Victoria.” Journal of the East African Natural History Society 166:1–12.
Dumbacher, J. (1991) Review of Moynihan (1990). Auk 108:457–58.
Fry, C. H., and K. Fry (1992) Kingfishers, Bee-eaters, and Rollers. London: Christopher Helm.
*Moynihan, M. (1990) Social, Sexual, and Pseudosexual Behavior of the Blue-bellied Roller, Coracias cyanogaster: The Consequences of Crowding or Concentration. Smithsonian Contributions to Zoology 491. Washington, D.C.: Smithsonian Institution Press.
Reyer, H.-U. (1986) “Breeder-Helper-Interactions in the Pied Kingfisher Reflect the Costs and Benefits of Cooperative Breeding.” Behavior 82:277–303.
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———(1980) “Flexible Helper Structure as an Ecological Adaptation in the Pied Kingfisher (Ceryle rudis rudis L.).” Behavioral Ecology and Sociobiology 6:219–27.
Reyer, H.-U., J. P. Dittami, and M. R. Hall (1986) “Avian Helpers at the Nest: Are They Psychologically Castrated?” Ethology 71:216–28.
Thiollay, J.-M. (1985) “Stratégies adaptatives comparées des Rolliers (Coracias sp.) sédentaires et migra-teurs dans une Savane Guinéenne [Comparative Adaptive Strategies of Sedentary and Migratory Rollers in a Guinean Savanna].” Revue d’Écologie 40:355–78.
GALAH
IDENTIFICATION: A medium-sized parrot (about 14 inches) with a pale pink forehead and crest, rose-pink face and underparts, and gray upperparts. DISTRIBUTION: Interior Australia. HABITAT: Savanna woodland, grassland, scrub. STUDY AREAS: Healesville Sanctuary and Monash University, Victoria, Australia; Helena Valley, Western Australia.
PEACH-FACED LOVEBIRD
IDENTIFICATION: A small parrot (6 inches) with a short tail, green plumage, blue rump, and a red or pink breast and face. DISTRIBUTION: Southwestern Africa. HABITAT: Savanna. STUDY AREAS: Cornell University, New York; University of Bielefeld, Germany.
ORANGE-FRONTED PARAKEET
IDENTIFICATION: A small parrot with green plumage, a long tail, and an orange forehead. DISTRIBUTION: Western Central America from Mexico through Costa Rica. HABITAT: Tropical and scrub forests. STUDY AREAS: Near Managua, Nicaragua; University of Kansas and University of California—Los Angeles; subspecies A.c. canicularis and A.c. eburnirostrum.
Social Organization
Galahs and Peach-faced Lovebirds are gregarious birds, gathering in large flocks that can number up to several hundred in Lovebirds and up to a thousand in Galahs. They typically form mated pairs, and Peach-faced Lovebirds usually nest in colonies. In addition, there are nomadic flocks of juveniles and younger nonbreeding adult Galahs. Orange-fronted Parakeets are also highly social, traveling in groups of 12-15 birds (often composed of mated pairs) and sometimes forming flocks of 50-200. During the breeding season, pairs generally separate from the flock to nest, although they periodically recongregate in small groups.
Description
Behavioral Expression: Galahs of both sexes form stable, long-lasting homosexual pairs that participate in courtship, sexual, and pair-bonding activities. Same-sex bonds are strong, often developing in juvenile birds and then continuing for the rest of their lives (as do most heterosexual bonds). Homosexual pairs of at least six years’ duration have been documented in captivity. If one partner dies before the other, the remaining Galah may stay single or may eventually form a homosexual (or heterosexual) partnership with another bird. Pair-bonded Galahs almost always stay close to each other (rarely more than a few inches apart), feeding and roosting together both day and night. When one bird flies to a new location, it calls after its mate to join it, using a special two-syllable warbled call that sounds like sip-sip or lik-lik. If another bird intrudes between them, both partners threaten the intruder and may force it to leave by edging it out or simultaneously stabbing their beaks at it. Pair-mates spend considerable time preening each other; this intimate behavior, sometimes known as ALLOPREENING, involves one bird lowering its head in front of the other, allowing its mate to gently nibble and run its bill through the feathers. After a short time the birds switch positions, and often this develops into a playful fencing bout, in which the birds gently clash beaks and dodge each other.
Homosexual (and heterosexual) Galah pairs also perform a number of synchronized, highly stylized displays while perching side by side or facing toward or away from each other. One of the most elegant of these is WING-STRETCHING, in which each bird simultaneously fans open one of its wings. Often, one bird fans its left wing while the other opens its right to give a strikingly symmetrical, “mirror-image” effect, while in other cases each pair member fans the same wing in a parallel, but nonsymmetrical, pattern. Other synchronized displays include HEAD-BOBBING (in which the birds dip their heads down and to the side) as well as crest-raising and feather ruffling. In addition, such activities as self-preening, feeding, and leaf- and bark-stripping can also be performed in unison by pair members—in fact, homosexual pairs synchronize their behaviors about 65 percent of the time. Galahs in same-sex pairs may also court and copulate with each other. Courtship includes a sideways shuffling movement toward the partner with crest raised and facial feathers fanned forward, followed by head-bobbing and BREAST POINTING (in which mates touch their own or their partner’s breast feathers with their beaks). Sexual activity involves one bird mounting the other and making pelvic thrusts against its mate; this may occur even when the birds are still juveniles.
Peach-faced Lovebirds also sometimes form stable homosexual pairs; as in Galahs, these are probably lifelong bonds that usually originate while the birds are still youngsters. Same-sex pairs of Lovebirds also engage in frequent mutual preening. In their courtship and sexual activity, some homosexual pairs combine elements of male and female behavior. In female pairs, for example, each partner may feed the other (a typically male activity in heterosexual pairs) or invite the other to mount (a typically female activity). Other pairs are more role-differentiated, with one bird performing the behaviors most typically associated with males while the other exhibits the patterns of a female. However, in their parenting behaviors both members of female homosexual pairs adopt typically “female” duties. After having investigated several potential nest sites, they jointly select a suitable cavity that they occupy together, and each female contributes to building the nest. In Peach-faced Lovebirds, this involves a unique method of collecting nesting material: long strips of bark, grass, or leaves are tucked directly into the birds’ back and rump feathers to be carried back to the nest. Both partners lay eggs (usually infertile) and simultaneously incubate them. In contrast, male homosexual pairs never build nests.
A homosexual pair of female Galahs performing a mirror-image “wing-stretching” display
A male Orange-fronted Parakeet nuzzling his male pair-mate
Both male and female homosexual pairs also occur in Orange-fronted Parakeets. Same-sex couples often sit side by side—sometimes for half an hour or more at a time—preening and nuzzling each other while fluffing their plumage. Males also sometimes engage in sexual behavior with their pair-mate: one bird mounts the other, usually preceded by a display known as FAWNING or CLAWING, in which he lifts one foot in the air and places it gently on the other male’s back or wing. Female partners often COURTSHIP-FEED each other: one bird regurgitates some food and feeds it to her mate, and the two partners interlock their bills while jerking their heads back and forth. Unlike in heterosexual pairs, either bird may feed the other. This is usually accompanied by several stylized visual and vocal displays such as head-bobbing, rubbing or kneading of the bill on the branch (often producing a distinctive popping sound), fluffing of the cheek feathers, and flashing the iris of the eyes while whistling. The two mates sometimes play-fight with one another by BILL-SPARRING, in which they grasp and tug at each other’s beak. Female pairs may also jointly prepare a nest, usually constructed in arboreal termite nests: one partner excavates the entrance tunnel (as do males in heterosexual pairs) while the other hollows out the nest chamber (as do females in heterosexual pairs). Some female couples successfully compete against heterosexual pairs for nesting sites; pair-bonded females often become powerful allies that support one another and may even come to dominate opposite-sex pairs through attacks and threat behavior.
Frequency: Homosexual bonds are common in these Parrot species. In some captive populations of Galahs, for instance, one-half to two-thirds of pair-bonds are between birds of the same sex. A study of Peach-faced Lovebirds in captivity revealed that 4 of 12 pair-bonds (33 percent) were between females; a similar study of Orange-fronted Parakeets found 5 of 9 pair-bonds (56 percent) between females. Although male homosexual pairs of Orange-fronted Parakeets have been documented in wild birds, the overall incidence of same-sex bonds in the wild is not known for any of these species. However, about 1 out of every 180 nests of wild Galahs contains a SUPERNORMAL CLUTCH of 10–11 eggs, double the number of most other nests. These are undoubtedly laid by two females, perhaps members of a homosexual pair (although they could also result from alternative heterosexual arrangements—see below).
Orientation: Among captive Galahs that form some sort of pair-bond, about 44 percent of birds only form homosexual bonds, another 44 percent only develop heterosexual pairings, while about 11 percent bond with birds of both sexes. Of the latter group, a variety of bisexualities occur, usually in the context of trios or quartets of birds. One female, for example, formed a polygamous bond with two males, then went on to develop a bond with another female while maintaining her trio bond. Another female was bonded to a male who also had another female partner; she then “divorced” him and paired with another female. One male in a homosexual pair later also developed simultaneous bonds with two females. Similar bisexual trios and quartets also occur in Orange-fronted Parakeets, and females in this species sometimes compete successfully against both males and other females for the attentions of another female. In wild Galahs (especially males), it is possible that many birds form same-sex pairings in the juvenile flocks, with some later developing opposite-sex associations as adults. In Lovebirds (as well as in Galahs and Parakeets that only form same-sex pairs), at least some birds in homosexual bonds appear to be more exclusively same-sex oriented. For instance, bonds sometimes form between females even if there are available unpaired males, and one widowed female Lovebird who lost her female partner went on to form another homosexual pairing.
Nonreproductive and Alternative Heterosexualities
Although most heterosexual bonds in Galahs are lifelong and between only two birds, several other variations occur: some birds form polygamous trios (as discussed above), while 6–10 percent of Galahs divorce their partners and seek new mates. Infidelity in the form of copulations by paired Galahs with birds other than their mate is common, especially during the incubation period. Sometimes a mated pair changes partners after their eggs have been laid, usually resulting in loss of the eggs (accounting for about 2 percent of all clutches that fail to hatch). In addition, parenting in this species is not confined to a strictly nuclear-family structure: youngsters from several different families are pooled together into a CRÈCHE or “day-care” flock as soon as they are old enough to leave the nest. This allows their parents to forage on their own (although a few tending parents are always on hand in the crèche). Youngsters spend nearly as much time in these crèches as they do being cared for solely by their parents in the nest. Sometimes two pairs share the same nest hollow, with both females laying eggs in a combined clutch.
Although divorce and alternative bonding arrangements are not as prominent among Lovebirds, there is nevertheless often considerable antagonism between the sexes in heterosexual pairs. Males tend to become sexually ready each season before females; as a result, their courtship advances are frequently ignored or rejected, and females may even respond with overt aggression. Heterosexual copulations often do not culminate in ejaculation because the female refuses to allow the male to remain mounted, walking or flying out from under him while making threatening displays at him. A similar asynchrony in male and female sexual cycles may also occur in Galahs: in some years, males become ready to mate before females, but by the time the latter are ready, the males often lose interest and many pairs end up not breeding at all. Besides pairs that do not reproduce in a particular year, there is always a sizable proportion of single birds. As many as 60 percent of the adult Galahs in foraging flocks are nonbreeding birds from the nomadic population. Sometimes a nonbreeding female associates regularly with a breeding pair, “tagging along” with the male when he leaves the nest (perhaps in the hope of pairing with him). Such birds are known as “aunts” even though they are probably not related to the birds they associate with.
When a female Lovebird does consent to mate, nonreproductive REVERSE mounts may occur: as a part of courtship, males sometimes solicit females, who briefly mount them the way a male would. Other forms of nonprocreative sexual behavior also take place. Both Lovebirds and Galahs form pair-bonds as juveniles, long before they begin to reproduce—Galahs, in fact, may commence pairing and copulation up to three years before they can breed. In addition, some of the mating activity among younger Galahs involves birds mounting and thrusting against their partner’s head rather than the genital region. Among adults, at least 12 percent of all copulations occur well before fertilization is possible (four to five weeks prior to egg laying).
Other Species
Homosexual pairs occur in several Parrot species related to these, including Masked Lovebirds (Agapornis personata) and Red-faced Lovebirds (Agapornis pullaria), from Africa, and female Aztec Parakeets (Aratinga astec), from central America. Same-sex pairs (both male and female) have also been documented in numerous other species of Parrots (usually in captivity). Canary-winged Parakeets (Brotogeris versicolurus) and Rose-ringed Parakeets (Psittacula krameri) in homosexual pairs engage in frequent mutual preening and soft grasping and nibbling of each other’s beak. Female pairs of Elegant Parrots (Neophema elegans) from Australia courtship-feed and mount one another, as do male pairs of Senegal Parrots (Poicephalus senegalus) and White-fronted Amazon Parrots (Amazona albifrons). Male pairs have also been reported in Mealy Amazon Parrots (Amazona farinosa). Homosexual pairing is found as well in Ornate Lorikeets (Trichoglossus ornatus) and several other species of Lories from the islands of Southeast Asia, in which courtship-feeding and copulation are regular features of same-sex pairing. One male pair of Yellow-backed (Chattering) Lorikeets (Lorius garrulus flavopalliatus) remained together for more than 14 years.
Sources
*asterisked references discuss homosexuality/transgender
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