*King, C. E. (1990) “Reproductive Management of the Oriental White Stork
Stowell, R. F. (1954) “A Note on the Behavior of
Wilson, R. T., and M. P. Wilson (1984) “Breeding Biology of the Hamerkop in Central Mali.” In J. Ledger, ed.,
IDENTIFICATION: The largest flamingo species (4—5 feet tall) with plumage ranging from pale whitish pink to bright orange-pink. DISTRIBUTION: The Mediterranean, sub-Saharan Africa, western Asia, Caribbean and Galapagos Islands, temperate South America. HABITAT: Shallow lakes, lagoons, mudflats, salt pans. STUDY AREAS: Zoo Atlanta, Georgia; Audubon Park Zoo, New Orleans, Louisiana; Chester Zoo, United Kingdom; Rotterdam Zoo, the Netherlands; Basel Zoo, Switzerland; subspecies
Social Organization
Flamingos are extremely gregarious birds, often congregating in enormous groups numbering in the tens of thousands. During the mating season pair-bonds are formed and the birds nest in large colonies.
Description
Once formed, homosexual pair-bonds are strong and may persist from one breeding season to the next. Most pairings are monogamous; however, in some male pairs the partners also attempt to mount other birds (usually incubating birds of either sex). Sometimes two males and a female will even form a TRIAD in which the two males are bonded or sexually interested in each other as much, if not more so, than they are in the female. Homosexual partners sometimes also build nests together; in the case of male pairs, the nest (a pedestal-shaped mud platform) may become exceptionally large because of the contributions of both partners. Some male pairs, rather than building their own nest, “steal” or take over the nest of a heterosexual pair, occasionally breaking eggs in the process (this behavior also occurs between heterosexual pairs).
Homosexual couples often engage in parenting behavior. Male pairs incubate, hatch, and successfully raise foster chicks (for example, from a nest they have taken over, or from eggs supplied in captivity). Described as “model” parents, male partners may even “nurse” their chick. Flamingo parents (of either sex) typically feed their chicks a blood-red “milk” produced in their crops, and both males in homosexual couples feed their chicks with this crop milk. Some male pairs, however, do not attempt to acquire eggs, even if they have their own nest, while others do not appear to be interested in parenting at all, since they may roll the egg out of a nest they have acquired. Female pairs take turns incubating eggs on their nest; such eggs may be infertile, having been laid by the females themselves rather than acquired from another nest. As in heterosexual pairs, variation exists in the amount of incubation time contributed by each partner. Some share incubation duties equally, while in other pairs, one female puts in more incubation shifts than the other. Overall, though, females in lesbian pairs contribute about five to six incubation shifts each, which is comparable to the average for heterosexual partners.
Nonreproductive and Alternative Heterosexualities
Although the standard social unit in Flamingos is the breeding monogamous pair, a number of alternative heterosexual pairing and family arrangements occur. Trios or triads—one male with two females or one female with two males—are fairly common (at least in zoos). Typically all three birds share incubation and chick-raising duties (although no same-sex bonding occurs); in trios with two females, there may be two separate nests, or both females may share a nest. Flamingo pairs also sometimes engage in nonreproductive copulations, mating far in advance of the female’s fertile (or the male’s sperm-producing) period. Many mated pairs are nonmonogamous, with both males and females seeking copulations with outside partners. In one zoo population, 47 percent of the females and 79 percent of the males participated in such “infidelity,” and about 8 percent of all copulations were with outside partners; at another zoo, 25—60 percent of all pairs were nonmonogamous. Furthermore, divorce is extremely common in wild Flamingos: nearly all birds change partners between breeding seasons, and about 30 percent of males even switch mates during the season (in contrast, most pairings in zoos are long-lived).
Once chicks are hatched, a number of social systems are available to relieve the biological mother and father of some of their parenting duties. For example, nonbreeding birds sometimes produce crop milk and “nurse” other birds’ chicks or else act as foster feeders for orphaned chicks. In addition, as they get older, Flamingo chicks typically gather into large nursery groups or CRECHES, which may contain several thousand youngsters. These groups provide them with safety in the absence of direct parental supervision, and adults also sometimes feed youngsters other than their own in these creches. Chicks are often forced into creches as a result of attacks from adult birds, including their own parents, and creches may therefore also provide refuge from aggression by other Flamingos. Breeding in wild Flamingos can be irregular, with entire colonies sometimes forgoing reproduction for three or four years at a time—one colony in France failed to produce chicks for 13 out of 34 years (38 percent of the time). In addition, even if breeding is undertaken, it may be abruptly halted, with all or a large portion of the colony—often as many as half of all pairs—abandoning their eggs. Usually it is the female who initiates desertion of a nest.
Other Species
Homosexual pairs occur among both male and female Lesser Flamingos
