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.
Douthwaite, R. J. (1978) “Breeding Biology of the Pied Kingfisher
Dumbacher, J. (1991) Review of Moynihan (1990).
Fry, C. H., and K. Fry (1992)
*Moynihan, M. (1990)
Reyer, H.-U. (1986) “Breeder-Helper-Interactions in the Pied Kingfisher Reflect the Costs and Benefits of Cooperative Breeding.”
———(1984) “Investment and Relatedness: A Cost/Benefit Analysis of Breeding and Helping in the Pied Kingfisher (
———(1980) “Flexible Helper Structure as an Ecological Adaptation in the Pied Kingfisher (
Reyer, H.-U., J. P. Dittami, and M. R. Hall (1986) “Avian Helpers at the Nest: Are They Psychologically Castrated?”
Thiollay, J.-M. (1985) “Strategies adaptatives comparees des Rolliers (
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
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
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.
