Behavior of Ocellated Antbirds. Smithsonian Contributions to Zoology, Number 144.

摘要

A ten-year study of color-banded Ocellated Antbirds (Phaenostictus mcleannani) on Barro Colorado Island, Panama, showed that they persistently follow army ants for arthropods flushed by the ants. Dominant over the smaller antbirds that follow ants, they take the best zone low over the center of an ant swarm and drop to the ground for prey. They rest and preen for long periods of maintenance behavior each day, probably because as dominant birds they get food easily. Alarm behavior is similar to that of other antbirds. Agonistic behavior contrasts with other antbirds in having a silent challenging display and an unusually wide spectrum of submissive calls and postures. Courtship is mainly courtship feeding and singing; monogamous mates stay together for years. The nest is probably sunk in the ground between tree buttresses. Males incubate in the morning and late afternoon, females in the early afternoon and at night. Males and females feed nestlings and fledglings. Pairs renest repeatedly during the rainy season, April to December, but nest predation is high. Young are feeding themselves a month after appearing at swarms with their parents, but then irregularly stay with their parents up to several months (females) or years (males). Loose patrilineal clans form, in which gene transfer between clans is mainly by movement of young females. Daughters-in-law are tolerated. Clan members sometimes forage together, but use much submissive display. They close ranks or 'bunch' in disputes with other pairs or clans. The social system is somewhat like that of chimpanzee groups and perhaps like that of early man two other dominant animals dependent on local and varying sources of food. The clan system permits complete overlap of home ranges of pairs. The parental pair in an area tends to dominate trespassing pairs and their own offspring. This social system permits great local concentration over good ant swarms. It is facilitated by tolerance for related birds, silent (and thus less disturbing) challenging, and by a wide variety of submissive displays. The Ocellated Antbirds on Barro Colorado concentrated at ant swarms on escarpment zones near the center of the island. Even with these concentrations, however, the species declined to near extirpation between 1960 and 1971.