Breeding biology of the Bahama parrot (Amazona leucocephala bahamensis).
Item
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Title
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Breeding biology of the Bahama parrot (Amazona leucocephala bahamensis).
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Identifier
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AAI9130317
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identifier
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9130317
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Creator
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Gnam, Rosemarie Sophie.
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Contributor
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Advisers: Lester Short | Robert Rockwell
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Date
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1991
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Language
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English
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Publisher
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City University of New York.
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Subject
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Biology, Zoology | Biology, Ecology | Biology, General
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Abstract
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Although the Bahama Parrot (Amazona leucocephala bahamensis) was once abundant and ranged throughout the Bahamas archipelago, it is endangered now and survives only on two islands--Abaco and Great Inagua. Bahama Parrots on Abaco nest in limestone solution cavities beneath the ground, a habit unique among New World psittacines. Between 1985-1988, I located and monitored 76 parrot nests in two nesting areas on southern Abaco. Eggs were laid in late May and early June and hatched asynchronously, 26-28 days after the female began incubation. While the female incubated the eggs, the male visited the nest on average four times per day to feed her. After the first week post-hatching, the female left the nest to forage with the male. Parents returned to their nests four to six times per day to feed the nestlings. Chicks fledged asynchronously in late August and early September, 56-58 days after hatching. I evaluated reproductive investment and loss in this population using a fitness components model which corresponded to stages of the reproductive cycle. On average, a pair produced 3.6 eggs and fledged only 0.8 young. While losses accrued throughout the cycle, they were highest during the hatching and post-hatching stages. Partial hatching failure and total brood failure were the primary sources of loss at these stages. These components did not change significantly over the four years of this study. Causes of nest failure were (in ascending order of importance): poaching of chicks, flooding of nest cavities, abandoned eggs, chick deaths, and predation by snakes, rats, land crabs, and feral cats. I observed parrots feeding upon 18 plant species in the nesting area. Major staples in their diet were seeds extracted from unripe cones of Caribbean pine, and fruits of wild guava and poisonwood. Between 1986 and 1989, three population counts were made to estimate the size of the parrot population on Abaco. Current population estimates range from a well-defined minimum of 860-1142 parrots (actual birds counted) to a less well-defined maximum of 1300 parrots. Present threats to this population include nest predation by feral cats, poaching and unprotected habitat.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
