Factors affecting daily activity budgets of South Georgian shags during chick rearing at Bird Island, South Georgia

Article Abstract:

A research study used radio telemetry for gathering data on the daily activity budgets of 26 South Georgian shags at Bird Island, GA, at a time when chicks are being reared. A significant sex difference was observed in feeding times. The female makes the first trip of the day, as observed in 93% of the shag pairs. Results show that the breeding shags sampled are limited in their ability to increase the time available to capture their prey. In addition, the population could be overly sensitive to food availability changes.

author: Wanless, S., Harris, M.P., Morris, J.A.
South Georgia Island

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Does male-like coloration of female hooded warblers increase nest predation?

Article Abstract:

A study tests the hypothesis that the risk of nest predation in the female hooded warbler species is increased due to the female's male-like coloration. The sexually dimorphic songbirds have different black hoods, which could be non-existent in yearlings or almost totally black in some older female warblers. The nest predation frequency did not change much with the extent of male-like plummage during the various nest stages. Results show that predators do not locate nests by relying on plumage coloration.

author: Stutchbury, Bridget J., Howlett, Joan S.
Predation (Biology), Color of birds, Bird coloration

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Nest-site characteristics of the socorro green parakeet

Article Abstract:

A research study presents information on the nesting habits and nest-site characteristics of the Socorro green parakeet to make up for the non-existence of published information and the lack of biological information on the species. The Aratinga holochlora brevipes is endangered by the increasing degradation of its habitat as a result of overgrazing by sheep on the Mexican island inhabited by the birds. Overgrazing also threatens most of the island's endemic avifauna.

author: Rodriguez-Estrella, Ricardo, Rodriguez, Laura Rivera, Anguiano, Francisco
Mexico, Parrots

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subjects list: Analysis, Natural history, Ornithological research, Dimorphism (Animals), Dimorphism (Biology), Research, Birds, Bird eggs, Bird nests
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