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Impacts of Intraspecific Kleptoparasitism and Diet Shifts on Razorbill Alca torda productivity at the Gannet Islands, Labrador
journal contribution
posted on 2023-05-17, 11:57 authored by Jennifer Lavers, Jones, ILIntraspecific kleptoparasitism, the stealing of food from members of the same species, has received widespread but mostly superficial attention in the scientific literature. However, the effects of such behavior can be significant. Here we report on high rates of intraspecific kleptoparasitism in the Razorbill Alca torda at the Gannet Islands, a behavior that appears to be colony-specific. Razorbills carry their prey conspicuously in the bill, making them vulnerable to kleptoparasitic attacks from neighboring birds. We examined the relationship between the frequency of kleptoparasitic attacks and the prey species carried by breeding adults. During 2003–2006, 69% of all Razorbills carrying food to a chick were attacked (n = 182) and of these attacks, 18% (n = 22) were successful. Group attacks (two or more kleptoparasites) were more successful numerically (27%, n = 71), but only one member of the group ever received the reward. The frequency of kleptoparasitism observed by Razorbills at the Gannet Islands is one of the highest reported for any seabird, including many specialist kleptoparasites such as frigatebirds. This finding, combined with the lowest observed Razorbill productivity (overall success = 0.39, n = 222) for the Gannet Islands and drastic shifts in diet, may indicate decreased food availability.
History
Publication title
Marine OrnithologyVolume
35Pagination
1-7ISSN
1018-3337Department/School
Institute for Marine and Antarctic StudiesPublisher
African Seabird GroupPlace of publication
South AfricaRights statement
Copyright 2007 Marine OrnithologyRepository Status
- Restricted