| タイトル |
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en
Individual differences in nest defense in the colonial breeding Black-tailed Gulls
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| 作成者 |
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| アクセス権 |
open access |
| 権利情報 |
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en
The original publication is available at www.springerlink.com
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| 主題 |
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Other
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Aggressiveness
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Other
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Black-tailed Gull
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Other
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Coloniality
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Other
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Group living
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Other
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Nest defense
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Other
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Neighbor
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Other
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Mobbing
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NDC
468
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| 内容注記 |
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Abstract
en
Often in colonial seabirds, all colony members are believed to defend against nest predators and experience equal nest predation risk. However, the variation of defense behavior among members and its reproductive consequences are largely unknown. We investigated 1) individual variation in the nest defense of breeding Black-tailed Gulls Larus crassirostris against a natural egg predator, the Jungle Crow Corvus macrorhynchos and 2) how this behavioral variation affects an individual's own nest predation risk and that of their neighbors. Results were compared between two years where crow attack levels were manipulated to average 5 and 22 times normal rates ("low" and "high" predation risk years, respectively) by the placement of varying numbers of artificial nests containing unguarded eggs at the perimeter of the gull colony. In both years, 23-38% of parents, mostly males, showed "aggressive" defense behavior (strikes or chases) against crows and decoys. Other "non-aggressive" gulls showed no defense. In the year of low predation risk, intrusion rates by crows (landing within 0.5 m of an individual gull's nest) were similar for aggressive and non-aggressive gulls. In the year of high predation risk, however, the rates of intrusion for aggressive gulls (4%) and for non-aggressive gulls with an aggressive neighbor (37%) were significantly lower than for non-aggressive gulls without an aggressive neighbor (76%). These results indicate that aggressive individuals reduce nest predation risk for themselves and conspecific neighbors in a colonially breeding species.
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| 出版者 |
en
Springer Berlin / Heidelberg
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| 日付 |
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| 言語 |
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| 資源タイプ |
journal article |
| 出版タイプ |
AM |
| 資源識別子 |
HDL
http://hdl.handle.net/2115/46866
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| 関連 |
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isVersionOf
DOI
https://doi.org/10.1007/s00265-010-0938-8
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| 収録誌情報 |
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en
Behavioral Ecology and Sociobiology
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巻64
号8
開始ページ1239
終了ページ1246
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| ファイル |
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| コンテンツ更新日時 |
2023-07-26 |
