Sexual and individual foraging segregation in Gentoo penguins Pygoscelis papua from the Southern Ocean during an abnormal winter
Sexual and individual foraging segregation in Gentoo penguins Pygoscelis papua from the Southern Ocean during an abnormal winter
复制标题
异常冬季期间南大洋巴布亚巴布亚巴布亚企鹅的性别和个体觅食隔离
作者：
J. Xavier;P. Trathan;F. Ceia;G. Tarling;S. Adlard;D. Fox;Ewan W. J. Edwards;R. Vieira;Renata Medeiros;C. De Broyer;Y. Cherel
在过去十年中，关于海洋生物的性别隔离和性别区分，或实际上是个体专门化的知识有了很大提高。在这种情况下，我们测试了企鹅的“间性竞争假说”，通过调查巴布亚企鹅在其南方冬季非繁殖季节的摄食生态。我们认为这是在不寻常的环境条件下（即2009年有高海面和空气温度的观测）与长期平均在鸟岛，南格鲁吉亚。通过常规（即胃内容物）和稳定同位素值从红细胞，血浆和羽毛的男性和女性巴布亚企鹅，我们发现，有显着的性别差异，男性主要以鱼类为食（54%质量）其次是甲壳类动物（38%），而女性主要以甲壳类动物为食（89%质量）其次是鱼类（4%）。Themisto gaudichaudii是最重要的甲壳类猎物的男性（64%的质量，82%的数量，53%的出现频率）和女性（63%的质量，77%的数量，89%的出现频率），与以往的研究发现南极磷虾磷虾superba通常是主要的猎物。稳定同位素数据显示，在生境利用方面（基于δ 13 C），雄性和雌性之间的短期碳特征（基于血浆和红细胞）存在显著差异，表明两性探索不同的生境，雌性探索更多的近海远洋沃茨，雄性则更多地在沿海底栖沃茨觅食。基于δ 15 N，雄性的营养水平显著高于雌性（基于血浆和红细胞），与我们的饮食结果一致。因此，巴布亚企鹅的行为方式与其他非繁殖企鹅物种（例如王企鹅，通心粉企鹅和跳岩企鹅）相似，尽管空间尺度较小（因为它们不像其他企鹅那样分散），因为它们在南极冬季（与夏季相比）有更广泛的栖息地和营养生态位。我们还检测到个别专业化的喂养/营养水平为每个性别，与某些男性主要以鱼类和某些女性主要以甲壳类动物为食，这可能是驱动流行的环境条件，导致个人寻找替代猎物，并导致性别饮食隔离。我们的研究结果提供了进一步的信息，有助于提高对海洋生物性分离和个体专业化的了解，同时为南极监测计划和南极海洋食物网建模提供有关冬季饮食的宝贵信息。
Knowledge about sexual segregation and gender-specific, or indeed individual specialization, in marine organisms has improved considerably in the past decade. In this context, we tested the “Intersexual Competition Hypothesis” for penguins by investigating the feeding ecology of Gentoo penguins during their austral winter non-breeding season. We considered this during unusual environmental conditions (i.e. the year 2009 had observations of high sea surface and air temperatures) in comparison with the long term average at Bird Island, South Georgia. Through conventional (i.e. stomach contents) and stable isotopic values from red blood cells, plasma and feathers of both male and female Gentoo penguins, we showed that there were significant differences between sexes, with males feeding mainly on fish (54% by mass) followed by crustaceans (38%) whereas females fed mainly on crustaceans (89% by mass) followed by fish (4%). Themisto gaudichaudii was the most important crustacean prey for males (64% by mass; 82% by number; 53% by frequency of occurrence) and females (63% by mass; 77% by number; 89% by frequency of occurrence), contrasting with all previous studies that found Antarctic krill Euphausia superba were generally the main prey. Stable isotopic data showed that, in terms of habitat use (based on δ 13C), there were significant differences in short-term carbon signatures between males and females (based on plasma and red blood cells), suggesting that both sexes explored different habitats, with females exploring more offshore pelagic waters and males feeding more in coastal benthic waters. Based on δ 15N, males fed on significantly higher trophic level than females (based on plasma and red blood cells), in agreement with our diet results., Thus, Gentoo penguins behave in a similar manner to other non-breeding penguins species (e.g. king, macaroni and rockhopper penguins), albeit at a smaller spatial scale (as they do not disperse as these other penguins do), in that they have a wider habitat and trophic niche during the Antarctic Winter (in comparison to Summer). We also detected individual specialization in feeding/trophic levels for each gender, with certain males feeding mainly on fish and certain females mainly on crustaceans, which may be driven the prevailing environmental conditions that lead individuals to search for alternative prey, and cause sexual diet segregation. Our results provide further information to help improve understanding about sexual segregation and individual specialization of marine organisms, while contributing valuable information on the winter diet for Antarctic monitoring programs and for modelling Antarctic marine food webs.
影响因子：
5.7
作者：
Votier, Stephen C.;Bearhop, Stuart;Newton, Jason
通讯作者：
Newton, Jason