Geographical, temporal, and individual-based differences in the trophic ecology of female Cape fur seals.
Geographical, temporal, and individual-based differences in the trophic ecology of female Cape fur seals.
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DOI：
10.1002/ece3.9790
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发表时间：
2023-02
影响因子：
2.6
通讯作者：
中科院分区：
文献类型：
--
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海洋捕食者的资源利用和营养动态信息对于了解它们在生态系统功能中的作用和预测种群对环境变化的反应非常重要。当不同的种群经历不同的当地环境条件时，它们觅食生态的地理变异性往往是可以预料的。在种群内，个体在形态、生理和经验上也各不相同，导致资源利用的专业化。在这种情况下，增量生长组织（如角质毛发）的同位素组成为研究资源和栖息地利用的长期变化提供了宝贵的机会。我们调查的营养生态学的女性海角毛皮海豹（Arctocephalus pusillus pusillus）使用连续采样的胡须的碳和氮同位素组成，收集在四个繁殖地点沿着南非海岸。利用900多个同位素测量，我们评估了殖民地之间的同位素生态位宽度和个体专业化程度的地理变异。我们发现轻微的，但明显的同位素比值和同位素生态位宽度的地理差异，似乎与生态环境，与生态位宽度是成比例的可用的货架和货架斜坡栖息地周围的殖民地的面积。我们进一步确定了同位素比值的周期性振荡，这可能反映了觅食分布和猎物类型的时间模式，与猎物资源的可用性及其与个体雌性在整个繁殖周期中的相互作用的变化有关。最后，个人专业化指数显示，每一个研究人口包含专家的个人，只利用总人口生态位宽度的一个小子集。个体专业化的程度，但是，不一致的殖民地，可能反映了密度依赖效应和栖息地异质性之间的相互影响。总的来说，这项研究提供了重要的信息，在南非繁殖的海狗角的营养生态，并强调需要考虑地理和个体的变异性时，评估海洋捕食者的觅食生态。使用稳定同位素组成的连续采样的胡须，本文提供了一个详细的评估角毛皮海豹营养生态在四个南非繁殖殖民地。我们专注于饮食和栖息地使用的地理差异，同位素特征的长期时间趋势，以及个体专业化的地理差异。我们的研究结果突出了明显的地理梯度的同位素组成的胡须，支持最近的证据表明，栖息地利用和觅食策略的空间差异。
Information on resource use and trophic dynamics of marine predators is important for understanding their role in ecosystem functioning and predicting population‐level responses to environmental change. Where separate populations experience different local environmental conditions, geographic variability in their foraging ecology is often expected. Within populations, individuals also vary in morphology, physiology, and experience, resulting in specialization in resource use. In this context, isotopic compositions of incrementally grown tissues such as keratinous hairs offer a valuable opportunity to study long‐term variation in resource and habitat use. We investigated the trophic ecology of female Cape fur seals (Arctocephalus pusillus pusillus) using carbon and nitrogen isotopic compositions of serially sampled whiskers collected at four breeding sites along the coast of South Africa. Drawing on over 900 isotopic measurements, we assessed geographic variability in isotopic niche width between colonies and the degree of individual specialization. We found slight, but clear geographic differences in isotopic ratios and isotopic niche widths, seemingly related to ecological setting, with niche widths being proportional to the area of available shelf and shelf‐slope habitat surrounding the colony. We further identified periodic oscillations in isotopic ratios, which likely reflect temporal patterns in foraging distribution and prey type, linked to shifts in the availability of prey resources and their interaction with constraints on individual females throughout their breeding cycle. Finally, individual specialization indices revealed that each of the study populations contain specialist individuals that utilize only a small subset of the total population niche width. The degree of individual specialization was, however, not consistent across colonies and may reflect an interactive influence between density‐dependent effects and habitat heterogeneity. Overall, this study provides important information on the trophic ecology of Cape fur seals breeding in South Africa and highlights the need to consider geographic and individual variability when assessing the foraging ecology of marine predators. Using stable isotope compositions of serially sampled whiskers, this paper provides a detailed assessment of Cape fur seal trophic ecology across four South African breeding colonies. We focus on geographic differences in diet and habitat use, long‐term temporal trends in isotopic signatures, and geographic differences in individual specialization. Our results highlight clear geographical gradients in the isotopic composition of whiskers, which support recent evidence of spatial differences in habitat use and foraging strategies.
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DOI：
10.1139/cjz-79-1-35
发表时间：
2001-01-01
期刊：
CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE
影响因子：
--
作者：
Arnould, JPY;Hindell, MA
通讯作者：
Hindell, MA
影响因子：
3.7
作者：
Botha, Jonathan A.;Pistorius, Pierre A.
通讯作者：
Pistorius, Pierre A.
影响因子：
2.5
作者：
Bearhop, Stuart;Phillips, Richard A.;Croxall, John P.
通讯作者：
Croxall, John P.
影响因子：
2.5
作者：
Chambellant, Magaly;Stirling, Ian;Ferguson, Steven H.
通讯作者：
Ferguson, Steven H.
影响因子：
2.4
作者：
Angel LP;Barker S;Berlincourt M;Tew E;Warwick-Evans V;Arnould JP
通讯作者：
Arnould JP