Benefiting from a migratory prey: spatio-temporal patterns in allochthonous subsidization of an arctic predator
Benefiting from a migratory prey: spatio-temporal patterns in allochthonous subsidization of an arctic predator
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DOI：
10.1111/j.1365-2656.2011.01944.x
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发表时间：
2012-05-01
影响因子：
4.8
通讯作者：
Bety, Joel
中科院分区：
文献类型：
--
作者：
Giroux, Marie-Andree;Berteaux, Dominique;Bety, Joel
1.跨生态系统边界的营养和能量流动有可能补贴消费者群体并改变食物网的动态，但本地和外来资源的时空变化如何影响消费者补贴仍在很大程度上未被探索。我们研究了生活在一个相对简单的生态系统中的捕食者的异地补贴的时空模式。我们在拜洛特岛（加拿大努纳武特）工作，那里的北极狐（Vulpes lagopus L.）饲料优先旅鼠（Lemmus trimucronatus和Dicrostonyx groenlandicus Traill），并在殖民地大雪雁（雁caerulescens atlanticus L.）。鹅每年从它们的越冬地（在那里它们以农田和沼泽为食）迁移到加拿大北极地区，从而产生了跨越生态系统边界的营养和能量的强大流动。我们研究了在旅鼠周期的不同阶段，鹅的空间变化对狐狸幼崽的饮食（2003-2005年）和狐狸繁殖产量（1996-2005年）的影响。利用稳定同位素分析和一个简单的统计程序来分析多源混合模型（SIAR）的输出，我们发现鹅对北极狐幼崽饮食的贡献随着离鹅群的距离而减少.的概率，一个巢穴被用于繁殖狐狸减少与距离的补贴鹅殖民地和增加旅鼠丰富。当旅鼠数量非常丰富时，与殖民地的距离效应消失了。因此，鹅群对狐狸的繁殖概率产生了空间格局，而旅鼠周期对狐狸的繁殖概率产生了强烈的时间变化.这项研究表明，由于猎物的大规模迁移的能量输入如何影响的功能和生殖反应的机会主义消费者，以及如何通过消费者的觅食行为，这种输入是空间和时间调制。因此，景观和觅食生态学的观点，需要充分解决补贴对动物的人口过程和种群动态的影响。
1. Flows of nutrients and energy across ecosystem boundaries have the potential to subsidize consumer populations and modify the dynamics of food webs, but how spatio-temporal variations in autochthonous and allochthonous resources affect consumers subsidization remains largely unexplored.2. We studied spatio-temporal patterns in the allochthonous subsidization of a predator living in a relatively simple ecosystem. We worked on Bylot Island (Nunavut, Canada), where arctic foxes (Vulpes lagopus L.) feed preferentially on lemmings (Lemmus trimucronatus and Dicrostonyx groenlandicus Traill), and alternatively on colonial greater snow geese (Anser caerulescens atlanticus L.). Geese migrate annually from their wintering grounds (where they feed on farmlands and marshes) to the Canadian Arctic, thus generating a strong flow of nutrients and energy across ecosystem boundaries.3. We examined the influence of spatial variations in availability of geese on the diet of fox cubs (2003-2005) and on fox reproductive output (1996-2005) during different phases of the lemming cycle.4. Using stable isotope analysis and a simple statistical routine developed to analyse the outputs of a multisource mixing model (SIAR), we showed that the contribution of geese to the diet of arctic fox cubs decreased with distance fromthe goose colony.5. The probability that a den was used for reproduction by foxes decreased with distance from the subsidized goose colony and increased with lemming abundance. When lemmings were highly abundant, the effect of distance from the colony disappeared. The goose colony thus generated a spatial patterning of reproduction probability of foxes, while the lemming cycle generated a strong temporal variation of reproduction probability of foxes.6. This study shows how the input of energy owing to the large-scale migration of prey affects the functional and reproductive responses of an opportunistic consumer, and how this input is spatially and temporally modulated through the foraging behaviour of the consumer. Thus, perspectives of both landscape and foraging ecology are needed to fully resolve the effects of subsidies on animal demographic processes and population dynamics.