Prolonging the arctic pulse:: long-term exploitation of cached eggs by arctic foxes when lemmings are scarce
Prolonging the arctic pulse:: long-term exploitation of cached eggs by arctic foxes when lemmings are scarce
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DOI：
10.1111/j.1365-2656.2007.01278.x
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发表时间：
2007-09-01
影响因子：
4.8
通讯作者：
Lariviere, Serge
中科院分区：
文献类型：
--
作者：
Samelius, Gustaf;Alisauskas, Ray T.;Lariviere, Serge
1. 许多生态系统的特点是食物的脉冲量（脉冲资源）远远高于正常水平，动物通常会通过储存食物以供将来使用来应对。然而，大多数动物对动物使用储藏食物的程度以及其与其他食物的波动之间的关系如何变化知之甚少。2。北极狐 Alopex lagopus (L.) 每年在大型鹅群中储存数千枚卵，在鹅筑巢期间，这些卵往往过剩。我们使用程序 IsoSource.3 中的多源混合模型，通过比较狐狸组织的稳定同位素比率（δ C-13 和 δ N-15）与其食物的稳定同位素比率，估计了春季和秋季（研究区域中没有鹅）储藏的鸡蛋对北极狐饮食的贡献。藏卵对北极狐饮食的贡献与项圈旅鼠 Dicrostonyx groenlandicus (Trail) 的丰度呈负相关；藏蛋对狐狸总体饮食的贡献从带项圈旅鼠丰富的年份的<28%增加到项圈旅鼠稀缺的年份的30-74%。 4．此外，北极狐在来年春天一直使用储存的鸡蛋（获得鸡蛋后几乎一年），这种模式不同于食肉动物通常在食用前仅储存食物几天的模式。5。这项研究表明，夏季鹅群中的鹅数量过多时，长期使用储存的鸡蛋会随着带项圈旅鼠丰度（北极狐大部分栖息地的饮食的关键组成部分）的波动而变化，并表明当项圈旅鼠稀缺时，储存的鸡蛋可以起到缓冲作用。
1. Many ecosystems are characterized by pulses of dramatically higher than normal levels of foods (pulsed resources) to which animals often respond by caching foods for future use. However, the extent to which animals use cached foods and how this varies in relation to fluctuations in other foods is poorly understood in most animals.2. Arctic foxes Alopex lagopus (L.) cache thousands of eggs annually at large goose colonies where eggs are often superabundant during the nesting period by geese. We estimated the contribution of cached eggs to arctic fox diets in spring and autumn, when geese were not present in the study area, by comparing stable isotope ratios (delta C-13 and delta N-15) of fox tissues with those of their foods using a multisource mixing model in Program IsoSource.3. The contribution of cached eggs to arctic fox diets was inversely related to collared lemming Dicrostonyx groenlandicus (Traill) abundance; the contribution of cached eggs to overall fox diets increased from < 28% in years when collared lemmings were abundant to 30-74% in years when collared lemmings were scarce.4. Further, arctic foxes used cached eggs well into the following spring (almost 1 year after eggs were acquired) - a pattern that differs from that of carnivores generally storing foods for only a few days before consumption.5. This study showed that long-term use of eggs that were cached when geese were superabundant at the colony in summer varied with fluctuations in collared lemming abundance (a key component in arctic fox diets throughout most of their range) and suggests that cached eggs functioned as a buffer when collared lemmings were scarce.