The storage of food is widespread among mammals and birds and can be flexibly adjusted to various contexts such as competition, food availability or energetic demands. In bird species, nonbreeders often move through large areas whereby periods of long-term settlement can alternate with short-term visits. In food-caching species these differences in the degree of local settlement might change the benefits gained from storing food, and caching may only be advantageous during periods of prolonged settlement. We examined whether differences in local settlement influence food-caching behaviour of wild common ravens at a local anthropogenic food source with high interspecific and intraspecific competition. We found that individuals with a higher degree of site fidelity (i.e. prolonged periods of local settlement) engaged in food caching more than individuals with less site fidelity (i.e. short periods of local settlement); this effect was even stronger in the presence of potential predators representing a high-risk foraging situation. Further, juvenile ravens were less likely to cache than subadults and adults, and an increasing number of conspecifics present at the feeding site decreased the likelihood of caching. We found considerable individual variation in respect to the area used for caching. We suggest that individuals with higher site fidelity may gain more benefits from caching food and/or that they are more successful in obtaining food potentially due to more experience with the local foraging situation. Research is needed to examine the exact causes of the observed link between food-caching behaviour and the different degrees of site fidelity. Our findings show that differences in movement and settlement decisions can influence ecological aspects such as food acquisition and thus may have important consequences for individual fitness and population dynamics.

中文翻译：

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站点保真度、群体规模和年龄对普通乌鸦 (Corvus corax) 食物缓存行为的影响

食物的储存在哺乳动物和鸟类中很普遍，可以根据各种情况灵活调整，例如竞争、食物供应或能量需求。在鸟类物种中，非繁殖者经常穿越大片区域，长期定居和短期访问交替出现。在食物缓存物种中，这些本地定居程度的差异可能会改变从储存食物中获得的好处，而缓存可能只在长期定居期间有利。我们研究了当地定居点的差异是否会影响野生乌鸦在具有高度种间和种内竞争的当地人为食物来源的食物缓存行为。我们发现网站保真度较高的个人（即 长时间的本地定居）比具有较低现场保真度的个人（即短期的本地定居）更多地从事食物缓存；在存在代表高风险觅食情况的潜在捕食者的情况下，这种影响甚至更大。此外，与亚成体和成年乌鸦相比，幼乌鸦不太可能缓存，并且在喂食地点存在的同种数量增加降低了缓存的可能性。我们发现在用于缓存的区域方面存在相当大的个体差异。我们建议具有较高现场保真度的个体可能会从缓存食物中获得更多好处和/或由于对当地觅食情况的更多经验，他们可能更成功地获取食物。需要研究来检查食物缓存行为与不同程度的网站保真度之间观察到的联系的确切原因。我们的研究结果表明，运动和定居决策的差异会影响食物获取等生态方面，因此可能对个体健康和种群动态产生重要影响。