Daily foraging routines in food-caching mountain chickadees are associated with variation in environmental harshness
Daily foraging routines in food-caching mountain chickadees are associated with variation in environmental harshness
复制标题
山雀储存食物的日常觅食行为与环境恶劣程度的变化有关
DOI：
10.1016/j.anbehav.2018.07.011
复制
发表时间：
2018
期刊：
影响因子：
2.5
通讯作者：
V. Pravosudov
中科院分区：
文献类型：
--
作者：
A. Pitera;C. Branch;E. Bridge;V. Pravosudov
在寒冷气候中越冬的小鸟必须应对每天的挑战，即在一天中积累足够的能量储备，以确保过夜生存。理论工作表明，饥饿的风险是一个主要的力量塑造最佳的日常觅食程序。据预测，动物会根据环境的恶劣程度来调整它们的日常觅食活动，这在很大程度上决定了饥饿的风险。在这里，我们使用射频识别（RFID）功能的喂鸟器，以测试是否山雀，Poecilegambeli-小，居民，食物缓存鸟类-表现出不同的日常觅食例程在恶劣（海拔较高）与温和（海拔较低）的环境中，在内华达州的塞拉利昂。此外，我们评估了四个不同时期的非繁殖季节，从秋季（温和的条件），冬季和早春（恶劣的条件）和晚春（温和的条件）之间的觅食例程。我们还测试了与食物缓存相关的空间认知的个体差异是否与日常觅食习惯的差异相关，食物缓存代表了一种更可靠的食物来源，可以降低饥饿的风险。来自这两个海拔高度的山雀分布在整个非繁殖季节不同的日常觅食的努力，与理论预测的温和和苛刻的条件。在严酷的冬季，来自高海拔和低海拔的山雀之间的差异尤其明显，来自高海拔的山雀表现出双峰的日常生活，而低海拔的鸟类表现出倒U形的日常生活，大多数觅食在一天的中间。最后，日常生活的显著差异与空间学习和记忆表现的变化有关。总的来说，我们的研究表明，日常觅食习惯与不同程度的环境严酷下的饥饿风险是一致的，无论是在非繁殖季节还是在海拔之间，对严酷的感知可能与认知能力有关。
Small birds overwintering in cold climates must meet the daily challenge of accumulating sufficient energy reserves throughout the day to ensure overnight survival. Theoretical work suggests that risk of starvation is a major force shaping optimal daily foraging routines. Animals are predicted to adjust how they distribute their daily foraging activity in relation to environmental harshness, which largely determines the risk of starvation. Here, we used radiofrequency identification (RFID)-enabled bird feeders to test whether mountain chickadees,Poecilegambeli– small, resident, food-caching birds – exhibited different daily foraging routines in harsher (higher elevation) versus milder (lower elevation) environments in the Sierra Nevada. In addition, we assessed foraging routines between four different periods of the nonbreeding season ranging from autumn (milder conditions) to winter and early spring (harsher conditions) and to late spring (milder conditions). We also tested whether individual variation in spatial cognition associated with food caching, which represents a more reliable food source that can be expected to lower risk of starvation, is associated with differences in daily foraging routines. Chickadees from both elevations distributed their daily foraging efforts differently throughout the nonbreeding season, consistent with theoretical predictions for milder and harsher conditions. Differences between chickadees from high and low elevations were especially pronounced during harsher winter periods, with chickadees from high elevations showing a bimodal daily routine, while low-elevation birds showed an inverted U-shaped daily routine, with most foraging during the middle of the day. Finally, significant differences in daily routines were associated with variation in spatial learning and memory performance. Overall, our study shows that daily foraging routines are consistent with risk of starvation under different degrees of environmental harshness, whether across nonbreeding seasons or between elevations, and that perception of harshness may be associated with cognitive abilities.