Department of Biology, Eastern Michigan University, Ypsilanti, MI, USA.
Department of Neurobiology, Physiology, and Behavior, University of California, Davis, CA, USA.
Anim Cogn. 2021 Nov;24(6):1305-1317. doi: 10.1007/s10071-021-01520-5. Epub 2021 May 28.
Meeting metabolic demands through foraging is a basic animal need that drives the evolution of foraging adaptations. The use of social information is one adaptation that could improve foraging success and fitness if it helps animals locate food when conditions are challenging. It is unknown if food limitation-or the glucocorticoid hormones that are often released when food is limited-can influence the extent to which animals use social information or their ability to learn novel foraging techniques. We explored the effects of limited access to food on activity levels, corticosterone secretion, and social information use in red crossbills, a highly social songbird species adapted to cope with high degrees of resource unpredictability. Using an observer/demonstrator paradigm, food limited or well fed observers were allowed to watch demonstrators solve a novel feeding puzzle before being allowed to attempt the puzzle themselves across repeated trials. Our findings suggest that food limitation transiently increased activity levels but did not result in long-term elevations of corticosterone and did not increase the speed at which red crossbills utilized social information to solve the novel foraging task. However, food limitation may have increased the value of using socially acquired information, as foraging technique performance improved faster in food limited birds relative to controls. Social learning was further demonstrated by the red crossbills in this study when naïve observers overwhelmingly learned a socially-demonstrated task over an undemonstrated task when tested on a two-task foraging board.
通过觅食来满足代谢需求是动物的基本需求，推动了觅食适应性的进化。如果社交信息能够帮助动物在条件具有挑战性时找到食物，那么它是一种可以提高觅食成功率和适应性的适应能力。目前尚不清楚食物限制（或食物有限时经常释放的糖皮质激素）是否会影响动物使用社交信息的程度或它们学习新觅食技术的能力。我们探索了食物获取受限对红交嘴雀（一种高度社会化的鸣禽，适应应对高度资源不确定性）的活动水平、皮质酮分泌和社交信息使用的影响。使用观察者/演示者范式，允许食物受限或充足的观察者在自己尝试解决新的觅食难题之前观看演示者解决新的喂食难题。我们的研究结果表明，食物限制会短暂增加活动水平，但不会导致皮质酮的长期升高，也不会增加红交嘴雀利用社交信息解决新觅食任务的速度。然而，食物限制可能增加了使用社交获得信息的价值，因为与对照组相比，食物受限的鸟类的觅食技术表现更快地得到改善。在这项研究中，红交嘴雀还表现出了社交学习，当在双任务觅食板上进行测试时，与未演示的任务相比，未经验证的观察者压倒性地从社会演示的任务中学习。
