Abstract:
Understanding how animals respond to large-scale environmental changes is difficult to achieve because monitoring data are rarely available for more than the past few decades, if at all. Here, we demonstrate how a variety of palaeoecological proxies (e.g. isotopes, geochemistry and DNA) from an Andean Condor (Vultur gryphus) guano deposit from Argentina can be used to explore breeding site fidelity and the impacts of environmental changes on avian behaviour. We found that condors used the nesting site since at least approximately 2200 years ago, with an approximately 1000-year nesting frequency slowdown from ca 1650 to 650 years before the present (yr BP). We provide evidence that the nesting slowdown coincided with a period of increased volcanic activity in the nearby Southern Volcanic Zone, which resulted in decreased availability of carrion and deterred scavenging birds. After returning to the nest site ca 650 yr BP, condor diet shifted from the carrion of native species and beached marine animals to the carrion of livestock (e.g. sheep and cattle) and exotic herbivores (e.g. red deer and European hare) introduced by European settlers. Currently, Andean Condors have elevated lead concentrations in their guano compared to the past, which is associated with human persecution linked to the shift in diet.
摘要:
了解动物如何应对大规模的环境变化是难以实现的,因为过去几十年来,监测数据很少可用。如果有的话。这里,我们展示了各种古生态代理(例如同位素,来自阿根廷的安第斯秃鹰(Vulturgryphus)鸟粪矿床的地球化学和DNA)可用于探索繁殖地点的保真度以及环境变化对鸟类行为的影响。我们发现秃鹰至少在2200年前就开始使用筑巢地,大约1000年的嵌套频率从大约1650年放缓到现在的650年(年BP)。我们提供的证据表明,筑巢放缓与附近南部火山带火山活动增加的时期相吻合,这导致腐肉的可用性下降,并阻止了食腐鸟类。返回巢穴大约650年BP后,秃鹰的饮食从本地物种和海滩海洋动物的腐肉转移到欧洲定居者引入的牲畜(例如绵羊和牛)和外来食草动物(例如马鹿和欧洲野兔)的腐肉。目前,与过去相比,安第斯秃鹰的鸟粪中的铅浓度升高,这与与饮食转变有关的人类迫害有关。