Institute of Marine and Antarctic Studies, University of Tasmania, Sandy Bay, Tasmania 7005, Australia.
Biol Lett. 2013 May 1;9(3):20121036. doi: 10.1098/rsbl.2012.1036. Print 2013 Jun 23.
Diet is a fundamental aspect of animal ecology. Cetacean prey species are generally identified by examining stomach contents of stranded individuals. Critical uncertainty in these studies is whether samples from stranded animals are representative of the diet of free-ranging animals. Over two summers, we collected faecal and gastric samples from healthy free-ranging individuals of an extensively studied bottlenose dolphin population. These samples were analysed by molecular prey detection and these data compared with stomach contents data derived from stranded dolphins from the same population collected over 22 years. There was a remarkable consistency in the prey species composition and relative amounts between the two datasets. The conclusions of past stomach contents studies regarding dolphin habitat associations, prey selection and proposed foraging mechanisms are supported by molecular data from live animals and the combined dataset. This is the first explicit test of the validity of stomach contents analysis for accurate population-scale diet determination of an inshore cetacean.
饮食是动物生态学的一个基本方面。鲸目动物的猎物物种通常通过检查搁浅个体的胃内容物来确定。这些研究中的一个关键不确定性是，搁浅动物的样本是否代表了自由活动动物的饮食。在两个夏季，我们从一个广泛研究的宽吻海豚种群中健康的自由活动个体中收集了粪便和胃样本。这些样本通过分子猎物检测进行了分析，并将这些数据与从同一种群中收集的 22 年来搁浅海豚的胃内容物数据进行了比较。这两个数据集之间的猎物物种组成和相对数量存在显著的一致性。过去关于海豚栖息地关联、猎物选择和拟议觅食机制的胃内容物研究的结论得到了来自活体动物的分子数据和综合数据集的支持。这是对胃内容物分析在近海鲸类动物种群规模饮食确定方面的有效性的首次明确测试。
