CESCO, UMR7204 MNHN-CNRS-Sorbonne Université, CP135, 43 Rue Buffon, 75005 Paris, France.
Environment and Climate Change Canada, 11 Innovation Boulevard, Saskatoon, Saskatchewan S7N 3H5, Canada.
Forensic Sci Int. 2019 Sep;302:109884. doi: 10.1016/j.forsciint.2019.109884. Epub 2019 Jul 26.
Naturally occurring stable isotopes of several elements are important tracers in the study the wildlife ecology including the identification of origins for migration research, investigations of trophic relationships, and in the forensic determination of illegally harvested and captive fauna. Extensive illegal trapping for use as decoys and in cuisine has contributed to drastic declines of Ortolan Bunting Emberiza hortulana populations breeding and migrating through France. We contrasted feather hydrogen isotope (δH) values in illegally captured and subsequently confiscated Ortolan Buntings (n=234), including feathers known to have grown in captivity (n=34) or of unknown growing environment (wild or cage), with δH values in birds legally caught (ringed and released) in the wild (n=40). We sought to determine if feathers from these bird groups could be differentiated based on this single isotope. Feathers grown in captivity had considerably lower δH relative to feathers of wild birds, which is potentially indicative of tap water consumption and the use of different diets in captive birds. Further, applying mixing models to δH values revealed similar proportions of captive vs. wild origins for birds illegally captured in 2012, 2014 and 2015, and a larger proportion of individuals with feathers grown in the wild in 2013. This potentially mirrors the confiscation of birds at poaching sites only in the former years, but also of recently caught wild buntings kept captive in 2013. Our results show that even a single stable isotope (δH) with good association with origins where feather keratins are produced is potentially useful in understanding origins of captive birds and may advance the monitoring of illegally captured birds.
天然存在的几种元素的稳定同位素是野生动物生态学研究中的重要示踪剂，包括确定迁徙研究的起源、调查营养关系，以及在非法收获和圈养动物的法医鉴定中。为了用作诱饵和烹饪而广泛非法捕捉，导致欧椋鸟种群在法国繁殖和迁徙的数量急剧减少。我们对比了非法捕获并随后没收的欧椋鸟（n=234）的羽毛氢同位素（δH）值，包括已知在圈养中生长的羽毛（n=34）或未知生长环境（野生或笼养）的羽毛，以及在野外合法捕获（环志并释放）的鸟类的 δH 值（n=40）。我们试图确定这些鸟类群体的羽毛是否可以根据这单个同位素来区分。圈养中生长的羽毛的 δH 值明显低于野生鸟类的羽毛，这可能表明圈养鸟消耗自来水，并使用不同的饮食。此外，应用混合模型对 δH 值进行分析表明，2012 年、2014 年和 2015 年非法捕获的鸟类中，圈养和野生起源的比例相似，而 2013 年有更多个体的羽毛是在野外生长的。这可能反映了前几年在偷猎地点没收鸟类的情况，但也反映了 2013 年最近捕获的野生椋鸟被圈养的情况。我们的结果表明，即使是与产生羽毛角蛋白的起源具有良好关联的单个稳定同位素（δH），也可能有助于了解圈养鸟类的起源，并可能有助于监测非法捕获的鸟类。
