Abstract:
The study of spatial (paleo)ecology in mammals is critical to understand how animals adapt to and exploit their environment. In this work we analysed the 87Sr/86Sr, δ18O and δ13C isotope composition of 65 moose bone and antler samples from Sweden from wild-shot individuals dated between 1800 and 1994 to study moose mobility and feeding behaviour for (paleo)ecological applications. Sr data were compared with isoscapes of the Scandinavian region, built ad-hoc during this study, to understand how moose utilise the landscape in Northern Europe. The 87Sr/86Sr isoscape was developed using a machine-learning approach with external geo-environmental predictors and literature data. Similarly, a δ18O isoscape, obtained from average annual precipitation δ18O values, was employed to highlight differences in the isotope composition of the local environment vs. bone/antler. Overall, 82% of the moose samples were compatible with the likely local isotope composition (n = 53), suggesting that they were shot not far from their year-round dwelling area. \'Local\' samples were used to calibrate the two isoscapes, to improve the prediction of provenance for the presumably \'non-local\' individuals. For the latter (n = 12, of which two are antlers and ten are bones), the probability of geographic origin was estimated using a Bayesian approach by combining the two isoscapes. Interestingly, two of these samples (one antler and one bone) seem to come from areas more than 250 km away from the place where the animals were hunted, indicating a possible remarkable intra-annual mobility. Finally, the δ13C data were compared with the forest cover of Sweden and ultimately used to understand the dietary preference of moose. We interpreted a difference in δ13C values of antlers (13C-enriched) and bones (13C-depleted) as a joint effect of seasonal variations in moose diet and, possibly, physiological stresses during winter-time, i.e., increased consumption of endogenous 13C-depleted lipids.
摘要:
哺乳动物的空间(古)生态学研究对于了解动物如何适应和利用其环境至关重要。在这项工作中,我们分析了87Sr/86Sr,来自瑞典的65个驼鹿骨和鹿角样品的δ18O和δ13C同位素组成,这些样品来自1800年至1994年之间的野生个体,以研究驼鹿的流动性和摄食行为(古)生态应用。Sr数据与斯堪的纳维亚地区的等景图进行了比较,在这项研究中建立了临时的,了解驼鹿如何利用北欧的景观。87Sr/86Sr等值线是使用具有外部地质环境预测因子和文献数据的机器学习方法开发的。同样,δ18O等值线,从年平均降水量δ18O值获得,被用来强调当地环境与同位素组成的差异骨/鹿角。总的来说,82%的驼鹿样本与可能的局部同位素组成相容(n=53),这表明他们在离他们全年居住地区不远的地方被枪杀。\'本地\'样本用于校准两个等高线,提高对可能的“非本地”个体的出处预测。对于后者(n=12,其中两个是鹿角,十个是骨头),通过结合两个等值线,使用贝叶斯方法估计地理起源的概率。有趣的是,其中两个样本(一个鹿角和一个骨头)似乎来自距离猎杀动物的地方250多公里的区域,表明可能存在显著的年度内流动性。最后,将δ13C数据与瑞典的森林覆盖率进行比较,并最终用于了解驼鹿的饮食偏好。我们将鹿角(富含13C)和骨骼(耗尽13C)的δ13C值的差异解释为驼鹿饮食季节性变化的联合影响,可能,冬季的生理压力,即,内源性13C耗尽脂质的消耗增加。