Observations of intraspecific killing, cannibalism, and aggressive behavior among polar bears (Ursus maritimus) in the eastern Barents Sea and the Kara Sea
Observations of intraspecific killing, cannibalism, and aggressive behavior among polar bears (Ursus maritimus) in the eastern Barents Sea and the Kara Sea
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DOI：
10.1007/s00300-020-02771-7
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发表时间：
2020-11-18
期刊：
影响因子：
1.7
通讯作者：
Rozhnov, V. V.
中科院分区：
文献类型：
--
作者：
Ivanov, E. A.;Mizin, I. A.;Rozhnov, V. V.
北极熊（U. maritimus）杀死和食用异种动物的能力是公认的，但这种行为及其流行背后的原因尚不清楚。在这里，我们报告了14例北极熊的种内杀戮、同类相食和攻击行为，其中7例发生在弗兰斯约瑟夫岛、新地岛和维泽岛的巴伦支海和喀拉海。除了一次之外，所有的观测都是在无冰季节在陆地上进行的。行凶者，当被发现时，大多很瘦。由于未能在春季获得脂肪储备而导致的饥饿似乎激发了行凶者，而岛屿上的熊聚集可能有助于成功的种内杀戮。令人惊讶的是，即使在前一年春天海冰状况相对较好的年份，也观察到种内杀戮的情况。在一个案例中，今年春天一只幼崽被一只又大又胖的公熊杀死，这很难用营养需求来解释。这可能是一种性选择的杀婴行为，因为在交配季节杀死幼崽会增加雄性繁殖的机会。
The ability of the polar bear (U. maritimus) to kill and consume conspecifics is accepted, but the reasons behind this behavior and its prevalence remain unclear. Here, we report 14 cases of intraspecific killing, cannibalism, and aggressive behaviors among polar bears observed in seven instances in the Barents Sea and the Kara Sea on Frans-Josef Land, Novaya Zemlya, and Vize Island. All but one of the observations were made on land during the ice-free season. Perpetrators, when observable, were mostly thin. The hunger resulting from a failure to gain fat reserves in spring appears to motivate perpetrators, while bear aggregation on islands could facilitate successful intraspecific killing. Surprisingly, cases of intraspecific killing were observed even in years when sea-ice conditions in the previous spring were relatively good. In one case, the killing of a cub of the year in the spring by a large, fat male could hardly be explained by nutritional demands. This could be a case of sexually selected infanticide, as the killing of cubs during the mating season increases the male's opportunity to breed.