Many apex predator populations are recolonizing old areas and dispersing to new ones, with potential consequences for their prey species and for livestock. An increasing population of the White-tailed Eagle (Haliaeetus albicilla) has settled north of the Arctic Circle in northern Finland, mainly at two big water reservoirs but also in areas with mainly terrestrial habitat. We examined nesting habitat preferences and prey use of White-tailed Eagles in this environment, where reindeer husbandry is a traditional livelihood and concerns are rising that the growing White-tailed Eagle population poses a threat to reindeer calves. Lakes, peat bogs, and marshlands were preferred habitats in the nesting territories. Fish constituted 64.3% of the identified prey items, with birds accounting for 28.5% and mammals 7.2%. The nesting territory habitat within a 10 km radius and the latitude influenced the prey composition at both the group and species level. The occurrence of reindeer calves as prey increased with latitude but was not associated with any habitat. Knowledge of the diet and territory preferences can be used to predict future dispersal and local prey use of this species. Nesting White-tailed Eagles do not seem to pose a threat to traditional reindeer herding, but further research is needed regarding non-breeding sub-adults and whether the White-tailed Eagles actually kill reindeer calves or simply exploit their carcasses.

中文翻译：

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北部内陆环境中白尾鹰的饮食和繁殖栖息地偏好

许多顶级捕食者种群正在旧地区重新定居并分散到新地区，这对它们的猎物物种和牲畜有潜在的影响。越来越多的白尾鹰 (Haliaeetus albicilla) 定居在芬兰北部的北极圈以北，主要分布在两个大型水库中，但也分布在主要为陆地栖息地的地区。我们研究了这种环境中白尾鹰的筑巢栖息地偏好和猎物使用情况，在这种环境中，驯鹿放牧是一种传统的生计，人们越来越担心不断增长的白尾鹰种群对驯鹿幼崽构成威胁。湖泊、泥炭沼泽和沼泽地是筑巢领地的首选栖息地。鱼类占确定的猎物的 64.3%，鸟类占 28.5%，哺乳动物占 7.2%。10 公里半径内的筑巢领地栖息地和纬度影响了群体和物种水平的猎物组成。驯鹿小牛作为猎物的发生率随纬度增加而增加，但与任何栖息地无关。饮食和领土偏好的知识可用于预测该物种未来的传播和当地猎物使用。筑巢的白尾鹰似乎不会对传统的驯鹿放牧构成威胁，但需要进一步研究非繁殖亚成体，以及白尾鹰是否真的杀死驯鹿小牛或只是利用它们的尸体。饮食和领土偏好的知识可用于预测该物种未来的传播和当地猎物使用。筑巢的白尾鹰似乎不会对传统的驯鹿放牧构成威胁，但需要进一步研究非繁殖亚成体，以及白尾鹰是否真的杀死驯鹿小牛或只是利用它们的尸体。饮食和领土偏好的知识可用于预测该物种未来的传播和当地猎物使用。筑巢的白尾鹰似乎不会对传统的驯鹿放牧构成威胁，但需要进一步研究非繁殖亚成体，以及白尾鹰是否真的杀死驯鹿小牛或只是利用它们的尸体。