Milleret Cyril, Ordiz Andrés, Chapron Guillaume, Andreassen Harry Peter, Kindberg Jonas, Månsson Johan, Tallian Aimee, Wabakken Petter, Wikenros Camilla, Zimmermann Barbara, Swenson Jon E, Sand Håkan
Faculty of Applied Ecology and Agricultural Sciences Inland Norway University of Applied Sciences Koppang Norway.
Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life Sciences Ås Norway.
Ecol Evol. 2018 Nov 11;8(23):11450-11466. doi: 10.1002/ece3.4572. eCollection 2018 Dec.
Identifying how sympatric species belonging to the same guild coexist is a major question of community ecology and conservation. Habitat segregation between two species might help reduce the effects of interspecific competition and apex predators are of special interest in this context, because their interactions can have consequences for lower trophic levels. However, habitat segregation between sympatric large carnivores has seldom been studied. Based on monitoring of 53 brown bears () and seven sympatric adult gray wolves () equipped with GPS collars in Sweden, we analyzed the degree of interspecific segregation in habitat selection within their home ranges in both late winter and spring, when their diets overlap the most. We used the K-select method, a multivariate approach that relies on the concept of ecological niche, and randomization methods to quantify habitat segregation between bears and wolves. Habitat segregation between bears and wolves was greater than expected by chance. Wolves tended to select for moose occurrence, young forests, and rugged terrain more than bears, which likely reflects the different requirements of an omnivore (bear) and an obligate carnivore (wolf). However, both species generally avoided human-related habitats during daytime. Disentangling the mechanisms that can drive interspecific interactions at different spatial scales is essential for understanding how sympatric large carnivores occur and coexist in human-dominated landscapes, and how coexistence may affect lower trophic levels. The individual variation in habitat selection detected in our study may be a relevant mechanism to overcome intraguild competition and facilitate coexistence.
确定属于同一功能群的同域物种如何共存是群落生态学和保护学的一个主要问题。两个物种之间的栖息地隔离可能有助于减少种间竞争的影响，在此背景下，顶级捕食者特别受关注，因为它们的相互作用可能会对较低营养级产生影响。然而，同域大型食肉动物之间的栖息地隔离很少被研究。基于对瑞典53只佩戴GPS项圈的棕熊（ ）和7只同域成年灰狼（ ）的监测，我们分析了它们在冬季末和春季（此时它们的饮食重叠最多）的家域内栖息地选择的种间隔离程度。我们使用了K选择方法，这是一种基于生态位概念的多变量方法，以及随机化方法来量化熊和狼之间的栖息地隔离。熊和狼之间的栖息地隔离程度大于随机预期。狼比熊更倾向于选择驼鹿出没的地方、幼林和崎岖地形，这可能反映了杂食动物（熊）和专性食肉动物（狼）的不同需求。然而，两种物种在白天通常都避开与人类相关的栖息地。弄清楚在不同空间尺度上驱动种间相互作用的机制，对于理解同域大型食肉动物如何在人类主导的景观中出现和共存，以及共存如何影响较低营养级至关重要。我们研究中检测到的栖息地选择个体差异可能是克服功能群内竞争并促进共存的一个相关机制。
