The most common invasive mesopredator in large parts of Europe is the raccoon dog ( Nyctereutes procyonoides). In large parts of Europe, apex predators have been exterminated, which may have increased mesopredator numbers, both native and invasive (Terborgh and Estes 2010). This is indicated by the more pronounced population declines in ground-nesting bird species than in other bird groups (McMahon et al. 2008 Ritchie and Johnson 2009 Prugh and Sivy 2020).įor example in Europe, increasing mesopredator numbers are suggested to be a threat for ground-nesting birds due to increased nest predation (Dahl and Åhlen 2019, Nummi et al. Thus, the effect of mesopredators on their prey depend on the presence of apex predators in the community (Crooks and Soulé 1999 Salo et al. In addition, the lack of apex predators may facilitate invasions by alien mesopredators, as well as population outbreaks of native mesopredators (Terborgh and Estes 2010 Wallach et al.
The arrival of an alien mesopredator may increase competition between mesopredator species in the community (Baum and Worm 2009 Wallach et al. The role of an alien predator in the community depends on its interaction with native predators. Thus, apex predators can play an important role in controlling invasive mesopredators.
We conclude that the effect of apex predators on mesopredators depends on the environment and, in our case, was more suppressive on the alien mesopredator than on the native mesopredators. We also observed that the invasive raccoon dog currently appears to be the most common mesopredator within the study area. For the occurrence of red foxes, wolves had a positive effect when agricultural fields were sparse in the landscape and lynxes had no effect. For the occurrence of badgers, the presence of wolves had a weak negative effect and the presence of lynxes had a positive effect. The effect of lynxes on raccoon dogs was clearer in areas with short growth season. This effect appeared clear compared to the effects of habitat and human density. We observed negative effect of increasing presence of wolves and lynxes on the occurrence of raccoon dogs. The observations in cameras were analysed in relation to the presence of apex predators in the landscape (grey wolf and Eurasian lynx), human density, and habitat.
We analysed the occurrence of a common invasive mesopredator in Europe, the raccoon dog ( Nyctereutes procyonoides), and native mesopredators, the red fox and the Eurasian badger, in camera-trap data from Finland. The absence of apex predators may facilitate outbreaks of invasive mesopredators, but the effect of apex predators may vary between species and environments.
0 kommentar(er)
