Where have all the young wolves gone? Traffic and cryptic mortality create a wolf population sink in Denmark and northernmost Germany

Abstract

Large carnivores are currently recolonizing Europe following legal protection, but increased mortality in landscapes highly impacted by humans may limit further population expansion. We analyzed mortality and disappearance rates of 35 wolves (of which three emigrated, nine died and 14 disappeared by 1 January 2020) by genetic monitoring in the heavily cultivated and densely populated Jutland peninsula (Denmark and Schleswig-Holstein, Germany). Annual traffic kill rate estimates ranged from 0.37 (95% CI: 0.11-0.85) to 0.78 (0.51-0.96) in the German part, equivalent to 0.08 (0.02-0.29)-0.25 (0.13-0.46) for the entire region, in the absence of any registered Danish roadkills. In Denmark, annual mortality rate estimates ranged from 0.46 (0.29-0.67) to 0.52 (0.35-0.71), predominantly from cryptic mortality. Despite successful reproductions, we conclude the region is a wolf population sink, primarily driven by cryptic mortality, most likely illegal killing. We hypothesize that frequent encounters between wolves and wolfaverse persecutors in cultivated landscapes may cause unsustainably high mortality rates despite the majority of hunters respecting protection laws.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Men and wolves: are anthropogenic causes the main driver of wolf mortality in human-dominated landscapes in Italy?

“…The very high proportion of wolves showing signs of human-driven mortality was certainly affected by our data collection methods and the consequent detection probabilities (e.g., road-killed wolves are easier to find than those who die in the wild). Nevertheless, our findings are highly suggestive that human-driven wolf mortality in our study area can be considerable, similarly to other studies conducted in Europe [26][31][56][58][60] [61] and North America [32][57] [62] . For all causes of anthropogenic mortality, there were no statistically significant differences between sex and age classes, suggesting a rather even impact on all of them.…”

“…On the other hand, if persecution arises from cryptic conflicts with shepherd, hunters or other categories, not measuring them can have extremely negative consequences for wolf populations, in case lethal control will be considered in the future without accounting for extra human-related mortality [32] . Also, ignoring these conflicts can prevent agencies from designing adequate mitigation and communication initiatives, at the local scale, which could further exacerbate mistrust and the polarization of public attitudes toward their presence and management [61] .…”

Patterns and determinants of dispersal in grey wolves (Canis lupus)

“…It is not known what proportion of the dispersal events whose fate was unknown or not specified corresponded to mortality, in particular to poaching events. Poaching is an important source of wolf mortality (Treves et al ., 2017; Sunde et al ., 2021) and investigating the extent to which it affects dispersers is paramount to reducing uncertainty in dispersal estimates. Data on pairing, denning and reproductive status corresponding to each dispersal event were not available or not easily derived from the information provided and so no reliable conclusions can be drawn.…”

Wolf Conservation and Management in Spain, An Open Debate

“…Large carnivores are recolonizing former grounds in Europe (Chapron et al, 2014) and North America (Bruskotter and Shelby, 2010), yet carnivore recovery pace and success vary across regions. In central Europe, wolf recovery has been quite fast in Germany (Reinhardt et al, 2019), and wolves even reproduced in Denmark for the first time in ~200 years, although poaching may prevent further expansion (Sunde et al, 2021). In northern Europe, the Scandinavian wolf population started its recovery in the 1990s, but nowadays wolves are more numerous in Sweden than in Norway due to differences in policy (Bischof et al, 2020).…”