Deer density drives habitat use of establishing wolves in the Western European Alps

Abstract

1. The return of top carnivores to their historical range triggers conflicts with the interests of different stakeholder groups. Anticipating such conflicts is key to appropriate conservation management, which calls for reliable spatial predictions of future carnivore occurrence. Previous models have assessed general habitat suitability for wolves, but the factors driving the settlement of dispersing individuals remain ill-understood. In particular, little attention has been paid to the role of prey availability in the recolonization process.2. High spatial resolution and area-wide relative densities of the wolf's main ungulate prey species (red deer, roe deer and chamois) were assessed from snow-track surveys and modelled along with wolf presence data and other environmental descriptors to identify the main drivers of habitat selection of re-establishing wolves in the Western European Alps.3. Prey species abundance was estimated from the minimum number of individuals recorded from snow-tracks along two hundred and eighteen 1-km transects surveyed twice a year during four successive winters (2012/2013-2015/2016).Abundance estimates per transect, corrected for species-specific detection probabilities and averaged across winters, were used to model area-wide relative prey density and biomass.2008; but see Mladenoff et al., 1995); so, clearly, there is an urgent the most profitable prey in the Western Alps, was the main driver of winter habitat selection during the settlement phase.7. Synthesis and applications. We demonstrate the crucial importance of including accurate, fine-grained information about prey supply for predicting recolonization patterns of carnivores and thus anticipating areas with potential human-wildlife conflicts where preventive measures should be prioritized. K E Y W O R D SCanis lupus, habitat modelling, human-wildlife interactions, Maxent, predator-prey relationships, recolonization patterns, ungulate density, wolf | 997

Poaching Threatens the Establishment of a Lynx Population, Highlighting the Need for a Centralized Judiciary Approach

“…Based on imprint size and track configuration, we estimated the minimum number of individuals present during each visit. Multiple individuals were counted if tracks of different sizes (i.e., from different sexes or age classes) or individuals traveling together in a group could be distinguished, using a conservative approach: when in doubt, we always recorded the lower number of individuals (for details see Roder et al, 2020).…”

“…To obtain detection-corrected relative abundance (hereafter called "abundance") estimates of roe deer and chamois along the transects, N-mixture models were fitted with the R package unmarked (Fiske et al, 2017), taking into account the sampling occasion (i.e., first or second survey as described in Roder et al, 2020), with snow predictors as detection variables (Table 3) and environmental predictors (Table 2) as habitat variables (Roder et al, 2020; Supplementary Data Sheet 3). We used Poisson models for roe deer abundance and zero-inflated Poisson models for chamois abundance.…”

Illegal hunting threatens the establishment of a lynx population and highlights the need of a centralized judiciary approach

“…To obtain detection-corrected abundance estimates of roe deer and chamois along the transects, N-mixture models were fit with R package unmarked 39 , taking into account the sampling occasion (i.e. first or second survey as described in 40 ) and the snow condition variables as detection variables (Table 3) and the environmental predictors (Table 2) To compare prey densities between the two study areas, a regular grid of 1-km side length, based on the Swiss grid coordinate system, was applied to the whole study area.…”

“…Based on imprint size and track configuration, we estimated the minimum number of individuals present at each visit.Multiple individuals were counted if tracks of different sizes (i.e. from different sexes or age classes) or individuals travelling together in a group could be distinguished, using a conservative approach: when in doubt, we always recorded the lower number of individuals (for details see29 ).…”

Eyes, ears, or nose? Comparison of three non-invasive methods to survey wolf recolonisation

“…Perceived and actual interference with human activities, and particularly predation on sheep and goats, has caused a heated debate countrywide (Behr et al 2017;Hunziker et al 2001). Despite the wolf has become a major topic in Switzerland, data collection is not systematic at the national level, and regional authorities have been using different methods to gather information (Dufresnes et al 2019;Roder et al 2020).…”