Diogo Cabecinha’s research while affiliated with Faculdade de Medicina da Universidade de Lisboa and other places

Human-Induced Rapid Environmental Change (HIREC), particularly climate change and habitat conversion, affects species distributions worldwide. Here, we aimed to (i) assess the factors that determine range patterns of European badger (Meles meles) at the southwestern edge of their distribution and (ii) forecast the possible impacts of future climate and landcover changes on those patterns. We surveyed 272 cells of 5 × 5 km, to assess badger presence and confirmed its occurrence in 95 cells (35%). Our models estimate that badger’s presence is promoted by the occurrence of herbaceous fields and shrublands (5%–10%), and low proportions of Eucalyptus plantations (50% of podzols and eruptive rocks, higher sheep/goat density (>4 ind/km2), an absence of cattle, intermediate precipitation regimes (800–1000 mm/year) and mild mean temperatures (15–16 °C) are also more likely to host badgers. We predict a decrease in favourability of southern areas for hosting badgers under forecasted climate and landcover change scenarios, which may lead to a northwards retraction of the species southern distribution limit, but the overall landscape favourability is predicted to slightly increase. The forecasted retraction may affect community functional integrity, as its role in southern ecological networks will be vacant.

European badgers (Meles meles) are considered central-place foragers, whose spatial ecology is predominantly determined by sett location. Many studies have assessed the factors determining sett site selection throughout this species’ range, but these have often been geographically limited and have primarily identified locally dependent factors. To infer key factors determining sett location, a broader scale approach is needed. Between June 2014 and January 2017, we surveyed mainland Portugal to detect badger setts in 10 × 10 km cells, corresponding to a total of 657.5 km walked line transects. We detected 54 main setts in 136 surveyed cells. Each sett and non-sett site (i.e. transects without setts) was characterised using bioenvironmental variables (e.g. land cover, presence of human infrastructure, soil). We used generalized linear mixed models to test five hypotheses potentially explaining sett location: land cover composition; anthropogenic disturbance; abiotic environmental drivers; trophic resource availability; and a combined effect of all these factors. Our findings show that the key factors for badger sett site selection in Portugal are: (1) disturbance avoidance (low beehive density; absence of livestock; far from hunting reserves), but with a tendency to be located close to highways and unpaved roads; and (2) ease of excavation (avoidance of sedimentary/metamorphic composite rocks). Although specific factors among these drivers may be more important locally or regionally, these major drivers have also been identified elsewhere in Europe. Our nationwide approach contributes to a broader understanding of general patterns of sett site selection by badgers in southern Europe. Furthermore, it provides the national authorities with novel and broad-scale data to facilitate sustainable species conservation of badgers in the southwestern limit of their range.

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