Effect of competition and landscape characteristics on mesocarnivore cohabitation in badger setts

Patterns of coexistence between two mesocarnivores in presence of anthropogenic disturbances in Western Himalaya

Species' coexistence depends on species-specific resource utilization in a given habitat. Human disturbances in this context can constrain the realized niche by altering their community dynamics. In this study, we considered Western Himalaya as a case study to test the hypothesis that human disturbances influence mesocarnivore coexistence patterns. We regarded red fox and leopard cat as the focal species and assessed the coexistence patterns in low and high human disturbance areas in three dimensions: spatial, temporal, and dietary habit. We used camera trap detections and mitochondrial DNA-based species identification of fecal samples. We used generalized linear mixed-effect modelling (GLMM), activity overlap, Levin's niche breadth, and Pianka's overlap index to capture the spatial, temporal, and dietary interactions respectively. We found that red fox and leopard cat coexisted by spatial segregation in low human disturbance area, whereas dietary segregation was the means of coexistence in high human disturbance area. We observed a broader dietary breadth for red fox and a narrower for leopard cat in high human disturbance area. The altered coexistence pattern due to differential human disturbances indicates intensive anthropogenic activities adjacent to natural forests. It can link to increased opportunities for shared spaces between mesocarnivores and humans, leading to future disease spread and conflicts. Our study contributes to scant ecological knowledge of these mesocarnivores and adds to our understanding of community dynamics in human-altered ecosystems. The study elucidates the need for long-term monitoring of wildlife inhabiting interface areas to ensure human and wildlife coexistence.

Reproduction success in European badgers, red foxes and raccoon dogs in relation to sett cohabitation

The setts of the European badger Meles meles can be cohabited during reproductive season by the red fox Vulpes vulpes and raccoon dog Nyctereutes procyonoides. There is no information on the possible impact of both species on the size of badgers’ litter. The aim of the study was to show the influence of cohabitation of the same setts by badger, raccoon dog and fox on the litter size. The research was conducted in 2012–2014 and 2018 in the lowland forests of western Poland. We conducted the survey of setts by direct observations and analysis of photographic material from trap cameras during mid-April–July each year. We recorded 85 badger litters, 18 fox litters, and 15 raccoon dog litters. Average litter size was 1.71 (±0.90), 2.44 (±1.34) and 4.93 (±2.76) litter mates in badgers, foxes and raccoon dogs, respectively for all observed pairs. Badger litter size did not differ between setts used only by badgers including pairs with no cubs (1.66 ± 0.98) and cohabited with foxes (1.90 ± 0.32) or raccoon dogs (1.88 ± 0.81). However, foxes reared even more cubs in setts cohabited with badgers than when badger was absent (2.90 ± 1.37 vs. 1.88 ± 1.13 respectively). In the case of raccoon dogs, there were no differences in the mean number of their cubs in setts with badgers (5.25 ± 2.92) and without badgers (4.57 ± 2.76). The results indicate that the cohabitation of setts by badgers, foxes and raccoon dogs does not affect litter size negatively.

Altitude shapes the environmental drivers of large-scale variation in abundance of a widespread mammal species

AIM

Habitat quality and heterogeneity directly influence the distribution and abundance of organisms at different spatial scales. Determining the main environmental factors driving the variation in species abundance is crucial to understand the underlying ecological processes, and this is especially important for widely distributed species living in contrasting environments. However, the responses to environmental variation are usually described at relatively small spatial scales. Here, we studied the variation in abundance of a widely distributed mustelid, the European badger (Meles meles), across France.

LOCATION

The whole metropolitan France.

METHODS

We used (a) direct detections of 9,439 dead and living badgers, from 2006 to 2009, to estimate badger relative abundance in 703 small agricultural regions of metropolitan France and (b) a Bayesian modeling approach to identify the main environmental determinants influencing badger abundance.

RESULTS

Despite a continuous distribution of badger in France, we found large variation in badger abundance between regions, explained by environmental factors. Among a set of 13 environmental variables, we demonstrated that badger abundance in lowlands (<400 m a.s.l.) was mostly driven by biotic factors such as potential food resources (earthworm abundance and fruit crops) and forest fragmentation. Conversely, in mountainous areas, abiotic factors (i.e., soil texture and climate) drove the variation in badger relative abundance.

MAIN CONCLUSIONS

These results underline the importance of mapping the abundance of wildlife species based on environmental suitability and highlight the complexity of drivers influencing species abundance at such large spatial scales. Altitude shaped the environmental drivers (biotic vs. abiotic) that most influenced relative abundance of a widespread species. In the case of badger, such abundance maps are crucial to identify critical areas for species management as this mustelid is a main wild vector of bovine tuberculosis in several countries.