The interaction between agricultural production and wildlife can shape, and even condition, the functioning of both systems. In this study, we i) explored the degree to which a widespread European bat, namely the common bent-wing bat Miniopterus schreibersii, consumes crop-damaging insects at a continental scale, and ii) tested whether its dietary niche is shaped by the extension and type of agricultural fields. We employed a dual-primer DNA metabarcoding approach to characterize arthropod 16S and COI DNA sequences within bat faecal pellets collected across 16 Southern European localities, to first characterize the bat species' dietary niche, second measure the incidence of agricultural pests across their ranges and third assess whether geographical dietary variation responds to climatic, landscape diversity, agriculture type and vegetation productivity factors. We detected 12 arthropod orders, among which lepidopterans were predominant. We identified >200 species, 44 of which are known to cause agricultural damage. Pest species were detected at all but one sampling site and in 94% of the analysed samples. Furthermore, the dietary diversity of M. schreibersii exhibited a negative linear relation with the area of intensive agricultural fields, thus suggesting crops restrict the dietary niche of bats to prey taxa associated with agricultural production within their foraging range. Overall, our results imply that M. schreibersii might be a valuable asset for biological pest suppression in a variety of agricultural productions and highlight the dynamic interplay between wildlife and agricultural systems.

Inferences of the interactions between species' ecological niches and spatial distribution have been historically based on simple metrics such as low-resolution dietary breadth and range size, which might have impeded the identification of meaningful links between niche features and spatial patterns. We analysed the relationship between dietary niche breadth and spatial distribution features of European bats, by combining continent-wide DNA metabarcoding of faecal samples with species distribution modelling. Our results show that while range size is not correlated with dietary features of bats, the homogeneity of the spatial distribution of species exhibits a strong correlation with dietary breadth. We also found that dietary breadth is correlated with bats' hunting flexibility. However, these two patterns only stand when the phylogenetic relations between prey are accounted for when measuring dietary breadth. Our results suggest that the capacity to exploit different prey types enables species to thrive in more distinct environments and therefore exhibit more homogeneous distributions within their ranges.

White-Nose Disease (WND) has killed millions of hibernating bats in the US and Canada. Its causative agent, the fungus Pseudogymnoascus destructans was introduced to North America, but is native to Europe and Asia, where it is not associated with mass mortality. Although it is nearly impossible to eradicate an emerging wildlife disease, research on P. destructans spread mechanisms can aid in prevention of new introductions and development of better environmental management strategies. It is of particular importance to quantify the potential role of people visiting caves (cavers, tourists, bat researchers, etc.) whom inadvertently move P. destructans spores between sites, and to limit spread, particularly to areas where the fungus is absent. In the course of two consecutive field seasons, samples were collected from the equipment before and after work in Bulgarian caves where P. destructans is present. Viable P. destructans spores were isolated from field equipment after nearly 100% of cave visits, irrespective of the season. Results from lab experiments show the pathogen’s spores can remain viable on pieces of contaminated caving equipment under room temperature for at least 25 days, with no significant reduction in germination rates. This is concerning evidence indicating the potential for movement of viable P. destructans spores across countries and continents. Results further demonstrated that any type of regular washing can successfully remove the majority of P. destructans spores from several fabric types. Brushing complemented by washing in a ‘washing machine’ was slightly more effective than brushing alone, while a washing temperature of 50°C was more effective than temperatures of 30 and 40°C. However, none of the methods herein tested fully removed P. destructans and hence they are not a substitute for decontamination. Since many cavers forgo washing equipment after surveys, and bat workers often visit several underground sites per day during monitoring activities without cleaning equipment in between sites, it is essential to raise awareness on this subject and introduce hygienic protocols for the prevention of pathogen pollution in underground sites.

7 Large-scale species' distributions have been traditionally attributed to physiological 8 traits related to abiotic factors, while behavioural features linked to biotic interactions 9 have received little attention. We tested the relationship between trophic and spatial 10 niche breadths through combining species distribution modelling with dietary DNA 11 metabarcoding of over 400 bats sampled across Europe belonging to seven species. Our 12 results point to a causality cascade between hunting plasticity, trophic niche breadth and 13 spatial niche breadth, and thus indicate that behavioral plasticity and dietary 14 diversification can contribute to shaping broad-scale species distributions. 15 16 Affiliations 17