Bats in Urban Sweden : A multiple regression analysis of bats’ relationship to urbanization

Abstract: Human development continues to use up more physical space in the natural world, threatening the natural habitats of many organisms. To combat the loss of biodiversity science needs to explore what landscape features are important for different organisms so that we can incorporate these into the modern environment. As bats play an important role in many ecosystems and can reflect changes through trophic levels, analyzing their preferred habitats can help planners improve biological diversity of the urban habitat. Using acoustically identified bat sightings from Artportalen.se for the years 2017-2018, this paper studied the habitats of bats in Sweden. Through multiple regression analysis we examine the response in abundance and/or diversity of bats to physical and socio-cultural attributes of the urban habitat. We examined a total of 10160 bats from 18 species in 418 land cover locales and 306 demographical statistical areas with varying degrees of urbanization. Our results indicate that bat abundance and diversity decrease significantly with higher urbanization while deciduous forests are the most important land cover type for all bats. The results also indicate that wealthier areas have less abundance and diversity even when factoring in population density. Species specific analysis suggested that bat species who are better adapted at foraging in open vegetated landscapes and over water were less susceptible to the negative impacts of the urban habitat. We conclude that diverse habitats with a mixture of open vegetated areas, watercourses and broadleaf forests are the most important land features for a diverse bat fauna along with high connectivity via tree cover and linear landscape elements. If urban planning could incorporate these features into the urban habitat, some of the negative impacts of urbanization could be prevented.