Modelling the distribution of bats in relation to landscape structure in a temperate mountain environment
C. Jaberg, Centre de coordination ouest pour l’étude et la protection des chauves-souris c/o Musée d’histoire naturelle, Av. Léopold-Robert 63, CH-2300 La Chaux-de-Fonds, Switzerland (fax +41 32 913 3976; e-mail email@example.com).
- 1Landscape modification is often considered the principal cause of population decline in many bat species. Thus, schemes for bat conservation rely heavily on knowledge about species–landscape relationships. So far, however, few studies have quantified the possible influence of landscape structure on large-scale spatial patterns in bat communities.
- 2This study presents quantitative models that use landscape structure to predict (i) spatial patterns in overall community composition and (ii) individual species’ distributions through canonical correspondence analysis and generalized linear models, respectively. A geographical information system (GIS) was then used to draw up maps of (i) overall community patterns and (ii) distribution of potential species’ habitats. These models relied on field data from the Swiss Jura mountains.
- 3Eight descriptors of landscape structure accounted for 30% of the variation in bat community composition. For some species, more than 60% of the variance in distribution could be explained by landscape structure. Elevation, forest or woodland cover, lakes and suburbs, were the most frequent predictors.
- 4This study shows that community composition in bats is related to landscape structure through species-specific relationships to resources. Due to their nocturnal activities and the difficulties of remote identification, a comprehensive bat census is rarely possible, and we suggest that predictive modelling of the type described here provides an indispensable conservation tool.