Description:    To gain insight into the drivers of pollinator loss, a holistic approach to land-use change including habitat size, isolation, habitat quality and the surrounding landscape matrix is necessary. Moreover, species’ responses to land-use change may differ depending on their life history traits such as dispersal ability, trophic level, or sociality. We assessed species richness and life history traits of wild bees in 32 calcareous grasslands in central Germany that differ in size, connectivity, resource availability and landscape context. Declining habitat area and, to a lesser degree, reduced diversity of the surrounding landscape were the key factors negatively influencing species richness. In the community-wide analysis, small body size and solitary reproduction were traits that made species particularly vulnerable to habitat loss. Contrary to our expectations, cleptoparasitic species were not more affected by reduced habitat area and landscape diversity than nest-building species. We performed further detailed trait analyses within the family Halictidae to prevent possible confounding effects due to trait correlations across families. Here, social as opposed to solitary species were more affected by habitat loss. We conclude that the opposite pattern observed for all social bees was mainly caused by large-sized social bumblebee species with high mobility and large foraging distances. Our results demonstrate the risks of concealed trait interference when analyzing community-wide patterns of life history traits. As a consequence, conservation requirements of small social bee species might be overlooked by generalizations from community responses. Content Type Journal Article Category Research Article Pages 1-14 DOI 10.1007/s10980-012-9820-6 Authors Birgit Jauker, Agroecology, Georg August University Göttingen, Grisebachstr. 6, 37077 Göttingen, Germany Jochen Krauss, Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany Frank Jauker, Department of Animal Ecology, Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany Ingolf Steffan-Dewenter, Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany Journal Landscape Ecology Online ISSN 1572-9761 Print ISSN 0921-2973