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Université de Fribourg

Ineffective crypsis in a crab spider: a prey community perspective

Brechbühl, Rolf ; Casas, Jérôme ; Bacher, Sven

In: Proceedings of the Royal Society B: Biological Sciences, 2009///doi: 10.1098/rspb.2009.1632

Cryptic coloration is assumed to be beneficial to predators because of an increased encounter rate with unwary prey. This hypothesis is, however, very rarely, if ever, studied in the field. The aim of this study was to quantify the encounter rate and capture success of an ambush predator, in the field, as a function of its level of colour-matching with the background. We used the crab spider...

Université de Fribourg

Impact of flower-dwelling crab spiders on plant-pollinator mutualisms

Brechbühl, Rolf ; Kropf, Christian ; Bacher, Sven

In: Basic and Applied Ecology, 2009///10.1016/j.baae.2009.07.001

Indirect effects in interactions occur when a species influences a third species by modifying the behaviour of a second one. It has been suggested that indirect effects of crab spiders (Thomisidae) on pollinator behaviour can cascade down the food web and negatively affect plant fitness. However, it is poorly understood how different pollinator groups react to crab spiders and, thus, when a...

Université de Fribourg

Body size–climate relationships of European spiders

Entling, Wiebke ; Schmidt-Entling, Martin H. ; Bacher, Sven ; Brandl, Roland ; Nentwig, Wolfgang

In: Journal of Biogeography, 2009///doi: 10.1111/j.1365-2699.2009.02216.x

Aim: Geographic body size patterns of mammals and birds can be partly understood under the framework of Bergmann's rule. Climatic influences on body size of invertebrates, however, appear highly variable and lack a comparable, generally applicable theoretical framework. We derived predictions for body size–climate relationships for spiders from the literature and tested them using three...

Université de Fribourg

Determinants of local ant (Hymenoptera: Formicidae) species richness and activity density across Europe

Kumschick, Sabrina ; Schmidt-Entling, Martin H. ; Bacher, Sven ; Hickler, Thomas ; Espadaler, Xavier ; Nentwig, Wolfgang

In: Ecological Entomology, 2009, vol. 34, no. 6, p. 748 - 754

1. Species richness is influenced by local habitat features and large-scale climatic gradients. Usually, both influences are studied in isolation because of the divergent spatial scales at which they occur. Here, we compared the influence of large-scale climate and local habitat type on European ants using a continent-wide, standardised sampling programme.2. We investigated species richness and...

Université de Fribourg

Alien species in a warmer world: risks and opportunities

Walther, Gian-Reto ; Roques, Alain ; Hulme, Philip E. ; Sykes, Martin T. ; Pyšek, Petr ; Kühn, Ingolf ; Zobel, Martin ; Bacher, Sven ; Botta-Dukát, Zoltán ; Bugmann, Harald ; Czúcz, Bálint ; Dauber, Jens ; Hickler, Thomas ; Jarošík, Vojtěch ; Kenis, Marc ; Klotz, Stefan ; Minchin, Dan ; Moora, Mari ; Nentwig, Wolfgang ; Ott, Jürgen ; Panov, Vadim E. ; Reineking, Björn ; Robinet, Christelle ; Semenchenko, Vitaliy ; Solarz, Wojciech ; Thuiller, Wilfried ; Vilà, Montserrat ; Vohland, Katrin ; Settele, Josef

In: Trends in Ecology & Evolution, 2009, vol. 24, no. 12, p. 686-693

Climate change and biological invasions are key processes affecting global biodiversity, yet their effects have usually been considered separately. Here, we emphasise that global warming has enabled alien species to expand into regions in which they previously could not survive and reproduce. Based on a review of climate-mediated biological invasions of plants, invertebrates, fishes and birds, we...