Are landscape structures insurmountable barriers for foraging bees? A mark-recapture study with two solitary pollen specialist species

Les structures du paysage sont-elles d'insurmontables barrières pour les abeilles butineuses ? Une étude par la méthode de capture-recapture sur deux espèces solitaires oligolectiques

Antonia Zurbuchen , Christoph Bachofen , Andreas Müller , Silke Hein , Silvia Dorn

To investigate whether landscape structures act as insurmountable barriers for foraging bees, we conducted mark-recapture studies with two pollen-specialist solitary species. Foraging options of the bees were confined to host plant stands across different landscape structures. Differences in altitude of more than 130 m were overcome and forests covering a distance of up to 480 m were crossed by Chelostoma florisomne. A broad river and a motorway with intense traffic did not represent insurmountable barriers for Hoplitis adunca. For C. florisomne, total foraging distances of up to 650 m were measured, but foraging females were recorded predominantly on host plant patches available in relatively close vicinity to their nesting site. While landscape structures might impede foraging in endangered bees, the investigated landscape structures clearly did not act as insurmountable physical barriers for the two common solitary bee species tested in our study.

Mots clés: landscape barrier; fragmentation; foraging distance; Chelostoma florisomne; Hoplitis adunca<br>---<br>obstacles; paysage; distance d'approvisionnement; Hoplitis adunca

Domaines: Zoologie des invertébrés; Biodiversité; Ecologie, Environnement; Science des productions animales

Antonia Zurbuchen, Christoph Bachofen, Andreas Müller, Silke Hein, Silvia Dorn. Are landscape structures insurmountable barriers for foraging bees? A mark-recapture study with two solitary pollen specialist species. Apidologie, 2010, 41 (4), ⟨10.1051/apido/2009084⟩. ⟨hal-00892083⟩