Bumblebees experience landscapes at different spatial scales: possible implications for coexistence Westphal, Catrin ; Steffan-Dewenter, Ingolf ; Tscharntke, Teja Abstract Publication: Oecologia Pub Date: August 2006 DOI: 10.1007/s00442-006-0448-6 Bibcode: 2006Oecol.149..289W