Spatial segregation of home ranges between neighbouring colonies in a diurnal raptor

Enhancement of information transfer has been proposed as a key driver of the evolution of coloniality.Transfer of information on location of food resources implies that individuals from the same colonyshare foraging areas and that each colony can be associated to a speciic foraging area. In colonialbreeding vertebrates, colony-speciic foraging areas are often spatially segregated, mitigatingintercolony intraspeciic competition. By means of simultaneous GPS tracking of lesser kestrels (Falconaumanni) from neighbouring colonies, we showed a clear segregation of space use between individualsfrom diferent colonies. Foraging birds from diferent neighbouring colonies had home ranges that weresigniicantly more segregated in space than expected by chance. This was the case both between largeand between small neighbouring colonies. To our knowledge, the lesser kestrel is the only terrestrialspecies where evidence of spatial segregation of home ranges between conspeciics from neighbouringcolonies has been demonstrated. The observed spatial segregation pattern is consistent with theoccurrence of public information transfer about foraging areas and with the avoidance of overexploitedareas located between neighbouring colonies. Our indings support the idea that spatial segregation ofexploited areas may be widespread among colonial avian taxa, irrespective of colony size.