Why are migrant Robins (Erithacus rubecula) territorial in winter?: the importance of the anti-predatory behaviour

摘要: The functional explanation of nonbreeding territories in birds was analyzed a migratory population Robins (Erithacus rubecula) over-wintering southern Spain. behaviour ringed territorial compared with that classified as floaters, or not, during the winter 19921993 to test two non-exclusive hypotheses. First, good feeding patch hypothesis, are most profitable areas, is not supported because body condition (fat score, mass and index) rates did differ between owners floaters. Second, antipredation select protected areas cover reduce mortality, does account for maintenance since spent higher percentage time hidden were able forage lessexposed (i.e. closer shelter) than Consequently, territory should be interpreted long-term defense rewarding foraging patch. Instead, refuge shelter seem important properties territories. Thus, by attacking intruders, defending safe area close shelter. anti-predation benefits familiar well roosting place) would explain per se intense competition conspecifics other ecologically similar species wintering Mediterranean.