Nuthatches Sitta europaea do not delay postfledging dispersal in isolated forest fragments

We followed the fate of colour-ringed Nuthatch Sitta europaea fledglings in six territories within a large forest and eight territories within small (<15 ha) forest fragments. Almost half of the young birds had disappeared by day 8 after fledging, before any dispersal was expected to have occurred. This high level of mortality was probably mainly due to predation. After day 15 the rate of disappearance increased markedly due to dispersal, and all young had left the study areas by day 28. The pattern of disappearance was highly similar in both study areas, suggesting thar dispersal was not delayed in forest fragments, nor was the pattern of early fledgling mortality different from a large forest.