Veerafwijkingen bij nestjonge roofvogels

In recent years, we noticed a slight upsurge in the number of nestlings showing “pinching off”, a feather abnormality in which the nestling develops malformed remiges and/or rectrices that are easily lost already on the nest. Such nestlings are unable to take flight and often jump from the nest to perish on the ground. Malformed feathers are often symmetrically positioned in wing and/or tail, leaving substantial gaps that prohibit taking flight. The rachis is of poor quality, easily bendable or broken, sometimes split lengthwise. The calamus is very short and malformed. Barbules are often missing in (part of) the barbs, resulting in hair-like feathers lacking internal structure. In The Netherlands, this phenomenon has been recorded in Northern Goshawk Accipiter gentilis (at least 5 individuals), Common Buzzard Buteo buteo (2) and European Honey-buzzard Pernis apivorus (1), in Germany also in White-tailed Eagles Haliaeetus albicilla.