Are Belgian Kestrels Falco tinnunculus migratory: An analysis of ringing recoveries

Abstract

In this paper we describe the movements of Belgian European Kestrels and try to distinguish between dispersal and migration, based on 1,199 recovery records from birds ringed in Belgium and Luxemburg. Young Kestrels show rapid initial dispersal in all directions (often over more than 500 km). In winter as well as during later breeding seasons less than one third of the nestlings was recovered close to their place of birth. Once settled adult birds seemed to be much more sedentary. Recovery directions did not show any obvious concentration in southwesterly direction, even at distances over 250 km. A higher average dispersal distance during the first summer compared to the breeding season, as well as a decreasing proportion of long distance recoveries towards the breeding season could be explained by some degree of migratory return movements. However, similar effects could be expected if, as suggested by the data, survival might be negatively correlated with recovery distance. The analyses showed that in most movements probably no return behaviour is involved, but that, in addition to the wide-ranging dispersal, probably a low proportion of the Belgian Kestrel population is migratory. © 1997 British Trust for Ornithology.