Kestrels of the same colony do not overwinter together

Abstract

Coloniality is one of the most common strategies in birds. While the lesser kestrel (Falco naumanni) is a colonial raptor during the breeding period, it is not known whether individuals from the same breeding colony aggregate during the non-breeding period too. We GPS-tracked 40 adult lesser kestrels from different Spanish breeding colonies to study the degree of spatial aggregation between individuals from the same breeding colony in their West African non-breeding range. Lesser kestrels in our study used a large area from a wide longitudinal strip in the western Sahel: individuals used 143,697 plus/minus 98,048 km2 on average during the entire non-breeding period (95% KDE), and 1,359 plus/minus 1,424 km2 per week. On the other hand, the individuals traveled 6205 plus/minus 2407 km on average during the entire non-breeding period, and 41.1 plus/minus 11.8 km per day. There were no differences between the sexes in any of those variables. Individuals from the same breeding colony were not aggregated during the non-breeding period because the overlap between their areas (38.8 plus/minus 21.4 %) was not higher than that randomly expected. In conclusion, our study reveals some aspects of the non-breeding spatial ecology of the lesser kestrel, allowing a better understanding of the relationship of colonial birds out of the breeding season.

Itinerant lifestyle and congregation of lesser kestrels in West Africa

“…the Mediterranean Sea and Sahara Desert) in a broad front (Lopez‐Ricaurte et al 2021). Although there is a large‐scale connectivity between their breeding and non‐breeding areas (Sarà et al 2019); however, kestrels breeding in the same colony may disperse across distinct non‐breeding areas in West Africa (García‐Macía et al 2023). Furthermore, lesser kestrels are known to aggregate at super roosts situated in wetlands (e.g.…”