In the avian world, site fidelity may be considered as the tendency of individuals
to remain in the same area during breeding season. The Corncrake (Crex crex) is a
polygynous species, with some males moving considerable distances to new singing
areas. The aim of this study was to quantify site fidelity of male Corncrakes during
one breeding season. We used telemetry in two monitoring areas to track bird movements
and estimate their home ranges. In Slovenia, a high dynamic situation among
males was shown, with replacement of individuals in some singing areas. Meanwhile in
Italy, a high site fidelity during daylight was shown. Monitoring of Corncrakes relies on
counting singing males during breeding season; however, this work provides evidence
that males can change their position, possibly leading to an underestimate of singing
males. Our results highlight an important problematic in monitoring a polygynous bird.
