Fidelity of corncrakes (Crex crex) to a singing position during one breeding season

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.