Sex-specific seasonal variation in home range size in a sedentary avian predator

Spatial ecology of species is determined by the interplay of various social and demographic factors. Variation in utilisation of space may also reduce the conflict between individuals competing for the same resources. We simultaneously evaluated the effects of sex, territoriality and reproductive performance on the space use of the Eurasian goshawk, Accipiter gentilis, by analysing the home range sizes of 25 individuals across various stages of the annual cycle for up to 7 years. The mean annual home range (90% autocorrelated kernel density estimate) of territorial goshawks was slightly smaller than that of non-territorial hawks, and the ranges of successful birds tended to be smaller than those of non-successful territorial goshawks. The median home range of territorial females (295 km²) was five times larger than that of males (58 km²). While the home ranges of males overlapped by 89-100% with those of females, only 7-14% of females' ranges were utilised by their male counterparts. The home ranges of territorial females gradually increased after the incubation stage, and their fidelity to nest sites weakened. Males maintained their association with their nest sites throughout the year. These sex-specific differences may be attributed to distinct strategies, with males acting as territory holders and females exploring potential mates and nest sites, or to the reduction of competition between partners. The findings underscore the significance of long-term tracking across annual cycles in determining annual home ranges and show how complex space use patterns are in sedentary dietary specialists under seasonally varying food resources and intra- and extrapair competition.