Occupancy and Success of Nesting Territories in the European Sparrowhawk
Abstract
Of 150 nesting territories occupied by European Sparrowhawks at least once in a five-year period, 82-110 were occupied in individual years. Certain territories were occupied more often, and others less often, than expected on a chance basis at the population levels found (P < 0.001). The most popular territories were those in which nesting attempts were most often successful (P < 0.001 ).
On particular territories, about 75 percent of all males and more than 50 percent of all females were replaced between one year and the next. This high turnover was due partly to movement, for at least 30 percent of all marked birds changed territories between years. Most individuals had different mates for each breeding attempt. Changes of females on territories occurred more often after unsuccessful breeding attempts than after successful ones (P = 0.0025), but changes of males occurred at the same high rate regardless of success or failure.
