Goshawk Hunting Behaviour, and Range Size as a Function of Food and Habitat Availability

(1) Four released goshawks were radio-tracked for up to 29 days at a time in Oxfordshire. Their hunting flights were mostly at 3-4 min intervals, for an average of 200 m in open country. They remained in woodland for 50% of the time although only 12% of their ranges was wooded. This preference resulted not from hawks flying less frequently in woodland, but because they flew half the distance between perches and doubled back twice as often in woodland as in open country. (2) Most attacks were initiated from perches, and only 3% were at prey already in flight. Six percent of observed attacks were successful, but hawks were most successful when hunting out of sight. They killed, on average, once in every 262 minutes of hunting. Seventy percent of prey was taken in or from woodland, a higher proportion than expected from the time spent there. (3) There were no sex or age differences in the preference for woodland of twenty-two wild goshawks radio-tracked in Sweden. Woodland within 200 m of open country was the most preferred habitat, and the majority of kills were made there. Range size was related to the proportion of a range that was woodland edge, and to prey availability. It is suggested that hawks covered the amount of woodland edge which gave adequate kills at the prevailing prey density, range size then being the area which happened to include that amount of woodland edge.