The foods and feeding rates of Montagu's HarriersCircus pygargusbreeding in arable farmland

Abstract

Foods brought to the nest by Montagu's Harriers breeding within an area of intensive arable farmland in England are described. About 50% of prey identified from pellets and prey remains was small birds (< 50 g), which, together with gamechicks and small mammals, made up 70–90% of the diet. At one nest, twothirds of small bird prey were juveniles or nestlings. Live prey weight varied between 6-300 g, with an estimated mean of 36–51 g, about 14–18 and 10–13% of male and female harrier weights, respectively. A male harrier ate (or discarded) about 10% of the prey before delivery, about 9% of his own body weight. The frequency of prey deliveries varied after hatching within and between males, and was linked to brood size. There was no uniform pattern to daily delivery times.