Breeding Biology and Diet of the Square-tailed Kite on the Mid-north Coast of New South Wales

Abstract

The breeding cycle of a pair of Square-tailed Kites Lophoictinia isura was observed for 155 h over 113 days, from nest-building to post-fledging, from late July to early December 2003 at Port Macquarie, northern coastal New South Wales. Both sexes shared incubation and also brought food to the incubating mate; the male incubated on at least one night. Incubation lasted an estimated 40 days, and the nestling period 52 days although fledging may have been slightly premature. Parental behaviour during each phase of the cycle, and growth of the nestling, are described. Parental food-delivery rates to the nest increased from 0.1 item/h in the pre-laying phase to 0.3 item/h during incubation and 0.4 item/h in the nestling phase, then dropped to 0.2 item/h in the post-fledging period. By number (n = 66), the breeding diet consisted of 76% birds (84% of which were nestlings), 2% lizard, and 23% unidentified though probably nestlings. Inclusion of data from four other pairs monitored in the district, 1997-2002, gave a nesting density of about 13 km between neighbouring pairs or approximately one pair per 170 km', and a fledging rate of 0.7 young per attempt.