Breeding Biology of the Common Blackbird Turdus merula in Australia

Abstract

RAOU Nest Records of Common Blackbirds Turdus merula, from 1963-64 to 1986-87, were analysed (n = 1284). The results showed that Common Blackbirds breed predominantly in urban habitats selecting low, exotic shrubs as nest sites, but neither habitat nor nest environs affected size of clutch, brood or number of fledglings. Breeding season was August to February; median clutch size was 4.0 (mean 3.5). For successful nests median brood size was 3.0 (mean 3.1), and median number of fledglings 3.0 (mean 2.75). Nest failure (58.6% ) was more common than success, and predation (33.1%) the most common cause of failure. Success in urban habitats was 44.9% and in woodlands/forests 33.6%. Predation was more common (47%) in woodlands/forests than urban habitats (27.6%). Results of these analyses were compared with data from New Zealand and Europe.