Breeding biology and nesting success of the Eastern Yellow Robin and the New Holland Honeyeater in a southern Victorian woodland

Abstract

This study examines the nesting success and the role of nest predation in the breeding biology of birds in a woodland remnant of southern Victoria. In total, 225 nests of 21 species were found within the study area during the 1999–2000 breeding season, including 90 nests of the Eastern Yellow Robin (Eopsaltria australis), and 52 nests of the New Holland Honeyeater (Phylidonyris novaehollandiae). Overall, only 39% of nests were successful, and 48% of nests were preyed upon. For nests of the Eastern Yellow Robin and the New Holland Honeyeater, the predation rate was 50% and 42%, respectively. The mean clutch size was 2.3 (±0.06, s.e.) for the Eastern Yellow Robin and 2.1 (±0.05, s.e.) for the New Holland Honeyeater. Eastern Yellow Robin clutches of three eggs were initiated significantly later in the season than clutches of two eggs. The clutch initiation dates of successful New Holland Honeyeater nests were significantly earlier than New Holland Honeyeater nests that were preyed upon, but this was not the case for the Eastern Yellow Robin. Nests of the Eastern Yellow Robin with two eggs were no more successful than nests with three eggs. The incubation and nestling periods of the Eastern Yellow Robin were 15.9 (±0.1, s.e.) and 12.9 (±0.2, s.e.) days, respectively, and for the New Holland Honeyeater were 13.6 (±0.2, s.e.) and 12.2 (±0.3, s.e.) days, respectively. There was no significant difference in the nestling periods of Eastern Yellow Robin nests with a clutch size of two and three.