Breeding biology of the speckled warbler, Chthonicola sagittata

Abstract

I studied the breeding biology of the speckled warbler in a large (>1000 ha) remnant of eucalypt woodland in the Australian Capital Territory, monitoring 160 nesting attempts over three breeding seasons. In many aspects of breeding the species is a typical member of the Acanthizinae. It laid a small clutch (usually 3 eggs) with a laying interval of two days, and had long incubation and nestling periods, 17-20 days and 15-19 days respectively. There was biparental care of the altricial young and fledglings were dependent for a long period; fledglings were fed for about 5 weeks and all dispersed about 7 weeks after leaving the nest. Females were multi-brooded, fledging up to 3 broods in a season from a maximum of 6 clutches, but despite this had a low reproductive rate over a long breeding season. Low reproductive success, about 1.0 fledgling per female per season, resulted mainly from nest failure due to predation; all nests were built directly on the ground and were thereby exposed to a wide range of predators and other forms of mishap. The implications of this invariable nesting strategy are discussed for populations nesting in fragmented landscapes in small remnants of habitat.