Predation of artificial nests in a fragmented landscape on the New England tablelands of New South Wales

Artificial, cup-shaped nests containing one quail egg and one plasticine egg were placed in small (20 ha), medium-sized (90 ha) and large (350 ha) remnants of eucalypt woodland. Nests were placed near edges and centres of the two larger sites; the small site was considered all edge. Overall, 69% (659/960) of nests were preyed upon within 4 days, reflecting a high predation pressure. More nests were preyed upon in the medium-sized than in the larger or smaller sites. Loss of nests was no higher at the edge than in the centre overall, though it was significantly higher at the edge than the centre of the largest site. The main predators were identified (from beak marks on plasticine eggs) as large and medium-sized birds. Our results provide only weak support for the hypothesis that habitat fragmentation has increased predation on open nests. It is possible that nest predators and their impact have increased regionally, rather than locally. Habitat degradation may also lead to higher predation of nests, due to loss of understorey and an increase in nest predators.