Nesting, foraging and aggression of noisy miners relative to road edges in an extensive Queensland forest

Abstract

Increased abundance of noisy miners (Manorina melanocephala), a large, aggressive honeyeater, is one of the most important mechanisms through which habitat fragmentation and degradation threaten populations of eastern Australian woodland birds. In inland Queensland, however, noisy miners dominate avian assemblages throughout extensive forest areas as well as fragmented landscapes, and our understanding of the factors influencing their behaviour and habitat selection in such relatively intact landscapes is limited. I investigated how road edges influenced noisy miners by comparing the species’ aggressive and foraging behaviour, and location of nests, between road-edge and interior transects in a southern Queensland forest. I also investigated noisy miner foraging microhabitat preferences and targets of aggression. Noisy Miner nests were more likely to be located near to road edges, but foraging and aggressive interactions occurred with similar frequency near and far from road edges. Such interactions selectively targeted close competitors and a nest predator. Most foraging activity was in the canopy, and selectively within ironbarks (Eucalyptus spp.), suggesting that higher densities of noisy miners in more open areas of the forest are unlikely to be related to facilitation of ground-foraging activity. Despite some evidence of a preference for nesting near road openings, road edges do not appear to influence noisy miners as strongly as edges between forest and agricultural land do elsewhere in eastern Australia.