Roadside habitat connectivity for declining woodland birds in Australian farmland: A case study from the New South Wales South Western Slopes

Abstract

The decline of birds in farmland is a conservation and land-management issue of global concern. Linear woodland corridors along roadsides in Australian farmland can play an important network role, maintaining ecological connectivity at the landscape scale and thereby supporting the survival of disturbance-sensitive woodland species. This paper presents a case study investigating the connectivity value of Old Narrandera Road, an old (pre-1870) roadside woodland corridor linking three larger woodland remnants near Wagga Wagga, in southern inland New South Wales, Australia. A survey of 120 plots along this corridor during 2018–2019 identified 81 bird species including 25 declining woodland birds of known conservation concern. Presence of the hyper-aggressive Noisy Miner Manorina melanocephala in survey plots was negatively correlated with total species richness and declining woodland bird assemblage richness and several species (predominantly small to medium-sized declining woodland birds rather than common farmland birds) exhibited a degree of spatial separation with Noisy Miners. One decliner, Grey-crowned Babbler Pomatostomus temporalis, showed a significant positive association with Noisy Miner, potentially reflecting a greater tolerance to harassment by Miners. Although the Noisy Miner is probably limiting realisation of the connectivity value of this woodland corridor at present, corridors as substantial and significant as Old Narrandera Road are scarce in the local landscape, and the woodland complex of three interconnected remnants it brings together is likely to be important for the local conservation of many declining woodland bird species.