Conservation in Changing Rural Landscapes: Responses of Bird Communities to Diverse Land-uses and Habitats

Submission note: A thesis submitted in total fulfilment of the requirements for the degree of Doctor of Philosophy to the School of Life Sciences, College of Science, Health and Engineering, La Trobe University, Victoria, Australia.

Rural regions cover a significant proportion of Earth’s surface and are important for biodiversity conservation. They are shaped by human land-uses, including agricultural intensification and expanding human settlement. This study aimed to: i) determine how common land-uses influence the composition and richness of bird communities; ii) identify important properties of rural landscapes for bird guilds; iii) examine species traits associated with the persistence of forest birds; and iv) document how native bird species use a spectrum of modified site types. The study region, the western Strzelecki Ranges, in rural Victoria, south-east Australia, has experienced extensive deforestation (greater than 80 percent loss) and landscape change. I selected 25 study landscapes, each 1 km2 , representing common land-uses: grazing, dairying, horticulture, lifestyle properties, townships, tree plantations, natural forest. Birds were surveyed by point counts at 10 sites in each landscape. Avifaunal richness (from 31 to 53 species) and composition within landscapes varied greatly, reflecting structural gradients from forest to human-dominated habitats. Native bird occurrence was influenced by native vegetation extent, but large gardens and exotic woody cover provided additional habitat. Thirty-nine of 46 forest bird species occurred in Preface xi modified landscapes (less than10 percent average forest cover) but showed marked variation in distribution. Seven forest species were absent, typically native vegetation specialists and ground foragers. Forest species common in modified landscapes used diverse site types, foraged in tree canopy and were abundant in natural forest landscapes. Bird communities in rural regions are dynamic and responsive to land-use. All rural landuses can provide opportunities for enriching habitat for native birds but some (e.g. lifestyle properties) more so than others (e.g. townships). Native vegetation protection and restoration remain high priority for biodiversity conservation in rural regions, but modified habitats will play an increasingly important role. Further insights are required into seasonal movements and long-term population dynamics of birds in modified habitats, and of social factors that will improve uptake of conservation by rural land managers.