Factors Influencing the Breeding Distribution of the Peregrine Falcon in Victoria, Australia

Abstract

Since 1950, 199 nesting sites of peregrine falcons (Falco peregrinus) have been found in Victoria. Over half (51%) are on natural cliffs, 37% in trees and 12% on human-made structures and stone quarry faces. Most eyries on natural cliffs occur in the uplands (>200 m elevation) or along the coast. Tree eyries are located in hollows and in stick nests of other birds; most of these are within the distributions of red gums and belahs. Human-made structures (other than quarries) supporting nests include dam walls, silos, electricity pylons and buildings. Factors believed to influence the breeding distribution of peregrine falcons in Victoria are discussed; these include volcanic activity, landform and elevation, water, vegetation, climate, other birds and humans. The influence of human activities on the distribution of nesting peregrine falcons appears to have been positive. However, the future of the population of peregrine falcons nesting in tree hollows is of concern: it is likely that large trees with nest hollows will be destroyed or will fall from decay long before sufficient numbers of replacement trees are available.