The status and distribution of the Peregrine Falcon in Victoria, Australia

Abstract

Between 1974 and 1979 two hundred and seventeen historical, active or probable nesting sites of Peregrine Falcons were documented in Victoria. A conservative estimate of the total population is 300 to 350 breeding pairs. Nests on cliffs predominate with stick nests in trees and nests in hollows in trees in about equal proportions. The tree nests usually oc- curred where cliffs were not present but may also occur with cliffs nearby. Some regions such as the Little Desert and Alpine area are poorly studied and may contain more eyries than at present known. The density of Peregrines in Vic- toria may be about one pair per 650 to 750 square kilometres based on known values for various parts of the State. Thus, Victoria may have a density similar to those of continental Europe before the late 1940s. Availability of food may be the overriding limiting factor but local lack of nest sites or suitable area on existing sites (cliffs) may also restrict breeding. Also locally abundant and easily caught food, mainly columbiformes and psittaciformes, may be the prime factor allowing nesting in some seemingly otherwise unsuitable locations. In Victoria there is probably no competition for nesting on cliffs with other raptors but other tree-nesting congeners may compete for trees. Local traditions in nest site selection may also affect the population but this has yet to be tested. Factors in selecting nest sites should be studied further. The Peregrine generally seems to be holding its own in Victoria in the face of human encroachment.