Comparisons between nesting densities of Tawny Frogmouths (Podargus strigoides) in open- and closed-canopy woodlands

Abstract

The Tawny Frogmouth (Podargus strigoides) is a common and familiar bird, yet there is little known of their densities in different woodland habitats. Nests of Tawny Frogmouths were surveyed in partly cleared open grassy woodland, open-canopy grassy woodland and closed-canopy dry sclerophyll forest in 2006–08. Thirty-nine nesting attempts were recorded. In 2008, when all sites were thoroughly searched, more nests were found in the open-canopy grassy woodland (0.02 nests ha-1) than in closed-canopy dry sclerophyll forest (0.006). The highest recorded density was 0.05 nests ha-1 in the partly cleared woodland in 2006. Nests were evenly spaced but at different densities in the different habitat types, with the mean nearest-neighbour distance shorter in the open-canopy grassy woodland (594 m) than in the closed-canopy dry sclerophyll forest (1322m). Overall, Tawny Frogmouths nested at highest densities in partly cleared grassy woodland, which grows on moderately rich loamy soils, at intermediate densities in open grassy woodland, which grows on similar soils, and at lowest densities in closed-canopy dry sclerophyll forest, which grows on shallow infertile soils. These findings provide a baseline against which results of future surveys of Tawny Frogmouths can be compared and so assist in monitoring the status of the species in relation to changes in the environment.