Within-Habitat Relationships Between Invading Bufo-Marinus and Australian Species of Frog During the Tropical Dry Season

Abstract

Four tropical Australian frog species do not alter their dry season patterns of habitat and/or food utilisation following invasion by introduced Bufo marinus. Breadths of utilisation of habitat and food resources by B. rnarinus are less than those of one or more native species. Levels of overlap of resource use between B. marinus and native frog species are not different from those occurring among the native species. Differences in body sizes of native species and B. marinus are not related to levels of resource overlap. The population sizes of individual species, species richness and equitabilities of native frog communities in the dry season are not influenced by the presence of B. marinus. B. rnarinus has no observable impact on recovery of native frog communities or populations following experimental perturbation. At the time of year when resources are likely to be most limiting (the dry season), B. marinus is a relatively 'narrow-niched' invader with no measurable competitive impact on a native frog community that may be in a state of disequilibrium.