In the mallee woodlands of south-eastern Australia two closely related bird species, Red-lored Whistler and Gilbert's Whistler have overlapping ranges, and in some areas they co-exist. These two species are morphologically and ecologically similar; however, despite the similarities, the Red-lored Whistler has undergone greater declines in distribution and abundance than the Gilbert's Whistler. The ecology of these two species was for long poorly known, rendering adequate management impracticable. A sound knowledge of the ecology of the two species is needed to underpin appropriate actions for their management and conservation. This book provides new and valuable information on the key habitat requirements for the two species, their habitat use, and documents the ecology and behaviour of the two species, particularly their foraging, and intra- and interspecific interactions. This study should be especially useful for people working in the field of biodiversity conservation, or anyone else with a particular interest in ecology and behaviour or, generally, in the natural world.