The ecology, morphology, distribution and speciation of a new species and subspecies of the genus Egernia (Lacertilia: Scincidae)
Abstract
A new scincid species (Egernia saxatilis) from the Warrumbungle Mountains, New South Wales, and a new subspecies (Egernia saxatilis intermedia) from Kanangra Walls, New South Wales, are described. Morphological variations in these forms, and in the closely allied Egernia striolata (Peters), are tabulated. Egernia saxatilis saxatilis appears to be confined to the Warrumbungle Mountains, while Egernia saxatilis intermedia is distributed throughout various parts of the eastern highlands. Egernia striolata is found largely west of the Great Dividing Range. Although the latter occurs in many parts of Australia, the present study is restricted to specimens from south-eastern Australia. A micro distributional study within the Warrumbungle Mountains of Egernia saxatilis saxatilis and Egernia striolala has shown that the former is strictly saxatile in its habits, whereas the latter is equally strict in its preference for an arboreal habitat. It is suggested that these habitat preferences may have been important in maintaining isolation between these two forms in the final stages of speciation. Such morphological features as colour, size and scale rugosity are discussed in relation to the possible advantages which they confer on these two species within their selected habitats. The available evidence suggests that where Egernia saxatilis intermedia and Egernia striolata come into contact hybrid zones may occur.
