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The 71 reptile species occurring in the Perth region make this area as diverse as any similar sized coastal region in Australia. Cluster analysis of the lizard assemblages of 17 bushland remnants in the region indicate that three main sub-regions can be identified; Darling Plateau and Scarp, Offshore Islands and Swan Coastal Plain. Within the Swan Coastal Plain the lizard and skink faunas of remnant bushlands on the same landform are more similar to one another than they are to those of adjacent landforms. The Swan River appears to be a distributional boundary for some species. Species-area relationships indicate a variety of responses amongst the different taxonomic groups of reptiles, with snakes being the most sensitive to loss of habitat. The isolated remnant bushlands of inner urban areas retain a variety of reptile species, but there is no significant relationship with remnant size. The implications of zoogeographic and area relationships to conservation are discussed.
Key words: Zoogeography, Reptiles, Bushland remnants, Urban, Diversity, Landforms, Conservation.
INTRODUCTION
EVALUATIONS of relictual fauna have been widely reported in the last decade (Soulé and Wilcox 1980; Simberloff 1988; Saunders et al. 1987, 1991). Rapid alteration of environments has been shown to occur in areas of urban development (Goode 1989) and several studies have specifically studied the role of urban remnants in the persistance of native fauna (Dickman and Doncaster 1987; Soulé et al. 1988; Yalden 1980).
With nearly 80 per cent of the population of Australia focussed in coastal areas, there is a growing awareness of the role that remnants of native ecosystems in urban environments can play in the continued survival of coastal native biota. Earlier studies of the vertebrates in areas surrounding Perth showed that major changes had occurred in both species number and composition since European settlement of Western Australia in 1829 (Kitchener et al. 1978; Storr et al. 1978; Storr and Johnstone 1988).
On the Swan Coastal Plain, on which Perth is sited, 21 of the 33 native mammal species have become locally extinct since European settlement (Kitchener et al. 1978). Many species of mammal had, however, begun to disappear well before the landscape had been substantially altered by Europeans. There have been six local extinctions of birds and 83 (47%) of the 176 species...