Home ranges of, and habitat use by, the grassland earless dragon (Tympanocryptis pinguicolla) in remnant native grasslands near Canberra

The grassland earless dragon (Tympanocryptis pinguicolla) is a habitat specialist restricted to the highly fragmented native temperate grasslands of the Australian Capital Territory (ACT) and nearby New South Wales (NSW). These grasslands, which are listed as an endangered ecological community, continue to be affected by a range of processes including development and overgrazing. Although changes to its habitat present a significant threat to the grassland earless dragon, little is known about its spatial and habitat requirements. We used radio-tracking to study the home-range areas and habitat requirements of 10 adult lizards in native grassland adjacent to Canberra, ACT. We found that burrows excavated by arthropods are an important resource for grassland earless dragons, with individuals having one or two home burrows around which they maintained home ranges of between 925 m(2) and 4768 m(2). Fidelity to these burrows increased with the onset of winter, indicating their importance as over-winter refuge sites. Within the native grasslands, grassland earless dragons were found to use a broad range of grassland structure as habitat. This result contrasts with the prevailing view that these dragons are confined to well drained, minimally disturbed areas, which include large patches of short grass dominated by Austrodanthonia. We conclude that habitat management (i.e. grazing, mowing, burning) for this species should aim to retain structural heterogeneity of native grasslands rather than impose a uniform structure.