Activity Patterns and Movements of Free-Ranging Bluetongue Lizards (Tiliqua scincoides intermediaandTiliqua multifasciata) in the Australian Wet-Dry Tropics

Abstract

Abstract We used GPS-based radiotelemetry to quantify diel activity patterns and movements by two species of large scincid lizards in the Australian wet-dry tropics. From an average of 63 days tracking of 54 Northern Bluetongues (Tiliqua scincoides intermedia) and 42 days tracking of 8 Centralian Bluetongues (Tiliqua multifasciata), we obtained 53,801 and 8,139 data points, respectively, on lizard locations over a 13-month period. Lizard species, sex, and study site had relatively little effect on distances moved, at both daily and hourly levels. However, Northern Bluetongues moved further per day than did Centralian Bluetongues at a site where they were sympatric. Most movements were <20 m, with longer movements (dispersal between core areas within the wider home range) occurring primarily during midmorning and late afternoon. The only major effect of ambient temperatures on lizard activity patterns likely was that midday movements were precluded by the risk of overheating; at all other times of the day ...