Michael Bull, Mark Hutchinson and Aaron Fenner
Elijah J. Staugas, Aaron L. Fenner, Mehregan Ebrahimi and C. Michael Bull
Natural refuges are sometimes supplemented with artificial refuges to enhance populations of endangered species, or to improve the success of translocation and relocation programs. The design and structure of these artificial structures should incorporate key features of natural refuges. We aimed to improve the design of artificial burrows currently used in the conservation of the pygmy bluetongue lizard, Tiliqua adelaidensis, by comparing burrows with or without a basal chamber. We found that lizards chose burrows with chambers significantly more often, but that neither the size of the chamber, nor the substrate lining the chamber influenced the choice. Incorporating a basal chamber into the design of artificial burrows should provide more favourable artificial refuges for these lizards and should be incorporated into future conservation management programs.
Mehregan Ebrahimi, Stephanie S. Godfrey, Aaron L. Fenner and C. Michael Bull
We used video recordings of 29 pygmy bluetongue lizards for ten days of each month during their spring and summer activity season to observe scatting behaviour. This was possible because resident lizards rarely moved from their single entrance burrows. We used these observations to ask questions about social communication that might be relevant to conservation of this endangered species. We found lizards produced more scats in the middle of the day than earlier or later in the day, and more scats in the spring and early summer than later in the summer. Lizards moved an average of 68.54 ± 0.09 cm from their burrow entrance to deposit scats, taking an average of 2.4 min per defecation trip. They tended to use the same path direction for most defecation trips, but used more different directions if there were more close neighbours, strongly supporting a hypothesis that scats mark burrow ownership. The results suggested that conservation managers might reduce stress for relocated lizards by removing scat piles in the early stages of settlement.
C. Michael Bull, Stephanie S. Godfrey, Mehregan Ebrahimi and Aaron L. Fenner
The pygmy bluetongue lizard (Tiliqua adelaidensis) is an endangered species which is restricted to native grassland remnants in South Australia. Individuals live in vertical burrows with a single entrance from which they ambush invertebrate prey. We monitored marked burrows over two entire spring-summer seasons, the period when the lizards are active, and found that the population contained a mixture of dispersers that remained in a burrow briefly, and residents that occupy a burrow for the entire study period. There were more females than males among the residents and most of the burrow abandonment happened in the early spring, the time when male lizards probably move around to seek matings. Our study described burrow occupancy dynamics, and will assist the conservation management of this endangered species.