The use of visual cues for spatial orientation in the sleepy lizard (Tiliqua rugosa)

• Published in: Canadian journal of zoology Vol. 78; no. 4; pp. 515 - 520
• Main Authors: Zuri, I, Bull, C M
• Format: Journal Article
• Language: English
• Published: Ottawa, Canada NRC Research Press 02.04.2000
• ISSN: 0008-4301; 1480-3283
• DOI: 10.1139/z99-243

The sleepy lizard (Tiliqua rugosa) is a large, long-lived terrestrial Australian skink. In the present study we investigated the ability of sleepy lizards to use different visual cues for spatial orientation. The lizards were trained to locate shelters in certain places and then trained to certain signals associated with their shelters. In the absence of surrounding visual cues the lizards preferred familiar sites that were previously associated with their shelters. However, when presented with signals that had been associated with their shelters, they chose the vicinity of these familiar signals, even after their displacement to new sites. The lizards discriminated between black and white signals and between triangular and circular signals but not between red and green signals. Previous studies had shown that sleepy lizards exhibit home-range fidelity, raising the question of which environmental cues are important for them for spatial orientation within their home ranges. We suggest that the ability of sleepy lizards to discriminate between visual signals of different shapes and degrees of brightness enables them to "memorize" certain fixed landmarks in their large home ranges and to orient accordingly.