Rapid solving of a problem apparatus by juvenile black-throated monitor lizards (Varanus albigularis albigularis)

Abstract

It is widely accepted that providing stimulus enrichment is an important part of the development and maintenance of behavior and well-being in mammals. However, extending this idea to non-avian reptiles has barely been explored, certainly as an aid to cognitive development. Monitor lizards have a reputation for being highly curious and intelligent lizards, but quantitative experiments are necessary to evaluate such impressions as well as the value of providing enrichment to captive squamate reptiles. In this study eight juvenile black-throated monitors, Varanus albigularis, were tested in their home enclosures with three presentations, at weekly intervals, of a novel task apparatus: a transparent food tube containing several prey. The food tube allowed the monitors to obtain prey by using hinged doors at either end of the tube to access food. All eight lizards learned to open the tube, insert head, and capture the prey within 10 min in the first trial. By the second trial, both mean latencies to access the tube and capture the first prey item decreased significantly, as did the use of ineffective responses such as shaking the tube. A further slight decrease occurred in the third trial. Due to the results of this and similar studies, serious consideration should be given to further testing of cognitive abilities in squamate reptiles. Incorporating problem solving tasks may also be useful to increase the activity level and captive well-being of squamate reptiles, especially monitor lizards.