Honours Research
During my third year at uni I became interested in reptiles, and the dormancy periods they undergo in winter; even pet ones that have a stable thermal environment. These observations lead me to investigate the wintering thermal biology of sub-tropical ectotherms, using the Eastern Water Dragon (Physignathus lesueurii) as my study species. I investigated whether P. lesueurii underwent periods of dormancy during the cooler winter months and whether any periods of dormancy were due to the thermal constraints of the environment or facultative changes in behaviour.
 |
| Skye marking an Eastern Water Dragon, Physignathus lesueurii for ID |
We found that in a sub-tropical environment these lizards have a choice in whether to go dormant. Specifically, dormancy periods were not due to body condition or size, but females went dormant generally twice as long as males, and dominant males remained active or had very short dormancy periods throughout winter. Interestingly I also found arousal periods (spikes in body temperature for the period of one day) in lizards that were dormant. These arousals were not linked to any environmental factor, leading us to question why these lizards have random periods of arousal during dormancy.
|