Microhabitat and thermal ecology of two sympatric species of lizard in Otago grassland
Spencer, Nicholas John
Spatial and temporal variation in the use of the thermal microhabitat by the skink, Leiolopisma maccanni, and the gecko, Hoplodactylus maculatus, was studied during March and April of 1990 and 1991. The field study site was at the southern end of the Strath Taieri Plain, Otago, New Zealand where the two species occurred sympatrically. In conjunction with this field study, lizard preferred environmental temperature and activity were investigated in a laboratory thermogradient using captured individuals of the two species. Both species were found to be sympatric in all study sites. Within these sites they were selective for non-random microhabitat use. Microhabitat was partitioned by the two species, with a small amount of overlap in the use of under rock areas. L. maccanni used a wide range of rnicrohabitats, experiencing varying physical characteristics and varying light conditions. H. maculatus were largely limited to under rock microhabitats and appeared restricted to microhabitats which provided thigmothermic requirements. Differences in air temperatures selected in experimental thermogradients and differences in field operative temperatures were evident. L. maccanni selected, and were active at, higher temperatures in the thermogradients and in the tield. H. maculatus were active at cooler temperatures in both the thermogradients and the field. H. maculatus activity was not constrained by the temporal availability of temperature whereas L. maccanni was. The environmental constraints of substrate, temperature and time controlled and limited the use of the microhabitat by L. maccanni and H. maculatus.
Degree Name: Master of Science
Degree Discipline: Department of Zoology
Publisher: University of Otago
Keywords: lizards; skinks; geckos; McCann's skink; Hoplodactylus maculatus; habitat; New Zealand; Otago
Research Type: Thesis