Comparative census techniques and modelling of habitat utilization by reptiles in northern Victoria

As part of a larger study investigating the distribution and status of reptiles in northern Victoria, the effectiveness of three reptile census techniques was compared over 29 sites in remnant woodland and grassy woodland patches. These techniques revealed no significant differences in the number of species recorded, but differed markedly in estimates of abundance. Transect censusing and active searching techniques provided comparable density estimates overall, in contrast to estimates using spot censusing which were markedly greater. Skinks constituted most of the records for all three techniques, although active searching yielded the only species of gecko for the study. Reptile species showed distinct substrate preferences and vertical distribution. Cryptoblepharus carnabyi, for instance, revealed the greatest degree of arboreality of any of the study species, with specimens observed up to 6 m above ground-level. Statistical modelling indicated that certain microhabitat characteristics are potentially important determinants of reptile occurrence and abundance; for example, the abundance of Morethia boulengeri was found to be significantly related to stump density. The models presented here suggest a combination of transect censusing and active searching as the most suitable approach to reptile censusing in northern Victoria and provide a clear pointer to future analysis.