A Technique For estimating the Size of Lizard Populations

We describe a mark—resight procedure for estimating population size which integrates field techniques with a method of statistical estimation. The field protocol consists of an efficient method of applying marks to a large fraction of the population. The statistical method provides a number of different models with which to project an estimate of the total population from the census data, and enable choice of the model giving an estimate with small error and good fit to the data. This method enables one to detect and correct for differences in the properties of marked and unmarked animals, an important consideration in mark—resight methods. We illustrate the method with our data on two species of the lizard Anolis.