Sophia Zheng

Estimating abundance in a closed population using capture-recapture methods

Capture-recapture experiments are widely used to study population dynamics of wildlife populations. The Lincoln-Petersen estimator is one of the oldest and simplest methods to estimate population abundance, as it is based on a single recapture occasion. We consider a more general case that allows for multiple recapture occasions assuming that the capture probability for each individual is homogeneous. Here we introduce the process of collecting capture information for each individual and discuss the formulation of a commonly used maximum likelihood estimator based on the full likelihood. Further, we obtain an interval estimate using a profile interval. We apply these methods to data from a white stork multiple recapture study. We find that maximum likelihood estimation using the full likelihood provides a useful inference procedure for estimating population size.