Modelling banding effect and tag loss for Little Penguins, Eudyptula minor, using Matlab

Abstract

We present a framework for using Matlab to analyse mark-recapture data arising from studies that use more than one type of tag to mark animals for later identification. We consider life history data collected for groups of single and double tagged animals. We include tag loss probabilities in the likelihood function, which removes a common source of bias in the estimation of survival rates. We show how the formation of appropriate summary statistics, and use of vectorisation, vastly improves speed in computing the likelihood function. We illustrate our methods by analysing seven years of mark-recapture data for 2483 Little Penguins Eudyptula minor on Phillip Island in south-eastern Australia.