Bayesian Estimation of Humpback Whale Population Abundance and Movement Patterns in Northern Southeast Alaska

• Activity Number: 526
• Type: Contributed
• Date/Time: Wednesday, August 4, 2010 : 10:30 AM to 12:20 PM
• Sponsor: Section on Statistics and the Environment
• Author(s): Albert Noble Hendrix*+
• Companies: R2 Resource Consultants, Inc.
• Keywords: mark-recapture ; abundance ; whale ; WinBUGS ; lognormal-Poisson

Abstract

We propose a mark-recapture model open to mortality with movement among sampling areas. Previous work indicated improved fit over Petersen and Darroch estimators in a maximum likelihood context, and here we extend that work to a Bayesian framework. We evaluated Poisson and over-dispersed Poisson (lognormal-Poisson) distributions for the count data. We fit the model to long-term sighting history data collected by two research groups from 1993 to 2005 on humpback whales in northern Southeast Alaska. Models with lognormal-Poisson errors were selected over Poisson based on DIC and posterior predictive checks. The population abundance was 1515 (95% credible interval: 1373, 1631), median rate of increase was 8.7% (5.4%, 11.1%), and a median survival rate of 0.997 (0.985, 0.999). Whales had a 0.75 median probability of returning to the same area, indicating strong site fidelity.