Accounting for Behavioral Response to Capture When Estimating Population Size from Hair Snare Studies with Missing Data

• Activity Number: 675
• Type: Topic Contributed
• Date/Time: Thursday, August 13, 2015 : 10:30 AM to 12:20 PM
• Sponsor: Section on Statistics and the Environment
• Author(s): Ben Augustine* and Simon J. Bonner and Catherine Tredick
• Companies: Virginia Tech and University of Kentucky and The Richard Stockton College of New Jersey
• Keywords: behavioral response ; mark recapture ; closed population ; hair snare

Abstract

Hair snares have become an established method for obtaining mark-recapture data for population size estimation in a wide range of species, but no statistical methodology exists to accommodate a behavioral response to capture in the presence of missing data. In a hair snare mark-recapture experiment, data can be missing if animals encounter a hair snare without leaving a hair sample, not all collected samples are genotyped due to cost considerations, and/or not all genotyped hair samples provide an individual identification. We present methodology that extends classical closed mark recapture models to account for a behavioral response to capture in the presence of missing data from one form of subsampling and failure of hair samples to produce an individual identification. Four subprocesses are modeled-animal capture, hair deposition, researcher subsampling, and DNA amplification with key parameters estimated from functions of the number of hair samples left by individuals at traps. We compare the frequentist properties of this estimator to the classical estimator that does not account for missing data and then apply our methodology to a previously published data set.