Comparing Camera Survey Methods for Monitoring Eastern Wild Turkey Populations

Abstract

Conflicting estimates of the size and productivity of Eastern Wild Turkey (Meleagris gallapavo silvestris) populations led biologists in Alabama to seek repeatable, less-biased, survey methods. Previously, estimates of turkey populations were based on opportunistic surveys, expert opinion, or population reconstruction from uncorrected harvest data. I conducted 2 surveys to compare camera trapping methods on 3 study areas in Alabama: Barbour, Oakmulgee, and James D. Martin-Skyline Wildlife Management Areas in July–August during 2017 and 2018. My objectives were to: 1) compare estimates of detection and occupancy dynamics for turkey populations between camera surveys conducted on wildlife openings (WLO) versus randomly selected sites; and 2) investigate the effects of bait on estimates of detection and occupancy dynamics for turkey populations. I compared surveys on WLO greater than 0.2 ha (n = 90), and a stratified random sample of sites generated from a uniform 554 ha grid (n = 133). I surveyed each site for 5 days without bait and 5 days with bait. I developed encounter histories from 1,200,000 images and conducted dynamic occupancy analysis on 6 different turkey classes (all turkeys, adult males, adult females, total poults, Poult 2, and Poult 3). For every class of turkeys except Poult 3, the best model for detection included study area, bait presence, site type, and time of day. For Poult 3, the best detection model included only study area and time of day. The best model of occupancy dynamics also varied among classes of turkeys. For all turkeys and adult females, variation in occupancy was best explained by year, study area, and site type. For adult males, all poults, and Poult 3, variation in occupancy was best explained by study area, year, and bait. For Poult 2, study area and site type best explained variation in occupancy rates. My results suggest that surveys conducted only at wildlife openings using bait may result in biased estimates of some classes of turkeys. These results will be used to make recommendations for the design of surveys to monitor turkey populations.