Research ArticleEvaluation of a Global Positioning SystemBackpack Transmitter for Wild TurkeyResearchJOSHUA D. GUTHRIE, Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX 77843, USAMICHAEL E. BYRNE, School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USAJASON B. HARDIN, Texas Parks and Wildlife Department, 1320 FM 860, Palestine, TX 75803, USACHRISTOPHER O. KOCHANNY, Sirtrack Wildlife Tracking Solutions, Havelock North 4157, New ZealandKEVIN L. SKOW, Institute of Renewable Natural Resources, Texas A&M University, College Station, TX 77843, USAROBERT T. SNELGROVE, Institute of Renewable Natural Resources, Texas A&M University, College Station, TX 77843, USAMATTHEW J. BUTLER, Department of Natural Resources Management, Texas Tech University, Lubbock, TX 79409-2125, USAMARKUS J. PETERSON, Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX 77843, USAMICHAEL J. CHAMBERLAIN,1School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, LA 70803,USABRET A. COLLIER,2Institute of Renewable Natural Resources, Texas A&M University, College Station, TX 77843, USAABSTRACT Radiotelemetry is the standard method for monitoring wild turkey (Meleagris gallapavo)movements and habitat use. Spatial data collected using telemetry-based monitoring are frequently inac-curate due to triangulation error. However, new technology, such as Global Positioning Systems (GPS) hasincreased ecologists’ ability to accurately evaluate animal movements and habitat selection. We evaluated theefficacy of micro-GPS backpack units for use on wild turkeys. We tested a micro-GPS developed specificallyfor avian species that incorporated a GPS antenna with a lightweight rechargeable battery and a very highfrequency (VHF) transmitter. We conducted a series of static tests to evaluate performance in varying types ofvegetative canopy cover and terrain. After static testing, we deployed micro-GPS on 8 adult male Rio Grandewild turkeys (M. g. intermedia) trapped in south Texas and 2 adult females trapped in the Texas panhandle.Micro-GPS units collected 26,439 locations out of 26,506 scheduled attempts (99.7% fix rate) during statictesting. Mean distance error across all static tests was 15.5 m (SE ¼ 0.1). In summer 2009, we recoveredmicro-GPS from 4 tagged males and both females to evaluate data collection. Units on males acquiredapproximately 2,500 locations over a 65-day test period (94.5% fix rate). We recovered units from the 2females after 19 days and 53 days; those units acquired 301 and 837 locations, respectively, for a 96% fix rate.Cost analysis indicated that VHF will be cost effective when 1 location per day is required up to 181 days, butmicro-GPS becomes less expensive as frequency of daily locations increases. Our results indicate that micro-GPS have the potential to provide increased reliable data on turkey movement ecology and habitat selectionat a higher resolution than conventional VHF telemetric methods. ß 2011 The Wildlife Society.KEY WORDS Global Positioning System, habitat selection, Meleagris gallapavo intermedia, movement ecology, RioGrande wild turkey, telemetry, Texas.Telemetry-based monitoring has been the standard forresearch on movements and habitat selection for wildlifesince the late 1950s (Rogers et al. 1996). Radiotelemetrictechniques provide a wide array of information on animalsurvival, movements, habitat use, and demographicparameters (White and Garrott 1990, Millspaugh andMarzluff 2001). Information acquired using telemetry, how-ever, often exhibits high variance due to errors in triangu-lation angle definition, animal movements between bearings,signal strength, and tracking frequency (White and Garrott1986, Saltz 1994, Millspaugh and Marzluff 2001,Thogmartin 2001). Although telemetry biases are wellknown, researchers using radiotelemetry frequently do notemploy techniques available to correct telemetry errors or failto report these estimates with their results (Saltz 1994,Chamberlain and Leopold 2000, Moser and Garton2007). Additionally, logistical and fiscal constraints caninfluence telemetry accuracy due to labor associated withmanual data collection and the resulting number of locationscollected (Bowman et al. 2000).Advancements in technology, such as Global PositioningSystem (GPS)-based telemetry, have provided researcherswith a cost effective means for monitoring wild animalsReceived: 7 May 2010; Accepted: 5 August 20101Present Address: Warnell School of Forestry and Natural Resources,University of Georgia, Athens, GA 30602, USA.2E-mail: [email protected] Journal of Wildlife Management 75(3):539–547; 2011; DOI: 10.1002/jwmg.137Guthrie et al.Micro-GPS Turkey Backpack 539remotely. Global Positioning System-based telemetry hasbeen widely used to obtain accurate location data for largemammals using less labor than required for radio triangu-lation (Moen et al. 1997, Rempel and Rodgers, 1997,Dussault et al. 2000, Lindzey et al. 2001, D’Eon et al.2002). Satellite telemetry has been the primary non-laborintensive method used to monitor movements of medium tolarge birds (Fuller et al. 1995, Cadahia et al. 2005). Inaddition, GPS units have been used for capercaille (Tetraourogallus; Wegge et al. 2007). Satellite telemetry, althoughuseful for monitoring long distance animal movements, lacksthe accuracy required for monitoring small-scale movementsand habitat use (Keating 1994).Historically, research on wild turkeys (Meleagris gallapavo)utilized point locations acquired via radiotelemetry and tri-angulation methods to evaluate topics such as individualmovements, range sizes, habitat selection (e.g., use vs. avail-ability), and identifying critical habitats for nesting andbrooding (e.g., Miller et al. 1999, Chamberlain andLeopold 2000, Miller and Conner 2005, Hall et al. 2007).New techniques are required to identify habitat selection atthe local scale, especially for evaluating phenological changesin habitat use between breeding and non-breeding seasons(Bingham and Brennan 2004). In 2008, we initiated a studyto determine the efficacy of using micro-GPS backpack unitsto identify movements and habitat use of wild turkeys. Ourobjectives were to 1) evaluate and test a micro-GPS unit forspatial accuracy, 2) implement a field test of micro-GPSunits on Rio Grande wild turkeys in Texas, and 3) comparecost effectiveness for