Genetic tagging free-ranging white-tailed deer using hair snares

Ohio Journal of Science, The, Sept, 2007 by Jerrold L. Belant, Thomas W. Seamans, David Paetkau

ABSTRACT: Use of noninvasive DNA-based tissue sampling (e.g., hair, scats) for individual identification in wildlife studies has increased markedly in recent years. Although field techniques for collecting hair samples have been developed for several species, we are unaware of their use with free-ranging ungulates. From December 2004 to August 2005 we evaluated the efficacy of barbed wire for snaring hair samples suitable for genetic analyses from white-tailed deer (Odocoileus virginianus) on trails and at baited sites. During initial trials on a semi-captive deer herd in northern Ohio, deer demonstrated avoidance of barbed wire positioned on game trails through four weeks but entered baited sites with barbed wire in <3 days. Field trials on free-ranging deer in Michigan using two snare configurations at baited sites checked at one-or-two-week intervals also were successful in obtaining hair samples suitable for extracting DNA. Number of hair samples appeared to increase with deer activity. Number of hair samples and amount of hair in individual samples were greater during winter and spring than during summer. Adequate genetic material was present in 98% (n = 53) of samples collected during winter. Obtaining hair samples noninvasively from white-tailed deer has numerous applications including determining natal origin, population monitoring, and density estimates. We recommend use of baited sites encircled with a single strand of 15.5 gauge, four-point, barbed wire 80 cm above ground attached to [greater than or equal to] 3 trees. In treeless areas, metal or wood posts could be substituted. Hair snare height and configuration could be adapted for other ungulate species.

OHIO J SCI 107 (4): 50-56, 2007

INTRODUCTION

Overabundance of white-tailed deer (Odocoileus virginianus) populations has become one of the most difficult issues facing wildlife managers (Warren 1997). At high densities, deer browsing and herbivory can adversely affect plant community composition and structure (Waller and Alverson 1997, Frankland and Nelson 2003, Pedersen and Wallis 2004). Cascading ecological effects include indirect influences on avian composition and insect abundance (Miller et al. 1992, deCalesta 1994, Ostfeld et al. 1996). Additionally, conflicts between humans and deer may include agricultural loss, zoonoses, property damage to landscaping, and collisions with vehicles (Conover et al. 1995, Conover 1997).

Similarly, deer overabundance is a pervasive management issue in National Park units in the eastern United States (e.g., Shafer-Nolan 1997); with deer-vehicle collisions and impacts on native plants the most frequently reported issues (Frost et al. 1997, Porter 1997). For example, six of nine national park units within the western Great Lakes region contain overabundant white-tailed deer populations that have or are presently adversely affecting native vegetation (e.g., Robinson 1980, Balgooyen and Waller 1995, EDAW 2003). Development of long-term monitoring and associated research is considered necessary to resolve these issues and ensure effective deer management (Waller and Alverson 1997).

Numerous techniques are available to monitor white-tailed deer abundance including aerial surveys, spotlighting, forward-looking infrared, and pellet counts (e.g., Beringer et al. 1998, Belant and Seamans 2000). More recently, genetic markers (e.g., microsatellite DNA) have been identified for numerous wildlife species (e.g., Foran et al. 1997). For example, a microsatellite DNA panel has been developed for white-tailed deer and validated for several populations (Anderson et al. 2002, DeYoung et al. 2003). Individual assignment testing for assessing natal origin can be used to determine dispersal and population history (Beaumont and Bruford 1999 [in DeYoung et al. 2003]), in addition to monitoring abundance and population estimates that include estimates of precision (Foran et al. 1997). An important advantage of using hair for DNA analysis is that it can be obtained from flee-ranging animals without capture (e.g., Belant 2003, Belant et al. 2005).

Although hair snares have been developed for several wildlife species (Raphael 1994, Foran et al. 1997, Woods et al. 1999, McDaniel et al. 2000, Belant 2003), we are unaware of any techniques used to noninvasively collect hair from free-ranging white-tailed deer. Development of a hair snare could provide a cost-effective and accurate means to monitor deer abundance or estimate their population size in areas where deer are not harvested or where other techniques are impractical (e.g., large roadless forested areas). Our goal was to develop a noninvasive method for monitoring abundance and determining genetic relatedness of white-tailed deer. Specifically, we sought to determine the effectiveness of barbed wire to remove hair that is suitable for determining genotype from free-ranging white-tailed deer.

MATERIALS AND METHODS

Study Area

We conducted initial trials at the National Aeronautic and Space Administration's Plum Brook Station (PBS), Erie County, Ohio (41[degrees] 22' N, 82[degrees] 41' W). The 22-[km.sup.2] facility is enclosed by a 2.4 m high chain-link fence with barbed-wire outriggers. Deer ingress and egress occurs through several gaps between the fence and ground. Vegetation within PBS consisted of canopy dogwood shrubs (Cornus spp.), grasslands, open woodlands, and mixed hardwood forests (Rose and Harder 1985). Estimated deer density during winter 2004-2005 was 54/[km.sup.2] (J. Cepek, U.S. Department of Agriculture, personal communication).