Capture—recapture of white‐tailed deer using DNA from fecal pellet groups

Abstract

Traditional methods for estimating white‐tailed deer population size and density are affected by behavioral biases, poor detection in densely forested areas, and invalid techniques for estimating effective trapping area. We evaluated a noninvasive method of capture—recapture for white‐tailed deer Odocoileus virginianus density estimation using DNA extracted from fecal pellets as an individual marker and for gender determination, coupled with a spatial detection function to estimate density (spatially explicit capture—recapture, SECR). We collected pellet groups from 11 to 22 January 2010 at randomly selected sites within a 1‐km2 area located on Arnold Air Force Base in Coffee and Franklin counties, Tennessee. We searched 703 10‐m radius plots and collected 352 pellet‐group samples from 197 plots over five two‐day sampling intervals. Using only the freshest pellets we recorded 140 captures of 33 different animals (15M:18F). Male and female densities were 1.9 (SE = 0.8) and 3.8 (SE = 1.3) deer km‐2, or a total density of 5.8 deer km‐2 (14.9 deer mile‐2). Population size was 20.8 (SE = 7.6) over a 360‐ha area, and sex ratio was 1.0 M: 2.0 F (SE = 0.71). We found DNA sampling from pellet groups improved deer abundance, density and sex ratio estimates in contiguous landscapes which could be used to track responses to harvest or other management actions.

Estimating sex-specific abundance in fawning areas of a high-density Columbian black-tailed deer population using fecal DNA

“…By incorporating 10 microsatellites and a sex marker (i.e., 11 markers) in a single reaction, our assay enabled us to simultaneously minimize error and cost, representing a significant improvement over previous assays. Although we used fewer reactions per sample than previous studies, our proportional success was similar to that observed in previous genetic CMR studies for which samples were genotyped up to 7 times or more (Brinkman et al 2011, Goode 2011, Ebert et al 2012. In contrast to previous studies, which either did not incorporate sex markers (or sex) in analyses (Brinkman et al 2011) or conducted additional assays specifically to determine sex (Goode 2011, Ebert et al 2012, our incorporation of a sex marker in the same assay used to determine individual genotypes further reduced the number of reactions required.…”

Estimating Sonoran pronghorn abundance and survival with fecal DNA and capture–recapture methods

“…; Goode et al. ). Use of NGS‐CR eliminates capture expense and capture‐related stress on animals and provides accurate population estimates (e.g., DeBarba et al.…”

Applying spatially explicit capture–recapture models to estimate black bear density in South Carolina

“…Advantages associated with spatially explicit models are well‐documented and include inherent accommodation of spatial heterogeneity in capture probabilities, and accommodation of nonuniform sampling designs in space (Efford , Efford et al , Gerber et al , Efford and Fewster , Efford and Mowat ), provided intertrap spacing is not too small relative to animal movement such that spatial recaptures are feasible (Sollmann et al , Sun et al ). We modeled data assuming individuals had stationary activity centers (i.e., no permanent immigration or emigration) using the following model arguments: 1) we modeled capture events as binary (detector type = ‘proximity’); 2) we modeled number of activity centers as a Poisson distribution assuming uniform distribution of individuals across the study area, because bears are not gregarious and exhibit mutual avoidance within overlapping ranges (Obbard et al ); and 3) we modeled detection as a half‐normal function assuming that detection was a continuous (not step) function from the activity centers to a point of zero capture probability (Borchers and Efford , Goode et al ). Detection parameters for models were probability of individual detection at the activity center ( g 0 ), and rate of decrease in capture probability with distance from activity center (σ).…”