Movement Patterns, Survival, and Sightability of White-Tailed Deer (Odocoileus virginianus) in Eastern South Dakota

Limited information is available on white-tailed deer (Odocoileus virginianus) movements, survival, density, and resource selection in the Prairie Pothole Region of South Dakota where semi-permanent wetland densities are relatively high. Primary objectives of this study were to develop a sightability model for aerial surveying and document seasonal movement patterns and survival rates for white-tailed deer in this region. Secondary objectives were to calculate seasonal home ranges, daily and seasonal movements relative to management unit boundaries, determine cause specific mortality, and evaluate summer and winter resource use and selection. From February 2009 – February 2010, 43 adult female white-tailed deer along with 5 adult male white-tailed deer were monitored for survival and movements using radio telemetry. An additional 20 deer also were captured and ear-tagged. Capture methods included helicopter net guns and the use of Clover traps. A total of 6,877 locations was collected, with a mean 95% error ellipse of 1.8 ha. We documented a total of 55 seasonal movements during 4 migration periods. Snow depth and temperature were the primary causes of seasonal migration. Mean migration distance between seasonal home ranges was 4.76 km (SE= 0.38). A total of 119 individual home ranges was calculated during 4 periods of seasonal use. Mean 95% home range size was 2.94 km2 (n=58, SE= 0.38) during winter and 1.49 km2 (n=61, SE=0.10) during summer. No deer crossed management unit boundaries and no dispersals were documented throughout the study. Movement and migration distances were likely reduced because of the juxtaposition of suitable habitat (i.e., wetlands and CRP grasslands) in the Clark County area. During this study, 17 deer died, and overall (24 month) survival rate was 0.55 (SE=0.08, n=43). Annual survival rates of female deer during 2009 and 2010 were 0.78 (SE = 0.08, n = 26) and 0.70 (SE = 0.08, n= 37), respectively. Seasonal survival rates for post-hunt, pre-hunt, and hunting seasons during 2009 and 2010 were 0.96 (SE= 0.04, n=26), 1.00 (SE < 0.001, n= 25), 0.84 (SE = 0.07, n= 34) and 0.94 (SE = 0.04, n= 37), 1.00 (SE < 0.001, n= 36), 0.72 (SE = 0.07, n= 36), respectively. Survival was predominately dependent on hunting, which was responsible for 64.5% of all mortalities. Liberal antlerless deer-tag numbers, lengthy hunting seasons, and high hunter densities likely influenced human related mortality of white-tailed deer in this region. Habitat categories encompassing 61 summer and 58 winter home ranges of 42 radiocollared female white-tailed deer were mapped during summer 2009 (n=25) and 2010 (n=36), and winter 2009 (n=22) and 2010 (n=36). We collected 4,688 summer locations and 1,826 winter locations via radio telemetry. Habitat use differed slightly between seasons with CRP grasslands, standing corn, and wetlands being used the most throughout summer home ranges and CRP grasslands, trees, and wetlands being used the most during winter. Overall, wetland habitat was used the most by deer in the Clark County area, and provided essential thermal and escape cover; however, deer use of wetlands did not exceed availability. We evaluated winter and summer resource selection using design II and III analyses. Analysis using design II demonstrated that trees (ŵ = 3.81) were selected with higher probability (P<0.10) when compared to all other habitats available for both winter and summer. During the winter, CRP grasslands (ŵ = 1.45) and standing corn (ŵ = 2.89) also were selected by deer. Design III analysis indicated that extensive variation existed between animals and the proportions of habitat categories found within individual home ranges; however, the model using all animals indicated that trees (ŵ = 2.67) were selected with higher probability then other habitats (P<0.10). In the spring of 2009 and 2010, a total of seven sightability flights were conducted in late April and early May when potential color differences between sun-bleached deer and spring green-up were present. In the winter of 2010 and 2011, a total of 8 flights were conducted in January and February when 100% snow cover was present and deer were in large winter herds. Several variables were collected during the flights including; group size, activity, habitat, and canopy cover. Deer were sighted in the winter at a rate of 84.4% (146/173) and spring sightability rate was 54.6% (88/161). Logistic regression analysis indicated that visibility was significantly influenced by group size and canopy cover for both models. The winter model estimated deer sightability as μ = 3.064 + 0.044 (group size) – 1.13 (canopy cover) and the spring model estimated deer sightability as μ = 2.297 + 0.252 (group size) – 1.10 (canopy cover). These models will assist South Dakota Game, Fish and Parks in estimating population size of white-tailed deer in agricultural dominated landscapes throughout eastern South Dakota.

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis - Open Access

Discipline thesis:degree_discipline

Natural Resource Management

Year

2011

Author dc:creator

• Robling, Kevin A.

Contributors dc:contributor

• Jonathan A. Jenks

• white-tailed deer
• movement patterns
• south dakota
• survival
• mortaility
• Natural Resources and Conservation

Statement dc:rights

• Copyright © 2011 Kevin A. Robling. All rights reserved.

Language dc:language

en

Repository record dc:identifier

https://openprairie.sdstate.edu/etd/378

OAI identifier oai:identifier

oai:openprairie.sdstate.edu:etd-1378