Vicksburg National Military Park white‐tailed deer survey

Wang, Guiming; Strickland, Bronson; Shan, Xueyan

doi:10.36967/2307610

White-tailed deer (WTD) can exert substantial impacts on the ecosystems in the Southeastern United States, particularly by overabundant WTD populations that are sheltered from recreational hunting pressure such as those in the National Parks. Information on WTD abundance and density is indispensable for science-based WTD population management. WTD populations in Vicksburg National Military Park (VICK) have not been surveyed since 2010. Management of WTD populations has been challenged by the lack of reliable, cost-effective methods, such as a deer visual count-density calibration coefficient, for estimating WTD density within the park. This study aimed to develop a cost-effective visual count-density conversion method using WTD counts from spotlight surveys and density estimates from fecal-DNA spatially explicit capture-recapture (SECR) models. We conducted seven, six, and five spotlight surveys of WTD in January, March, and May, 2023, respectively. Average visual counts of WTD were 96.0 (standard deviation [SD]=23.98), 86.47 (SD=14.22), and 84.0 (SD=13.02) in January, March, and May, respectively. Direct visual deer counts were greater than those of the 2009 VICK WTD spotlight surveys by 40%-220%. Average WTD relative abundances were 8.5 (SD=4.94), 7.9 (SD=4.58), and 7.6 (SD=4.8) deer per mile in January, March, and May, respectively. Average WTD density estimated by distance sampling models was 0.65 deer per ha. The VICK WTD densities did not differ among the three months in our distance sampling model. We used eight microsatellite markers to genotype WTD fecal samples within VICK. Fecal DNA spatially explicit capture-recapture models estimated 778 WTD within VICK. The WTD densities were positively related to the proportions of forests and open fields (grass and crop) in VICK. White-tailed deer appeared to be overabundant within VICK, causing concerns relative to WTD-human conflicts and exacerbating the risk of wildlife disease transmission such as Chronic Wasting Disease. We proposed a cost-effective monitoring method for estimating WTD densities with visual counts based on significant inverse relationships between WTD densities estimated by fecal-DNA SECR models and visual counts from spotlight surveys. Our proposed method will allow park staff to convert WTD visual counts from spotlight surveys to WTD densities until substantial changes in VICK’s vegetation and (or) habitat management occur. The timely, cost-effective monitoring of WTD populations can help park staff better manage natural resources within VICK, including the mitigation of the damages caused by overabundant WTD to natural resources.

Vicksburg National Military Park white‐tailed deer survey

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