Pennsylvania Project: Developing an adaptive management approach for potential surveillance and spread of chronic wasting disease in white-tailed deer in Pennsylvania

Pennsylvania Project

Developing an adaptive management approach for potential surveillance and spread of chronic wasting disease in white-tailed deer in Pennsylvania

January 2012 - December 2014

Personnel

Participating Agencies

U.S. Department of Interior

Research on surveillance strategies, that consider demographic and environmental factors, is lacking in most states CWD has not been found. Developing surveillance strategies to maximize efficiency of sampling white-tailed deer has been described in an endemic area of Colorado (Walsh and Miller 2010) and in initial stages of CWD occurrence in Saskatchewan (Rees et al. 2011). Predictive models of pathways of CWD spread would also be beneficial to states that have CWD at their borders. Predictive models, based on previous research on deer demographics and environmental contributors to disease, could provide focused efforts on surveillance strategies in the short- and long-term for state agencies.

Research Publications

Research Publications	Publication Date
Evans, T.S., K.L. Schuler, W.D. Walter. 2014 Surveillance and monitoring of white-tailed deer for chronic wasting disease in the northeastern United States. Journal of Fish and Wildlife Management 5(2):387-393.	December 2014
Evans, T.S., M. Kirchgessner, B. Eyler, C.W. Ryan, and W.D. Walter. 2016. Habitat influences distribution of of chronic wasting disease in white-tailed deer. Journal of Wildlife Management \| Abstract	January 2016	Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy that was first detected in 1967 in a captive research facility in Colorado. In the northeastern United States (Northeast), CWD was first confirmed in 2005 in New York and West Virginia, and has since been found in Maryland, Virginia, and Pennsylvania. Because CWD is a new and emerging disease in populations of white-tailed deer (Odocoileus virginianus) in the central Appalachian region and has yet to be assessed within a Bayesian hierarchical modeling framework, we examined demographic and environmental factors to better understand the spatial epidemiology of CWD in the region. The objectives of our study were to (1) apply Bayesian hierarchical models to harvest location data of white-tailed deer tested for CWD in the central Appalachian region between 2005 and 2012, (2) identify covariates that best described the spatial distribution of CWD, and (3) predict probability of risk for CWD infection in the Northeast. Demographic covariates included sex and age, and environmental covariates included elevation, slope, riparian corridor, percent of clay-sized particles in the soil, and percent of three habitat types (developed, forested, and open). For each deer, environmental covariates were extracted within 6 km2 grid cells as this size reflected estimates of 99% isopleths for home range of white-tailed deer in the region. The model with the most support contained random spatial effects and percent habitat and accounted for 94.4% of the overall weight for the candidate set of hierarchical models. Percent forest cover had the strongest relationship with the distribution of CWD in the region, with increased risk of CWD occurring in areas that had lower amounts of forest cover. Our results will assist resource managers in understanding the spatial distribution of CWD not only within the study area, but also in surrounding areas where CWD has yet to be found. Efficiency of disease surveillance and containment efforts can be improved by allocating resources used for surveillance into areas that are at a greater risk for infection.
Walter, W.D., T.S. Evans, D. Stainbrook, B.D. Wallingford, C.S. Rosenberry, and D.R. Diefenbach. 2018. Heterogeneity of a landscape influences size of home range in a North American cervid. Scientific Reports 8:14667. DOI:10.1038/s41598-018-32937-7. \| Abstract \| Download \| Publisher Website	September 2018	Spatial heterogeneity, or composition and configuration of a landscape, plays a role in many biological and ecological processes. In spatial ecology, understanding movements of a species in relation to the landscape can assist wildlife managers in better understanding other processes, including habitat use and disease transmission. In the northeastern United States (Northeast), chronic wasting disease has been detected in populations of white-tailed deer (Odocoileus virginianus), and understanding the relationship between landscape and size of home range may provide a basis for disease surveillance and containment efforts. The objectives of our study were to (1) compare size of home range between sexes and among study areas for white-tailed deer occupying a continuum of forested landscapes from highly fragmented to contiguous and (2) investigate relationships between size of home range and measures of landscape composition and configuration. We observed differences in size of 95% home range between males (3.77 km2) and females (1.83 km2) across all study areas, as well as between deer in highly fragmented and contiguous landscapes. We developed 20 linear regression models that contained measures of landscape that were correlated with size of home range, and the best model showed that size of home range increased with connectivity of forest cover. Understanding this relationship may provide a foundation for disease surveillance efforts, because size of home range may represent the scale at which disease will spread. Therefore surveillance should be conducted in a manner that reflects connectivity of landscape at a local scale.

Presentations

Presentations	Presentation Date
Evans, T.S. and W.D. Walter. 2013. Development of a chronic wasting disease surveillance plan and modeling of the potential spread in Pennsylvania. The Wildlife Society Annual Conference, Milwaukee, WI.	October 2013
Evans, T.S. and W.D. Walter. Development of a chronic wasting disease surveillance plan and modeling of the potential spread in Pennsylvania. Pennsylvania Chapter of the Wildlife Society, State College, PA, 22-23 March 2013.	March 2013
Evans, T.S., M. Kirchgessner, B. Eyler, C. Ryan, and W.D. Walter. 2014. Bayesian hierarchical modeling of chronic wasting disease in the central Appalachian region. The 21st Annual Wildlife Society Conference, Pittsburgh, PA.	October 2014

Theses and Dissertations

Theses and Dissertations	Publication Date
Evans, T.S. 2014. Chronic wasting disease in the Central Appalachian region of the United States. The Pennsylvania State University, University Park, PA, 81 pp.	May 2015

Cooperative Fish and Wildlife Research Units Program: Pennsylvania Education, Research and Technical Assistance for Managing Our Natural Resources