Estimates of white-tailed deer density in Voyageurs National Park: 1989–2016
Gable TD, Windels SK, Olson BT. 2017. Estimates of white-tailed deer density in Voyageurs National Park: 1989–2016. Natural Resource Report. NPS/VOYA/NRR—2017/1427. National Park Service. Fort Collins, Colorado
White-tailed deer (Odocoileus virginianus) are an important component of southern boreal ecosystems, including those within and adjacent to Voyageurs National Park (VOYA), Minnesota. Voyageurs National Park staff has employed aerial and pellet-based methods of deer population monitoring for several periods from 1989 to present. Our objective for this report was to compile the results from these surveys, combine them with model-based estimates by the Minnesota Department of Natural Resources for areas adjacent to the park, and provide current and historical deer density estimates for VOYA and the adjacent areas. Deer pellet-count surveys were conducted during 1989, 1991, 1996, 1997, 2009–2011, 2015, and 2016 on randomly selected sampling units in and adjacent to VOYA in Minnesota and Ontario. Additionally, observations of white-tailed deer were recorded during aerial winter moose population surveys in 1992, 2009–2011, and 2013–2016. Based on pellet-count surveys, deer density has likely decreased during the period 1989 to 2016. We think the decrease in deer density in VOYA is likely due to changing forest composition and structure. VOYA was last logged in 1971, before the park was established, and little early successional habitat is available in the park, as natural disturbance is largely limited to small-scale events from beaver activity or wind throw. Density estimates based on aerial survey data were much lower than pellet-count density estimates for all years. We do not recommend using the estimates derived from aerial surveys as measures of either trends or abundance of deer in VOYA. Future aerial surveys for deer could be modified to improve accuracy and precision of estimates but such improvement may be cost-prohibitive. We suggest continued use of pellet-count-based estimates of deer density in VOYA as a low-cost, low effort method as an index to abundance and trends within the park.
- Type
- Published Report
- Authors
- Gable, Thomas; Windels, Steve; Olson, Bryce
- Date of Issue
- 2017-04
- Publisher
- National Park Service
- Units
- NRSS , VOYA
- Keywords
- density estimates, Minnesota, white-tailed deer