Study area
We investigated white-tailed deer neonate cause-specific mortality and survival in Grant and Dunn counties, North Dakota and Perkins County, South Dakota (Figure 1) during 2014 and 2015. All counties were located in the Northwestern Great Plains Level III Ecoregion (Bryce et al., 1998). We focused deer capture in a 1492 km2 area in the southwestern portion of Dunn County, an 1865 km2area in the southwestern portion of Grant County, and a 1492 km2 area in the central portion of Perkins County. Grasslands, cropland, and forested areas were the most common cover types and ranged from 60 to 86%, 11 to 26%, and 0.01 to 9%, respectively (Cropland Data Layer, U. S. Department of Agriculture 2015). Thirty-year mean annual precipitation ranged from 41.2 cm (Grant County) to 44.9 cm (Perkins County), and variation in thirty-year mean monthly temperature was greatest in Perkins County ranging from -12.1oC to 30.3oC (North Dakota State Climate Office 2016).
Neonates surviving to 6-months were available for harvest. Recreational hunting season dates were similar across study areas and occurred from 29 August 2014 to 4 January 2015 and 4 September 2015 to 3 January 2016 in North Dakota. Recreational hunting occurred from 27 September 2014 to 15 January 2015 and 26 September 2015 to 15 January 2016 in South Dakota.