Date of this Version
The need to accurately assess the use and suitability of elk (Cervus elaphus spp.) habitat at regional scales will continue to increase as human development encroaches into what was once optimum elk habitat. The objectives of this research were to calculate the relative proportions of habitat use by elk in the Pine Ridge region of Northwestern Nebraska from a set of radio-collared elk locations and generate a habitat suitability model. Habitat variables (Iandcover type, aspect, slope, distance to a road, road density, and distance from the ponderosa pine edge) were measured for each elk location (n = 5,787 dating from April 1995 to August 1997) using a Geographic Information System (GIS). The habitat variables were also measured for a random point coverage (n = 5,787) to compare and contrast the differences, if any, between elk-use and non-use areas. A logistic regression model describing elk habitat selection for two discrete, non-migratory herds of elk was developed. Slope, distance to a road, road density, distance from the ponderosa pine edge, and several landcover types including ponderosa pine (>70% canopy coverage), ponderosa pine (40-70% canopy coverage), western mixed-grass prairie, and alfalfa were habitat variables found to be statistically significant (p < 0.05) in explaining areas used by elk. Habitat variables that were not statistically significant (p > 0.05) were aspect and the landcover types including small grains agriculture and fallow agriculture. I used a GIS to apply the model to the entire Pine Ridge study area and create a map of potentially suitable elk habitat. The results of the logistic regression model suggest that the amount of suitable habitat in the study area ranges from low (34%), medium (38%), high (21 %), and optimal (8%). I estimate that the Pine Ridge region provides 140,000 ha (540 mi2 ) of high-to-optimal suitable elk habitat. This model may be used to direct management efforts to ensure that the number and distribution of elk in the Pine Ridge region is ecologically sound and socially acceptable.
Advisor: James W. Merchant