Selection of habitats by wintering elk in a rapidly subdividing area of La Plata County , Colorado

Scott Wait and Heath McNally La Plata County is currently undergoing rapid population growth. It is estimated that the county increased in population by 14% from 1990 to 1994, growing from 32,284 to 36,887 people. The projected population by the year 2000 is 44,556, a 38% increase from 1990. With this increased growth comes pressure to develop more land and natural resources throughout the county. New developments are geared toward single-family units on larger lots, which require larger parcels of land to house fewer people, versus multi-family units or small lot sizes which house a larger number of people per unit of land. As this development expands, it can adversely impact wildlife and wildlife habitats and can limit the ability of managers to manage wildlife. Part of La Plata County and particularly areas along a major U.S. highway or near public lands, have experienced proliferation of 1-4 ha lot subdivisions. This greatly increases human impacts in the forms of roads, fences, outdoor activity, dogs, structures, while at the same time removing land from agricultural use that provides forage and security cover. While this area is receiving increased human use, it is also home to part of the third largest elk herd in Colorado, and winters approximately 6,000 elk. Elk winter range and severe winter range maps closely coincide with the area of " ranchette " proliferation. This area of overlap causes elk-human and elk-auto conflicts, degradation in the quality of elk winter range, and permanent loss of elk wintering areas. A management study was initiated in the winter of 1996-97 within this heavily impacted area to identify areas of elk use in relation to subdivision presence, lot size, road development, habitat type, and surrounding land use. Elk appear tolerant of some subdivision attributes, but intolerant of others. In addition, elk navigate through some subdivisions, while other subdivisions are nearly totally avoided. If this elk herd is to be maintained, with severe development occurring on winter range and spring-fall transition ranges, the County staff and Division of Wildlife staff feel critical migration corridors and wintering areas must be maintained and protected through public and private methods. Approximately 30 radio-collared elk have been monitored in a 600 square km area through each winter and spring-fall migration period. A Geographic Information System was used to create mapped layers of subdivision attributes, habitat type, and land use to relate to elk habitat use areas. …