Distribution and population characteristics of mule deer along the East Front, northcentral Montana

This study was conducted from June 1979 to September 1980 on the Rocky Mountain East Front of northcentral Montana.It was the first phase of a 2 part investigation designed to provide quantitative baseline information on mule deer seasonal distribution, movements, population status and trend, and habitat usage on a representative portion of the East Front subject to oil and gas development.Areas used by deer during average and severe winters remained relatively constant during the last 3 years.Deer displayed a high degree of fidelity to seasonal ranges.On this basis, 6 essentially independent populations were delineated by winter range origin.Movement to summer home ranges appeared rapid and direct via distinct migration corridors.Summer distribution indicated that 3 subpopulations could be delineated for each winter range.Mean summer home range size for females was larger in 1979 (7.2 km^2) than 1980 (2.7 km^2).Fall transitional ranges were identified.The pattern of transitional range use appeared to concentrate deer from 1 of the 3 subpopulations during hunting season.Age distribution of a sample of 69 deer indicated an adult population structure of 26% males and 74% females.Poor representation of the 1 1/2, 2 1/2, and 6 1/2-year-old age-classes was noted.These anomalies appeared related to weather, fawn production and survival, and hunter harvest.Fawn:adult ratios for 1979-1980 were not significantly different among the 5 winter ranges intensively sampled.