SUMMER MOVEMENTS, HOME RANGE, HABITAT USE, AND BEHAVIOR OF MULE DEER FAWNS

Radiotelemetry was used to determine summer movements, home range, behavior, and habitat use of 77 mule deer (O. hemionus) fawns in the Missouri River Breaks of north-central Montana [USA]. Average distance between successive radiolocations was 0.78 km. Among individuals, movements were highly variable, but fawns were capable of extensive movements at any age; 77% made movements greater than 1 km prior to 1 mo. of age. Average home-range size was 185 ha. Home-range sizes decreased with increased population size, but did not overlap until peak population was attained. Fawns increased their activity and spent more time with does as they grew older. Maternal does were intolerant of other deer until their fawns were at least 1 mo. old. Regular spacing of adjacent home ranges and solitary behavior exhibited by does suggested that a social pattern that resembled territorial organization occurred. Fawns selected habitat types with dense vegetative cover and typically used the mid- and lower thirds of slopes. Seasonal shifts in habitat use were correlated with desiccation of herbaceous cover and associated diet changes by does. Findings are also discussed in relation to mule deer behavior, coyote (Canis latrans) predation, variation in vegetation production, and weather.