Whitetails on the Move
miles. On the opposite extreme, adult does with young fawns have home ranges less than 100 acres during the summer.
Seasonal or permanent movements of deer outside of their home ranges are common. These movements can be categorized as dispersals or migrations. Dispersals include permanent movements away from an established home range. Migrations include movements to and from established winter and summer ranges.
In a deer study conducted in north central Missouri, we found that 77 percent of the buck fawns dispersed in late spring when around one year of age. The average distance these young bucks dispersed was nine miles.
Dispersal movements by young males are common throughout the animal kingdom. No one knows for sure what causes a deer to leave its home area, but social pressures and habitat probably influence rates and distances of dispersals. Dispersals are more common in dense deer populations and tend to be longer in areas of limited habitat.
Some theorize that aggression by the doe about the time she is ready to give birth may drive fawns away. Others suggest that there is an "internal" driving force that causes these young males to leave home so that problems associated with inbreeding are avoided. Whatever the reason, that buck fawn you saw while hunting last fall probably won't be around your place next season. Also, the yearling buck you shot this year may have been born miles away.
Besides movements by young bucks we also found that 21 percent of older bucks, mostly 1.5-year-olds, dispersed. Unlike buck fawns, most of these dispersals occurred during the fall and averaged around 13 miles. We think these movements are in response to the breeding season, when there is much competition for mates and a lot of aggression toward younger bucks by older, dominant bucks. Generally, a buck establishes a permanent home range by two years of age and will remain within that home range for the rest of his life.
In our north Missouri study, we also found that a small percentage of fawn females dispersed (16 percent). The average dispersal distance was similar to that of fawn males, although one young doe moved over 90 miles and was eventually taken by a hunter in Iowa. Her movement began during spring and she wandered north throughout the summer and fall.
Most young females we studied did not disperse but remained in the vicinity of their mother, even after the older doe had given birth to young. The young doe typically rejoined the dam (mother), forming a family group.
The family group is a typical social arrangement for does and buck fawns. Common fall-winter groups include four to six deer composed of a matriarchal doe, her fawns from the current year, her doe fawn from the previous year and any fawns she may have had.
In some parts of the Midwest, however, especially where deer habitat is limited and agricultural activities dominate the landscape, a high percentage of does disperse at around one year of age, just like male fawns. Lack of cover may force these young does to move.
Migrations of yearling and adult bucks were uncommon, but around 12 percent of the fawn and adult does migrated to and from winter sites. These migrations may be more common during severe winters, when deer concentrate on areas with an abundance of food and cover. These "yards," more common in northern deer ranges where winters can be severe, may hold high concentrations of deer.
People often report 50 or more deer in fields with abundant food and become concerned about an overabundance of deer. Often, however, they are seeing deer from many miles around concentrating on one area. In spring, these concentrations break up with deer migrating back to their summer ranges. Deer truly are mobile animals.