The reestablishment of deer into the state can be traced to escapes and releases from captive herds and natural immigration from deer herds in surrounding states. A conservative estimate of the population in 1936 placed statewide numbers at between 500 and 700 animals. This small herd grew steadily. By 1950 deer were reported in most counties and the statewide estimate topped 10,000. Concentrations in some areas began to cause problems by damaging crops.
The first modern deer season was held in December of 1953 and 4,000 deer were killed. In 2010 the deer herd is estimated to be about 200,000 after the hunting season; harvests have approached 100,000 in recent years.
Although deer are normally associated with forested areas, deer will use many different types of habitat as long as the area provides adequate cover. Deer use almost all plants for food at one time or another during the year.
The white-tail's ability to thrive in Iowa is probably the result of an abundant, reliable food source and a winter climate where snow depths rarely exceed 12" for a prolonged length of time. These factors allow deer to come through the winter in excellent condition. Excellent nutrition also enable deer to have high reproductive rates. Many deer in Iowa have a single fawn their first year and 2 fawns each subsequent year. Deer in the wild can probably maintain these high reproductive rates until they are 10 years old. Past research in Iowa has found that 8% to 12% of adult does have 3 fawns.
Deer in Iowa are very mobile. Although many deer stay near the area where they were born, many leave and travel to new areas before establishing a core area. These core areas may change seasonally with deer shifting between wintering areas and breeding areas. These movements allow deer to fill voids left open due to deaths and easily pioneer into new areas when habitat is suitable. High rates of movement occur during 2 periods of the year. The first is in the spring when deer move to their fawning areas. Many of last years fawns are forced to find areas of their own at this time. The second period is in the fall during the breeding season. The breeding season begins in mid-October and runs through mid-January, although the peak of activity occurs during the first 3 weeks of November.
Unchecked, Iowa's deer herd could grow at a rate of 20% to 40% each year. At this rate, deer numbers would double in as few as 3 years. With Iowa's abundant agricultual crops providing food, densities could potentially reach 100 or more deer per square mile before natural regulatory mechanisms would begin to affect deer health and slow the rate of growth. Deer numbers this high would cause economic hardship to Iowa's landowners as well as alter the natural vegetative community. Maintaining a deer population in balance with the wants and needs of the people in the state is a difficult task, but hunting is the only viable management option to achieve this goal.
The urban deer population within Dubuque has remained fairly constant.
Dubuque's urban deer hunts began in 1997. Areas designated for hunting in 2010 included BUNKER HILL GOLF COURSE, EAGLE POINT PARK, MARSHALL PARK, MEDICAL ASSOCIATES west campus, VETERANS MEMORIAL PARK, FDR Park, and 23 acres south of the Fremont Avenue bridge. Without the hunting, it was estimated that the deer population would increase 33% each year.