Deer Population Goals

Since 1960, biologists have used hunter harvest and population modeling techniques to estimate herd size. Population goals were first established in 1962. Deer Management Unit (DMU) population goals are determined by a variety of factors dealing with biological and social carrying capacity. Approximately every 3 years deer goals are revised through a collaborative process between stakeholders, public input and the DNR.

Biological carrying capacity (K) is the maximum number of deer the landscape can support over a prolonged period of time. A deer herd managed at “K” will result in heavy competition between deer, overbrowsing, and a high percentage of winter mortality. Generally, population goals in forested units are set about 60-65% of K. A deer population managed at these levels has shown to result in a long-term sustainable harvest and a healthy deer herd.

In units that are more agricultural or urbanized, social carrying capacity is usually a bigger factor in determining deer goals. The social carrying capacity is the number of deer that people can tolerate related to agricultural damage, damage to commercial forests, damage to ornamental plants, etc. Generally these units have a higher nutrient base, which creates a higher K. However, if these units were managed at 60-65% of K, controlling the herd would be extremely difficult and the level of damage caused would be intolerable to many farmers. The goals in these units are set significantly below K to alleviate social problems with deer, yet they are set high enough to strongly consider hunter satisfaction.

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The original over winter (post hunting season) goal for the Wisconsin deer herd was 441,900 deer. As deer range expanded and hunting interest increased, the post-hunt goal has grown until today it stands at approximately 733,000, an increase in goal of more than 65%.

Between 1962 and 1984, the post-hunt estimate averaged 1% over goal. Between 1985 and 1994, the post-hunt estimate averaged 16% above goal, and between 1995 and 2008 the average was 48% over goal. The post-hunt estimate indicates that the statewide deer herd has been at or within 5% of goal only once in the last 20 years.

Wisconsin’s estimated post-hunt deer population is above goal again this year. However, at the end of the 2008 deer season, statewide harvest data suggests significant progress toward goal. Most units within farmland regions are still above goal, while many units in the north are currently near or below goal following the effects of a moderate to severe winter in 2007-2008.

Deer population goals may be expressed in terms of abundance or density. Density goals are shown as the average number of deer per square mile of deer range (suitable habitat) in the post-hunt population. In farmland management units, the proportion of deer range to total area is generally much less compared to heavily forested units. This means the contrast in deer numbers expressed in terms of square mile of “deer range” is much greater than the average number of deer per square mile of “total area” in a farmland unit.

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