How Deer Are Managed

The Division of Wildlife Resources of the Illinois Department of Natural Resources is mandated to restore, manage, and protect deer and their habitats.

Hunting has long been the standard tool to manage deer populations in Illinois. Development of an effective deer management program entails an annual evaluation of the deer population, establishing hunting season regulations and quotas in line with goals, and conducting hunting seasons to manage the deer population.

The Illinois Department of Natural Resources uses deer harvest and deer–vehicle accidents statistics as the basis for management recommendations and decisions.

To view examples of the information available from the deer harvest data, please go to the Harvest Information section.

Research is a cornerstone of effective deer management. A wildlife management program depends on sound scientific principles and an understanding of long-term trends to maintain a healthy, productive deer population. Illinois deer managers work with a variety of research institutions to develop a better understanding of the role of deer in a changing environment and to keep up-to-date on the diverse views and needs of hunters, landowners, and others with an interest in deer.

The Illinois Department of Natural Resources also encourages public involvement since including multiple perspectives is an important component of establishing deer management rules, regulations, and policies.

Setting Population Objectives

Safety First

Deer–vehicle accidents were identified as a primary concern involving human safety and damage to property by the Illinois “Joint Task Force on Deer Population.”

Management Basics

  • The frequency of deer–vehicle accidents is influenced by the number of deer in an area.
  • Deer numbers vary widely in the various landscapes throughout Illinois.
  • The 102 counties of the state provide biologists units of the landscape that are small enough to work with effectively.
  • Deer–vehicle accident numbers and details on vehicle traffic are routinely collected by the Illinois Department of Transportation for each county.
  • Hunting helps control the number of deer.

Making use of these facts, biologists developed a simple, yet effective, approach to deer management. See Reducing Deer–Vehicle Accidents below for details.

Reducing Deer–Vehicle Accidents

Reducing accidents by managing the number of deer

Since deer–vehicle accidents are one of the major conflicts caused by an abundance of deer, it is logical to use deer–vehicle accident rates, rather than using specific numbers of deer or deer densities, as a measure to judge whether management is maintaining deer populations at acceptable levels.

By dividing the number of accidents by the number of vehicle miles travelled, biologists developed a deer–vehicle accident rate for each county.

Each county in Illinois is assigned a goal for reducing the deer–vehicle accident rate to a level at or below a set rate, achieved primarily by deer hunting. More hunting permits are issued as the accident rate increases.

This graph displays Illinois deer harvest and deer-vehicle accident rate from 1989 to 2019.

Counties with deer infected with chronic wasting disease have objectives to reduce the size of the deer herd below the level determined by the deer-vehicle accidents index.

The Illinois Department of Natural Resources provides an Interactive Map for viewing deer–vehicle accidents across the state.

A snapshot of the Interactive Map showing DVAs in Illinois.

Tips for Motorists

In Illinois, deer–vehicle accidents increase slightly during June, but the peak of accidents happening October through December. Motorists can reduce their chance of a deer-vehicle accident by knowing basic deer behaviors and following these tips:

A deer road sign like this one near the busy road alerts motorists that deer may be in the area.
A deer road sign alerts motorists that deer may be in the area.
Photo: Sarah Marjanovic
  • Be on the lookout for deer in areas where deer have been spotted in the past.
  • Be aware that deer often cross a road and then double back.
  • If you see one deer, be on the lookout for more—deer often travel together.
  • Reduce your speed, keep a safe distance from other vehicles, and be prepared to stop.
  • Alert other motorists to the presence of deer by tapping your brakes.
  • Avoid swerving into traffic or off the road if deer are on the roadway. Instead, slow to a stop and wait for the deer to move.
  • Flash your headlights and honk your car horn to encourage deer to move off the road.

Disease Management and Prevention


Occasionally, a disease appears in the deer population, typically starting in one region.

Reports of animals displaying specific signs alert biologists of areas where a potential disease outbreak may be underway.

Definitive disease diagnosis requires testing tissue samples from a sick or freshly dead deer.


Many deer diseases are transmitted through saliva or fecal contamination by animals sharing common feeding sites. Consequently, Illinois law prohibits making food, salt, or mineral blocks available to wildlife in areas where wild deer are present.

Strict rules on feeding wildlife, including deer, are set in the Illinois Administrative Code: