Illinois is home to diverse wildlife, with deer being a prominent part of the state’s ecosystems. One particular deer species overwhelmingly dominates the landscape, shaping interactions within various habitats. Understanding this prevalence is key to appreciating the state’s deer population.
The Dominant Species: White-tailed Deer
The White-tailed Deer (Odocoileus virginianus) is the primary wild deer species found throughout Illinois. Historically, its population faced near elimination by the late 1800s due to unregulated hunting and land use changes. A restocking effort initiated in the 1930s allowed the population to rebound, leading to its current widespread presence. Today, the White-tailed Deer is considered the state mammal of Illinois and is found across all 102 counties. Its adaptability to various environments has solidified its ecological importance.
Identifying White-tailed Deer
White-tailed Deer have distinct physical characteristics. Their coat color changes seasonally, from reddish-brown in spring and summer to grayish-brown in fall and winter. The underside of their tail, throat, belly, and inner legs are white. When raised, their tail exposes its bright white underside, a behavior known as “flagging” that signals alarm or helps fawns follow their mothers. Fawns, or young deer, are born with a reddish-brown coat covered in 250 to 350 white spots, providing camouflage.
Adult White-tailed Deer vary in size, with males generally larger than females. Males, known as bucks, weigh between 150 and 300 pounds, while females, or does, range from 90 to 200 pounds. Their shoulder height can be between 2.5 and 3 feet. Male White-tailed Deer grow antlers annually, which are shed between late December and mid-March. These antlers are solid bone formations, with size and shape influenced by genetics, nutrition, and age.
Where White-tailed Deer are Found
White-tailed Deer are highly adaptable, inhabiting various environments across Illinois. They thrive in or near wooded areas, especially along streams or adjacent to agricultural fields. These deer are also commonly found at habitat edges, where forests meet open areas, providing both cover and abundant food sources. Their presence extends into suburban and urban natural areas, including forest preserves and intensively farmed regions.
Factors influencing their distribution include the availability of food, water, and cover, as well as climate and the presence of competitors. The highest densities of deer are often associated with wooded areas along the watersheds of major rivers like the Mississippi, Rock, Illinois, and Kaskaskia, and in the Shawnee Hills region. Their ability to utilize a mix of agricultural, forest, and urban habitats allows them to flourish statewide.
Are There Other Deer in Illinois?
While White-tailed Deer are the predominant species, other deer types are not typically found as native wild populations in Illinois. Historically, Elk (Cervus canadensis) were present but were extirpated from the state by around 1830. Although rare instances of Elk returning occur, they do not represent established wild herds. Mule Deer (Odocoileus hemionus) are primarily found in western North America and are not considered a resident wild species in Illinois.
Non-native deer species, such as Fallow Deer and Sika Deer, have been introduced to the state, often for hunting or as escaped captives. Fallow Deer, native to Europe, are medium-sized with variable coat colors and distinctive palmate antlers on males. Sika Deer, originating from Japan, are smaller and reddish-brown with white spots. These non-native species are not protected in Illinois and are not part of the wild, free-ranging deer population, with White-tailed Deer remaining the singular native deer species.