Laona Heights Sugar River Colored Sands Sugar River Two Rivers Ferguson Hartley Memorial Trask Bridge Four Lakes Pecatonica River Pecatonica Wetlands Crooked River Grove Creek Seward Bluffs Klehm Forest Preserve Severson Dells Fuller Memorial Cedar Cliff Indian Hill Hinchliff Memorial Kilbuck Bluffs Trailside Kishwaukee Gorge South Kishwaukee Gorge North Rockford Rotary Kishwaukee River Oak Ridge Blackhawk Springs Deer Run Espenscheid Memorial McKiski County Line Kieselburg Roland Olson Stone Bridge Clayton Andrews Ledges Hononegah J. Norman Jensen Millrace Isle Macktown Atwood Homestead Forest Preserve Headquarters


Humans have impacted the mammals of Winnebago County in many ways. Historically, there were many species of large mammals that no longer exist here today. Changes in land use and habitat destruction have caused the extinction of most of this area’s large mammals.
In the 1800’s when settlers began populating Winnebago County, the land was “filthy” with wild critters. Creeks and roads in our county still bear the names given to them by early settlers. Among them are Otter Creek that travels through Durand and empties into the Sugar River; and Coon Creek which flows into the Pecatonica River. Auburn Street in Rockford was originally named Wolf Grove Road.

In the late 1800’s and 1900’s much of the prairies and forests were converted to cropland. This changed the way of life for many mammals that lived here. Some mammals were hunted and trapped intensively during this period. The black bear, wolf and mountain lion were hunted to extinction in the area. Beaver, river otter, white-tailed deer, elk and buffalo were not sought out to be eliminated but their populations were over harvested. Hard winters, uncontrolled harvesting and reduced habitat in the now cultivated land all contributed to their extirpation or severely reduced number in the county.

Some of these mammals such as deer and river otters have responded to habitat restoration and wildlife protection measures of recent decades and can once again be seen in Winnebago County’s forest preserves and other natural areas.
Today, forty-eight species of mammals can be found in our county, and the nearly 10,000 acres of forest preserves provide critical habitat for many of them.


The American Badger is a squat medium-sized animal about 30 inches long, with short legs and a short bushy tail. If seen from the front the badger can easily be recognized by a white stripe that begins near its nose and goes to the back of its head.


Bats are truly unique among mammals because they are the only ones in the world that can fly. They navigate in part by emitting high-frequency sounds and then using their funnel-shaped ears to listen for the echoes those sounds make as they bounce off nearby objects.


At 4 feet long and 40 to 60 pounds, the American beaver (Castor canadensis) is North America’s largest rodent. It has a stocky body with glossy brown fur, short legs with webbed hind feet and a paddle-shaped tail.

Chipmunks and 13-lined Ground Squirrels

People commonly mistake eastern chipmunks (Tamias striatus) and 13-lined ground squirrels (Spermophilus tridecemlineatus) for the same animal, but both species have distinguishing marks and habits.

Eastern Cottontails

Eastern cottontails (Sylvilagus floridanus) vary in color from gray to brown. They have big ears, large hind feet and small white tails.

Foxes and Coyotes

Statewide surveys of furbearers in Illinois indicate gray (Urocyon cinereoargenteus) and red (Vulpes vulpes) foxes have experienced substantial declines in relative abundance, whereas other species such as raccoons (Procyon lotor) and coyotes (Canis latrans) have exhibited dramatic increases during the same time period.

Mice, Voles, Shrews and Moles

Mice and voles — like squirrels, chipmunks, muskrats, beavers and woodchucks — belong to the order Rodentia. This means that they have two pairs of ever-growing incisors, which they use to eat nuts, seeds, fruits, leaves, grasses and insects.

Minks and Weasels

Minks are members of the weasel (Mustelid) family, as are otters and badgers. These fearless carnivores are becoming much less common in Winnebago County, but if you are a careful observer, you may see them in the river and wetland habitats of the forest preserves.


A muskrat (Ondatra zibethicus) has a stocky dark brown body, small eyes and ears, and webbed hind feet. When fully grown, it’s about 1 foot long and 2 to 4 pounds.


Virginia opossums (Didelphis marsupialis) have white fur tipped with gray or black; long snouts with pink noses; bare ears; nearly hairless tails; and 50 teeth, the most of any North American land mammal.


The raccoon (Procyon lotor) has grayish brown fur, a black “mask” and a ringed tail. It’s dexterous, intelligent and shy by nature, although individuals can become bold when near humans.

River Otters

Otters were once found throughout Illinois but have become very rare in the state. Just ten years ago, otters were considered extirpated from Winnebago county, but the population has rebounded somewhat, due to river habitat protection and enhancement.


Aside from their recognizable black-and-white-striped coats, striped skunks (Mephitis mephitis) have small, pointed faces and sharp front claws, which they use for digging.

Tree Squirrels

Three species of tree squirrels occur in Winnebago County. All are small mammals characterized by a long, bushy tail, prominent ears, and long hind feet.

White-tailed Deer

The White-tailed Deer (Odocoileus virginianus), the largest wild mammal in Winnebago County, is a common sight in the forest preserves.