Mammals
The interspersion of life zones provides habitat that accommodates a wide assortment of mammals. On quiet nights, coyotes can sometimes be heard howling along the shorelines and in large timber areas. Fox and coyote trails circle marsh edges and follow the timbered edges of fields. Foxes and raccoons are the most abundant predators, while cottontails and fox squirrels are the most common rodents. Whitetail deer are often seen along the refuge roads, and dike areas are often signed with their tracks.
Badgers are seen rarely, but their diggings are obvious along the dike areas. Beavers, muskrats, and woodchucks are common but infrequently seen. The squeaking of southern flying squirrels is commonly heard at night.
List of Mammals of the Illinois River National Wildlife and Fish Refuges
The following mammal list includes only those that have actually been observed on the refuges. Additional species can be expected, and will be added to the list as time passes. The 28 species listed are represented by official records and specimens preserved in the U.S. Fish and Wildlife Service collections at Washington, D.C., in the Museum of Natural History of the University of Illinois, and elsewhere.
Because common names for mammals vary, scientific names have been included.
- Opossum (Didelphis marsupialis)
- Common in sandy-loam bluff areas, lowlands, and dike areas.
- Eastern Mole (Scalopus aquaticus)
- Common in sandy-loamy areas along the eastern bluff of Chautauqua Refuge.
- Little Brown Myotis (Myotis lucifungus)
- This bat is abundant during the period April-November throughout the refuges.
- Big Brown Bat (Eptesicus fuscus)
- Abundant during summer months.
- Hoary Bat (Lasiurus cinereus)
- Common during summer months along bottomlands and wooded uplands.
- Eastern Cottontail (Sylvilagus floridanus)
- Abundant throughout the refuges in all but very wet areas. Frequent prey of foxes and owls during the winter months. Its nests are often found on the Headquarters lawn and it feeds on the spillage under the bird feeders at night.
- Woodchuck (Marmota monax)
- Common along the eastern sandy-loam bluff and wooded dike areas of Chautauqua Refuge.
- Eastern Fox Squirrel (Sciurus niger)
- Abundant throughout bottomland and upland timber areas. Competes with wood ducks for nesting cavities in large trees.
- Southern Flying Squirrel (Glaucomys volans)
- Abundant throughout upland hardwoods. Can often be heard squeaking on quiet, warm nights.
- Plains Pocket Gopher (Geomys bursarius)
- Common in grassland areas.
- Beaver (Castor canadensis)
- Common in borrow ditch areas near young cottonwood stands. Bank dens are used with brush over entrances. Winter food caches can usually be found.
- Deer Mouse (Peromyscus maniculatus)
- Abundant in upland areas.
- White-footed Mouse (Peromyscus leucopus)
- Abundant in upland areas and along dry areas of bottomland mixed hardwoods.
- Southern Bog Lemming (Synaptomys cooperi)
- Occasionally found in marsh areas. Dead ones are occasionally seen in or near owl nests.
- Meadow Vole (Microtus pennsylvanicus)
- Common in fields and wooded areas.
- Pine Vole (Pitymys pioneetorum)
- Occasionally found in bottomland areas and along the wooded east bluff of Chautauqua Refuge.
- Muskrat (Onodatra zibethicus)
- Abundant throughout marsh, shore, and dike areas. Damages dikes by tunneling. Benefits waterfowl by cutting openings in lotus, and ducks use muskrat houses for loafing areas.
- Norway Rat (Rattus norvegicus)
- Occasionally found along marsh and shore areas.
- House Mouse (Mus musculus)
- Common near buildings. Makes extensive tunnels in ground near grain bins and under heavy equipment.
- Meadow Jumping Mouse (Zapus hudsonius)
- Occasionally seen along the wooded edge and grassland areas.
- Coyote (Canis latrans)
- Rare, but howling is frequently heard in early spring, and tracks are often seen in the snow.
- Red Fox (Vulpes fulva)
- Common throughout the refuges, particularly in the winter months and when vegetation is low.
- Gray Fox (Urocyon cinereoargenteus)
- Common throughout the refuges, especially in the winter months and when vegetation is low.
- Raccoon (Procyon lotor)
- Abundant in all areas of the refuges. Competes with wood ducks for nesting cavities in large trees.
- Mink (Mustela vison)
- Common in lowland, shore, and dike areas.
- Badger (Taxidea taxus)
- Uncommon, but its extensive diggings can usually be found along the eastern bluff of Chautauqua Refuge and on wooded dikes.
- Striped Skunk (Mephitus mephitus)
- Uncommon on the refuges, but occasionally found along dikes and roads.
- Whitetail Deer (Odocoileus virgineanus)
- Common throughout wooded, marsh, and dike areas.
