Prairie State Wildlife

Beavers   Castor canadensis

Beavers are amazing and magnificent animals and although they require a great deal of labor they are our favorite species to work with.  Calls to our office for beaver control usually occur in the spring and fall.  Young beavers often seek out new territories in spring and make themselves known to landowners with their tree removal in order to build a new lodge or denning area.  In fall, calls for service increase as beavers prepare for long periods locked under the ice.  This preparation period requires the cutting of trees and the relocation of the branches etc. under the surface of the water.  The collection of trees serves as a food source throughout the long winter.  Landowners, at this time of year, often notice increased cutting activity and it is not uncommon to lose more than one tree from a property in one fall evening.Large flattened tail of the Illinois beaver.

Beavers are found throughout the state of Illinois and are very common in our service area.  They are the largest North American rodent with a large specimen reaching 80 pounds or more.  The largest beaver captured by our company to date was an eighty two pound female.  Most beavers average 35 to 55 pounds and are very suited to it's aquatic habitat.  Although beavers are seen on land they are most often observed in the water.  They are well adapted for life in the water as they possess closable nostrils, closable ears, nictitating membranes (translucent eye covering) and lips that close behind the animals large incisors.  The most well-known and identifiable parts of the beaver are its large front teeth, large webbed back feet and its unmistakable paddlelike tail used for swimming.  The tail is also used as a tool to warn of approaching danger and is “slapped” against the surface of the water in order to warn other members of the beaver colony a predator may be near.  Live beaver trapped in suitcase trap.

Beavers live in colonies consisting of an adult breeding pair, two to four kits from the previous spring litter, two or three yearlings, and occasionally one or more 2.5 year olds.  Large colonies may contain as many as twelve beaver.  Beaver can be found anywhere a stable water source can be found.  They colonize creeks, ponds, lakes and large impoundments with plenty of food sources nearby.  Once a wetland is suitable to the beavers, a dam is constructed of branches, sticks and mud from the bottom of the creek.  Denning areas include the construction of a lodge located in the wetland or a den created by burrowing into a steep bank.  Entrances into both the lodge and the bank den are located underwater.  Beavers feed on numerous woody species of tree including aspen, cottonwood, willow, sweetgum, tulip, poplar and black cherry.  They also eat numerous other species of herbaceous and aquatic plants.  Beavers also feed on many farm crop species including corn and soybeans.  Large areas of corn, near a creek or wetland, can be decimated by a colony of beavers.  Trees cut down and stored for winter are often located near the lodge or den site and is referred to as a “feed pile”.  Obvious sign a beaver is present.

Beavers breed between January and March and are generally monogamous.  After a 128 day gestation period 2 to 4 kits are born but as many as nine have been reported.  The young are generally weaned by 3 months and join the rest of the colony on their nightly forays to feed.  Upon reaching 2.5 years of age, and sexual maturity, young beaver are driven out from the colony and seek out new territory.  It is this movement of young beavers that results in numerous calls to the office in spring and early summer.

Beavers are very active and may spend up to 12 hours every evening (they are mostly nocturnal) repairing their dams, tending to the lodge and feeding. Beaver dam blocking local creek. Signs of beaver activity include flooding, bank burrowing, dammed-up culverts, tree cutting, dam construction and “snack bars” (areas littered with sticks peeled of their bark lying along the bank).

Damage prevention includes the wiring of trees, installation of pond levelers and the capture of problem animals.     



Prairie State Wildlife
P.O. Box 224 Oswego, IL 60543 US
Phone: (630) 687-3414 Website: