Beaver
- Physical Appearance: The beaver is the largest of the rodents of North America with adults weighing between 26 and 90 pounds and ranging from 34 to 54 inches in length. Individuals weighing over 100 pounds have been documented. The sexes cannot be distinguished based on size or other external physical characteristics, except lactating females. The pelage color of most beavers is reddish dark brown although the fur may be black, pale silver, or even blonde.
- Range: Beavers occur throughout North America except in arid and desert environments and the Florida peninsula.
- Habitat: Beavers are highly adapted to freshwater environments and will rarely venture far from a water source. Beavers live in and along lakes, wetlands, rivers, and streams. In locations where slow-running water is present, extensive dams are often constructed. In such environments, beavers will often construct a den in a high stream bank. In still waters, beavers often build lodges from tree limbs and other debris.
- Food Habits: Beavers are strict herbivores, and their food habits depend highly on the season. In the spring and fall, their diet is about half woody vegetation and half non-woody vegetation. In the summer months, the amount of non-woody vegetation increases to about 90%. In the winter months, woody vegetation makes up 100% of their diet. When consuming woody plants, beavers generally eat the bark and the cambium layer above the wood layer.
- Reproduction: The breeding season for beavers varies based on latitude. In the southern United States, the breeding season occurs from October through March; while farther north, breeding begins in January or February, generally concluding by late March. The gestation period is 105 to 107 days with only one litter per year. The average litter size is three to four young (kits) with extremes of one to eight. Large litters are typically born in favorable environmental conditions and to older, larger females. Beavers do not reach sexual maturity until they are 18 to 21 months of age. Individuals do not breed until at least their second year of life, but it is more common to begin breeding in the third year. Young rarely leave the den before one month of age.