 Beaver
scientific name
Castor canadensis
size
Body. 28"
Tail. 12" long " 4 1/2" wide
Weight. 35-60 lbs.
among largest rodents
characteristics
Front Feet: unwebbed; strong digging claws
Hind Feet. webbed " help swim 5 mph
Front Teeth. special flap of skin behind front teeth allows gnawing bark underwater without getting mouth full of water or wood chips " front incisors never stop growing - worn down with use
Fur. keeps beaver warm & dry (undercoat traps layer of air to insulate skin) even in cold water
Nostrils/Ears. valves stop water from entering
Tail. scaly; broad; used as rudder & to make warning sounds by slapping water
behavior
diurnal: become nocturnal with human encroachment; does not hibernate
Dam:. branches, grass, & mud; creates deep water needed for protection; main lodge 6-10' diameter; said to cause floods but (on other hand) help control runoff, aid in checking erosion & aid in maintaining suitable water table for fish & waterfowl
Enemies. bears, wolves, fishers, otters, & lynx
Colony. 4-8 related beavers
Winter Food. collects & anchors supply green branches underwater in fall
Enemies: bears, wolves, fishers, otters, lynx
reproduction/lifespan
Lifespan: 13-20 years
Gestation: 3 months
Litter. 2-4; usually born in spring; swim within 1 day " leaves parents at 2 years
diet
Herbivore
Wild. leaves, juicy green inner layer of bark (cambium layer), roots, water plants, herbs, & algae; does not eat wood
Zoo. rat chow, monkey chow, carrots, apples, broccoli, & browse
habitat/range
Streams, rivers, marshes, & small lakes; Canada & U.S.
status
Stable to increasing in what remains of suitable habitat; Threats are civilization, habitat destruction, water pollution, & hydro-electric dam construction; regulated by ODFW
other
Among largest rodents - largest in North America; "Engineer" of animal kingdom; Can fell 8' tree in 5 minutes; Probably contributed more to development of U.S. & Canada than any other animal; Their pelts value motivated trappers to move farther & farther west; Trappers followed by settlers; Pelts used as currency in colonial times
oregon zoo exhibit
Cascades
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