olena
<font color=green>Emerald Angel<br><font color=mag
- Joined
- May 12, 2001
State Animal
American Beaver
Castor canadensis
Description A very large, bulky rodent, with rounded head and small, rounded ears. Dark brown fur is fine and soft. Scaly tail large, black, horizontally flattened, and paddle-shaped. Large, black, webbed hindfoot has 5 toes, with inner 2 nails cleft. Eyes and ears small. Large, dark orange incisors. L 34' (9001,200 mm); T 11 3/417 1/2" (300440 mm); HF 6 1/88 1/8" (156205 mm); Wt usually 4460 lb (2027 kg), but sometimes up to 86 lb (39 kg).
Similar Species Muskrats and Nutria are much smaller and have slender tails.
Breeding Mates late Januarylate February; 18 kits (usually 4 or 5) born after gestation of 4 months.
Habitat Rivers, streams, marshes, lakes, and ponds.
Range Most of Canada and U.S., except for most of Florida, much of Nevada, and s California.
Discussion Active throughout the year, the American Beaver is primarily nocturnal and most likely to be observed in the evening. Beavers living along a river generally make burrows with an underwater entrance in the riverbank; these are known as bank beavers. Those in quiet streams, lakes, and ponds usually build dams and a lodge. The lodge has one or more underwater entrances; living quarters are in a hollow near the top. Wood chips on the floor absorb excess moisture, and a vent admits fresh air. The chief construction materials in the northern parts of the American Beavers rangepoplar, aspen, willow, birch, and mapleare also the preferred foods. To fell a tree, the beaver gnaws around it, biting out chips in a deep groove. Small trees 2 to 6 inches (50150 mm) in diameter are usually selected, though occasionally larger ones as much as 33 inches (850 mm) thick are felled; a willow 5 inches (125 mm) thick can be cut down in three minutes. The beaver trims off branches, cuts them into convenient sizes (about 1 to 2 inches /2550 mm thick and 6 feet/1.8 m long), and carries them in its mouth to the dam site. There it either eats the bark, turning the branches in its forefeet as humans eat an ear of corn, or stores them underwater for winter use by poking the ends into the muddy bottom of the pond or stream. Dam designs vary widely: To lessen water pressure in swift streams, dams may be bowed upstream; in times of flood, temporary spillways may be constructed. Dam repair is constant; the sound of running water stimulates the beaver to repair the dam. Well adapted to its highly aquatic life, the beaver swims, using its webbed hindfeet, at speeds up to 6 mph (10 km/h). The tail serves as a rudder, and the forefeet are held close to the chest, free to hold objects against the chest or to push aside debris. When the animal is submerged, valves close off the ears and nostrils; skin flaps seal the mouth, leaving the front incisors exposed for carrying branches; and clear membranes slide over the eyes, protecting them from floating debris. A beaver can remain submerged for up to 15 minutes before surfacing for air. When the animal is swimming, usually only the head is visible, whereas with muskrats, both head and back are partially above water. The beaver combs its fur with the two split nails on its hindfoot, and waterproofs it by applying castoreum, an oily secretion from scent glands near the anus. A thick layer of fat beneath the skin provides insulation from chilly water in winter. On land, the beaver is far less at ease than when in the water, and frequently interrupts its activity to sniff the air and look for signs of danger. Beavers are believed to pair for life. Kits are born well furred, with eyes open, and weighing about 1 pound (.5 kg). They may take to the water inside their lodge within a half hour and are skillful swimmers within a week; if tired, they may rest or be ferried upon the mothers back. On land, the mother often carries kits on her broad tail and sometimes walks erect and holds them in her forepaws. The young remain with their parents for two years, helping with housekeeping chores until they are driven away just before the birth of a new litter.Great expanses of the U.S. and Canada were first explored by trappers and traders in search of beaver pelts, the single most valuable commodity in much of North America during the early 19th century. The fur was in constant demand for robes and coats, clothing trim, and top hats (sometimes called "beavers") that were fashionable in European capitals and urban areas of the eastern U.S. Some of Americas great financial empires and real estate holdings were founded on profits from the trade in beaver fur. Unregulated trapping continued for so longwell into the 20th century in some areasthat the American Beaver disappeared from much of its original range. Now reestablished over most of the continent and protected from overexploitation, it has become an agricultural pest in some regions, and it kills many trees, most of little value as timber. Its dams may block the upstream run of spawning salmon and flood stands of commercial timber, highways, and croplands, or change a farmers pond or stream into a slough that will eventually become a meadow. However, the dams also help reduce erosion, and the ponds formed by the dams may create a favorable habitat for many forms of life: Insects lay eggs in them, fish feed on the insect larvae, and many kinds of waterfowl and mammalsincluding otters, Minks, Moose, and deercome to feed and drink. The beavers fine, soft fur is highly prized, and its meat is considered a delicacy by some residents of the far north. Aside from trappers, the otter is the beavers most important enemy, though the Gray Wolf, Coyote, Common Red Fox, and Bobcat also prey upon it.
American Beaver
Castor canadensis
Description A very large, bulky rodent, with rounded head and small, rounded ears. Dark brown fur is fine and soft. Scaly tail large, black, horizontally flattened, and paddle-shaped. Large, black, webbed hindfoot has 5 toes, with inner 2 nails cleft. Eyes and ears small. Large, dark orange incisors. L 34' (9001,200 mm); T 11 3/417 1/2" (300440 mm); HF 6 1/88 1/8" (156205 mm); Wt usually 4460 lb (2027 kg), but sometimes up to 86 lb (39 kg).
Similar Species Muskrats and Nutria are much smaller and have slender tails.
Breeding Mates late Januarylate February; 18 kits (usually 4 or 5) born after gestation of 4 months.
Habitat Rivers, streams, marshes, lakes, and ponds.
Range Most of Canada and U.S., except for most of Florida, much of Nevada, and s California.
Discussion Active throughout the year, the American Beaver is primarily nocturnal and most likely to be observed in the evening. Beavers living along a river generally make burrows with an underwater entrance in the riverbank; these are known as bank beavers. Those in quiet streams, lakes, and ponds usually build dams and a lodge. The lodge has one or more underwater entrances; living quarters are in a hollow near the top. Wood chips on the floor absorb excess moisture, and a vent admits fresh air. The chief construction materials in the northern parts of the American Beavers rangepoplar, aspen, willow, birch, and mapleare also the preferred foods. To fell a tree, the beaver gnaws around it, biting out chips in a deep groove. Small trees 2 to 6 inches (50150 mm) in diameter are usually selected, though occasionally larger ones as much as 33 inches (850 mm) thick are felled; a willow 5 inches (125 mm) thick can be cut down in three minutes. The beaver trims off branches, cuts them into convenient sizes (about 1 to 2 inches /2550 mm thick and 6 feet/1.8 m long), and carries them in its mouth to the dam site. There it either eats the bark, turning the branches in its forefeet as humans eat an ear of corn, or stores them underwater for winter use by poking the ends into the muddy bottom of the pond or stream. Dam designs vary widely: To lessen water pressure in swift streams, dams may be bowed upstream; in times of flood, temporary spillways may be constructed. Dam repair is constant; the sound of running water stimulates the beaver to repair the dam. Well adapted to its highly aquatic life, the beaver swims, using its webbed hindfeet, at speeds up to 6 mph (10 km/h). The tail serves as a rudder, and the forefeet are held close to the chest, free to hold objects against the chest or to push aside debris. When the animal is submerged, valves close off the ears and nostrils; skin flaps seal the mouth, leaving the front incisors exposed for carrying branches; and clear membranes slide over the eyes, protecting them from floating debris. A beaver can remain submerged for up to 15 minutes before surfacing for air. When the animal is swimming, usually only the head is visible, whereas with muskrats, both head and back are partially above water. The beaver combs its fur with the two split nails on its hindfoot, and waterproofs it by applying castoreum, an oily secretion from scent glands near the anus. A thick layer of fat beneath the skin provides insulation from chilly water in winter. On land, the beaver is far less at ease than when in the water, and frequently interrupts its activity to sniff the air and look for signs of danger. Beavers are believed to pair for life. Kits are born well furred, with eyes open, and weighing about 1 pound (.5 kg). They may take to the water inside their lodge within a half hour and are skillful swimmers within a week; if tired, they may rest or be ferried upon the mothers back. On land, the mother often carries kits on her broad tail and sometimes walks erect and holds them in her forepaws. The young remain with their parents for two years, helping with housekeeping chores until they are driven away just before the birth of a new litter.Great expanses of the U.S. and Canada were first explored by trappers and traders in search of beaver pelts, the single most valuable commodity in much of North America during the early 19th century. The fur was in constant demand for robes and coats, clothing trim, and top hats (sometimes called "beavers") that were fashionable in European capitals and urban areas of the eastern U.S. Some of Americas great financial empires and real estate holdings were founded on profits from the trade in beaver fur. Unregulated trapping continued for so longwell into the 20th century in some areasthat the American Beaver disappeared from much of its original range. Now reestablished over most of the continent and protected from overexploitation, it has become an agricultural pest in some regions, and it kills many trees, most of little value as timber. Its dams may block the upstream run of spawning salmon and flood stands of commercial timber, highways, and croplands, or change a farmers pond or stream into a slough that will eventually become a meadow. However, the dams also help reduce erosion, and the ponds formed by the dams may create a favorable habitat for many forms of life: Insects lay eggs in them, fish feed on the insect larvae, and many kinds of waterfowl and mammalsincluding otters, Minks, Moose, and deercome to feed and drink. The beavers fine, soft fur is highly prized, and its meat is considered a delicacy by some residents of the far north. Aside from trappers, the otter is the beavers most important enemy, though the Gray Wolf, Coyote, Common Red Fox, and Bobcat also prey upon it.
