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Canadian Beaver Castor Canadensis. Bio 586/786 Jacob Stewart. Classification . Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Mammalia Order: Rodentia Suborder: Sciurognathi Family: Castoridae Genus: Castor Species: Castor canadensis. Identification.
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Canadian BeaverCastor Canadensis Bio 586/786 Jacob Stewart
Classification • Kingdom: Animalia • Phylum: Chordata • Subphylum: Vertebrata • Class: Mammalia • Order: Rodentia • Suborder:Sciurognathi • Family: Castoridae • Genus: Castor • Species: Castor canadensis
Identification • largest rodent in North America and second only to the Capybara in South America • Length of head and body: 22 to 27 inches • Length of tail: 12 to 16 inches • Total length: 34 to 43 inches • Weight: 30 to 68 lbs have been know to weigh up to 100 lbs!!!!
Identification cont. • Large flat, black tail • They have a waterproof, glossy, reddish brown or blackish brown coat. • The ears are short, round, and dark brown in coloration. • A beaver's hind legs are longer than its front legs, thus making the rear end to be higher than the front end while walking.
Distribution • In 1600 there were 60 to 100 million beaver in North America. • First exploitation of a natural resource by Europeans • Beaver pellets were used for currency by early settlers • The beaver went extinct east of the Mississippi River.
Distribution Whiteman exported 500,000 skins annually until 1800 when legislation was put in place to protect the beaver. Now 175,000 pelts are harvested annually. In some places the beaver has re-established itself to nuisance proportions. The population is still thought to be only 5 % of what it was when America was first settled
Life History • Beavers are monogamous • They stay together for life, but will remarry if mate dies. • beavers mate in their lodges, they often choose to couple under water, and in some cases, under the ice. • Breeding starts in January or February • Gestation lasts about 4 months • The kits are wined at 1 mounth. • male and female both take care of the young • The female can have 1-5 young • So a beaver lodge can have up to 12 beavers present at one time.
Life history cont. • The babies are about one pound at birth • Born with full coat of fur and their eyes open • Kits can swim, but it may take them a month or more to figure out how to hold their breath • The young stay with the parents until they are 1.5-2.5 years old. • They then leave their parents lodge and start to build their own lodge.
Life history • Beavers can live any were from 10 to 20 years in the wild • Have lived up to 50 years in captivity
Man is the main cause of mortality Wolves Coyotes Lynx Bears Wolverines Prey on Young Mink Hawks Owls Mortality
Diet • herbivores • Prefer herbs over woody plants when available • water lilies and other aquatic vegetation in the early spring • aspen, poplar, birch, maple, willow and alder In the winter
Behavior • Beavers are primarily nocturnal, dividing their time between feeding, grooming, repairing lodges and dams, resting and playing. • A successful beaver pair require cooperation and a strong bond. The couple shares a lodge, and collaborates in building duties and territorial defense. • Though beavers will defend their colony and lodge against members of other colonies, they may co- operate in the repair of a shared dam. • The beavers greatest protection against heat loss is its coat. Therefore, grooming takes on particular importance. Using a modified claw, beavers comb castoreum, into their fur. • Castoreum, a complex mixture of more than 50 different chemicals, is excreted by a gland near the anus. Aside from being an efficient waterproofing agent, • This concoction is likely pheromonal that is used by both the male and female to mark territories , and used in attracting mates .
Behavior cont. • Beavers are active year-round. • While ambient temperatures may fall to -40 C, the temperature within the chamber of occupied beaver lodges seldom drops below freezing. • The beaver caches food in the den in the late fall so the will have food for the winter. • The lodges also serve as a nearly impregnable defense against predators.
Wetland habitat needs • All beavers need is a source of water and a good supply of food (plants). • Usually in a flat wooded valleys • Beavers' ability to change the landscape is second only to humans
The beaver lodge • Beavers create their own impoundments called lodges or dams • These lodges are made of sticks, mud, and other vegetation. • They create these for protection against predators and for protection against the elements.
Vocalization • communicates through tail slapping, scent marking, postures, and various vocalizations. • Young and adult beavers communicate with soft chortling noises. • The young can make sounds that resemble a duck quacking.
Importance of the beaver • Indians called beaver ponds the “sacred center. This was because the beaver creates valuable habitat for mammals, fish, turtles, frogs, birds and ducks. • In essence beavers are a keystone species. They create habitat and species diversity.
Beaver Problems • Out law trapping in Colorado • Flooding agriculture fields • Cutting down trees • Road flooding • Redirect stream flows • loss of large specimen trees • higher water temperatures. .
Management • Trapping • Cylindrical Cages • Paint with Sand • Low Fences • Electric wire • Repellents and Other Methods • Learn to live with Beaver • Tree cutting
Trapping • Conibear Trap • Leghold Trap • Basket / suitcase type traps
When to use pipes • 1. There must be at least 4 feet of water depth available after the pipe is installed in climates where the water freezes. In other words you must have enough depth so that the beaver can still swim under the ice no matter how thick the ice gets. You will need more depth in more northern regions. • 2. There is enough land around the pond to allow for seasonal flooding. • 3. There is no concern with tree damage. Pipes don't protect trees. • In any event, we recommend the following definition of what constitutes an effective and working beaver pipe: • 1. Flooding must be controlled to tolerable limits of those living around the water shed. • 2. The pipe should only need to be cleaned no more than once per week. • 3. The pipe should solve the flooding problem for at least one year. • 4. Sue Langlois of the MDFW stated that she would like another criterion added namely, that the beavers stayed in the dam area after the pipe was installed.
Tree cutting • A man named Rawge, does not suggest removing trees to discourage beaver. He says, "having studied beaver for many years, and removing the trees will result in their eating telephone poles for gnawing and roots and tubers, or even grass for nutrients. I have studied their diets under stressed circumstances and would not recommend removing trees.; they just change to other sources, and its doubtful that they would abandon the area. I do agree with the tree wrapping.(http://www.wildlifedamagecontrol.com/beaverdamagesolutions.htm#Non-Lethal%20Beaver%20Control%20Methods)
Interesting Facts • A Beaver's chewing force is 80 kg (176 lbs) compared to man's 40 kg. (88 lbs). • Some Beavers are reported to travel as far as 147 miles from the lodge they were born in. • Beavers can chew through a six-inch tree in 15 minutes. • A single beaver can chew down hundreds of trees each year.
Works Cited • Lawrence, William H. 1954. Michigan beaver populations as influenced by fire and logging. Ann Arbor, MI: University of Michigan. 219 p. Dissertation. [16480] • http://www.csh.rit.edu/~snell/beaver.html • http://www.bear-tracker.com/beaver.html • http://www.beaversww.org/beaver.html • http://www.aquatic.uoguelph.ca/mammals/freshwater/accounts/beaver.htm • Allen, Arthur W. 1983. Habitat suitability index models: beaver. FWS/OBS-82/10.30 (Revised). Washingtion, DC: U.S. Department of the Interior, Fish and Wildlife Service. 20 p. [11716 • http://www.pfmt.org/wildlife/somethings/beaver.htm • http://www.wildlifedamagecontrol.com/beaverdamagesolutions.htm#Non-Lethal%20Beaver%20Control%20Methods • http://www.dec.state.ny.us/website/dfwmr/wildlife/beaver/handou11.htm