Canadian Beaver Castor Canadensis

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Canadian BeaverCastor Canadensis

• Bio 586/786
• Jacob Stewart

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Classification

• Kingdom Animalia
• Phylum Chordata
• Subphylum Vertebrata
• Class Mammalia
• Order Rodentia
• SuborderSciurognathi
• Family Castoridae
• Genus Castor
• Species Castor canadensis

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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!!!!

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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.

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Identification
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Identification of the skull
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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.

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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

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Distribution
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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.
•  

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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.

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Life history

• Beavers can live any were from 10 to 20 years in
  the wild
• Have lived up to 50 years in captivity

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Mortality

• Man is the main cause of mortality
• Wolves
• Coyotes
• Lynx
• Bears
• Wolverines

• Prey on Young
• Mink
• Hawks
• Owls 

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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

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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 .

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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.

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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

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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.

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Beaver lodge
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Beaver lodge cont.
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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.

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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.

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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.

.
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Management

• Trapping
• Cylindrical Cages
• Paint with Sand
• Low Fences
• Electric wire
• Repellents and Other Methods
• Learn to live with Beaver
• Tree cutting

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Trapping

• Conibear Trap
• Leghold Trap 
• Basket / suitcase type traps

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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.

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Beaver pipes
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Management
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Management
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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/bea
  verdamagesolutions.htmNon-Lethal20Beaver20Contr
  ol20Methods)

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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.

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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/beaverdamages
  olutions.htmNon-Lethal20Beaver20Control20Metho
  ds
• http//www.dec.state.ny.us/website/dfwmr/wildlife/
  beaver/handou11.htm