INF2011 North American Beaver _wikipedia

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05/06/2011 20:08North American Beaver - Wikipedia, the free encyclopedia

Page 1 of 16http://en.wikipedia.org/wiki/North_American_Beaver

Castor canadensis

Conservation status

Least Concern (IUCN 3.1)[1]

Scientific classification

Kingdom: Animalia

Phylum: ChordataClass: Mammalia

Order: Rodentia

Family: Castoridae

Genus: Castor

Species: C. canadensis

Binomial name

Castorcanadensis

Kuhl, 1820

Subspecies[2][3][4][5]

C. c. acadicus Bailey

C. c. baileyi Nelson

C. c. belugae Taylor

Cook Inlet beaverC. c. caecator Bangs

North American BeaverFrom Wikipedia, the free encyclopedia

The North American Beaver (Castor canadensis) is the onlyspecies of beaver in the Americas, native to North America andintroduced to South America. In the United States and Canada,

where no other species of beaver occurs, it is usually simply referredto as beaver. Its other vernacular names, including Americanbeaver[2] and Canadian beaver,[6] distinguish this species from theone other extant beaver, Castorfiber, native to Eurasia. ("Canadianbeaver" also refers to the subspecies Castor canadensis canadensis.)

Contents

1 Description2 Behaviour3 Subspecies4 Differences from European beaver5 Ecology

5.1 Effects on stream flows and water quality5.2 Effects on bird diversity5.3 Effects on trout and salmon5.4 Effects on riparian trees and vegetation5.5 Beavers and stream restoration

6 Urban beavers7 As introduced non-native species8 As food9 Symbolism10 References11 Further reading12 External links

DescriptionThis beaver is the largest rodent in North America and the thirdlargest rodent in the world, after the South American capybara andthe Eurasian beaver. Adults usually weigh 15 to 35 kg (33 to 77 lb),with 20 kg (44 lb) a typical mass, and measure around 1 m (3.3 ft) intotal body length. Very old individuals can weigh as much as 45 kg(99 lb).[7]

Like the capybara, the beaver is semi-aquatic. The beaver has many

traits suited to this lifestyle. It has a large flat paddle-shaped tail andlarge, webbed hind feet reminiscent of a human diver's swimfins.
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Newfoundland beaver

C. c. canadensis Kuhl

Canadian beaver

C. c. concisor

C. c. carolinensis Rhoads

Carolina beaver

C. c. duchesnei

C. c. frondator Mearns

Sonora beaver

C. c. idoneus

C. c. labradorensis

C. c. leucodonta Gray

Pacific beaver

C. c. mexicanus Bailey

Rio Grande beaver

C. c. michiganensis Bailey

Woods beaver

C. c. missouriensis Bailey

Missouri River beaver

C. c. pacificus Rhoads

Washington beaverC. c. pallidus

C. c. phaeus Heller

Admiralty beaver

C. c. rostralis

C. c. repentinus Goldman

C. c. sagittatus

C. c. shastensis Taylor

Shasta beaver

C. c. subauratus

California Golden beaver

C. c. taylori Davis

C. c. texensis Bailey

Texas beaver

Beaver lodge, Ontario, Canada

Beaver dam, northern California,USA

The unwebbed front paws are smaller, with claws. The eyes arecovered by a nictitating membrane which allows the beaver to seeunderwater. The nostrils and ears are sealed while submerged. Athick layer of fat under its skin insulates the beaver from its coldwater environment.

The beaver's fur consists of long, coarse outer hairs and short, fine

inner hairs (see Double coat). The fur has a range of colours butusually is dark brown. Scent glands near the genitals secrete an oilysubstance known as castoreum, which the beaver uses to waterproofits fur.

Before their near extirpation by trapping in North America, beaverwere practically ubiquitous and lived from the arctic tundra to thedeserts of northern Mexico, and from the Atlantic to the PacificOceans.[8][9] Explorer David Thompson, after crossing much ofNorth America in 1784, stated that "this Continent...from theAtlantic to the Pacific Ocean, may be said to have been in thepossession of two distinct races of Beings, Man and the Beaver."[10]

Behaviour

Beavers are mainly active atnight. They are excellentswimmers but are morevulnerable on land and tend toremain in the water as muchas possible. They are able toremain submerged for up to15 minutes. They use theirflat, scaly tail both to signaldanger by slapping thesurface of the water and as alocation for fat storage.

They construct their homes,or "lodges," out of sticks,twigs, and mud in lakes,streams, and tidal riverdeltas.[11] These lodges maybe surrounded by water, ortouching land, includingburrows dug into river banks.They are well known forbuilding dams across streams

and constructing their lodge in the artificial pond which forms.When building in a pond, the beavers first make a pile of sticks and
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C. c. canadensis, feeding in winter

then eat out one or more underwater entrances and two platforms above the water surface inside the pile.The first is used for drying off. Towards winter, the lodge is often plastered with mud which when it freezeshas the consistency of concrete. A small air hole is left in the top of the lodge.

The dam is constructed using sections of deciduous trees, especially birch, aspen, willow and poplar. Theinner bark, twigs, shoots and leaves of such trees are also an important part of the beaver's diet. [12] Thetrees are cut down using their strong incisor teeth. Their front paws are used for digging and carrying andplacing materials. Some researchers have shown that the sound of running water dictates when and where abeaver builds its dam. Besides providing a safe home for the beaver, beaver ponds also provide habitat forwaterfowl, fish, and other aquatic animals. Their dams help reduce soil erosion and can help reduceflooding.

Beavers are most famous, and infamous, for their dam-building. They maintain their pond-habitat byreacting quickly to the sound of running water, and damming it up with tree branches and mud. Earlyecologists believed that this dam-building was an amazing feat of architectural planning, indicative of thebeaver's high intellect. This theory was questioned when a recording of running water was played in a fieldnear a beaver pond. Despite the fact that it was on dry land, the beaver covered the tape player withbranches and mud.[13] The largest beaver dam is 2,790 ft (850 m) in lengthmore than half a mile longand was discovered via satellite imagery in 2007.[14] It is located on the southern edge of Wood BuffaloNational Park in northern Alberta and is twice the width of the Hoover Dam which spans 1,244 ft(379 m).[15]

Normally, the purpose of the dam is to provide water around theirlodges that is deep enough that it does not freeze solid in winter. Thedams also flood areas of surrounding forest, giving the beaver safeaccess to an important food supply, which is the leaves, buds, and

inner bark of growing trees. They prefer aspen and poplar, but willalso take birch, maple, willow and alder. They will also eat cattails,water lilies and other aquatic vegetation, especially in the earlyspring (and contrary to widespread belief,[16] they do not eat fish).In areas where their pond freezes over, beavers collect food in latefall in the form of tree branches, storing them underwater (usually bysticking the sharp chewed base of the branches into the mud on the

pond bottom), where they can be accessed through the winter. Often the pile of food branches projectsabove the pond and collects snow. This insulates the water below it and keeps the pond open at thatlocation.

Beavers usually mate for life. The young beaver "kits" typically remain with their parents for up to twoyears.

Common natural predators include gray wolves, coyotes, and mountain lions. Less significant predatorsinclude bears, which can dig into a lodge, wolverines, river otters, Canadian lynx, bobcats, and mink.[17]

Subspecies

There are 25 subspecies of beaver in North America, but different subspecies have been reintroduced toareas with previously geographically isolated subspecies, following population decline or extirpation of the
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indigenous subspecies. This has led to very substantial mixing of the subspecies gene pools, and somesubspecies may have disappeared entirely.

The most widespread subspecies are C. c. acadicus (New England beaver), C. c. canadensis (Canadianbeaver), C. c. carolinensis (Carolina beaver), and C. c. missouriensis (Missouri River beaver).[17] TheCanadian beaver originally inhabited almost all of the forested area of Canada,[18] and because of its more

valued fur, was often selected for reintroductions elsewhere. The Carolina beaver is found in thesoutheastern United States, the Missouri River beaver, as its name suggests, is found in the Missouri Riverand its tributaries, and C. c. acadicus is found throughout the New England area in the northeastern UnitedStates.

Differences from European beaver

Although superficially similar to the European beaver (Castor fiber), there are several importantdifferences between the two species. North American beavers tend to be smaller, with smaller, morerounded heads, shorter, wider muzzles, thicker, longer and darker underfur, wider, more oval-shaped tailsand have longer shin bones, allowing them a greater range of bipedal locomotion than the Europeanspecies. North American beavers have shorter nasal bones than their European cousins, with the widestpoint being at the middle of the snout for the former, and in the tip for the latter. The nasal opening for theNorth American species is square, unlike that of the European race which is triangular. The foramenmagnum is triangular in the North American beaver, and rounded in the European. The anal glands of theNorth American beaver are smaller and thick-walled with a small internal volume compared to that of theEuropean species. Finally, the guard hairs of the North American beaver have a shorter hollow medulla attheir tips. Fur colour is also different. Overall, 50% of North American beavers have pale brown fur, 25%are reddish brown, one fifth are brown and 6% are blackish, while in European beavers 66% have pale

brown or beige fur, 20% have reddish brown, nearly 8% are brown and only 4% have blackish coats.[19]

The two species are not genetically compatible. North American beavers have 40 chromosomes, whileEuropean beavers have 48. Also, more than 27 attempts were made in Russia to hybridize the two species,with one breeding between a male North American beaver and a female European resulting in one stillbornkit. These factors make interspecific breeding unlikely in areas where the two species' ranges overlap.[19]

Ecology

The beaver was trapped out and almost extirpated in North America as its fur and castoreum were highlysought after.[9] The beaver furs were used to make clothing and beaver hats. In the United States extensivetrapping began in the early 17th century with more than 10,000 beaver per year taken for the fur trade inConnecticut and Massachusetts between 1620 and 1630.[20] From 1630 to 1640, approximately 80,000beaver were taken annually from the Hudson River and western New York. [21] As eastern beaverpopulations were depleted, French and American trappers pushed west. In fact, much of the westwardexpansion and exploration of North America was driven by the quest for this animal's fur. Before the 1849California Gold Rush, there was an earlier 19th century California Fur Rush which drove the earliestAmerican settlement in that State. During the approximately 30 years (18061838) of the era of theMountain Man, the West from Missouri to California and from Canada to Mexico was thoroughly explored

and the beaver was brought to the brink of extinction.
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With protection in the late 19th and early 20th centuries the current beaver population has rebounded to anestimated 10 to 15 million; however this is still a fraction of the originally estimated 100 to 200 millionNorth American beaver before the days of the fur trade.[22][23]

These animals are considered pests in some parts of their range because their dams can cause flooding innearby areas. Because they are persistent in repairing any damage to the dam, they were historicallyrelocated or exterminated. However, non-lethal methods of containing beaver-related flooding have beendeveloped.[24] One such flow device has been utilized by both the Canadian and U.S. governments, called"Beaver Deceivers," or levelers, invented and pioneered by wildlife biologist, Skip Lisle. [25]

The beaver is a keystone species, increasing biodiversity in its territory through creation of beaver pondsand wetlands.[26] As wetlands are formed and riparian habitats enlarged, aquatic plants colonize newlyavailable watery habitat. Insect, invertebrate, fish, mammal, and bird diversity are also expanded. [27]

Effects on stream flows and water quality

Beaver ponds increase stream flows in seasonally dry streams by storing run-off in the rainy season, whichraises groundwater tables via percolation from beaver ponds. In a recent study using 12 serial aerial photomosaics from 1948 to 2002, the impact of the return of beaver on open water area in east-central Alberta,Canada found that the mammals were associated with a 9-fold increase in open water area. Beaver returnedto the area in 1954 after a long absence since their extirpation by the fur trade in the nineteenth century.Even during drought years, where beaver were present, there was 60 per cent more open water than thosesame areas during previous drought periods when beaver were absent. The authors concluded that beaverhave a dramatic influence on the creation and maintenance of wetlands even during extremedrought.[28][29]

From streams from the Maryland coastal plain in the east to Lake Tahoe in the west, beaver ponds havebeen shown to remove sediment and pollutants including total suspended solids, total nitrogen, phosphates,carbon and silicates, improving stream water quality.[30][31] In addition, fecal coliform and streptococcibacteria excreted into streams by grazing cattle are reduced by beaver ponds, where slowing currents lead tosettling of the bacteria in bottom sediments.[32]

The term beaver fever is a misnomer coined by the American press in the 1970s, following findings thatthe parasite Giardia lamblia, which causes Giardiasis, is carried by beavers. However, further research hasshown that the many animals and birds carry this parasite, and the major source of water contamination is

by other humans.[33][34][35] Recent concerns point to domestic animals as a significant vector of giardiawith young calves in dairy herds testing as high as 100% positive for giardia.[36] In addition, fecal coliformand streptococci bacteria excreted into streams by grazing cattle have been shown to be reduced by beaverponds, where the bacteria are trapped in bottom sediments.[37] In fact, New Zealand has giardia outbreaksbut no beaver, whereas Norway has plenty of beaver but had no giardia outbreaks until recently (in themost populous (by humans) south of the country.

Effects on bird diversity
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Canada Goose nest on beaver lodge

Salmon (Oncorhynchusnerka um in beaver dam

canadensis) often depend on beaver lodges as nesting sites.[27][38]

Canada's small trumpeter swan population was observed not to neston large lakes, preferring instead to nest on the smaller lakes andponds associated with beaver activity.[39][40]

Beaver may benefit the birds frequenting their ponds in several

additional ways. Removal of some pondside trees by beavers wouldincrease the density and height of the grassforbshrub layer, whichenhances waterfowl nesting cover adjacent to ponds.[41] Both forestgaps where trees had been felled by beaver and a "gradual edge"described as a complex transition from pond to forest with

intermixed grasses, forbs, saplings, and shrubs are strongly associated with greater migratory bird speciesrichness and abundance.[42] Coppicing of waterside willows and cottonwoods by beavers leads to denseshoot production which provides important cover for birds and the insects they feed on. [43]

As trees are drowned by rising beaver impoundments they become ideal nesting sites for woodpeckers, whocarve cavities that attract many other bird species including flycatchers (Empidonax spp.), tree swallows(Tachycineta bicolor), tits (Paridae spp.), wood ducks (Aix sponsa), goldeneyes (Bucephala spp.),mergansers (Mergus spp.), owls (Titonidae, Strigidae) and American kestrels (Falco sparverius).[27]

Piscivores, including herons (Ardea spp.), grebes (Podicipedidae), cormorants (Phalacrocorax ssp.),American bitterns (Botaurus lentiginosa), great egret (Ardea alba), snowy egret (Egretta thula),mergansers and belted kingfishers (Megaceryle alcyon), utilize beaver ponds for fishing. Hoodedmergansers (Lophodytes cucullatus), green heron (Butorides virescens), great blue heron (Ardea herodias)and belted kingfisher occurred more frequently in New York wetlands where beaver were active than atsites with no beaver activity.[44]

Effects on trout and salmon

Beaver ponds have been shown to have a beneficial effect on trout andsalmon populations, in fact many authors believe that the decline ofsalmonid fishes is related to the decline in beaver populations. Research inthe Stillaguamish River basin in Washington state, found that extensive lossof beaver ponds resulted in an 89% reduction in coho salmon(Oncorhynchus kisutch) smolt summer production and an almost equallydetrimental 86% reduction in critical winter habitat carrying capacity.[45]

The presence of beaver dams has also been shown to either increase thenumber of fish, their size, or both, in a study of brook trout (Salvelinusontinalis), rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo

trutta) in Sagehen Creek, which flows into the Little Truckee River at analtitude of 5,800 feet in the northern Sierra Nevada.[46] These findings areconsistent with a study of small streams in Sweden, that found that browntrout were larger in beaver ponds compared with those in riffle sections, andthat beaver ponds provide habitat for larger trout in small streams duringperiods of drought.[47] Similarly, brook trout, coho salmon and sockeye

salmon (Oncorhynchus nerka) were significantly larger in beaver pondsthan those in un-impounded stream sections in Colorado and Alaska.[48][49]
http://en.wikipedia.org/wiki/North_American_Beaver#cite_note-48http://en.wikipedia.org/wiki/North_American_Beaver#cite_note-47http://en.wikipedia.org/wiki/Alaskahttp://en.wikipedia.org/wiki/Coloradohttp://en.wikipedia.org/wiki/Sockeye_salmonhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_note-46http://en.wikipedia.org/wiki/Rifflehttp://en.wikipedia.org/wiki/Swedenhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_note-Gard-45http://en.wikipedia.org/wiki/Sierra_Nevada_(U.S.)http://en.wikipedia.org/wiki/Little_Truckee_Riverhttp://en.wikipedia.org/w/index.php?title=Sagehen_Creek&action=edit&redlink=1http://en.wikipedia.org/wiki/Brown_trouthttp://en.wikipedia.org/wiki/Rainbow_trouthttp://en.wikipedia.org/wiki/Brook_trouthttp://en.wikipedia.org/wiki/North_American_Beaver#cite_note-Stillaguamish-44http://en.wikipedia.org/wiki/Carrying_capacityhttp://en.wikipedia.org/wiki/Coho_salmonhttp://en.wikipedia.org/wiki/Washington_(U.S._state)http://en.wikipedia.org/wiki/Stillaguamish_Riverhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_note-43http://en.wikipedia.org/wiki/Great_blue_heronhttp://en.wikipedia.org/wiki/Green_heronhttp://en.wikipedia.org/wiki/Hooded_merganserhttp://en.wikipedia.org/wiki/Belted_kingfisherhttp://en.wikipedia.org/wiki/Snowy_egrethttp://en.wikipedia.org/wiki/Great_egrethttp://en.wikipedia.org/wiki/American_bitternhttp://en.wikipedia.org/wiki/Cormoranthttp://en.wikipedia.org/wiki/Grebehttp://en.wikipedia.org/wiki/Heronhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_note-Rosell-26http://en.wikipedia.org/wiki/American_kestrelhttp://en.wikipedia.org/wiki/Owlhttp://en.wikipedia.org/wiki/Merganserhttp://en.wikipedia.org/wiki/Goldeneye_(duck)http://en.wikipedia.org/wiki/Wood_duckhttp://en.wikipedia.org/wiki/Tit_(bird)http://en.wikipedia.org/wiki/Tree_swallowhttp://en.wikipedia.org/wiki/Empidonaxhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_note-42http://en.wikipedia.org/wiki/Coppicinghttp://en.wikipedia.org/wiki/North_American_Beaver#cite_note-41http://en.wikipedia.org/wiki/North_American_Beaver#cite_note-40http://en.wikipedia.org/wiki/North_American_Beaver#cite_note-39http://en.wikipedia.org/wiki/North_American_Beaver#cite_note-38http://en.wikipedia.org/wiki/North_American_Beaver#cite_note-37http://en.wikipedia.org/wiki/North_American_Beaver#cite_note-Rosell-26http://en.wikipedia.org/wiki/Canada_goosehttp://en.wikipedia.org/wiki/Trumpeter_swanhttp://en.wikipedia.org/wiki/Oncorhynchus_nerkahttp://en.wikipedia.org/wiki/Salmonhttp://en.wikipedia.org/wiki/File:Sockeye_salmon_jumping_over_beaver_dam_Lake_Aleknagik,_AK_Kristina_Ramstad_1997.jpghttp://en.wikipedia.org/wiki/File:Canada_Geese_Nesting_on_Beaver_Lodge,_Crawford_County,_PA_1960.jpg


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Tree felled by beaver (C. c.canadensis), diameter 20 cm

Contrary to popular myth, most beaver dams do not pose barriers to troutand salmon migration, although they may be restricted seasonally duringperiods of low stream flows.[50] Rainbow, brown and brook trout have been shown to cross as many as 14consecutive beaver dams.[46] Both adults and juveniles of coho salmon, steelhead trout, sea run cutthroat(Oncorhyncus clarki clarki), Dolly Varden trout (Salvelinus malma malma), and sockeye salmon are ableto cross beaver dams.[50] In southeast Alaska, coho jumped dams as high as 2 meters, were found above all

beaver dams and had their highest densities in streams with beaver. [51] In Oregon coastal streams, beaverdams are ephemeral and almost all wash out in high winter flows only to be re-built every summer.[52]

Migration of adult Atlantic salmon (Salmo salar) may be limited by beaver dams but the presence ofuveniles upstream from the dams suggests that the dams are penetrated by parr.[53] Downstream migration

of Atlantic salmon smolts was similarly unaffected by beaver dams, even in periods of low flows.[53] Twoyear old Atlantic salmon parr in beaver ponds in eastern Canada showed faster summer growth in lengthand mass and were in better condition than parr upstream or downstream from the pond.[54] Theimportance of winter habitat to salmonids afforded by beaver ponds may be especially important (andunderappreciated) in streams without deep pools or where ice cover makes contact with the bottom of

shallow streams. Cutthroat trout (Oncorhynchus clarki) and bull trout (Salvelinus confluentus) were notedto overwinter in Montana beaver ponds, brook trout congregated in winter in New Brunswick andWyoming beaver ponds, and coho salmon in Oregon beaver ponds.[53]

Efforts to restore salmonid habitat in the western United States have focused primarily on establishing largewoody debris in streams to slow flows and create pools for young salmonids. However research inWashington state found that the average summer smolt production per beaver dam ranges from 527 to1,174 fish, whereas the summer smolt production from a pool formed by instream large woody debris isabout 615 individuals, suggesting that re-establishment of beaver populations would be 80 times moreeffective.[45]

Recently, beaver have been discovered living in brackish water in estuarine tidal marshes, where Chinooksalmon (Oncorhynchus tshawytscha) densities were five times higher in beaver ponds than in neighboringareas.[11][55]

Effects on riparian trees and vegetation

Conventional wisdom has held that beaver girdle and fell trees andthat they diminish riparian trees and vegetation, but the opposite

appears to be true when studies are conducted longer-term. In 1987,Beier reported that beaver had caused local extinction of Quakingaspen (Populus tremuloides) and Black cottonwood (Populustrichocarpa) on 4-5% of stream reaches on the lower Truckee Riverin the Sierra Nevada mountains, however Willow (Salix spp.)responded by re-growing vigourously in most reaches. He furtherspeculated that without control of beaver populations that aspen andcottonwood could go extinct on the Truckee River.[56] However, notonly have aspen and cottonwood survived ongoing beavercolonization but a recent study of ten Sierra Nevada streams in the

Lake Tahoe basin utilizing aerial multispectral videography hasshown that deciduous, thick herbaceous, and thin herbaceous vegetation are more highly concentrated near
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Beaver before being drowned bytrapper's snare in Lincoln Park,Chicago 2008

beaver dams, whereas coniferous trees are decreased.[57] These findings are consistent with those ofPollock, who reported that in Bridge Creek, a stream in semi-arid eastern Oregon, the width of riparianvegetation on stream banks was increased several-fold as beaver dams watered previously dry terracesadjacent to the stream.[58] In a second study of riparian vegetation based on observations of Bridge Creekover a 17 year time period, although portions of the study reach were periodically abandoned by beaverfollowing heavy utilization of streamside vegetation, within a few years dense stands of woody plants of

greater diversity occupied a larger portion of the floodplain. Although black cottonwood and thinleaf alderdid not generally re-sprout after beaver cutting, they frequently grew from seeds landing on freshly exposedalluvial deposits secondary to beaver activity.[59] Therefore, beaver appear to increase riparian vegetationgiven enough years to aggrade sediments and pond heights sufficiently to create widened, well-wateredriparian zones, especially in areas of low summer rainfall.

The surface of beaver ponds are typically at or near bank-full, so even small increases in stream flowscause the pond to overflow its banks. Thus, high stream flows spread water and nutrients to beyond thestream banks to wide riparian zones when beaver dams are present.

Beavers and stream restoration

In the 1930s, the U.S. Government put 600 beaver to work alongside the Civilian Conservation Corps inprojects to stop soil erosion by streams in Oregon, Washington, Wyoming, and Utah. At the time it wasestimated that each beaver, whose initial cost was about $5, completed work worth $300. [60]

In a pilot study in Washington state, the Lands Council is reintroducing beavers to evaluate theirprojections that if 10,000 miles of suitable habitat were repopulated then 650 trillion gallons of springrunoff would be held back for release in the arid fall season.[61] This project was developed in response toa 2003 Washington Department of Ecology proposal to spend as much as ten billion dollars on constructionof several dams on Columbia River tributaries to retain storm season runoff.[62] The State of Utahpublished a Beaver Management Plan which includes re-establishing beavers in ten streams per year for thepurpose of watershed restoration each year from 2010 through 2020.[63]

Urban beavers

After 200 years, a beaver returned to New York City in 2007,making its home along the Bronx River, having spent time living at

the Bronx Zoo as well as the Botanical Gardens.[64]

Beavers havenot lived in New York City since the early 19th century whentrappers extirpated them completely from the state.[65] The return of"Jose", named after Representative Jose Serrano from the Bronx, hasbeen seen as evidence that efforts to restore the river have beensuccessful.[66][67][68] In the summer of 2010 a second beaver joinedJose, doubling the beaver population in New York City.[69] Beaverwere once important to the city's economy and a pair of beaversappears on the city's official seal and flag.

In Chicago, several beavers have returned and made a home near theLincoln Park's North Pond. The "Lincoln Park Beaver" has not been
http://en.wikipedia.org/wiki/Lincoln_Park_Beaverhttp://en.wikipedia.org/wiki/Lincoln_Parkhttp://en.wikipedia.org/wiki/Chicagohttp://en.wikipedia.org/wiki/North_American_Beaver#cite_note-68http://en.wikipedia.org/wiki/North_American_Beaver#cite_note-67http://en.wikipedia.org/wiki/North_American_Beaver#cite_note-66http://en.wikipedia.org/wiki/North_American_Beaver#cite_note-65http://en.wikipedia.org/wiki/Jos%C3%A9_Enrique_Serranohttp://en.wikipedia.org/wiki/North_American_Beaver#cite_note-64http://en.wikipedia.org/wiki/North_American_Beaver#cite_note-63http://en.wikipedia.org/wiki/Bronx_Zoohttp://en.wikipedia.org/wiki/Bronx_Riverhttp://en.wikipedia.org/wiki/New_York_Cityhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_note-62http://en.wikipedia.org/wiki/Utahhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_note-61http://en.wikipedia.org/wiki/Columbia_Riverhttp://en.wikipedia.org/wiki/Washington_Department_of_Ecologyhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_note-60http://en.wikipedia.org/wiki/Washington_(U.S._state)http://en.wikipedia.org/wiki/North_American_Beaver#cite_note-59http://en.wikipedia.org/wiki/Civilian_Conservation_Corpshttp://en.wikipedia.org/wiki/North_American_Beaver#cite_note-58http://en.wikipedia.org/wiki/North_American_Beaver#cite_note-57http://en.wikipedia.org/wiki/Bridge_Creek_(John_Day_River)http://en.wikipedia.org/wiki/North_American_Beaver#cite_note-Ayers-56http://en.wikipedia.org/wiki/File:Lincoln_Park_North_Pond_Beaver_Lodge_Dec_4,_2009.jpghttp://en.wikipedia.org/wiki/File:Lincoln_Park_Beaver_Facebook_Lindsay_Fox_Sept._2008.jpg


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The seal of NewNetherland featured thebeaver because of theimportance of the fur tradeearly in the colony'shistory

In contrast, areas with introduced beaver were associated with increased populations of native puye fish(Galaxias maculatus), whereas the exotic brook trout (Salvelinus fontinalis) and rainbow trout(Oncorhynchus mykiss) had negative impacts on native stream fishes in the Cape Horn Biosphere Reserve,Chile.[82]

As food

Beaver meat is similar tasting to lean beef, but care must be taken to prevent contamination from theanimal's strong castor (musk) gland. It is usually slow-cooked in a broth, and was a valuable food source toNative Americans.[citation needed] Early French Canadian Catholics considered beaver to be "four-leggedfish" that could be eaten at Lent. [83]

Despite their name, the fried pastries found in parts of Canada called beaver tails contain no beaver.

Symbolism

One of the national symbols of Canada, it'snational animal, the beaver is depicted on theCanadian five-cent piece and was on the firstCanadian postage stamp, the Three Penny Beaver.It is also the state animal of Oregon and NewYork, and a common school emblem forengineering schools, including the CaliforniaInstitute of Technology and the MassachusettsInstitute of Technology, as well as the mascot for

Oregon State University, Babson College, and theCity College of New York. The beaver also appears in the coats of arms ofthe University of Toronto, Wilfrid Laurier University, and the London Schoolof Economics.

Much of the early economy of New Netherland was based on the beaver furtrade. As such, the seal of New Netherland featured the beaver; likewise, thecoats of arms of Albany, New York and New York City included the beaver.

References1. ^ Linzey, A. V. & NatureServe (Hammerson, G. & Cannings, S.) (2008). Castor canadensis

(http://www.iucnredlist.org/apps/redlist/details/4003) . In: IUCN 2008. IUCN Red List of Threatened Species.Downloaded on 6 January 2009.

2. ^ ab Helgen, Kristofer M. (16 November 2005). "Family Castoridae (pp. 842843)"(http://www.bucknell.edu/msw3/browse.asp?id=12600004) . In Wilson, Don E., and Reeder, DeeAnn M., eds.Mammal Species of the World: A Taxonomic and Geographic Reference (http://google.com/books?

id=JgAMbNSt8ikC&pg=PA842) (3rd ed.). Baltimore: Johns Hopkins University Press, 2 vols. (2142 pp.). p. 842.ISBN 978-0-8018-8221-0. OCLC 62265494 (http://www.worldcat.org/oclc/62265494) .http://www.bucknell.edu/msw3/browse.asp?id=12600004.

3. ^ Warner, Richard E. and Kathleen M. Hendrix, editors. California Riparian Systems: Ecology, Conservation, andProductive Management (http://content.cdlib.org/xtf/view?
http://en.wikipedia.org/wiki/File:Canadian_Nickel_-_reverse.pnghttp://content.cdlib.org/xtf/view?docId=ft1c6003wp&doc.view=content&chunk.id=d0e108057http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-warner_2-0http://www.bucknell.edu/msw3/browse.asp?id=12600004http://www.worldcat.org/oclc/62265494http://en.wikipedia.org/wiki/Online_Computer_Library_Centerhttp://en.wikipedia.org/wiki/Special:BookSources/978-0-8018-8221-0http://en.wikipedia.org/wiki/International_Standard_Book_Numberhttp://en.wikipedia.org/wiki/Johns_Hopkins_University_Presshttp://google.com/books?id=JgAMbNSt8ikC&pg=PA842http://www.bucknell.edu/msw3/browse.asp?id=12600004http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-MSW3_1-1http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-MSW3_1-0http://en.wikipedia.org/wiki/IUCN_Red_Listhttp://www.iucnredlist.org/apps/redlist/details/4003http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-iucn_0-0http://en.wikipedia.org/wiki/Seal_of_New_York_Cityhttp://en.wikipedia.org/wiki/Coat_of_arms_of_Albany,_New_Yorkhttp://en.wikipedia.org/wiki/Fur_tradehttp://en.wikipedia.org/wiki/New_Netherlandhttp://en.wikipedia.org/wiki/London_School_of_Economicshttp://en.wikipedia.org/wiki/Wilfrid_Laurier_Universityhttp://en.wikipedia.org/wiki/University_of_Torontohttp://en.wikipedia.org/wiki/Coat_of_armshttp://en.wikipedia.org/wiki/City_College_of_New_Yorkhttp://en.wikipedia.org/wiki/Babson_Collegehttp://en.wikipedia.org/wiki/Oregon_State_Universityhttp://en.wikipedia.org/wiki/Massachusetts_Institute_of_Technologyhttp://en.wikipedia.org/wiki/California_Institute_of_Technologyhttp://en.wikipedia.org/wiki/Engineeringhttp://en.wikipedia.org/wiki/New_York_Statehttp://en.wikipedia.org/wiki/Oregonhttp://en.wikipedia.org/wiki/Nickel_(Canadian_coin)http://en.wikipedia.org/wiki/Beaver_tail_(pastry)http://en.wikipedia.org/wiki/North_American_Beaver#cite_note-82http://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_note-81http://en.wikipedia.org/wiki/Chilehttp://en.wikipedia.org/wiki/Cape_Horn_Biosphere_Reservehttp://en.wikipedia.org/wiki/Rainbow_trouthttp://en.wikipedia.org/wiki/Brook_trouthttp://en.wikipedia.org/wiki/Common_galaxiashttp://en.wikipedia.org/wiki/Fur_tradehttp://en.wikipedia.org/wiki/New_Netherlandhttp://en.wikipedia.org/wiki/File:New_Netherlands_Seal_Vector.svg


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docId=ft1c6003wp&doc.view=content&chunk.id=d0e108057) University of California Press, 1984, p. 952.Retrieved on 2007-08-04.

4. ^ Browse Genus equals Castor by Scientific Name for All Museums(http://bnhm.berkeley.edu/browse/vertebrates_Mammalia_Rodentia_Castoridae_Castor_all.php?ViewResults=vertebrates_Mammalia_Rodentia_Castoridae_Castor_all) . Berkeley Natural History Museums.Retrieved on 2007-08-04.

5. ^ Tesky, Julie L. Wildlife Species: Castor canadensis

(http://www.fs.fed.us/database/feis/animals/mammal/caca/all.html) Fire Effects Information System (Online), U.S.Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory. 1993.Retrieved on 2007-08-04.

6. ^ Invasive Species Specialist Group (ISSG) (2006). "Castor canadensis (mammal)"(http://www.issg.org/database/species/ecology.asp?si=981&fr=1&sts=&lang=EN) . Global Invasive SpeciesDatabase (GISD). IUCN Species Survival Commission. http://www.issg.org/database/species/ecology.asp?si=981&fr=1&sts=&lang=EN. Retrieved 16 July 2009: "Common names: American beaver (English), beaver(English), Canadian beaver, castor (French), castor americano (Spanish), North American beaver (English)"

7. ^ http://www.adfg.state.ak.us/pubs/notebook/furbear/beaver.php8. ^ Lewis H. Morgan (1868). The American Beaver and his Works (http://books.google.com/?id=gY4-

AAAAcAAJ&printsec=frontcover&dq=lewis+h.+morgan+1868+%22american+beaver%22#v=onepage&q=gila&f=

false) . J. B. Lippincott & Co.. p. 32. http://books.google.com/?id=gY4-AAAAcAAJ&printsec=frontcover&dq=lewis+h.+morgan+1868+%22american+beaver%22#v=onepage&q=gila&f=false. Retrieved 2010-12-29.

9. ^ ab Robert J. Naiman, Carol A. Johnston, and James C. Kelley (Dec. 1988). "Alteration of North AmericanStreams by Beaver"(http://www.landscouncil.org/documents/Beaver_Project/Articles/Naiman_et_al_1988_alter_n_american_streams_by_beaver.pdf) .BioScience: 753762.http://www.landscouncil.org/documents/Beaver_Project/Articles/Naiman_et_al_1988_alter_n_american_streams_by_beaver.pdf. Retrieved Feb. 28, 2010.

10. ^ David Thompson, Joseph Burr Tyrrell (1916). David Thompson's Narrative of his Explorations of WesternAmerica 1784-1812 (http://www.archive.org/details/davidthompsonsna00thom) . New York: Greenwood Press.

ISBN 978-1437017922. http://www.archive.org/details/davidthompsonsna00thom. Retrieved Mar. 7, 2010.11. ^ ab Lynda V. Mapes (May 18, 2009). "Scientist discovers beavers building prime salmon habitat in Skagit Delta"

(http://seattletimes.nwsource.com/html/localnews/2009231736_beavers18m.html) . The Seattle Times.http://seattletimes.nwsource.com/html/localnews/2009231736_beavers18m.html. Retrieved June 22, 2010.

12. ^ Gallant, D., C.H. Brub, E. Tremblay, & L. Vasseur (2004). "An extensive study of the foraging ecology ofbeavers (Castor canadensis) in relation to habitat quality"(http://www.colby.edu/academics_cs/courses/BI312/upload/ForagingBeaversHabitatQuality.pdf) . CanadianJournal of Zoology82 (6): 922933. doi:10.1139/z04-067 (http://dx.doi.org/10.1139%2Fz04-067) .http://www.colby.edu/academics_cs/courses/BI312/upload/ForagingBeaversHabitatQuality.pdf. Retrieved May 4,2010.

13. ^ Richard P.B. (1983). "Mechanisms and adaptation in the constructive behaviour of the beaver (C. fiber L.)".

Acta Zoologica Fennica174: 105108.14. ^ National Geographic photos (http://www.geostrategis.com/p_beavers-longestdam.htm)15. ^ Vince Soodin. "Beaver Dam Seen from Space" (http://www.thesun.co.uk/sol/homepage/news/2958779/Beaver-

dam-seen-from-space.html) . The Sun. http://www.thesun.co.uk/sol/homepage/news/2958779/Beaver-dam-seen-from-space.html. Retrieved May 5, 2010.

16. ^ Colorado Division of Wildlife: Do Beavers Eat Fish?(http://wildlife.state.co.us/Education/TeacherResources/ColoradoWildlifeCompany/CWCSum91Beavers.htm)

17. ^ ab Baker, B. W., and E. P. Hill. Beaver (Castor canadensis)(http://www.fort.usgs.gov/products/publications/909/909.pdf) . G. A. Feldhamer, B. C. Thompson, and J. A.Chapman, editors. Wild Mammals of North America: Biology, Management, and Conservation. Second Edition.The Johns Hopkins University Press, Baltimore, Maryland, USA, pp. 288-310. 2003. Retrieved on 2007-08-04.

18. ^ Kieffer, Michael Meadows in Mist (http://www.fobr.org/article-meadows_mist.html) Bull Run MountainsConservancy, Inc. Retrieved on 2007-08-04.
http://www.fobr.org/article-meadows_mist.htmlhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-17http://www.fort.usgs.gov/products/publications/909/909.pdfhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-baker_16-1http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-baker_16-0http://wildlife.state.co.us/Education/TeacherResources/ColoradoWildlifeCompany/CWCSum91Beavers.htmhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-15http://www.thesun.co.uk/sol/homepage/news/2958779/Beaver-dam-seen-from-space.htmlhttp://www.thesun.co.uk/sol/homepage/news/2958779/Beaver-dam-seen-from-space.htmlhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-14http://www.geostrategis.com/p_beavers-longestdam.htmhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-13http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-Richard_12-0http://www.colby.edu/academics_cs/courses/BI312/upload/ForagingBeaversHabitatQuality.pdfhttp://dx.doi.org/10.1139%2Fz04-067http://en.wikipedia.org/wiki/Digital_object_identifierhttp://www.colby.edu/academics_cs/courses/BI312/upload/ForagingBeaversHabitatQuality.pdfhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-11http://seattletimes.nwsource.com/html/localnews/2009231736_beavers18m.htmlhttp://seattletimes.nwsource.com/html/localnews/2009231736_beavers18m.htmlhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-skagit_10-1http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-skagit_10-0http://www.archive.org/details/davidthompsonsna00thomhttp://en.wikipedia.org/wiki/Special:BookSources/978-1437017922http://en.wikipedia.org/wiki/International_Standard_Book_Numberhttp://www.archive.org/details/davidthompsonsna00thomhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-9http://www.landscouncil.org/documents/Beaver_Project/Articles/Naiman_et_al_1988_alter_n_american_streams_by_beaver.pdfhttp://www.landscouncil.org/documents/Beaver_Project/Articles/Naiman_et_al_1988_alter_n_american_streams_by_beaver.pdfhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-Naiman_8-1http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-Naiman_8-0http://books.google.com/?id=gY4-AAAAcAAJ&printsec=frontcover&dq=lewis+h.+morgan+1868+%22american+beaver%22#v=onepage&q=gila&f=falsehttp://books.google.com/?id=gY4-AAAAcAAJ&printsec=frontcover&dq=lewis+h.+morgan+1868+%22american+beaver%22#v=onepage&q=gila&f=falsehttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-7http://www.adfg.state.ak.us/pubs/notebook/furbear/beaver.phphttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-6http://www.issg.org/database/species/ecology.asp?si=981&fr=1&sts=&lang=ENhttp://www.issg.org/database/species/ecology.asp?si=981&fr=1&sts=&lang=ENhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-5http://en.wikipedia.org/wiki/Rocky_Mountain_Research_Stationhttp://www.fs.fed.us/database/feis/animals/mammal/caca/all.htmlhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-4http://bnhm.berkeley.edu/browse/vertebrates_Mammalia_Rodentia_Castoridae_Castor_all.php?ViewResults=vertebrates_Mammalia_Rodentia_Castoridae_Castor_allhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-3http://content.cdlib.org/xtf/view?docId=ft1c6003wp&doc.view=content&chunk.id=d0e108057


12/16



19. ^ ab Kitchener, Andrew (2001).Beavers. p. 144. ISBN 187358055X.20. ^ Moloney, F. X. (1967). The Fur Trade in New England, 1620-1676. Hamden, Connecticut: Archon Books.

pp. 150.21. ^ Hays, W. J. (Sep., 1871). "Notes on the range of some of the animals in America at the time of arrival of the

whitemen". The American Naturalist5 (7): 2530. JSTOR 2447602 (http://www.jstor.org/stable/2447602) .22. ^ Seton-Thompson, cited in Sun, Lixing; Dietland Mller-Schwarze (2003). The Beaver: Natural History of a

Wetlands Engineer (http://books.google.com/?

id=eqIenKko3lAC&dq=the+beaver+natural+history+of+a+wetlands+engineer&printsec=frontcover#v=onepage&q=90%20million&f=false) . Ithaca, NY: Cornell University Press. p. 98. ISBN 080144098X.http://books.google.com/?id=eqIenKko3lAC&dq=the+beaver+natural+history+of+a+wetlands+engineer&printsec=frontcover#v=onepage&q=90%20million&f=false. pp. 9798; but note that to arrive at this figure he assumed a population densitythroughout the range equivalent to that in Algonquin Park

23. ^ Alice Outwater (1997). Water:A Natural History (http://books.google.com/?id=3_oRrNgE_mkC&dq=water+alice+outwater&printsec=frontcover#v=onepage&q=&f=false) . New York, NY:Basic Books. p. 89. ISBN 0465037801. http://books.google.com/?id=3_oRrNgE_mkC&dq=water+alice+outwater&printsec=frontcover#v=onepage&q=&f=false.

24. ^ Beavers: Wetlands & Wildlife: Solutions to Beaver/Human Conflicts (http://www.beaversww.org/solutions.html)

25. ^ Charles Agar (March 24, 2008). "Beaver Deceiver expert coming to Pitkin County"(http://www.aspentimes.com/article/20080324/NEWS/47844491) . The Aspen Times (Aspen, Colorado).http://www.aspentimes.com/article/20080324/NEWS/47844491. Retrieved Nov. 22, 2009.

26. ^ Wright, J.P.; Jones, C.G.; Flecker, A.S. (2002). "An ecosystem engineer, the beaver, increases species richnessat the landscape scale" (http://www.springerlink.com/index/0637GF0979LRU90J.pdf) . Oecologia132 (1): 96101. doi:10.1007/s00442-002-0929-1 (http://dx.doi.org/10.1007%2Fs00442-002-0929-1) .http://www.springerlink.com/index/0637GF0979LRU90J.pdf. Retrieved 2010-03-01.

27. ^ abc Rosell F, Bozser O, Collen P, Parker H (2005). "Ecological impact of beavers Castor fiber and Castorcanadensis and their ability to modify ecosystems"(http://teora.hit.no/dspace/bitstream/2282/536/1/Ecological_impact.pdf) .Mammal Review: 248276.http://teora.hit.no/dspace/bitstream/2282/536/1/Ecological_impact.pdf. Retrieved Mar. 1, 2010.

28. ^ Glynnis A. Hood, Suzanne E. Bayley (2008-02). "Beaver (Castor canadensis) mitigate the effects of climate onthe area of open water in boreal wetlands in western Canada" (http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6V5X-4RM89BG-1-H&_cdi=5798&_user=145269&_pii=S0006320707004557&_origin=search&_zone=rslt_list_item&_coverDate=02%2F29%2F2008&_sk=998589997&wchp=dGLbVzz-zSkzS&md5=b4a31ea30a18a30b121b34fa4345b577&ie=/sdarticle.pdf) .Biological Conservation: 556567.http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6V5X-4RM89BG-1-H&_cdi=5798&_user=145269&_pii=S0006320707004557&_origin=search&_zone=rslt_list_item&_coverDate=02%2F29%2F2008&_sk=998589997&wchp=dGLbVzz-zSkzS&md5=b4a31ea30a18a30b121b34fa4345b577&ie=/sdarticle.pdf. Retrieved 2011-02-23.

29. ^ "Busy Beavers Can Help Ease Drought" (http://www.sciencedaily.com/releases/2008/02/080220130511.htm) .Science Daily. 2008-02-26. http://www.sciencedaily.com/releases/2008/02/080220130511.htm. Retrieved 2011-02-23.

30. ^ David L. Correll, Thomas E. Jordan, Donald E. Weller (2000-06). "Beaver pond biogeochemical effects in theMaryland Coastal Plain".Biogeochemistry49 (3): 217239. JSTOR 1469618 (http://www.jstor.org/stable/1469618).

31. ^ Sarah Muskopf (October 2007). The Effect of Beaver (Castor canadensis) Dam Removal on Total PhosphorusConcentration in Taylor Creek and Wetland, South Lake Tahoe, California (http://hdl.handle.net/2148/264)(Thesis). Humboldt State University, Natural Resources. http://hdl.handle.net/2148/264. Retrieved 2011-02-27.

32. ^ Quentin D. Skinner, John E. Speck, Michael Smith, John C. Adams (1984-03). "Stream Water Quality asInfluenced by Beaver within Grazing Systems in Wyoming". Journal of Range Management37 (2): 142146.JSTOR 3898902 (http://www.jstor.org/stable/3898902) .

33. ^ Martin Gaywood, Dave Batty, Colin Galbraith (2008). "Reintroducing the European Beaver in Britain"(http://www.beaversinengland.com/downloads/ReintroducingtheEuropeanBeaverinBritain.pdf) .British Wildlife.
http://www.beaversinengland.com/downloads/ReintroducingtheEuropeanBeaverinBritain.pdfhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-32http://www.jstor.org/stable/3898902http://en.wikipedia.org/wiki/JSTORhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-31http://hdl.handle.net/2148/264http://hdl.handle.net/2148/264http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-Muskopf_30-0http://www.jstor.org/stable/1469618http://en.wikipedia.org/wiki/JSTORhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-29http://www.sciencedaily.com/releases/2008/02/080220130511.htmhttp://www.sciencedaily.com/releases/2008/02/080220130511.htmhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-28http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6V5X-4RM89BG-1-H&_cdi=5798&_user=145269&_pii=S0006320707004557&_origin=search&_zone=rslt_list_item&_coverDate=02%2F29%2F2008&_sk=998589997&wchp=dGLbVzz-zSkzS&md5=b4a31ea30a18a30b121b34fa4345b577&ie=/sdarticle.pdfhttp://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6V5X-4RM89BG-1-H&_cdi=5798&_user=145269&_pii=S0006320707004557&_origin=search&_zone=rslt_list_item&_coverDate=02%2F29%2F2008&_sk=998589997&wchp=dGLbVzz-zSkzS&md5=b4a31ea30a18a30b121b34fa4345b577&ie=/sdarticle.pdfhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-27http://teora.hit.no/dspace/bitstream/2282/536/1/Ecological_impact.pdfhttp://teora.hit.no/dspace/bitstream/2282/536/1/Ecological_impact.pdfhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-Rosell_26-2http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-Rosell_26-1http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-Rosell_26-0http://www.springerlink.com/index/0637GF0979LRU90J.pdfhttp://dx.doi.org/10.1007%2Fs00442-002-0929-1http://en.wikipedia.org/wiki/Digital_object_identifierhttp://www.springerlink.com/index/0637GF0979LRU90J.pdfhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-25http://www.aspentimes.com/article/20080324/NEWS/47844491http://www.aspentimes.com/article/20080324/NEWS/47844491http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-24http://www.beaversww.org/solutions.htmlhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-23http://books.google.com/?id=3_oRrNgE_mkC&dq=water+alice+outwater&printsec=frontcover#v=onepage&q=&f=falsehttp://en.wikipedia.org/wiki/Special:BookSources/0465037801http://en.wikipedia.org/wiki/International_Standard_Book_Numberhttp://books.google.com/?id=3_oRrNgE_mkC&dq=water+alice+outwater&printsec=frontcover#v=onepage&q=&f=falsehttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-22http://en.wikipedia.org/wiki/Algonquin_Parkhttp://books.google.com/?id=eqIenKko3lAC&dq=the+beaver+natural+history+of+a+wetlands+engineer&printsec=frontcover#v=onepage&q=90%20million&f=falsehttp://en.wikipedia.org/wiki/Special:BookSources/080144098Xhttp://en.wikipedia.org/wiki/International_Standard_Book_Numberhttp://books.google.com/?id=eqIenKko3lAC&dq=the+beaver+natural+history+of+a+wetlands+engineer&printsec=frontcover#v=onepage&q=90%20million&f=falsehttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-21http://www.jstor.org/stable/2447602http://en.wikipedia.org/wiki/JSTORhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-20http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-19http://en.wikipedia.org/wiki/Special:BookSources/187358055Xhttp://en.wikipedia.org/wiki/International_Standard_Book_Numberhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-andy_18-1http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-andy_18-0


13/16



http://www.beaversinengland.com/downloads/ReintroducingtheEuropeanBeaverinBritain.pdf. Retrieved 2011-03-26.

34. ^ Erlandsen, S. L., and W. J. Bemrick (1988). Waterborne giardiasis: sources of Giardia cysts and evidencepertaining to their implication in human infection in P. M. Wallis and B. R. Hammond (ed.), Advances in Giardia

research.. Calgary, Alberta, Canada: University of Calgary Press. pp. 227236.35. ^ Erlandsen SL, Sherlock LA, Bemrick WJ, Ghobrial H, Jakubowski W (1990-01). "Prevalence of Giardia spp. in

Beaver and Muskrat Populations in Northeastern States and Minnesota: Detection of Intestinal Trophozoites at

Necropsy Provides Greater Sensitivity than Detection of Cysts in Fecal Samples"(http://aem.asm.org/cgi/reprint/56/1/31?maxtoshow=&hits=10&RESULTFORMAT=&fulltext=erlandsen&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT) . Applied and Environmental Microbiology: 3136. http://aem.asm.org/cgi/reprint/56/1/31?maxtoshow=&hits=10&RESULTFORMAT=&fulltext=erlandsen&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT. Retrieved 2011-03-26.

36. ^ R. C. A. Thompson (2000-11). "Giardiasis as a re-emerging infectious disease and its zoonotic potential".International Journal of Parasitology30 (1213): 12591267. doi:10.1016/S0020-7519(00)00127-2(http://dx.doi.org/10.1016%2FS0020-7519%2800%2900127-2) . PMID 11113253(http://www.ncbi.nlm.nih.gov/pubmed/11113253) .

37. ^ Quentin D. Skinner, John E. Speck, Michael Smith, John C. Adams (1984-03). "Stream Water Quality as

Influenced by Beaver within Grazing Systems in Wyoming". Journal of Range Management37 (2): 142146.JSTOR 3898902 (http://www.jstor.org/stable/3898902) .38. ^ Brenner, F.J. (1960). "Canada geese nesting on a beaver lodge"

(http://elibrary.unm.edu/sora/Auk/v077n04/p0476-p0476.pdf) . The Auk: 476477.http://elibrary.unm.edu/sora/Auk/v077n04/p0476-p0476.pdf. Retrieved Mar. 1, 2010.

39. ^ McKelvey RW, Denningtonz MC, Mossop (Mar. 1983). "The Status and Distribution of Trumpeter Swans(Cygnus buccinator) in the Yukon" (http://pubs.aina.ucalgary.ca/arctic/Arctic36-1-76.pdf) . Arctic: 7681.http://pubs.aina.ucalgary.ca/arctic/Arctic36-1-76.pdf. Retrieved Mar. 1, 2010.

40. ^ Hilfiker, E.L. (1991).Beavers, Water, Wildlife and History. Interlaken, New York: Windswept Press. pp. 198.ISBN 978-1557870674.

41. ^ Frank Rosell, Orsolya Bozser, Peter Collen and Howard Parker (2005). "Ecological impact of beavers Castor

fibre and Castor canadensis and their ability to modify ecosystems"(http://www3.interscience.wiley.com/journal/118653847/abstract?CRETRY=1&SRETRY=0) . Mammal Review35(34): 248. doi:10.1111/j.1365-2907.2005.00067.x (http://dx.doi.org/10.1111%2Fj.1365-2907.2005.00067.x) .http://www3.interscience.wiley.com/journal/118653847/abstract?CRETRY=1&SRETRY=0. Retrieved May 2,2010.

42. ^ Jason F. Bulluck and Matthew P. Rowe (2006). "The Use of Southern Appalachian Wetlands by BreedingBirds, with a Focus on Neotropical Migratory Species" (http://www.bioone.org/doi/pdf/10.1676/04-116.1) . TheWilson Journal of Ornithology118 (3): 399. doi:10.1676/04-116.1 (http://dx.doi.org/10.1676%2F04-116.1) .http://www.bioone.org/doi/pdf/10.1676/04-116.1. Retrieved May 2, 2010.

43. ^ Travis Longcore, Catherine Rich, Dietland Muller-Schwarze (Feb. 2007). "Management by Assertion: Beaversand Songbirds at Lake Skinner (Riverside County, California)"

(http://www.springerlink.com/content/ch7n7545764245l5/) . Environmental Management: 460471.http://www.springerlink.com/content/ch7n7545764245l5/. Retrieved May 2, 2010.44. ^ Grover, A.M. & Baldassarre, G.A. (1995). "Bird species richness within beaver ponds in south-central New

York" (http://www.springerlink.com/content/1837v89602g6m186/) . Wetlands: 108118.http://www.springerlink.com/content/1837v89602g6m186/. Retrieved Mar. 1, 2010.

45. ^ ab M. M. Pollock, G. R. Pess, T. J. Beechie (2004). "The Importance of Beaver Ponds to Coho SalmonProduction in the Stillaguamish River Basin, Washington, USA"(http://duff.ess.washington.edu/grg/publications/pdfs/Pollock.pdf) .North American Journal of FisheriesManagement: 749760. http://duff.ess.washington.edu/grg/publications/pdfs/Pollock.pdf. Retrieved Feb. 28, 2010.

46. ^ ab Gard R (1961). "Effects of beaver on trout in Sagehen Creek, California". Journal of Wildlife Management25 (3): 221242. doi:10.2307/3797848 (http://dx.doi.org/10.2307%2F3797848) . JSTOR 3797848

(http://www.jstor.org/stable/3797848) .47. ^ Hgglund, . & Sjberg, G. (1999). "Effects of beaver dams on the fish fauna of forest streams". Forest
http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-46http://www.jstor.org/stable/3797848http://en.wikipedia.org/wiki/JSTORhttp://dx.doi.org/10.2307%2F3797848http://en.wikipedia.org/wiki/Digital_object_identifierhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-Gard_45-1http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-Gard_45-0http://duff.ess.washington.edu/grg/publications/pdfs/Pollock.pdfhttp://duff.ess.washington.edu/grg/publications/pdfs/Pollock.pdfhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-Stillaguamish_44-1http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-Stillaguamish_44-0http://www.springerlink.com/content/1837v89602g6m186/http://www.springerlink.com/content/1837v89602g6m186/http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-43http://www.springerlink.com/content/ch7n7545764245l5/http://www.springerlink.com/content/ch7n7545764245l5/http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-42http://www.bioone.org/doi/pdf/10.1676/04-116.1http://dx.doi.org/10.1676%2F04-116.1http://en.wikipedia.org/wiki/Digital_object_identifierhttp://www.bioone.org/doi/pdf/10.1676/04-116.1http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-41http://www3.interscience.wiley.com/journal/118653847/abstract?CRETRY=1&SRETRY=0http://dx.doi.org/10.1111%2Fj.1365-2907.2005.00067.xhttp://en.wikipedia.org/wiki/Digital_object_identifierhttp://www3.interscience.wiley.com/journal/118653847/abstract?CRETRY=1&SRETRY=0http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-40http://en.wikipedia.org/wiki/Special:BookSources/978-1557870674http://en.wikipedia.org/wiki/International_Standard_Book_Numberhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-39http://pubs.aina.ucalgary.ca/arctic/Arctic36-1-76.pdfhttp://pubs.aina.ucalgary.ca/arctic/Arctic36-1-76.pdfhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-38http://elibrary.unm.edu/sora/Auk/v077n04/p0476-p0476.pdfhttp://elibrary.unm.edu/sora/Auk/v077n04/p0476-p0476.pdfhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-37http://www.jstor.org/stable/3898902http://en.wikipedia.org/wiki/JSTORhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-36http://www.ncbi.nlm.nih.gov/pubmed/11113253http://en.wikipedia.org/wiki/PubMed_Identifierhttp://dx.doi.org/10.1016%2FS0020-7519%2800%2900127-2http://en.wikipedia.org/wiki/Digital_object_identifierhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-35http://aem.asm.org/cgi/reprint/56/1/31?maxtoshow=&hits=10&RESULTFORMAT=&fulltext=erlandsen&searchid=1&FIRSTINDEX=0&resourcetype=HWCIThttp://aem.asm.org/cgi/reprint/56/1/31?maxtoshow=&hits=10&RESULTFORMAT=&fulltext=erlandsen&searchid=1&FIRSTINDEX=0&resourcetype=HWCIThttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-34http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-33http://www.beaversinengland.com/downloads/ReintroducingtheEuropeanBeaverinBritain.pdf


14/16



Ecology and Management115 (23): 259266. doi:10.1016/S0378-1127(98)00404-6(http://dx.doi.org/10.1016%2FS0378-1127%2898%2900404-6) .

48. ^ Rutherford, W.H. (1955). "Wildlife and environmental relationships of beavers in Colorado forests"(http://www.ingentaconnect.com/content/saf/jof/1955/00000053/00000011/art00003;jsessionid=2k4r9ihuef8i6.alice). Journal of Forestry: 803806.http://www.ingentaconnect.com/content/saf/jof/1955/00000053/00000011/art00003;jsessionid=2k4r9ihuef8i6.alice.Retrieved Feb. 28, 2010.

49. ^ Murphy, M.L., Heifetz, J., Thedinga, J.F., Johnson, S.W. & Koski, K.V. (1989). "Habitat utilisation by juvenilePacific salmon (Onchorynchus) in the glacial Taku River, southeast Alaska". Canadian Journal of Fisheries andAquatic Science: 16771685.

50. ^ ab Michael M. Pollock, Morgan Heim, Danielle Werner (2003). "Hydrologic and Geomorphic Effects of BeaverDams and Their Influence on Fishes"(http://www.albergstein.com/cao/Best%20Available%20Science/Fish/Beaver%20dam%20effects%20paper%20final.pdf) . American Fisheries Society Symposium 37.http://www.albergstein.com/cao/Best%20Available%20Science/Fish/Beaver%20dam%20effects%20paper%20final.pdf. Retrieved Jan. 17, 2010.

51. ^ M. D. Bryant (1984). J.M. Walton and D.B. Houston. ed. "The Role of Beaver Dams as Coho Salmon Habitatin southeast Alaska Streams". Proceeding, Olympic Wild Fish Conferences (Port Angeles, Washington: Peninsula

College, Fisheries Technology program): 183192.52. ^ Karen Leidholt-Bruner, David E. Hibbs, and William C. McComb (1992). [Beaver Dam Locations and TheirEffects on Distribution and Abundance of Coho Salmon Fry in Two Coastal Oregon Streams "Beaver DamLocations and Their Effects on Distribution and Abundance of Coho Salmon Fry in Two Coastal OregonStreams"].Northwest Science. Beaver Dam Locations and Their Effects on Distribution and Abundance of CohoSalmon Fry in Two Coastal Oregon Streams. Retrieved 2011-04-16.

53. ^ abc Collen P, Gibson RJ (2001). "The general ecology of beavers (Castor spp.), as related to their influence onstream ecosystems and riparian habitats, and the subsequent effects on fish a review"(http://www.springerlink.com/content/v48769740n817601/fulltext.pdf) . Reviews in Fish Biology and Fisheries:439461. http://www.springerlink.com/content/v48769740n817601/fulltext.pdf. Retrieved Mar. 2, 2010.

54. ^ D. B. Sigourney, B. H. Letcher, R. A. Cunjak (2006). "Influence of Beaver Activity on Summer Growth and

Condition of Age-2 Atlantic Salmon Parr" (http://afsjournals.org/doi/abs/10.1577/T05-159.1) . Transactions of theAmerican Fisheries Society135 (4): 10681075. doi:10.1577/T05-159.1 (http://dx.doi.org/10.1577%2FT05-159.1). http://afsjournals.org/doi/abs/10.1577/T05-159.1. Retrieved Mar. 1, 2010.

55. ^ W. Gregory Hood (2009). "An Overlooked Ecological Web: Sweetgale, Beaver, Salmon, and Large WoodyDebris in the Skagit River Tidal Marshes" (http://www.nisquallydeltarestoration.org/pdf/hood-%20skagit%20rvr%20tidal%20marshes.htm) . Skagit River Cooperative.http://www.nisquallydeltarestoration.org/pdf/hood-%20skagit%20rvr%20tidal%20marshes.htm. Retrieved June 22,2010.

56. ^ Paul Beier, Reginald H. Barrett (1987-10). "Beaver Habitat Use and Impact in Truckee River Basin, California".Journal of Wildlife Management51 (4): 794799. doi:10.2307/3801743 (http://dx.doi.org/10.2307%2F3801743) .JSTOR 3801743 (http://www.jstor.org/stable/3801743) .

57. ^ Michael Benson Ayers (1997-10). Aerial Multispectral Videography for Vegetation Mapping and Assessment ofBeaver Distribution within Selected Riparian Areas of the Lake Tahoe Basin

(http://www.tahoe.unr.edu/pubs/dissCat.aspx?p_catID=3) (Thesis). University of Nevada at Reno. pp. 71.http://www.tahoe.unr.edu/pubs/dissCat.aspx?p_catID=3. Retrieved 2010-08-26.

58. ^ Michael M. Pollock, Timothy J. Beechie, Chris E. Jordan (2007). "Geomorphic changes upstream of beaverdams in Bridge Creek, an incised stream channel in the interior Columbia River basin, eastern Oregon"(http://onlinelibrary.wiley.com/doi/10.1002/esp.1553/pdf) .Earth Surface Processes and Landforms.doi:10.1002/esp.1553/pdf (http://dx.doi.org/10.1002%2Fesp.1553%2Fpdf) .http://onlinelibrary.wiley.com/doi/10.1002/esp.1553/pdf. Retrieved 2010-08-29.

59. ^ Rick Demmer, Robert L. Beschta (2008-09). "Recent History (19882004) of Beaver Dams along Bridge Creekin Central Oregon" (http://www.bioone.org/doi/full/10.3955/0029-344X-82.4.309) . Northwest Science82 (4):

309318. doi:10.3955/0029-344X-82.4.309 (http://dx.doi.org/10.3955%2F0029-344X-82.4.309) .http://www.bioone.org/doi/full/10.3955/0029-344X-82.4.309. Retrieved 2011-02-25.
http://www.bioone.org/doi/full/10.3955/0029-344X-82.4.309http://dx.doi.org/10.3955%2F0029-344X-82.4.309http://en.wikipedia.org/wiki/Digital_object_identifierhttp://www.bioone.org/doi/full/10.3955/0029-344X-82.4.309http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-58http://onlinelibrary.wiley.com/doi/10.1002/esp.1553/pdfhttp://dx.doi.org/10.1002%2Fesp.1553%2Fpdfhttp://en.wikipedia.org/wiki/Digital_object_identifierhttp://onlinelibrary.wiley.com/doi/10.1002/esp.1553/pdfhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-57http://www.tahoe.unr.edu/pubs/dissCat.aspx?p_catID=3http://www.tahoe.unr.edu/pubs/dissCat.aspx?p_catID=3http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-Ayers_56-0http://www.jstor.org/stable/3801743http://en.wikipedia.org/wiki/JSTORhttp://dx.doi.org/10.2307%2F3801743http://en.wikipedia.org/wiki/Digital_object_identifierhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-55http://www.nisquallydeltarestoration.org/pdf/hood-%20skagit%20rvr%20tidal%20marshes.htmhttp://www.nisquallydeltarestoration.org/pdf/hood-%20skagit%20rvr%20tidal%20marshes.htmhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-54http://afsjournals.org/doi/abs/10.1577/T05-159.1http://dx.doi.org/10.1577%2FT05-159.1http://en.wikipedia.org/wiki/Digital_object_identifierhttp://afsjournals.org/doi/abs/10.1577/T05-159.1http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-53http://www.springerlink.com/content/v48769740n817601/fulltext.pdfhttp://www.springerlink.com/content/v48769740n817601/fulltext.pdfhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-Collen_52-2http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-Collen_52-1http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-Collen_52-0http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-51http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-50http://www.albergstein.com/cao/Best%20Available%20Science/Fish/Beaver%20dam%20effects%20paper%20final.pdfhttp://www.albergstein.com/cao/Best%20Available%20Science/Fish/Beaver%20dam%20effects%20paper%20final.pdfhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-Pollock_49-1http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-Pollock_49-0http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-48http://www.ingentaconnect.com/content/saf/jof/1955/00000053/00000011/art00003;jsessionid=2k4r9ihuef8i6.alicehttp://www.ingentaconnect.com/content/saf/jof/1955/00000053/00000011/art00003;jsessionid=2k4r9ihuef8i6.alicehttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-47http://dx.doi.org/10.1016%2FS0378-1127%2898%2900404-6http://en.wikipedia.org/wiki/Digital_object_identifier


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60. ^ Rudolf Ruedemann, W. J. Schoonmaker (1938-12-02). "Beaver-Dams as Geologic Agents". Science: 523525.JSTOR 1664851? (http://www.jstor.org/stable/1664851?) .

61. ^ Isabelle Groc (April,2010). "Beavers Sign up to Fight Effects of Climate Change"(http://discovermagazine.com/2010/apr/19-beavers-sign-up-fight-effects-climate-change) .Discover.http://discovermagazine.com/2010/apr/19-beavers-sign-up-fight-effects-climate-change. Retrieved 2010-07-27.

62. ^ "The Beaver Solution: Solving our Water Storage Dilemma in Eastern Washington"(http://www.landscouncil.org/beaversolution/what_can_beavers_do.asp) . The Lands Council. March, 2010.

http://www.landscouncil.org/beaversolution/what_can_beavers_do.asp. Retrieved 2010-07-27.63. ^ (2010-01-06) Utah Beaver Management Plan (http://wildlife.utah.gov/furbearer/pdf/beaver_plan_2010-2020.pdf). Utah Division of Wildlife Resources, pp. 25. (Report). Retrieved 2010-08-29.

64. ^ "New York City Beaver Returns" (http://www.sciencedaily.com/releases/2008/12/081218080817.htm) . ScienceDaily. Dec. 20, 2008. http://www.sciencedaily.com/releases/2008/12/081218080817.htm.

65. ^ Peter Miller (Sept. 2009). "Manhattan Before New York: When Henry Hudson first looked on Manhattan in1609, what did he see?" (http://ngm.nationalgeographic.com/2009/09/manhattan/miller-text) . NationalGeographic. http://ngm.nationalgeographic.com/2009/09/manhattan/miller-text.

66. ^ Anahad O'Connor (Feb. 23, 2007). "After 200 Years, a Beaver Is Back in New York City"(http://www.nytimes.com/2007/02/23/nyregion/23beaver.html?_r=1) .New York Times.http://www.nytimes.com/2007/02/23/nyregion/23beaver.html?_r=1. Retrieved Dec. 4, 2009.

67. ^ Trotta, Daniel. "Beaver Returns to New York City After 200 Years."(http://www.planetark.com/dailynewsstory.cfm/newsid/40503/story.htm) World Environment News. Dec. 26, 2007.68. ^ Design Trust for Public Space (June 17, 2009). "Bronx River Crossing"

(http://designtrust.blogspot.com/2009/06/bronx-river-crossing.html) .http://designtrust.blogspot.com/2009/06/bronx-river-crossing.html. Retrieved Dec. 4, 2009.

69. ^ Barry Paddock (2010-09-19). "Another beaver makes Bronx River home - doubles total beaver population"(http://www.nydailynews.com/ny_local/2010/09/19/2010-09-19_2nd_beaver_makes_bronx_river_home.html) .NewYork Daily News. http://www.nydailynews.com/ny_local/2010/09/19/2010-09-19_2nd_beaver_makes_bronx_river_home.html. Retrieved 2010-09-19.

70. ^ ab Boehm, Kiersten (14 Nov 2008). "Lincoln Park Beaver Relocated" (http://www.insideonline.com/) . Inside atYour News Chicago, IL Edition. http://www.insideonline.com/. Retrieved 4 Dec 2009.

71. ^ Scott Holingue (Jan. 1, 1994). Tales from an Urban Wilderness: Wildlife's Struggle for Survival in a ParkWhere City & Wilderness Meet. Chicago, IL: Chicago Historical Bookworks. pp. 140. ISBN 0924772255.

72. ^ "Park District Kills Beaver in Lincoln Park"(http://www.myfoxchicago.com/dpp/news/beaver_north_pond_apr09) .MyFoxChicago.com. April, 2009.http://www.myfoxchicago.com/dpp/news/beaver_north_pond_apr09. Retrieved Dec. 4, 2009.

73. ^ John Greenfield (May 713, 2009). "Why are there signs that claim the Park District murdered a beaver?"(http://chicago.timeout.com/articles/museums-culture/74267/why-are-there-signs-that-claim-the-park-district-murdered-a-beaver) . Time Out Chicago. http://chicago.timeout.com/articles/museums-culture/74267/why-are-there-signs-that-claim-the-park-district-murdered-a-beaver. Retrieved Dec. 4, 2009.

74. ^ Carolyn Jones (April 16, 2008). "Moment of truth for Martinez beavers". San Francisco Chronicle.75. ^ "Worth a Dam website" (http://www.martinezbeavers.org) . http://www.martinezbeavers.org.

76. ^ Aleta George (2008). "Martinez Beavers" (http://baynature.org/articles/jan-mar-2008/ear-to-the-ground/martinez-beavers) .Bay Nature (Bay Nature Institute). http://baynature.org/articles/jan-mar-2008/ear-to-the-ground/martinez-beavers. Retrieved Nov. 6, 2009.

77. ^ Nicola DeRobertis-Theye. "Beavers and More in Martinez:New Habitat Thanks to Beavers"(http://baynature.org/articles/web-only-articles/beavers-and-more-in-martinez) . Bay Nature (Bay Nature Institute).http://baynature.org/articles/web-only-articles/beavers-and-more-in-martinez. Retrieved Nov. 6, 2009.

78. ^ Thomas Jefferson Farnham (1857).Life, adventures, and travels in California (http://books.google.com/?id=cwMNAAAAIAAJ&dq=travels+in+california+farnham&printsec=frontcover#v=onepage&q=beaver&f=false) .Blakeman & Co.. p. 383. http://books.google.com/?id=cwMNAAAAIAAJ&dq=travels+in+california+farnham&printsec=frontcover#v=onepage&q=beaver&f=false.

79. ^ Jonathan Aiken (April 7, 1999). "Beaver is bad guy at cherry blossom time"

(http://www.cnn.com/US/9904/07/chomping.cherry.trees/index.html) . CNN.com.http://www.cnn.com/US/9904/07/chomping.cherry.trees/index.html. Retrieved Nov. 22, 2009.
http://www.cnn.com/US/9904/07/chomping.cherry.trees/index.htmlhttp://www.cnn.com/US/9904/07/chomping.cherry.trees/index.htmlhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-78http://books.google.com/?id=cwMNAAAAIAAJ&dq=travels+in+california+farnham&printsec=frontcover#v=onepage&q=beaver&f=falsehttp://books.google.com/?id=cwMNAAAAIAAJ&dq=travels+in+california+farnham&printsec=frontcover#v=onepage&q=beaver&f=falsehttp://en.wikipedia.org/wiki/Thomas_Jefferson_Farnhamhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-77http://baynature.org/articles/web-only-articles/beavers-and-more-in-martinezhttp://baynature.org/articles/web-only-articles/beavers-and-more-in-martinezhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-76http://baynature.org/articles/jan-mar-2008/ear-to-the-ground/martinez-beavershttp://baynature.org/articles/jan-mar-2008/ear-to-the-ground/martinez-beavershttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-75http://www.martinezbeavers.org/http://www.martinezbeavers.org/http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-74http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-73http://chicago.timeout.com/articles/museums-culture/74267/why-are-there-signs-that-claim-the-park-district-murdered-a-beaverhttp://chicago.timeout.com/articles/museums-culture/74267/why-are-there-signs-that-claim-the-park-district-murdered-a-beaverhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-72http://www.myfoxchicago.com/dpp/news/beaver_north_pond_apr09http://www.myfoxchicago.com/dpp/news/beaver_north_pond_apr09http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-myfoxchicago.com_71-0http://en.wikipedia.org/wiki/Special:BookSources/0924772255http://en.wikipedia.org/wiki/International_Standard_Book_Numberhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-70http://www.insideonline.com/http://www.insideonline.com/http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-Inside_69-1http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-Inside_69-0http://www.nydailynews.com/ny_local/2010/09/19/2010-09-19_2nd_beaver_makes_bronx_river_home.htmlhttp://www.nydailynews.com/ny_local/2010/09/19/2010-09-19_2nd_beaver_makes_bronx_river_home.htmlhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-68http://designtrust.blogspot.com/2009/06/bronx-river-crossing.htmlhttp://designtrust.blogspot.com/2009/06/bronx-river-crossing.htmlhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-67http://www.planetark.com/dailynewsstory.cfm/newsid/40503/story.htmhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-66http://www.nytimes.com/2007/02/23/nyregion/23beaver.html?_r=1http://www.nytimes.com/2007/02/23/nyregion/23beaver.html?_r=1http://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-65http://ngm.nationalgeographic.com/2009/09/manhattan/miller-texthttp://ngm.nationalgeographic.com/2009/09/manhattan/miller-texthttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-64http://www.sciencedaily.com/releases/2008/12/081218080817.htmhttp://www.sciencedaily.com/releases/2008/12/081218080817.htmhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-63http://en.wikipedia.org/wiki/Utah_Division_of_Wildlife_Resourceshttp://wildlife.utah.gov/furbearer/pdf/beaver_plan_2010-2020.pdfhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-62http://www.landscouncil.org/beaversolution/what_can_beavers_do.asphttp://www.landscouncil.org/beaversolution/what_can_beavers_do.asphttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-61http://discovermagazine.com/2010/apr/19-beavers-sign-up-fight-effects-climate-changehttp://discovermagazine.com/2010/apr/19-beavers-sign-up-fight-effects-climate-changehttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-60http://www.jstor.org/stable/1664851?http://en.wikipedia.org/wiki/JSTORhttp://en.wikipedia.org/wiki/North_American_Beaver#cite_ref-59

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