CA North American Beaver Hunting Guide

Also known as: Beaver, American beaver, California beaver

The North American beaver is one of two extant beaver species, along with the Eurasian beaver. It is native to North America and has been introduced in South America (Patagonia) and Europe. The North American beaver is one of the national symbols of Canada and the official state mammal of Oregon and New York. North American beavers are widespread across the continental United States, Canada, southern Alaska, and some parts of northern Mexico.

Habitat & Range

Beavers were practically ubiquitous and lived from south of thearctic tundrato the deserts of northern Mexico, and from theAtlanticto the Pacific Oceans, but were trapped across the continent for economic gain and political competition, leading to regional extirpation in many regions like the Great Plains.[47][48][49][50]Certain areas saw near-extirpations and declining numbers, but not extirpation, partially due to various conservation measures were taken, with mixed results, by theHudson's Bay Company.[50][51]By the 1900s and 1910s, beavers existed largely in isolated pockets, but where those pockets existed is not well documented.[52]However, despite these difficulties reintroduction and natural spread has restored the species back into most of it natural range, with innovations in management allowing sustainable harvest yields now exceeding previous record harvests.[53][54][55]They are widely distributed in boreal and temperate ecoregions, where populations are rebounding from historic over-exploitation. Recently, beaver have been observed colonizing arctic tundra, likely as a result of climate-induced increases in riparian shrubs.[56][57][58] Physician naturalistEdgar Alexander Mearns' 1907 report of beaver on theSonora Rivermay be the earliest report on the southernmost range of this North American aquatic mammal.[59]However, beavers have also been reported both historically and contemporarily in Mexico on theColorado River,Bavispe River, andSan Bernardino Riverin the Mexican states ofSonoraandChihuahua.[60][61][62]

Life History

C. c. acadicusBailey and Doutt, 1942[4]C. c. baileyiNelson, 1927[5]C. c. belugaeTaylor, 1916[6]:429–433Cook Inlet beaverC. c. caecatorBangs (1913:513)[7]Newfoundland beaverC. c. canadensisKuhl 1820[3]Canadian beaverC. c. carolinensisRhoads 1898[8]: 420–421Carolina beaverC. c. concisorWarren and Hall, 1939[9]C. c. duchesneiDurrant and Crane, 1948[10]C. c. frondatorMearns, 1897[11]Sonora beaverC. c. idoneusJewett and Hall, 1940[12]C. c. labradorensisBailey and Doutt, 1942[4]C. c. leucodontaGray, 1869[13]Pacific beaverC. c. mexicanusBailey, 1913[14]Rio Grande beaverC. c. michiganensisBailey 1913[14]Woods beaverC. c. missouriensisBailey 1919[15]Missouri River beaverC. c. pacificusRhoads 1892[8]: 422–423Washington beaverC. c. pallidusDurrant and Crane, 1948[10]C. c. phaeusHeller, 1909[16]Admiralty beaverC. c. repentinusGoldman, 1932[17]C. c. rostralisDurrant and Crane, 1948[10]C. c. sagittatusBenson, 1933[18]C. c. shastensis(Taylor, 1916)[6]:433–436Shasta beaverC. c. subauratus(Taylor, 1912)[19][20]California golden beaverC. c. tayloriDavis, 1939[21]C. c. texensisBailey, 1905[22]Texas beaver; C. c. acadicusBailey and Doutt, 1942[4]; C. c. baileyiNelson, 1927[5]; C. c. belugaeTaylor, 1916[6]:429–433Cook Inlet beaver; C. c. caecatorBangs (1913:513)[7]Newfoundland beaver; C. c. canadensisKuhl 1820[3]Canadian beaver; C. c. carolinensisRhoads 1898[8]: 420–421Carolina beaver; C. c. concisorWarren and Hall, 1939[9]; C. c. duchesneiDurrant and Crane, 1948[10]; C. c. frondatorMearns, 1897[11]Sonora beaver; C. c. idoneusJewett and Hall, 1940[12]; C. c. labradorensisBailey and Doutt, 1942[4]; C. c. leucodontaGray, 1869[13]Pacific beaver; C. c. mexicanusBailey, 1913[14]Rio Grande beaver; C. c. michiganensisBailey 1913[14]Woods beaver; C. c. missouriensisBailey 1919[15]Missouri River beaver; C. c. pacificusRhoads 1892[8]: 422–423Washington beaver; C. c. pallidusDurrant and Crane, 1948[10]; C. c. phaeusHeller, 1909[16]Admiralty beaver; C. c. repentinusGoldman, 1932[17]; C. c. rostralisDurrant and Crane, 1948[10]; C. c. sagittatusBenson, 1933[18]; C. c. shastensis(Taylor, 1916)[6]:433–436Shasta beaver; C. c. subauratus(Taylor, 1912)[19][20]California golden beaver; C. c. tayloriDavis, 1939[21]; C. c. texensisBailey, 1905[22]Texas beaver C. c. acadicusBailey and Doutt, 1942[4]; C. c. baileyiNelson, 1927[5]; C. c. belugaeTaylor, 1916[6]:429–433Cook Inlet beaver; C. c. caecatorBangs (1913:513)[7]Newfoundland beaver; C. c. canadensisKuhl 1820[3]Canadian beaver; C. c. carolinensisRhoads 1898[8]: 420–421Carolina beaver; C. c. concisorWarren and Hall, 1939[9]; C. c. duchesneiDurrant and Crane, 1948[10]; C. c. frondatorMearns, 1897[11]Sonora beaver; C. c. idoneusJewett and Hall, 1940[12]; C. c. labradorensisBailey and Doutt, 1942[4]; C. c. leucodontaGray, 1869[13]Pacific beaver; C. c. mexicanusBailey, 1913[14]Rio Grande beaver; C. c. michiganensisBailey 1913[14]Woods beaver; C. c. missouriensisBailey 1919[15]Missouri River beaver; C. c. pacificusRhoads 1892[8]: 422–423Washington beaver; C. c. pallidusDurrant and Crane, 1948[10]; C. c. phaeusHeller, 1909[16]Admiralty beaver; C. c. repentinusGoldman, 1932[17]; C. c. rostralisDurrant and Crane, 1948[10]; C. c. sagittatusBenson, 1933[18]; C. c. shastensis(Taylor, 1916)[6]:433–436Shasta beaver; C. c. subauratus(Taylor, 1912)[19][20]California golden beaver; C. c. tayloriDavis, 1939[21]; C. c. texensisBailey, 1905[22]Texas beaver Castor fiber canadensis TheNorth American beaver(Castor canadensis) is one of twoextantbeaverspecies, along with theEurasian beaver(Castor fiber).[23]It is native to North America and has been introduced in South America (Patagonia) and Europe (primarilyFinlandandKarelia). The North American beaver is one of thenational symbols of Canadaand the official state mammal ofOregonandNew York.[28]North American beavers are widespread across the continentalUnited States,Canada, southernAlaska, and some parts of northernMexico. In Canada and the United States, the North American beaver is often referred to simply as "beaver", although this can cause some confusion because another distantly related rodent,Aplodontia rufa, is often called the "mountain beaver". Other vernacular names, includingAmerican beaver[23]andCanadian beaver,[29]distinguish this species from the otherextantbeaver species,Castor fiber, which is native toEurasia. The beaver is the largest rodent in North America and competes with its Eurasian counterpart, theEuropean beaver, for being the third-largest in the world, both following the South Americancapybaraandlesser capybara. The European species is slightly larger on average but the American has a larger known maximum size. Adults usually weigh from 11 to 32 kg (24 to 71 lb), with 20 kg (44 lb) being typical. In New York, the average weight of adult male beavers was 18.9 kg (42 lb), while non-native females inFinlandaveraged 18.1 kg (40 lb). However, adults of both sexes averaged 16.8 kg (37 lb) inOhio.[35][36][37]The species seems to conform toBergmann's rule, as northern animals appear to be larger. In theNorthwest Territory, adults weighed a median of 20.5 kg (45 lb).[38]The American beaver is slightly smaller in average body mass than the Eurasian species.[36]The head-and-body length of adult North American beavers is 74–90 cm (29–35 in), with the tail adding a further 20–35 cm (7.9–13.8 in). Very old individuals can exceptionally exceed normal sizes, weighing more than 40 kg (88 lb) or even as much as 50 kg (110 lb).[39][40][41][42] The beavers aresemiaquaticwith physical traits suited to this lifestyle. It has a large, scaly, paddle-shaped tail and webbed hind feet. The unwebbed front feet are smaller, have claws, and are highly dexterous. Beavers use their front feet for digging, to feed themselves, and to maneuver small stems as they gnaw bark off trees.[43]The eyes are covered by anictitating membranewhich allows the beaver to see underwater. The nostrils and ears are sealed while submerged. Their lips can be closed behind their front teeth so that they can continue to gnaw underwater.[44]A thicklayer of fat under its skinprovides insulation. The beaver'sfurconsists of long, coarse outer hairs and short, fine inner hairs, and is usually dark brown.Scent glandsnear the genitals secrete an oily substance known ascastoreum, which the beaver uses to waterproof its fur. There is also another set of oil glands producing unique chemical identifiers in the form of waxy esters and fatty acids.[43] The beaver, like all rodents, possesses continuously growingincisors, and is ahindgut fermenterwhosececum, populated by symbiotic bacteria, helps to digest plant-based material.[45]The beaver is specialized for efficient digestion of itslignocellulose-heavy diet.[46] Beavers are active mainly at night. They are excellent swimmers and may remain submerged up to 15 minutes. More vulnerable on land, they tend to remain in the water as much as possible.[63]They use their flat, scaly tail both to signal danger by slapping the surface of the water and as a location for fat storage. They construct their homes, or "lodges", out of sticks, twigs, rocks, and mud in lakes, streams, andtidalriver deltas.[64]These lodges may be surrounded by water, or touching land, including burrows dug into river banks. Beavers are well known for buildingdamsacross streams and constructing their lodges in the artificial ponds which form. When building in a pond, the beavers first make a pile of sticks and 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 freezes, has the consistency of concrete. A small air hole is left in the top of the lodge. Beavers are herbivorousgeneralistswith sophisticatedforagingpreferences based on taste, coarse physical shape, and odor. Beavers consume a mix ofherbaceousandwoody plants, which varies considerably in both composition and species diversity by region and season.[43]Beavers feed on bark, cambium,[77]branches, twigs, roots, buds,[77]leaves, stems, sprouts, and in some cases,sapandstorax.[43]They preferaspenand otherpoplars, but do also eatbirch,maple,willow,alder,black cherry,red oak,beech,ash,hornbeam, and occasionallypine,sweetgum, andspruce.[43][71]Beavers do not preferred maple, which can be the only tree left standing at the edges of some beaver ponds.[43][78]They also eatcattails,water lilies, and other aquatic vegetation, especially in the early spring. Contrary to widespread belief, they do not eat fish.[79] When herbaceous plants are actively growing, they make up much of the beaver's diet. In the winter, beavers switch to woody plants and the food they have stored over the winter. The protein to calorie ratio of a beaver's diet is 40 mg/calorie in summer and 8 mg/calorie for the rest of the year. In northern latitudes, the water liliesNymphaeaandNupharare the most important herbaceous component. Therhizomesare stored in the food cache and remain actively growing.[43] The beaver's gut microbiome is complex and specialized for a wood-heavy diet, and shows similarity to that of other mammalian herbivores.[46]Beavers' gut microbiome allows them to digest up to thirty percent of the cellulose they eat.[80] North American beavers have one litter per year, coming into estrus for only 12 to 24 hours, between late December and May but peaking in January. Beaver reproduction occurs earlier in warmer southern climates, however in their northern range beavers may wait until late spring to reproduce.[87]Depending on when beavers reproduce, their litters are typically born between April and June each year. Unlike most other rodents, beaver pairs are monogamous, staying together for multiple breeding seasons. Gestation averages 128 days and they have a range of three to six kits per litter (usually 4–5). Most beavers do not reproduce until they are three years of age, but about 20% of two-year-old females reproduce. Female beavers will prepare for birth by making a soft bed inside the lodge. After birth, young beavers stay sheltered in their lodges for up to a month before they begin to swim and eat solid foods. Juvenile beavers stay with their parents for up to 2 years before leaving to create their own homes. The beaver was trapped out and almost extirpated in North America because its fur andcastoreumwere highly sought after.[48]The beaver furs were used to make clothing andbeaver hats. In the United States, extensive trapping began in the early 17th century, with more than 10,000 beaver per year taken for the fur trade inConnecticutandMassachusettsbetween 1620 and 1630.[89]From 1630 to 1640, around 80,000 beavers were taken annually from theHudson Riverand western New York.[90]From 1670 onwards, theHudson's Bay Companysent two or three trading ships into the bay every year to take furs to England from Canada. Archaeological and historical evidence suggests that beaver ponds created "moth-hole like" habitats in the deciduous forest that dominated eastern North America. This nonforest habitat attracted bothNative Americanand early colonial hunters to the abundant fish, waterfowl, and large game attracted to the riparian clearings created by these aquatic mammals. The first colonial farmers were also attracted to the fertile, flat bottomlands created by the accumulated silt and organic matter in beaver ponds.[91] As eastern beaver populations were depleted, English, French, and American trappers pushed west. Much of the westward expansion and exploration of North America was driven by the quest for this animal's fur. Before the 1849California Gold Rush, an earlier, 19th-centuryCalifornia Fur Rushdrove the earliest American settlement in that state. During the roughly 30 years (1806–1838) 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. With protection in the late 19th and early 20th centuries, the current beaver population has rebounded to an estimated 10 to 15 million; this is a fraction of the originally estimated 100 to 200 million North American beavers before the days of thefur trade.[92][93] The beaver is akeystone species, increasing biodiversity in its territory through creation of ponds and wetlands.[95]As wetlands are formed and riparian habitats enlarged, aquatic plants colonize newly available watery habitat. Insect, invertebrate, fish, mammal, and bird diversities are also expanded.[96]Effects of beaver recolonization on native and non-native species in streams where they have been historically absent, particularly dryland streams, is not well-researched.[97]

Hunting Season

Furbearer trapping season. Typically Nov - Mar. Check current CDFW regulations for specific dates.

References

• California — North American Beaver