History
In 1805, Lewis and Clark saw beaver dams “extending as far up those streams as [we] could discover them.” Even before the famous explorers, French trappers and traders were drawn to the land teeming with beaver.
The beaver is North America’s largest rodent. Its pelt is waterproof and has a double layer of insulation making it highly desirable for human use. At the height of pelt demand, some estimates claim that between 60-400 million animals were taken.
Fortunately, we have beavers living along Deer Creek!
The beaver method of water retention, stream restoration, and habitat rehabilitation.
Beaver ponds and dams;
- reduce erosion
- act as a fire break
- slow water movement through a watershed, replenishing the water table, reducing the need for irrigation
- filter nitrogen and other chemicals that cause algae blooms resulting in oxygen-deprived dead zones
- retain sediments, increasing watershed biodiversity
Ponds volume keeps water temperatures cool, necessary for certain fish species
Discord Between Beavers and People
- beaver may eat landscape plants and trees within 165 feet of the water’s edge
- water pooling on the land will expand
- roads and structures may flood
- dams plug culverts and drains
- animals and wildlife are attracted to the habitats beavers create
In 2017, the USDA Animal and Plant Health Inspection Service killed 81 beavers in California.
Beaver Problem Remediation
- install a pond flow device, limiting water rise, eliminating flooding
- choose landscape plants that beaver don’t eat
- choose plants that resprout after a beaver visit
- keep landscape plants distant from the water source
Barrier methods;
- wrap large trees with 3 ft. high galvanized welded wire fencing or multiple layers of chicken wire
- paint tree trunks with sanded paint ( mix 2/3 cup masonry sand per quart of latex paint)
- surround groups of trees/ shrubs with 3 ft. high fencing strong enough to withstand a 60 lb animal pushing on it or attempting to get under it
- apply and reapply deer and big game repellent
Diet and Behavior
Nocturnal and non-hibernating, beavers eat plants; leaves, bark twigs, trees, willow, cottonwood and other deciduous trees. They’ll also eat garden plants if given the chance.
Pairs may mate for life but are not always monogamous. Kits are born between April and June, remaining with their parents for two years. A beaver colony usually consists of a breeding pair and several generations of their kits.
A full grown beaver can grow up to 60 pounds. (Fossil records show that they once reached 300 lbs!) Their lifespan in the wild is between 5 – 10 years.
Spending most of their time in the water, beavers have few predators. When on land, they are most vulnerable. Predators include; man, wolves, coyote, mountain lion, bears, bobcats, and dogs.
The Beaver Butt Thing – Castoreum
Aside from fur, trappers learned of another beaver special quality; castor glands, located near the anus, smell vanilla sweet. Castoreum is secreted with urine to mark territory. One can’t help imagining the very first gland discovery. A mountain man noticed it while taking the animal apart. To verify, he needed a close-and-personal secondary sensory test. Enthusiastic conversations between trappers spread the news and began a new industry.
Castoreum, a thick, syrup-like ooze was used in the perfume industry, starting in the 1800’s, to enhance other scents and increase their longevity.
“The United States, the Food and Drug Administration lists castoreum extract as a generally recognized safe (GRAS) food additive. … While it is mainly used in foods and beverages as part of a substitute vanilla flavor, it is less commonly used as a part of a raspberry or strawberry flavoring.” Wikipedia
Despite Castoreum’s listing with the FDA, it was never a substance in wide use. Anesthetizing and milking beavers was time-consuming and costly.
[Castoreum should not be confused with Castor, as in Castor Oil, which is a plant.]
Beaver Adaptations
- continuously growing incisors
- an insatiable need to build at the sound of water
- tail functions as extra leg while on land
- a mouth valve that keeps water out while carrying/floating a tree or branch
- ear valves with the same function
- back of throat valve – ditto
- nostril valves – ditto
- nictitating membrane covers eyes underwater acting like goggles
- tail slaps on water warn of danger
- hind foot has a split toenail used as a comb
- fur is waterproof, treated with an oily substance
- intestinal bacteria ferment cellulose to digest plant matter — this is why castoreum smells so good!
California Native & Aquatic Keystone Species
The National Geographic Society describes a keystone species as an organism that helps define an entire ecosystem. Without its keystone species, the ecosystem would be dramatically different or cease to exist altogether.
If you liked this post, you may also like, Singing Coyote – the Ultimate Adaptor.
Resources:
Bay Nature – For beaver believers salvation lies in a once-reviled rodent
Beavers: 8 things to know about nature’s most impressive landscape engineers
Dispatch – USDA fights endless battle of wits with ingenious beavers
Bridge Creek (Oregon) Beaver Dam Analog Steelhead Restoration (2004-2020)
Climate Change | Beavers Help Battle Ongoing Drought
Eager Beaver
author, Ben Goldfarb Radio Interview.
Mental Floss – A Brief History of Castoreum, the Beaver Butt Secretion Used as Flavoring
Nature World News – (Beaver) Dams Help Remove Nitrogen From Estuaries and Restore Streams | 2015
National Geographic – Beaver Butts Emit Goo Used for Vanilla Flavoring
National Geographic – Beavers Have Vanilla-Scented Butts and More Odd Facts
National Geographic – Beavers —Once Nearly Extinct—Could Help Fight Climate Change
National Park Service – Beaver
New York Post – Distillery has new bourbon flavored by beaver secretion
New York Times |2017 – Beavers Emerge as Gents of Arctic Destruction
NOAA Fisheries – Working with Beaver to Restore Salmon Habitat
NOAA – Working with Beaver to Restore Salmon Habitat
Science Magazine | 6/7/18 – Beaver dams without beavers? Artificial logjams are a popular but controversial restoration tool – rebeavering Bear Valley (an hour north of Redding)
Smithsonian’s National Zoo – Beaver
Spokane Lands Council – Beaver Solution
Time Magazine – The True History Behind Idaho’s Parachuting Beavers
USDA – 2017 California Animals Killed Report
USDA – How to Keep Beavers from Plugging Culverts [PDF]
USDA – Mountain Beaver Damage and Management
Washington Dept. Fish and Wildlife – Beavers
Wikipedia – Beaver in the Sierra Nevada
Wikipedia – California Fur Rush
Warning! Video below shows animal butchering – Beaver Castor Gland Removal
