Beavers

 
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Have you suddenly found yourself with new, unexpected beaver neighbors? Living with beavers can be tough, but Blue Heron wants to inform the public on how beavers and humans can happily coexist.

Below are valuable resources to help you understand how beavers work, how they can benefit the environment, and how you can humanely control their activity.

If you want to learn more about beavers and see firsthand how they live in their environment, check out our educational programming (link to family education page) about the animals that call the Preserve home.

 

Frequently Asked Questions About Beavers

What is a Beaver?

Beavers are in the Order Rodentia, the group which includes mice, rats, squirrels, prairie dogs, porcupines, beavers, guinea pigs and hamsters. The characteristic gnawing activity of all rodents is a physical necessity to file down their large incisors, which continue to grow throughout their life. Beavers eat the bark off trees and shrubs but will also eat the roots of aquatic plants such as cattails and water lilies.

Beavers have a relatively short lifespan of 10-15 years and can grow to be over 100 lbs. Baby beavers, known as kits, are born once a year and litters range from 1 to 9 kits each season.

There are only two species of beaver: the American beaver, Castor Canadensis, and the Eurasian beaver, Castor Fiber. Both American and Eurasian beavers were once widely trapped for their meat and pelts. The beaver fur trade was so lucrative that both species nearly became extinct. Reintroduction programs in both North America and Europe have been successful since scientists came to understand the many ecological benefits these creatures provide.

 

Why are Beavers Important?

Beavers are unique animals. They are known as a keystone species for their ability to engineer entire ecosystems. Humans are the only other animal that can alter their environment to such an extreme degree. Damming, digging, foraging and flooding by the beavers can create a lush wetland environment, which in turn becomes a home for many species of insects, amphibians, reptiles, fish, birds and other mammals. Some of the species found in beaver wetlands may be threatened or endangered.

Once a beaver family abandons the wetland, a process known as succession takes place. As the wetland drains, grasses and shrubs colonize the rich soils and the old wetland transforms into a lush meadow, eventually becoming a forest.

Beaver wetlands are also vital to water quality protection. Their ponds provide a perfect place for decomposers to break down nutrients such as ammonia and phosphates. Dams help slow the flow of water in the creek or stream and allow sediments to settle out of the water. The surrounding vegetation and anoxic soils may also act as a carbon sink by taking in carbon dioxide and locking the carbon inside living plants and peat. These natural processes together improve water quality for human and wildlife consumption.

Beaver dams also help reduce flooding downstream by retaining excess water or diverting the flow over floodplains where the water is caught and allowed to slowly infiltrate into the ground. When several beaver ponds are located within a single watershed, flooding is localized within the wetlands but less potential damage will occur to communities downstream.

 

Why do Beavers Build Dams?

There are several reasons why beavers build dams to create ponds. Beavers are agile swimmers and feel safest when their lodge is surrounded by water. Deep water makes it difficult for predators to catch the beavers or break into their lodge. Most predators such as foxes, bears, wolves and coyotes are not adept swimmers and will opt for easier prey.

Beavers also impound water to reach more food without leaving the safety of the water. Even after a beaver has dammed a stream, they will dig out channels to help move limbs and logs from far away (up to 100 feet from the lodge); this is like how humans build canals for transportation.

Beavers continue to maintain their dams. Beavers are triggered by the sound of running water, which indicates that a dam has sprung a leak or the water level has risen higher. They build the dams higher and higher as sediments collect behind the dam and the pond deepens. Beaver dams can be several feet high and may extended for hundreds of feet across the wetland. In Georgia, all naturally occurring (non-manmade) ponds and lakes are created by beavers.

 

Do Beavers Hibernate?

Beavers do not hibernate, even in the far northern extent of their range. They will create stockpiles of branches underwater as winter food stores and will survive off the stockpiles until the ice on the pond melts in the spring. Southern beavers will continue to forage and build dams throughout the winter months.

 

Are Beavers Monogamous?

Beavers mate for life. If the mate dies, the surviving beaver will mourn the loss of its partner but may try to find a new mate. Beavers form large family groups, with several generations of kits and juveniles living together in the same lodge. When kits reach one year of age, they begin learning all the important beaver habits like how to chew bark, build and repair dams, and alert for predators. Older siblings will care for the kits and teach these behaviors while also maintaining the dams and lodges. Mature beavers usually leave the family unit when they are about two years old and will travel several miles away to build their own pond and look for a mate.

 

Are Beavers Dangerous?

Beavers are usually nocturnal and naturally shy creatures. They rely on their agility in the water to run from predators. Beavers are territorial towards other beavers and create “scent mounds” of mud and musk to mark their wetland. Humans are very rarely attacked by beavers; however, as with all wild animals, a beaver will become agitated when cornered or trapped and may bite to get away.
Like all mammals, including humans, beavers can carry a range of diseases including parasites, bacteria, and viruses. The most commonly linked disease is Giardia lamblia, a freshwater parasite which can survive in freshwater environments outside a host. There is little research on how prevalent Giardia is in beaver ponds, and cysts may occur in any freshwater river, stream, or lake contaminated with human or animal feces. It is not recommended to drink water directly from a stream or lake, regardless how clean it appears.

 

What if a Beaver Becomes a Problem?

Trapping beavers is regulated by the state Department of Fish and Wildlife or Department of Natural Resources. When a beaver has been deemed a nuisance, it can be trapped by a trained professional with the proper permitting and licensed traps. Once captured, beavers will either die in the trap (usually by drowning) or be euthanized. There is currently no beaver relocation program in Georgia. Typically, within a few months of removal a new beaver will move into the area which is why removal is not recommended as a sustainable method of control.

There are many alternative ways to protect valuable trees, reduce flooding, and keep culverts clear.

 

The Beaver Restoration Guidebook

This comprehensive guide contains information about beaver ecology and management. The Beaver Restoration Guidebook includes alternative non-lethal management techniques, including Beaver Dam Analogs (BDAs), tree painting, and fencing methods.

Download the PDF

 

Videos About Beavers

Leave It to Beavers – [48:13]

A PBS Nature Hour special on beaver life cycles, their habitat, and 3 success stories of how humans learned to coexist with beavers.

Beaver: Back to the Future – [13:17]

This fantastic short film chronicles 3 successful beaver colonies in the western US, by the Grand Canyon Trust

Coexisting with Busy Beavers at the Cornell Lab – [2:38]

The story of beavers at Cornell University in Ithaca, NY and the installation of flood control devices at Sapsucker Woods Pond