Unbelievable Beaver Series Part 2: Ecosystem Engineers

Over the years, beavers have gained a reputation as “ecosystem engineers.” For millions of years, they have stayed busy building dams and lodges. After being severely threatened by the fur trade and seen as a nuisance species, conservation efforts changed the way people think about beavers and revitalized beaver populations. In part two of the Unbelievable Beaver Series, I will talk about the hard work beavers do to protect water and the hard work humans do to protect beavers.

Since they’re nocturnal, beavers do most of their work at night. They use whatever they can get their large orange teeth on; typically sticks, grasses, rocks, and mud to build dams and create ponds. The sound and sight of running water puts beavers into work mode where they create dams to decrease the speed of the current. The average dam ranges 0.7 and 2.0 meters in height, with an average length of 32 meters ¹. Beaver dams have an astounding impact on the environment. These semi-porous structures slow down the stream’s current which recharges groundwater and reduces erosion creating deep ponds that provide habitat for fish and other aquatic life. Beaver dams also create floodplains that improve water quality and reduce the risk of flood damage to structures such as houses.

When beavers aren’t constructing dams, it’s likely that they’re busy building lodges. Beavers’ homes, which are called lodges, are brilliantly engineered using three tons of raw materials and taking only twenty days to build [2]. After the initial framework of branches and rocks is set, beavers apply thick layers of mud to the exterior of the lodge. When the mud solidifies, the rock-hard shell protects beavers from predators such as wolves and coyotes [2]. The only entrances to the lodge are hidden underwater making it nearly impossible to access for most animals. Lodges have different chambers that serve different purposes. During the spring, the innermost chamber is used for giving birth to kits [2]. While lodges are designed to protect beavers from natural predators, during the 20^th century, they were not enough to stop determined trappers so a new form of defense was needed for the recovery of diminishing beaver populations. After the fur trade nearly wiped out the North American and Eurasian beaver populations and felt hats began to fall out of style, a new movement began.

While beavers no longer held much monetary value, their ecological value began to grab the attention of conservationists. In 1928, Grey Owl began promoting the idea of reintroducing beavers back to the landscape. He was hired by the Canadian Government to educate the general public about the importance of beavers in an effort to restore the landscape ³. Adding to the efforts, a team of scientists and activists called the Beaver Believers are live trapping and relocating beavers to restore and conserve water in the American West. Beaver reintroduction and protection has resulted in resurgence in beaver populations, although they haven’t reached pre-fur trade numbers. Before the fur trade, it was estimated that there were hundreds of millions of North American beavers. Excessive trapping and hunting reduced the population to approximately 100,000. Today there are an estimated 10-15 million North American beavers ⁴.

As periods of drought prolong and intensify in the Blackfeet Nation, we need to protect beavers so they can continue helping us conserve water. Throughout the Ksik Stakii (Beaver) Project, we will work with natural resource managers and producers to properly manage beaver populations in the Blackfeet Nation.

In part three of the Unbelievable Beaver Series, I will share some unbelievable facts about beavers!

Sources:

1. Fritch, Lorne. “Beaver- Our Watershed Partner.” Apr. 2016, pp. 7–20., cowsandfish.org/publications/documents/BeaverOurWatershedPartnerWEB.pdf.
2. “Beavers: The Master Builders?” Performance by David Attenborough, Wildlife on One, BBC One, 2007, http://www.bbc.co.uk/programmes/b007cklf.
3. Loo, Tina. States of Nature: Conserving Canada’s Wildlife in the Twentieth Century.Vancouver: UBC Press, 2006, pg. 111.
4. McKenzie, Liz. “Beaver – Ecology.” Encounters, http://www.encountersnorth.org/wildexplorer/beaver/ecology.html.