Hey there, time traveller!
This article was published 5/7/2017 (1613 days ago), so information in it may no longer be current.
What better way to mark the 150th year of Canada’s confederation than by taking steps to co-exist with our national animal?
Beavers can be a handful for land managers: they can quickly change an environment, creating wetlands, diverting waterways and felling trees, as was pointed out in a recent article by Bill Redekop ("Dam those beavers," June 23). But the benefits these incredible engineering feats provide, while not immediately visible, have long-term advantages for local ecosystems and the planet. And that means it’s vital to find a balance between their industrious activities and our agricultural or industrial use of land.
The primary concern for many managers is the construction of dams that can lead to flooding, particularly of agricultural lands or infrastructure. Removal of dams, or of beavers themselves, is the traditional response, though history has shown this to be short-term, costly and ultimately ineffective. Beavers will return to ideal lodging sites due to availability of resources (including the ability to dam), and as keystone species, their role in the ecosystem warrants protection. That’s where flow devices come in.
Systems of fencing and piping that can be built from hardware store materials, flow devices can create a situation where flooding or water levels are managed safely and beavers are able to remain in place, creating a stable population and providing their ecological benefits. They can also be used to stop damming from taking place, which is particularly helpful when managing roadside culverts. There are three primary types of pond levellers that can be made by managers.
Pond levellers work by putting a large pipe through an existing dam (which the beavers quickly repair and seal into place). One end is surrounded by a fence to protect it from large debris and curious beavers, then sunken into the pond-side. The other end exits out the back of the dam, where the beavers can’t plug it and allows water to pass through. This allows water to naturally move through the dam, but can be adjusted so the pond remains at a certain height (allowing for the beavers to access their caches, lodges, and so on).
Exclusion fences work by using the beaver’s building style against them. A trapezoid-shaped fence is built out from the spot the beavers would try and dam, frequently culverts, which forces them away as they move sticks into position. They are excluded from accessing the culvert and are unable to build across the water flow, quickly giving up.
Combo devices are the marriage of exclusion fences and pond levellers, and are used when a bit of both types of device are necessary.
When properly installed, these devices have success rates exceeding 90 per cent over a five-to-10-year span. Each device costs as little as $400 in materials (frequently materials that municipalities already have on site from other projects), and can take as few as two or three hours to build, with minimal maintenance over their lifespan.
The Fur-Bearers have built approximately 50 devices across British Columbia, Alberta, and Ontario, both for private land owners and municipalities, and are returning to Alberta later this year to co-host a second training event for municipalities, non-profits and individuals.
We understand the frustration of land managers facing the damage caused by beaver damming. We have seen the success of the devices and would be thrilled to consult with municipalities or non-profits who are interested in adding co-existence to their management toolbelt.
More can be learned about these co-existence strategies, along with videos, and a soon-to-be-published beaver co-existence ebook, at TheFurBearers.com.
Adrian Nelson is manager of wildlife conflict for The Fur-Bearers, which was founded in 1953 as the Association for the Protection of Fur-Bearing Animals. It works to end the commercial fur trade and promotes co-existence with wildlife.