This commentary is by Jennifer Lovett, of Starksboro. She is a conservation biologist, author of “Beavers Away!” and a former museum curator and educator.
Beavers are amazing animals who are simultaneously admired for their industrious engineering skills and disliked when their activities flood roads and fields. Our often-contentious relationship with them is long overdue for change.
Recently, several studies have demonstrated the financial benefits of managing beavers humanely with beaver deceivers, pond levelers and fences rather than traditional methods of trapping, shooting or blowing up dams. Now that federal disaster relief is not guaranteed and emergency funds may not be available to towns for infrastructure protection and flood remediation, towns could save thousands of dollars by employing non-lethal beaver controls.
As a keystone species, beavers create, enhance and maintain habitat that countless other species rely on for survival. As ecosystem engineers, beavers change the landscape by converting small streams into vast dynamic wetlands, swamps and meadows.
Beaver wetlands slow the rate of snowmelt and runoff by storing and cooling vast amounts of water underground, which, in turn, reduce the erosive impact of floods and can be released during droughts. Wetlands also act as firebreaks and critical places of refuge for wildlife during wildfires. Moreover, the sediment at the bottom of ponds filters out pollutants and improves water quality downstream.
While beavers could be among our best allies in the ongoing battle with the changing climate, I admit that they can be frustrating and can cause serious problems in areas prone to flooding. Flooded roads, farm fields, building sites and blocked culverts are often extremely expensive and recurring problems for towns and landowners.
Beaver conflicts are often handled by killing the beavers and destroying their dams. However, this is rarely a permanent solution since any good territory will be claimed by new beavers, resulting in a continual cycle of flooding, road or culvert damage, infrastructure repairs and repeated annual killing of numerous animals.
Alternatively, non-lethal means of controlling beaver activity can be achieved by simply regulating the flow of water out of ponds or wetlands. Devices can allow water to flow through a dam or culvert without the beavers’ desire or ability to block it. This permits the many benefits beavers provide to ecosystems and biodiversity to remain in place while also protecting infrastructure.
In Alberta, Canada, researchers assessed the efficacy of pond-leveling devices and fencing to manage beaver activity in areas with chronic flooding. A cost-benefit analysis compared the cost of traditional management approaches, such as trapping, with non-lethal alternatives. The difference was remarkable. Over a period of seven years, traditional management cost the province more than $3 million, while the installation of non-lethal devices cost $179,440.
In Billerica, Massachusetts, 55 beaver-conflict sites were studied from 2000 to 2019. Again, results showed that the sites managed with non-lethal controls cost much less than those managed by lethal removal. While it cost $409 to trap beavers at each site per year, installations of flow devices at each site cost on average $229 per year. Thus, the town saved $7,740 annually with non-lethal management.
Another study analyzed the efficacy and comparative costs of using flow devices to resolve beaver conflicts along roads in seven counties in the Coastal Plain of Virginia.
Flow devices were installed in 14 sites damaged by beavers. The average maintenance cost at each site was less than $20 after flow devices were installed, compared with $21,490 per site per year for maintenance, road repairs and population control prior to this installation.
The work on this project was also executed by Skip Lisle, the inventor of the Beaver Deceiver and president of Beaver Deceivers International, which is based in Grafton. Lisle has successfully installed his flow devices — with lifespans estimated at 30-40 years — all over the country and in several locations in Europe.
With such a resource here in Vermont, this state should be leading the transition away from lethal management toward coexistence.
Cost-benefit studies have not been done in Vermont. However, the small town of Andover, New Hampshire, resolved decades of costly beaver conflicts by rejecting traditional lethal management in favor of beaver deceivers and coexistence. In 2007, the town hired Lisle, who, over 10 years, installed protective devices at eight sites where culverts had been repeatedly blocked and roads damaged by flooding.
Although financial considerations were paramount, Andover’s transition from lethal management strategies also reflects changing attitudes toward beavers and the critical role they play in wetland ecosystems. Andover town officials estimated that over 10 years, the town saved about $130,000 and projected a savings of almost $500,000 to town coffers over 30 years. Alternatively, repeated killing of the beavers and the associated repairs to infrastructure would cost the town well over that amount.
Fiscal savings are quantifiable when it comes to the time, equipment and labor involved in repairing culverts and roads, but the value of a functional, ecologically balanced wetland system is immeasurable.
Sadly, traditional methods for controlling beaver activity are still commonplace and seem to be the first choice of towns, landowners and wildlife managers. The resulting loss of wetlands has dire ecological detriments. Floods, droughts, biodiversity losses and wildfire are all symptomatic of our rapidly changing environment.
Clearly, harnessing the beaver’s ability to mitigate impacts from climate change makes sense and is far preferable to removing them again and again from the landscape in a way that damages ecosystems and needlessly drains municipal funds.
