Calgary officials are trying out a new way to manage beavers that are causing problems in Fish Creek Provincial Park.
The rodents keep packing mud and logs against a culvert in a city-owned storm pond.
If left, the dam would cause the pond to overflow and flood a popular pathway.
In the spring, the city's water services department is going to install something called an exclusion fence — a trapezoid shaped fence made of wire that prevents the beavers from plugging the culvert.
The city used to deal with situations like this by trapping and killing the beavers, but it reviewed that policy after an incident in July.
A beaver got caught in a trap, but didn't die and was spotted struggling to free itself.
Upset animal lovers launched a petition to stop trapping in the city. That prompted a review, which revealed that debris got caught in the trap, causing it to malfunction.
Since then, the city has been working with the Association for the Protection of Fur-Bearing Animals to come up with non-lethal alternatives.
"We want to go a different route so we don't actually have to kill beavers," said water services spokesman Randy Girling.
"We don't want to be known as killers or anything like that. We want to do the best we can for the wildlife in our parks."
The exclusion fence is the best option for this particular situation, according to Adrian Nelson from the Protection of Fur-Bearing Animals.
It will be installed around the end of the culvert, and will extend out about three metres and then across about three metres — so instead of having to plug up a metre-long culvert, the beavers now have a much tougher job.
It also moves the beavers farther away from the sound of running water.
"Beavers have an instinctual trigger that when they hear that trickling effect of water, they want to dam it up," said Nelson. "So as they start damming near the culvert, the fence moves them further and further away from the culvert and ultimately away from the stimulus."
Nelson says exclusion fences are used in municipalities across North America and are very successful.
The fence won't be installed until the ice melts in the spring. Girling says the beaver activity is tapering off right now as the rodents prepare for winter hibernation. If they start building the dam again, city workers will clear the debris away by hand.
Next year, city crews will monitor the fence on a weekly basis as part of their regular storm pond maintenance. If the pilot project is successful, Girling says the city will consider using similar systems in other places where beavers are causing problems. It would be another tool for officials to use as part of their beaver management program.
In the meantime, a spokesperson from the parks department says the city will still consider trapping and killing beavers as a last resort. Nelson, as wells as the Association for the Protection of Fur-Bearing Animals, hope that will change.
"A lot of municipalities trapped and killed problem animals. It was the go-to solution for pretty much everybody, but now we're seeing more and more municipalities moving over to non-lethal solutions and having great success with them," said Nelson.
"I think Calgary is just on its path now where it's starting to implement some non-lethal alternatives and we hope the success of these alternatives will prompt them to use more and more and ultimately give up trapping."
Trapped beaver survived
It appears the critter that sparked the review and pilot project survived its trapping ordeal.
Wildlife photographer Susan Heaven, who spoke out after the incident in July, has spotted a beaver that is missing a front paw in the same Fish Creek Park storm pond.
She says it appears to be managing quite well and seems to be healthy. She is pleased to hear that trapping is off the table, at least for now.
"It leaves the beavers in the park, and hopefully nature can get back to doing its thing and let things run its course," said Heaven.
"Kudos to the city for keeping an open mind and trying something else out."
The below video is an example of an exclusion fence in Ontario. On mobile? Click here.