Because the beaver isn't just an animal; it's an ecosystem!

The Martinez Beavers

Be Careful Out There

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Beavers are notoriously vulnerable on roadways. They are low to the ground and usually crossing in the dark which makes them a prime target for roadkill. image002Do they ever use wildlife crossings? Inquiring minds wanted to know. Some fine investigative beaver reporting comes from Robin Ellison of Napa. She was interested in whether beavers ever use the crossings trans Canada offers. You know the ones I mean.

Turns out they have an extensive system to document the wildlife crossings with trail cam footage, and trackpads keep records to monitor use. They were only too happy to share the info with Robin and wrote back:

Thank you for your inquiry and interest in the wildlife crossing structures as they relate to beaver species movements.  I’ve had our database specialist look through the history of wildlife crossing documentation and have found some results for you.  We’ve not been able to find documentation on whether or not road mortality numbers for beavers were affected.  However, we did find information on beavers using the Trans-Canada highway wildlife crossing structures.  There are only 5 incidences that have been documented on all of Banff National Park’s highway wildlife crossing structures (we currently monitor 44 of these structures).  As you mentioned, all the beavers that have been documented on wildlife crossing structures were associated with waterway travel–in these cases the beavers were on a flat pathway in an underpass that has a creek running through it.

Below I’ve listed the information we have on beavers using the Trans-Canada highway wildlife crossing structures.  I’ve also found a photo of a beaver using a wildlife crossing structure (you can see the creek in the background).   

Screen shot 2017-05-17 at 6.07.19 AMNot a ton of observations, beavers are probably less likely than others to venture out of the water. But there are more observations than I might have expected. You can see three identifications came from trackpads which I had to look up. Here’s a nice description from some research they did trying to find which tool worked better. They found that trackpads had their place but cameras were better if there was a lot of wildlife traffic.

Field Data Collection
All 24 CS in the study area were continuously monitored forlarge mammal use since 1996 using track-pads (Clevengerand Waltho 2000, 2005). At least one track-pad (range 2–7pads/CS) was constructed at each end of every underpass,and each track-pad spanned the width of the underpass and was approximately 2 m long in the axis of animalmovement. Track-pads on the overpasses consisted of onetrack-pad located at the center, spanning the width, and were approximately 4 m long in the axis of animalmovement. Tracking material consisted of a dry, loamy mixture of sand, silt, and clay, 1–4 cm deep. We visited eachCS every other day, and at each visit we classified thetracking medium as Good, Fair, Poor, or Too many,depending on our ability to detect tracks. A track-padcondition of Good occurred when our ability to detect tracks

Here’s what one of the cameras documented. That lucky beaver made it safely across and back into the water. (The darker area is the creek). Beaver_external distribution ok

I haven’t been doing this beaver work for very long, but I’ve already come across several beavers and otters struck by vehicles. We could learn a lot from our Canadian friends. Thanks to the helper who shared this information

J. Kimo Rogala, M.Sc.
a Resource Management Officer II
Ecological Integrity Monitoring, Banff National Park
Parks Canada Agency | Government of Canada
Box 900, 216 Hawk Ave, Banff, AB, T1L 1K2

for keeping track of this information. And thanks Robin for doing the legwork! This is a wonderful insight into something we understand very little about. I’m just glad these beavers never had to go through this:

(For the record I spoke years ago with the fellow who filmed this beaver. Not the news site  that made his footage into a comedy. And the witness swears he made it across safely. Although one foot did appear injured in the photos I saw.)