American Beavers are one of a few keystone species of mammals living in North America that are considered vital for their role as ecosystem service engineers; meaning, their activities in nature provide significant economic benefit for humans and other animals. The local landscape where beavers reside help the environment in so many ways, from mitigating problems due to climate change to increasing levels of biodiversity, improving water quality in lakes and streams, preventing natural disasters from occurring such as the spread of wildfires or flooding, and more. Only 10% of beavers populate our continent compared to the times of pre-European settlement largely because of excessive hunting pressure and loose wildlife damage management practices, yet they continue to persist today and reward us with their existence.
Two young beavers were admitted to Dane County Humane Society's (DCHS’s) Wildlife Center this year, which is uncommon for those of us here to have experienced. The first was patient #24-0235, a juvenile (2-year-old) female beaver who was found cold and quiet, huddled up next to a building in the middle of a commercial complex in downtown Monona, WI. It hadn’t moved after a few hours, and a kind citizen called in to report its location. Initially, they stated it was a muskrat, but they weren’t sure because it was very big. The caller was worried that it was sick or injured because it was out of the water and in the middle of a “concrete jungle”, so to speak. After discussing the case, we suggested they call Public Health Madison & Dane County to assist with a rescue. Animal Services Officer and DCHS Wildlife Caretaking Volunteer, Julie Bigley, arrived on-scene and was surprised to find that, indeed, it was a beaver in need of help. The beaver had suffered a significant tail fracture and vertebral luxation, most likely due to impact with a car or other kind of vehicle running over her tail.
The second beaver was a wee-baby, #24-0960, found near Lake Wingra in Madison, WI. It was described as going in and out of traffic alone, somehow displaced from its parents and with no way of re-uniting them. It appeared healthy upon examination, but only weighed 964 grams (about 2.13 pounds) compared to the juvenile who came in at 16 pounds. They were mis-matched in age and weight, so they could not be joined together for fear of hurting each other unintentionally.
DCHS’s Wildlife Center staff reached out to beaver rehabilitation specialists in our area for guidance and assistance regarding these two youngsters. Yvonne Wallace Blane, co-founder and Director of Wildlife Rehabilitation at Fellow Mortals Wildlife Hospital in Lake Geneva, WI was consulted first, and the youngest baby beaver was accepted as a transfer to their facility so that it could grow up with others of its same species. They’ve written about the process of raising orphaned beavers before, but for those who don’t know, it takes approximately two years until a newborn beaver disperses from its natal habitat, away from its parents, to establish a new territory. It takes hard work to care for them that long in rehabilitation, and it’s even more difficult to find good release sites on private property. According to Yvonne, it takes an understanding property owner who know that released beavers will make extensive future landscape modifications, knowledge that no existing beavers already live on site, and the right kind of habitat near a pond or river with adequate populations of willow and poplar trees for them to eat.
As for the juvenile beaver that stayed in care at DCHS, Dr. Alyssa Scagnelli took lead on its case as the new Wildlife Clinical Instructor for the Wildlife Medicine Program, a grant-funded teaching selective led by Dr. Christoph Mans at the UW-Madison School of Veterinary Medicine that partners with rehabilitators to provide specialty medical services to wild animals. With advice from Fellow Mortal’s team of experts, along with our licensed wildlife rehabilitators and sponsoring veterinarians, we collectively agreed to pursue treatment for the juvenile beaver who had a tail fracture and luxation. It was suggested that the injury could take approximately 3 to 4 months to heal, if it would heal at all. The beaver would need a fully functioning tail to be released back in the wild; otherwise, we would need to consider educational placement or humane euthanasia if it didn't recover. Surgery was too risky, and not recommended in this situation, especially because beavers typically require frequent access to water – at least, as much as they can get, both for maintaining bodily functions and for their mental health and well-being.
Here’s what Dr. Scagnelli had to say about her experience in rehabilitating this beaver:
“I recently moved to Wisconsin in April of this year and was excited to work with different species than what I was used to in the Sonoran Desert of the American southwest. The American beaver is probably one of my favorite animals, but as you can imagine, there’s not too many of them in the desert! When I learned that a beaver was being brought to DCHS’s Wildlife Center, I was simply ecstatic, but also equally worried that the beaver would not have a favorable outcome. This animal was presumed to be hit by a vehicle, a common fate for urban wildlife. When the beaver arrived, she was quiet and shy, which told us she was likely weak, dehydrated, and in pain. Most animals will attempt to defend themselves, even when they are injured. So, when we see an animal not fighting back, this is often a bad sign.
“The beaver had been carrying her tail low to the ground and was not moving it, so the team took some radiographs (x-rays) and found a completely dislocated tail, up towards the base. Beavers use their tails not only to navigate through the water, but also to communicate with other beavers. Tail function is paramount to survival, and it would be unethical to release a beaver that did not have use of their tail. I was immediately worried that this animal would need to be euthanized with such a poor prognosis but was determined to see if anything could be done.
“I performed a neurological exam on the tail which revealed that some reflexes and pain sensation were still present towards the tail tip. This is a good sign that implies that the spinal cord is working properly. Our team consulted with other rehabilitators and veterinary surgical specialists, looking for some way to repair her tail. Unfortunately, there were no options with the type of injury she had. So, then we had to make a choice: give her a chance to heal on her own or perform humane euthanasia. It would take a couple of months before we would even be able to see any progress, and this length of time in captivity is stressful for wild animals. I guess we were all feeling optimistic, and with her intact spinal cord function, I had one of those odd “’gut feelings”’ that things would work out.
“For the first month, we limited her activity to allow initial healing to occur. Her neurologic and motor function improved! We then moved her into a pen with a full-size pool where she could begin her “’hydrotherapy”’. When she first went into the water, she could only move her tail slightly, but over time, the tail improved and by the end of the second month, she was undulating her tail and swinging it side to side. Her tail palpated stable on exam as well – I couldn’t have been happier!”
Jackie Sandberg is the Wildlife Program Manager at DCHS's Wildlife Center.
