EDMONTON — If you didn’t know there was a day dedicated to our dam-building friend the beaver, now you do! Created in 2009 by Beavers: Wetlands & Wildlife, International Beaver Day is celebrated on April 7. To help us observe the day, University of Alberta beaver expert Glynnis Hood from Augustana Campus in Camrose shares five facts about the industrious rodent:
Beavers are monogamous
Beavers tend to mate for life, a rare trait in wildlife. Unless a mate dies or is forced out by a more competitive beaver dispersing into the pair’s territory, a couple typically stays together for years. Both parents care for their youngsters (kits), however, the pair doesn’t spend a lot of time together when they’re out foraging for food, which might reduce their vulnerability to predation.
Beavers can stay underwater for up to 15 minutes
A beaver does mostly shallow (under one meter deep) and short dives, and they can slow their heart rate during the dive to allow for more oxygen to go to the heart. Then they speed it up afterwards to recover lost oxygen. Beavers can also stay active under the ice all winter long. They use ice pockets to extend the amount of time they can swim in the water.
Beavers front teeth grow continuously throughout their life
Beavers have a bite almost three times stronger than any other animal of this size — I mean, you’d need powerful teeth to cut down a tree. Meanwhile, their incisors are constantly growing. If one tooth is lost, the opposite tooth continues to grow and can extend into the opposite jaw if left untreated; there are records of dental procedures done on captive beavers. Incisors grow to be roughly 10 to 15 centimetres long.
Even in frigid temperatures, an occupied beaver lodge rarely drops below freezing
When temperature sensors were placed inside and outside a beaver lodge in Ontario, temperatures inside ranged from 0.8°C to 1.8°C even though outside it ranged from -6.8°C to -21°C during the study period. Temperatures were warmest at night when all the beavers were inside. Snow cover on the lodge also helps with insulation.
All in the family: beavers stay with their parents for at least 2 years
It’s rare for beavers to leave their parents before the age of two because they usually don’t survive due to body size and inexperience. A long-term study of Eurasian beavers in Norway found some waited as long as seven years to leave, although the average was 3.5 years. During that time at home, they help look after the new kits. Interestingly, a study in the Eastern US discovered that female beavers disperse farther away than males.
Bonus fact: The world’s longest beaver dam is in northern Alberta
At 850 meters or 2,788 feet long, the massive structure located in Wood Buffalo National Park can be seen from space.
More information on why beavers build dams and the impact they have on the land around them can be found in this TED-Ed video, based on information provided by Glynnis Hood.
To schedule an interview with Glynnis Hood, please contact:
Sarah Vernon | University of Alberta communications associate | svernon@ualberta.ca