Wednesday's Wildlife: Beavers

 SLAP! A beaver tail hits the water, frightening quacking ducks into silence.  Across the pond, a young beaver slips into the safety of the water, alerted by its parents that danger is nearby. What is dangerous to a beaver? Can people coexist with beavers? What are some beaver benefits?

Figure 1: North American beaver foraging on the shores of a wetland.

The ponds and lakes that make picturesque sunset photos across the Canadian Shield are in-

part due to the industrious Castor canadensis, or North American beaver.  This rodent, the largest in North America, is often described as an ecosystem engineer, modifying its environment to create dams and raise water levels to evade predators. 

Beavers are not agile land animals but are well-adapted to living in water.  They have flaps that close over their nose and ears as well as a third eyelid (the nictitating membrane) for swimming.  Their tail serves as a rudder, and the webbing between their toes helps them navigate underwater for up to fifteen minutes.

Figure 2: North American beaver swimming.

Beavers’ historical importance has landed them a spot on our nickel, but they are also important to solving problems in our future! Once a concern in causing floods, the beaver is now combating floods.  Beaver habitat is full of canals, twisting waterways, healthy aquifers, and vegetation ready to act like a sponge to slow the flow of heavy rainfall or snow melt. Conversely, this habitat also shows resilience in the face of drought and is an important fire-break and refuge for wildlife during fire season. Wetlands also help restore water purity, filtering out pollution by letting heavy metals and other pollutants settle in the slower-moving ponds and streams. Wetland habitat also increases biodiversity building homes for so many other creatures!

Figure 3: Friends in Wet Places Calgary Wildlife Comic.

Beavers don’t hibernate but set aside leafed branches of willow and poplar in an “underwater fridge” near their lodge which they forage from during the winter months.

Figure 4: North American beaver carrying twigs.

Beavers are family-oriented animals, living with their parents for their first two years. Kits are born in the spring.  Kits are nursed for the first six weeks. Parents will often carry kits in their paws or on their tails.

Figure 5: Beaver kit orphan at Calgary Wildlife.

But what about that tail slap? Natural predators of beavers include bears, wolves, cougars, and coyotes, all of which the beaver family will be alert for.  Keeping pets leashed and out of beaver habitat is safest for the beavers and the pets.

Figure 6: North American beaver tail.

Coexistence with beavers is happening! Flooding caused by beaver dams can now be regulated using pond levelers or flow devices.  These devices allow beavers to keep a safe depth of water without causing overland flooding that might affect homes in the area. Trees can be preserved by wrapping their lower trunks in metal wire cages, with some un-caged trees left for beavers!

Uncertain whether wildlife needs help? Found injured or orphaned wildlife? Please call our hotline at: 403-214-1312.

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