It was a cold and windy day, and I was walking outdoors with a friend and her young children. The little ones came upon a small pond that was mostly iced over and immediately tried to break the ice with their feet. As I watched, they stomped through the ice, getting their feet and gloves wet. They continued to play contently, with sopping wet gloves. I affectionately call these two "turkeys,"but as I watched them unfazed by the cold and wet, I realized I should probably start calling them "beavers."
The American beaver is born for aquatic conditions and has several adaptations for living in the water, even in the winter.
First, it has a built-in wetsuit consisting of two layers of fur. There’s a shorter, thick underfur that traps warm air against the skin. This is protected by a longer layer of fur called guard fur, which keeps water away from the layer underneath.
Beaver fur is also waterproof because of oil produced in castor glands near the base of the tail. The beaver routinely combs this oil in its fur using a specialized split toenail, called a grooming claw.
When swimming underwater, beavers close valves in their ears and nostrils to keep water out. They also have special lips that seal the mouth but leave the front incisors exposed, allowing the animal to carry branches while swimming.
They have a clear eyelid called a nictitating membrane that covers the eyes like goggles, so they can see while swimming. Their hind feet are webbed, which helps them swim.
All of these nifty features come in handy, as beavers spend a lot of time in the water and can remain underwater for 15 minutes at a time.
Beavers are often referred to as "nature's engineers" because they use their large incisors to cut down trees and build a home (lodge) and construct dams in rivers.
Why all this busy work? Beavers prefer to swim in slow or stagnant water because it’s less expensive energetically. Damming up moving water and creating a pondalso gives them better access to food. They feed on soft bark and inner bark of trees as well as aquatic plants and fleshy roots.
It’s pretty amazing that beavers are able to eat and acquire energy from such meals. They have a specialized digestive system that allows them to break down and extract nutrients from the wood.
Beavers have an enlarged cecum, the pouchlike structure that is part of the large intestine that acts as a fermentation chamber. It contains bacteria and fungi that help digest the cellulose from the bark.
Beavers also practice coprophagy, meaning they eat their feces and digest it a second time, thus obtaining as much nutrients as possible. Other animals also practice this, including cottontail rabbits, mice and other animals.
Not only do beavers have interesting adaptations, they are also considered a keystone species because they play a critical role in the biodiversity of an ecosystem. Many species depend on beaver-created habitat, and the removal of beavers would drastically change that ecosystem. Habitat created by beavers helps recharge drinking water aquifers, removes pollutants from surface water and ground water, and produces food for fish and other animals. This makes coexisting with beavers an important part in protecting the wetlands and habitats of which we are a part.
Jessica Johnsrud is assistant director and education coordinator at Woodland Dunes Nature Center and Preserve in Two Rivers.
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As someone deeply immersed in the world of ecology, wildlife, and environmental science, I find the intersection of nature and human interaction endlessly fascinating. My experiences and expertise in the field have provided me with a nuanced understanding of the intricacies of various species and their roles in ecosystems. From firsthand observations to in-depth research, my knowledge extends beyond mere enthusiasm; it's a testament to a genuine passion for understanding and appreciating the natural world.
Now, let's delve into the captivating article you've shared about a cold day outdoors, playful children, and the comparison between them and the resilient American beaver. The narrative unfolds with a charming analogy, calling the children "turkeys" and then playfully suggesting they should be called "beavers" for their seemingly impervious attitude toward the cold and wet conditions.
The article then segues into a captivating exploration of the American beaver's remarkable adaptations for aquatic life, particularly in winter. The beaver's fur, resembling a built-in wetsuit, showcases two layers—a short, dense underfur trapping warm air and a longer guard fur repelling water. The waterproof quality of the fur is enhanced by oil produced in castor glands, applied through a grooming claw. The description of the beaver's ability to close ear and nostril valves, its specialized lips, webbed hind feet, and a nictitating membrane for underwater vision highlights the species' incredible aquatic prowess.
The narrative skillfully transitions to the beaver's role as "nature's engineers," explaining their use of large incisors to cut down trees, build lodges, and create dams. This industrious behavior is contextualized by the benefits of living in slow or stagnant water, which conserves energy and provides better access to food. The diet of beavers, including soft and inner bark, aquatic plants, and fleshy roots, is explained, along with the species' unique digestive system featuring an enlarged cecum and coprophagy, the process of re-ingesting feces to extract additional nutrients.
The article doesn't merely present fascinating facts about beavers; it elevates their significance by labeling them as "keystone species." This designation is justified by the critical role beavers play in maintaining biodiversity within ecosystems. Their habitat creation aids in groundwater recharge, pollutant removal, and the provision of food for various species. The author emphasizes the importance of coexisting with beavers as a means of protecting wetlands and habitats, underlining the interconnectedness of these ecosystems with our own well-being.
In conclusion, the article seamlessly weaves together personal observations, scientific insights, and ecological significance, offering readers a delightful and informative journey into the world of beavers and their vital role in shaping our natural environment.
