We learned last week how the removal of one species — the gray wolf — can devastate an ecosystem. This week’s focus, the North American beaver, is another. Both are “keystone” species, which means their well-being directly influences the rest of their ecosystem.
The American beaver (Castor canadensis) is the largest rodent in North America, tipping the scale at an average 44 pounds and measuring 3 to 4 feet from nose to tail. Beavers are well known for being one of the few animals to change their environment to suit their own purposes; specifically, they build lodges from wood, mud and rocks to live in, and they raise the local water level by constructing a dam that blocks the flow of water. Beavers are perfectly suited for semi-aquatic life, with webbed feet and a flat, paddle-shaped tail to propel them gracefully through the water. They also have a transparent third eyelid so they can see underwater without “opening” their eyes. To stay warm underwater, they’re covered in not only a layer of fat beneath the skin but also two types of fur above it — one long and coarse, another that’s short and fine.
Beaver’s fur led to the brink of disaster. Humans have bare skin and are inefficient at keeping warm in cold climates. We must use clothes to keep warm. Having just arrived in the New World, european settlers quickly took notice of the continent’s 400 million beavers roaming the wilderness. Trappers sought to catch as many beavers as they could, founding an entire industry. Pretty soon, beaver fur wasn’t just used to keep warm; people found they could make a good sum of money for clothing and accessories (notably hats) made from beaver fur.
People also discovered they could sell beaver meat for food. Even today, castoreum, a yellowish fluid that beavers produce in special scent glands, is used in some of the food we eat, often labeled as “natural flavoring,” to give it a vanilla, raspberry or strawberry taste.
When beaver populations dwindled in the east, trappers moved westward. About 200,000 pelts were exported each year in the late 19th century. By 1900, beavers (or at least their body parts) were in such high demand that their population dropped as low as 100,000.
Thanks to the work of conservationists in the early 20th century, the American beaver was not wiped out. It is no longer considered an endangered species.
The benefits of conserving beavers are clear when we look at the animals and plants that live around them. Many species of fish use the ponds beavers create when they dam up a river as a nursery for their young. The hooded merganser, a duck-like waterbird with a crest of feathers on its head, also prefers to raise its chicks around beaver ponds, as do several other bird species. These species’ well-being is directly influenced by the beaver population.
“Humans have been a plague to this earth,” wrote a young woman who responded to one of my Instagram posts. “[They’re] killing off everything for their own greed.” It’s certainly true that humans have caused much destruction to the natural world. We’ve wiped out countless species, cleared forests and other animal habitats and we’re polluting the very air we breathe. But does this really mean we are a plague?
As we conclude this summer series of animal conservation success stories, the message I leave with you is that we must continue in the direction of the preservation of other creatures. We should understand that our role in nature is to make the world our responsibility over every living thing that moves on the earth.
Contact Christian Ryan at firstname.lastname@example.org