The Copper River is in Alaska proper not far too far out of Anchorage. It got it’s name from the many copper deposits along it’s upper sections. The copper was used by everyone from the natives to the Russians to the settlers that came later. Now the river is most famous for its salmon, which is considered among the best in the world. The long river is the 10th largest in the nation, so salmon have to work hard to travel its length and stock up on extra fat reserves to survive the journey. That makes them a prime catch for any sportsman who travel to the Yukon region specifically for the chance.
Of course you know any great river with that many salmon must also have a very healthy beaver population.
The furry ecosystem engineers of the Copper River Delta
The Copper River Delta is dominated by a coastal marine climate, making both the summer and winter seasons mild and wet. The climate is maintained by the Alaska Current, which delivers warm ocean air and low-pressure systems to Alaska’s Gulf. The climate, mixed with the natural history of the Copper River Delta, provides an ecosystem that is dynamic and thriving. Whether it is summer, or winter, you will be sure to find a furry animal, scurrying off on a mission. One of these furry animals, has picked a luxurious career as a landscape architect. Due to their ability to cut large trees and turn streams into ponds, they have rightfully received the title of ecosystem engineers.
Okay, you got our attention. What will you have to say about these architects?
On the Copper River Delta alone, they have left a noticeable signature that can be seen when driving the Copper River Highway. Since the 1964 earthquake and geologic uplift, they have expanded their range southward, to new areas of uplifted marsh on the delta. After many years, the dams created by these furry engineers have created new habitats for other plants and animals.
Of course they have. It’s what beavers do. But its interesting you can track changes since the earthquake.
When the spring ice melts, the search for the perfect “home” is on. Beavers will examine the landscape, honing in on steady sources of water and mapping out potential areas to construct a dam. The dams they build are strong enough to hold back the force of a stream that will flood to become a pond. Once the area is flooded, they begin floating larger branches to the construction site. Once the dam is satisfactory, the beavers switch their attention to building their huts.
A hut is an essential part of a beaver’s life, like a house for us humans. Their huts provide shelter from predators and severe weather (e.g., the wintry delta). When building a hut, beavers must gather tons of branches, debris, and aquatic vegetation. Once the materials are gathered, they form them into a cone-shape. Most of the structure is then coated with mud, leaving the “peak” open for ventilation. This peak is the equivalent of a chimney. Within the hut is a chamber that has been dug out. This chamber typically has two underwater tunnels with openings
above the water level. These openings are the entrance and exit to the hut. The main chamber is divided into two levels. The first level is a platform just above water level that is used for feeding and drying off. The second is a higher, drier platform cushioned with shredded wood fibers and grasses, used for sleeping. The chamber walls are thick (2-3 feet at the bottom) keeping the beavers warm. The snow that covers the hut in the winter also acts as insulation, keeping the temperature, inside the hut, relatively stable. This makes for a rather warm and cozy living area, compared to the cold, stark, windy conditions of Mother Nature, just outside the hut.
It’s nice to read some explaining this like we were hearing it for the first time. I love the idea of beavers keeping warm inside their ‘hut’. Obviously lots of other people do too.
To make the icy water more comfortable, beavers have thick fur. Beaver fur is so thick that a stamp-sized patch of skin is carpeted with over 125,000 individual hairs — this is more than the average human has on their entire head! This thick, fuzzy coat helps insulate them from the cold. To give their coat extra waterproofing, beavers will groom themselves with natural oil. The oil is produced from glands beneath their tails. When grooming, a beaver will use a modified toenail on each hind foot, to coat themselves in the waterproof oil. Once coated, they can comfortably swim beneath the frozen surface. Grooming also creates a thin layer of air near the skin. This air pocket acts as another insulating layer while underwater. Historically, however, having this beautiful, thick fur coat was not always very advantageous. When Europeans arrived in North America, as many as 400 million beavers swam the continent’s rivers and ponds. Between the 1700s and 1800s, most beaver populations were decimated by fur trappers, primarily to support the European fashion for felt hats. Because of this, beaver populations in the eastern United States were largely removed and the continent’s population was estimated at only about 100,000. Fortunately, these declines caught public attention. Concern for the beaver eventually led to regulations that controlled harvest and methods of take, generating a continent-wide recovery of beaver populations. Although pristine beaver habitat has been heavily reduced in the lower 48 states via human land-use practices, beaver have proven to be a highly adaptable animal, able to occupy a variety of human-made habitats.
Hmm if I didn’t know better I’d say that someone has been reading Ben’s book. Stamp-sized? That metaphor just randomly sprang to mind? I wonder how.
Beavers now occupy much of their former range in North America, although habitat loss has severely restricted population growth. Since the 1830s, about 195,000-260,000
square kilometers of wetlands have been converted to agricultural or other use areas in the United States. Many of these wetlands were most likely beaver habitat. Beaver are adaptable, being marginally able to subsist above timberlines in mountainous areas and occupy very cold regions. Beaver have yet to colonize Alaskan or Canadian arctic tundra, possibly due to the lack of essential woody plants for winter food and lodge construction, or because thick ice limits surface access in the winter. However, in milder areas of Alaska, beavers thrive. The Copper River Delta supports a healthy population of beavers due to their low natural mortality and an abundance of suitable habitat. Because of their large size and limited amount of time away from the protection of water, adult beavers have relatively few natural predators! Young beavers, also known as kits or yearlings, on the other hand may be eaten by black bears, coyotes, bobcats, and even great horned owls.
Come on, sir. You’re in ALASKA There are plenty of predators that would enjoy a nice juicy beaver. Like bear or wolf or mountain lion. For goodness sake we’ve seen footage of it.
Next time you are out on the Delta, look for signs of beaver including newly cut alders or a hut on the edge of a pond or slough. Take note of the area, see if you can find aquatic plants and insects in the water, look for waterfowl and fish. Take a minute to count how many different species you find and think about the natural relationships that might be happening. You might not have to ask scientific questions or consider the ecological richness that beavers create in order to enjoy them! Maybe sitting and soaking in the serene area, while beavers motor across the pond is enough. But while enjoying the vast, lush landscape, be sure to thank the furry ecological engineer that is the North American Beaver.
Well said, we certainly will.
