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Beavers

As I write, the full Beaver Moon is dancing brightly behind passing clouds on a blustery Sunday (November 17) evening. Known as the Beaver Moon because this is the best time to set traps prior to the marshes freezing and because beavers are actively making preparations for winter. To celebrate the November full moon, let’s learn a little about this interesting creature that has been remarkably important in our history. In fact, the Beaver has been so important to the development of Canada through fur trade, that the animal was designated the “national animal” in 1975. It also holds noble places on Canadian coins, stamps and was even the official Olympic mascot for the 1976 Summer Olympics held in Montreal.

Nature’s Engineers

The North American Beaver (Castor canadensis) is second only to humans in its ability to manipulate the surrounding environment for their benefit. They are truly Nature’s Engineers. Beavers are industrious and capable of changing the landscape in a very short period of time. Dams of sticks and mud are built to flood an area primarily for protection. Beavers are much more adept in the water than land (they are fast swimmers and can stay submerged for nearly 15 minutes), and are therefore able to avoid predation, primarily by coyotes and wolves. On land, they are much more vulnerable. Lodges are also build of sticks and mud and may be near the middle of the flooded wetland or along the banks of a wetland or river. Excavations, usually about the diameter of a bowling ball, may also carved out of the banks of rivers and lakes. As if dam, lodge and tunnel-building isn’t enough, beavers dig and maintain canals to enable them to easily and safely float sticks and logs from more upland areas into the wetland.

A common misconception about beavers is that they use their tails to carry and pack mud into dams, lodges and canals. This is untrue. These tasks are carried out by the front paws. The tail of a beaver serves many other purposes, though. The broad, flat, hairless tail serves as an alarm signal. A loud wallop from smacking the water with the tail warns other members of the colony of danger. The tail serves as a rudder during swimming and a prop while sitting up on land. Finally, the tail stores fat and helps beaver survive long winters when their food supply is limited.

Beavers are the second largest rodent in the world (only the Capybara in S. America is larger), often reaching 70 pounds or more. Typically adult beavers average about 55 pounds and can live 15-20 years or more.

Beavers are strictly herbivores, but they don’t eat what most people think they eat. Beaver eat cattail shoots, pond lily roots and stems, and a variety of other herbaceous plants. They also eat bark from trees. Look closely at a felled beaver log, however, and you will notice the pile of wood chips at the base of the tree. The wood is not eaten by the beaver. Rather, the beaver prefers the tender inner bark.  Paul Bunyan had nothing on beavers when it comes to cutting trees down. A 10-inch diameter cottonwood can be felled in less than 6 minutes! This is possible thanks to the four large, chisel-like incisors in the front of their mouths. These teeth never stop growing and require constant chewing to keep them from growing too long and curved to be useful. Beaver do not hibernate. They remain active throughout the winter and usually feed from a stored cache of sticks anchored to the bottom of the pond with mud.

In addition to the useful tail, the rear paws of beavers are webbed, making swimming second-nature. The most valuable part of a beaver, according to humans that is, is the fur. Their double-fur coat consists of long guard hairs and a dense inner coat that keeps water away from the skin of the beaver. The beaver has no difficulty swimming and surviving in frigid waters.

Of course, this splendid fur nearly caused the complete demise of the beaver.

The Comeback Kit

The beaver population in N. America was once believed to be 60-90 million. With an ever westward expanding population beginning in earnest in the 1600’s, rapid deforestation and draining of natural wetlands, and growing demand for stately top hats in Europe, the fur trade flourished. The Hudson Bay Company alone sold over 3 million beaver pelts during a 25 year period after 1850. Unregulated trapping and habitat destruction resulted in beaver being scarce and even extirpated over much of its range. By the 1830’s, beaver were extirpated from Ohio.

Fortunately, wildlife management strategies in the early 1900’s and, most importantly, the regrowth of habitat as agricultural land was abandoned aided the comeback of beaver. In some areas, including Ohio, beaver were trapped and relocated. Beaver have a high reproductive potential and are capable of rapidly re-establishing populations, as up to 8 kits can be born in spring to each adult pair, although 1-4 is more common. Current estimates put the beaver population of N. America at between 12 and 15 million.

Beaver pelts were used primarily to make the fashionable top hats that were the rage in England. A “hatter” would soak the pelts and remove the long guard hairs. The dense inner coat was torn away from the skin and used to make felt, which could be molded into stiff top hats. Interestingly, hatters used mercury in their vats. After years of dipping their hands in mercury and breathing in the vapors, it is no wonder they went mad. Thus the term “mad hatters” was born.

 

Did You Know . . . 

During the spring, two-year old beavers set out on their own to begin a new colony (either by choice or by the parents driving them out before the next kits are born. These wandering, young adult beavers may travel many miles before they select an appropriate place to build a dam and establish a new colony. How do they do this? It’s in their name: Castor. Castor is a pungent, oily substance secreated by both males and females from glands near their anus. The young adults quickly mark new territory by building small mud and debris mounds and marking them with castor. Beavers have a remarkable sense of smell and these castor mounds are of interest to beavers of the opposite sex. Thus, a new colony begins with a bad smell.

 

More Nearby Nature

 

“Loon Lake and Apple Pie” – Saturday, November 30 (9:30-11:30am)

Explore the hidden trails and the obscure pathways of the East Branch Reservoir in the rolling Amish Hills of Geauga County near Middlefield. This refuge from the hunting season attracts a variety of waterfowl, bald eagles, loons and swans. There are some sections of old growth forest and the trails offer a variety of opportunities to view the lake. This is one of the most beautiful and peaceful preserves in the region. Following the walk will be an optional lunch at a nearby Amish style restaurant. Leader: naturalist Bob Faber. Fee: $8 for members of the Friends of the Hiram College Field Station ($10 for non-members). Call 330.569.6003 or email sorrickmw@hiram.edu to register.

 

 

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