As a Beaverton resident, how much do you know about the Beaver?

The importance of the beaver in Oregon history is obvious from the State flag itself: the reverse shows just a beaver on a blue ground. Oregon is known as the “Beaver State”, Beaver is a small town in Tillamook County, Beaver Creek is a State Natural Area and Beaverton High School’s mascot is of course the beaver.

Before Europeans arrived, there were probably 200 million beavers in North America; by 1900 there were just 100,000 left; They had been hunted and trapped almost to extinction. For what? You won’t believe this: it was to make men’s top hats! Remember all those pictures of Abraham Lincoln? That top hat was made of beaver fur. Fortunately for the beavers, fashions changed and the population in North America has surged back to more than one million beavers.

The North American Beaver (castor canadensis) is the largest rodent in North America, weighing 20 to 60 pounds. Beavers are semi-aquatic “ecosystem engineers” that build dams and lodges in waterways to create wetland habitats. There is a beaver dam in north Canada which is so large that it can be seen from space!

After selecting a suitable site, the beaver family sets to work. They chop down small trees, drag them into the water and arrange them in a crisscross fashion across the stream. They then drag branches, reeds, grasses, and mud to fill the gaps between the logs. Once the stream is dammed the water behind the dam forms a pond which provides essential habitat for fish, birds and other animals.

To cut down trees, beavers have very special teeth. The front surface of their incisors Is coated with thick enamel containing strengthening iron which gives them a characteristic rusty color. The back surface is of softer dentin which wears away to leave a chisel shaped tooth. Because the teeth grow continuously, the beaver must never stop gnawing to avoid a dental disaster.

Unlike fish, the beaver has a broad, horizontal tail which it uses to get around its pond. A beaver can hold its breath for 15 minutes while swimming underwater with its nostrils and ears closed and a membrane covering its eyes.

A family of beavers consists of two parents who are in a lifelong, monogamous relationship, that year’s babies called kits, plus the offspring from the previous year. All family members cooperate in the tasks of maintaining the dam and gathering food. In Oregon, the family gathers and stores food near the dam for winter.

Do beavers still reside in Beaverton? According to THPRD, beavers have been spotted in Fanno Creek, Summerlake Park, and Commonwealth Lake areas. Note: Nutria (Myocastor coypus) are an invasive species from South America that are often mistaken for beavers. If you think you see a beaver, look at the tail. If it’s round like a rat’s tail, then it’s a nutria.

Tony Woodward is a retired physician with four wonderful grandchildren. He spends a lot of time reading and reviewing books, especially on art and history.