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Beavers' ability to shape their environment is
beyond impressive—but you already knew about the dam building. Let’s look at
some other things that make beavers incredible.
· They used to be giant
Although they didn’t have the characteristic flat
tail, giant beavers of the Ice Age, known as “Castoroides,” looked remarkably
similar to their modern descendants—just much, much bigger. They grew to be up
to 8 feet long and 200 pounds and lived a semi-aquatic life.
· They secrete a goo that smells like vanilla
In fact, it’s sometimes used in vanilla flavorings. Castoreum is a chemical compound that mostly comes from a
beaver’s castor sacs, which are located under the tail. It is secreted as a
brown slime that's about the consistency of molasses and smells like musky
vanilla. It’s an FDA-approved natural flavoring.
· Their dams can be enormous
The world’s largest beaver dam stretches 850 meters
deep in the thick wilderness of northern Alberta. It was discovered after being
spotted on a satellite image in 2007, but scientists believe multiple
generations of beavers have been working on the dam since the 1970s. Last
September, explorer Rob Mark became the first person to ever reach the dam.
· Beavers are romantics at heart
Or at least they're monogamous.
Dams are usually started by a young male looking for love or by a
mated-for-life new couple. A whole beaver family will live in a single dam—mom, dad, young
kids, and yearlings.
· They once traveled by parachute
In 1948, new human inhabitants of western Idaho
began to clash with the local beaver population. The Idaho Department of Fish
and Game wanted to put these threatened beavers in a nearby protected area, but
they didn't know how to get them there. Elmo Heter of Idaho Fish and Game
devised an ingenious solution: By using surplus parachutes from World War II,
the department could drop boxes of beavers down from planes. After some
careful calibrations, 76 beavers made the skydive into the basin, and all but
one survived the fall.
· Beavers do not bite off their own testicles
This one may sound obvious, but up until the 1100s,
people thought that beavers did. The myth originated in ancient
Egypt and reappeared in the bestiaries of medieval Europe. The story went that
beavers knew hunters were after them for the valuable castoreum oil in their
testicles. This myth was not terribly difficult to disprove, largely because
beaver testicles do not hang outside their bodies.
· Beavers' front teeth are orange
And not just because they have terrible dental
hygiene. To gnaw through tree trunks, they need extra-strong teeth.
Fortunately, their tooth enamel contains iron, which makes them incredibly
strong, sharp, and orange. Because the orange enamel on the front of their
teeth wears away more slowly than the white dentin on the back, a beaver’s
teeth self-sharpen as he chews on trees.
· Dams help them avoid ice
Beavers build dams for a myriad of reasons, and one
is so that the lake behind it will grow deep enough to ensure it doesn’t freeze
all the way through during the winter. This bit of temperature control is
especially crucial because beavers anchor a food cache to the bottom of the lake to serve as
sustenance during the cold months.
· They have multi-purpose tails
A beaver’s oversized leathery tail, which can grow
up to 15 inches long and six inches wide, has uses both on land and in the
water. While swimming, the beaver uses his tail as a rudder or as a siren by
slapping it against the water to warn other beavers of a predator. On dry land,
the tail acts a prop to allow the beaver to sit upright or as a counterbalance
so he doesn’t tip over while carrying heavy supplies in his teeth.
· England's beavers are back?
Until recently, the last mention of a beaver
sighting in England came in 1789 when a bounty was paid for a beaver head in
Yorkshire. By that point, the once prolific beaver had dwindled due to over-hunting
for their valuable pelts and medicinal glands. For several hundred years, the
species disappeared from Great Britain, and it was assumed they’d gone extinct.
Last year, a retired environmental scientist documented a family of beavers living near his home, but
now the rodents are causing a controversy. Although beavers are also making a
comeback on the continent—after numbers dwindled to just 1,200 the population
is now estimated around 300,000—British officials are concerned the ecosystem
has changed too much to accommodate them.
· They have lots of clever adaptations
In order for this mammal to live a semi-aquatic life,
beavers utilize a host of adaptations that help them navigate the water. Nose and ear
valves shut to keep out water while submerged, and nictitating
membranes or transparent "third eyelids" act as goggles. Perhaps most
useful is that their lips close behind their oversized front teeth, allowing
the beaver to transport building materials and food without drowning.