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| American Wigeons dabbling in Cherry Creek |
Walking a stretch
of the Cherry Creek bike path lined with the naked willows of winter and the
occasional cottonwood tree looming large, I heard the unmistakable sound of a
child’s squeaky toy. Well, perhaps it was a dog’s squeak toy? I looked around
for a shaggy canine sporting a well-worn rubber toy in his mouth but found
none. Glancing further and looking into the stream, I saw the noise makers.
There they were - a pair of adorable American Wigeons - complete with their
unmistakable pale blue beak. Now, seeing a blue-beaked duck may not excite very
many people but to me it is like finding a semi-precious jewel in the dirt.
Something not expected on my daily sojourn. I am used to seeing the ubiquitous
Mallard in the creek, a handsome duck indeed; yet when I see something other
than the Mallards I tend to get excited. And then, not a minute later, I saw a
different duck with a huge white cheek mark vivid against its otherwise dark
head, a Common Goldeneye. Not that a casual observer can really see his “golden eye”
from this distance but that is this duck’s name nonetheless.
These dabbling ducks were
enjoying a glassy-surfaced little lake that had been created by twigs,
branches, brush, and a felled tree that were slowing down the water flow of the
creek. For a few weeks it was hard not to notice the chewed-up remains of tree
trunks I had observed along the path, and I knew there could only be one animal
doing the chewing. Indeed, it was the North American Beaver (
Castor canadensis). This hard working animal had inhabited this creek on and off
for centuries. Long ago, about the time that the historic
Four Mile House (located
a mile downstream) stood as a respite for Colorado immigrants, travelers, and Native Americans, they frequented
Cherry Creek until trapping diminished their populations. How
lucky I was living in a city and seeing wildlife doing wildlife things right
before my eyes not from a TV screen.
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| The hard work of the North American Beaver |
Beavers are what
is called a “keystone species,” which is a term given to an animal that alters
an ecosystem in such a way that it paves the way for other species to exist in
this environment. Like the keystone in antique arched doorway, if it is removed,
the whole arch collapses in on itself. The beaver’s diligent dam building
creates a wetlands environment that opens a door for other species to inhabit.
While it is true that none of us want every cottonwood tree felled along the
creek because of the negative impacts this would cause, nor do we desire flooding
from the ponds onto private property. However, there are ways to mitigate the
beaver’s behavior without destroying this amazing animal. Wouldn't it be interesting if both beaver and humans could both live in and enjoy this area?
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| Beaver tree sculpture? |
For people to
coexist with beaver there are several solutions that have been developed. Flexible
pipe can be installed as “pond levelers”; these devises are simple (
see "beaver solutions"). They allow a creek to continually flow through an opening in the beaver’s dam without
completely restricting the water flow thus managing any flooding that is the goal of the beaver's dam. This
is a win/win situation; it allows a portion of the beloved
pond habitat to remain and the beaver's living quarters while minimizing damage. To protect important riparian area trees from being felled by the beaver, various cylindrical wire cages can be wrapped
around the trunks to discourage this behavior. Both
solutions are not expensive or difficult to apply.
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| An amazing feat of dam building |
A recent success story of beavers living alongside human development occurred in Martinez,
California. After the town spent huge
sums of money to restore a once channeled creek called Alhambra Creek, the
waterway became not only more attractive to the human eye but also to a beaver family that
quickly took up residence. The beaver started building dams along this nicely
refurbished waterway and flooding certain locations. Soon, the beavers and
their dams were slated for removal or extermination in October of 2007. An outcry throughout the
community allowed for further investigation, research, and education to
determine the best way to solve the situation. A community effort called “
Worth a Dam” coalesced that saved the beavers along Alhambra Creek. Experts were
brought in (Skip Lisle from Vermont) to install a flow device made from
flexible pipe. Today the Alhambra Creek beavers, now known as the
“Martinez Beavers,” are a large tourist attraction. Their antics are viewed from a town
bridge to the delight of children and adults. It has made the locals proud and
happy to live successfully with wildlife.
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