The Wonders Of Chemistry: Beavers, Beetles, And Cottonwoods

In the great stands of old cottonwood trees along prairie rivers, chemical skirmishes are taking place between beavers, cottonwoods, and a certain species of beetle. Beavers gnaw on the trees; the trees fight back with toxic compounds; and the beetles move in to feast on the toxins. But in this apparent conflict, all three species benefit.

The great stands of old cottonwood trees along the prairie rivers are called “gallery” forests, which aptly describes their spacious coolness and towering branches.  Beaver favor cottonwoods for food and building material for their lodges. When beaver fell cottonwood trees, the roots often re-sprout, establishing clones of young trees from the same parent. Although this is another way for the cottonwoods to regenerate, these sprouts rarely do well enough to grow into large gallery forests.

Now we get to the subtle intrigue. Tom Whittam, an ecologist in Arizona, discovered that cutting and foraging by beaver induce young cottonwood sprouts to produce large amounts of salicins and salicortins – toxic compounds that deter many animals and insects from feeding on the sprouts. 

 Beaver also accumulate these compounds in their castoreum, a stinky musk beavers use for scent marking and, incidentally, perfumers traditionally used in colognes. The salicin compounds in the castoreum help the beaver attract a mate, like adding a little extra spice to the beaver’s own cologne.

So by pruning the cottonwood beavers actually cultivate their ideal target crop. Isn’t that just what you’d expect from beavers?  They’re like farmers cultivating the perfect harvest. Since salicin is a main ingredient of Aspirin I bet it also helps with all those toothaches beavers must get on the job! I sure would like to see a gallery forest of cottonwood. It must sound amazing! (I used to call them ‘whispery trees‘.)

Here’s our farmer harvesting a little willow last night. Also rich in salicin by the way.

That’s a nice story of species coexistence. Just in time for another rabid beaver story. It’s officially summer you know.

Person bitten by suspected rabid beaver in Northern Harford, others may be exposed, health officials warn

Harford County health officials say a suspected rabid beaver bit a county resident on Friday afternoon in the Deer Creek Conservation Area off Sandy Hook Road in the Street area of Northern Harford.

 Although the victim is receiving the appropriate post-exposure rabies treatments, health officials say they remain concerned that the beaver came into contact with at least one dog that belongs to another person, and they are trying to find the dog’s owner who may have also been exposed.

 After biting the victim, the beaver quickly returned to the woods but might also have had contact around the same time of the other incident with a dog, believed to be a husky-chow mix, owned by another visitor to the park, the Health Department said.

I’m expecting this to blanket the news for the coming week. So the beaver wasn’t killed outright? That’s too bad because it means officials will just parole the area and kill every one  they find. I’m never comfortable with these stories because they seem to coincide so much with kit time. I guess if rabies incubation is 3-6 weeks, and the beaver was bit by a rabid dog when protecting the lodge because the kits were just born, the timing is about right for the west. Not really for Connecticut though.

Here’s mom beaver last night with a willow bouquet. Definitely not rabid.