You might not have ever noticed, but there are two species of willow tree at the beaver dam. One is called “Arroyo Willow” (Salix lasiolepis) and the beavers think its delicious. It has smooth grey bark and trailing green branches decorated with little catkins in the spring. The stand next to the primary dam is all Arroyo willow, as are the trees in the annex that we planted.
The other type is “Shining Willow” (Salix Lucida). It has rough striated bark and similar trailing green leaves. (When I had this conversation with the city engineer he was surprised because they had never realized there were two species.) (!) The area next to starbucks is almost entirely covered with Shining willow. It was mostly cut out by humans last year, but is growing back at a bountiful rate. If you did a careful beaver-tree-nibble inventory of both areas you’d notice that the beavers have metaphorically strolled down the aisle of our willow shopping mall and taken arroyo off the shelf, leave shining to its own devices.
They don’t like it.
The research says that beavers eat both willows, but our beavers are obviously unfamiliar with the research because they haven’t. Until recently. Allow me to explain. We have been offering some natural greens at the primary dam for our motherless kits, bringing willow or cottonwood from other areas to make sure that everyone got enough to eat. Clearly our indulgent efforts have been successful because these are three little beaver fatties now. Recently Jon took some shining willow branches down by mistake and what do you suppose happened?
They ate them!
In thinking about their eager willingness to eat a tree that they won’t bother to fell, I realized that it’s probably the bark they dislike. Remember this is a rough, grainy, textury bark – not unlike the texture of the sand-painted trees that discourage beaver chewing – however if the branches are delivered to them without all that pesky chewing, they are happy to oblige.
I think its interesting because it means that our beavers might get around to felling some Shining Willow eventually. Which means the habitat could sustain them a little longer than we expected. I guess its like halloween candy. You sort through and eat all the snickers bars first, and eventually have nothing left but suckers.
By the way, our motherless beavers are officially 6 months old now. Happy half-birthday Half-yearlings!
