Saturday, October 17, 2009

Lumberjack Beavers

There's one drawback to providing so many pickup loads of aspen branches to the beavers each fall. Because they don't cut their own trees, nobody gets to see the results of their normal behaviour. Fortunately all one has to do is hike the Happy Creek Trail to see one of the active colonies upstream in action. This photo taken this afternoon shows a large aspen that the beavers have been working on. We counted more than a dozen large trees that were either felled or showing evidence of serious gnawing.

The second photo shows a large lodgepole pine cut about half through. Beavers don't normally cut conifer trees because they prefer deciduous species like aspen, balsam poplar, paper birch, and willows. In fact, cutting conifers might indicate not enough preferred food. Most of the aspen close to the upper Happy Creek ponds has long since been cut. Beavers will travel further from water, but this increases the risk they will be killed by a predator. There may be another reason to cut conifers though. I've noticed over the years that sometimes conifers and other non-preferred species like alder are placed on top of the food cache. This weighs down the preferred species that are stuffed underneath. When the pond freezes the ice isolates the capping and keeps the good stuff available below.

No comments: