What Black Bears Do

Explanation: They rip, they tear, they are the American black bears that perform some important ecological functions in the woodlands and forests.

Yes, a black bear was the culprit that tore apart the log in the above photo, hunting for prey, be it grubs or squirrels or whatever it might encounter. This is indeed what black bears do. (Photo taken in Fort Wainwright, outside Fairbanks, central boreal Alaska.)

This action is destructive -- to the down logs of the forest. But it is also productive in several ways.

It helps physically break down parts of down logs to better accommodate the process of decay and thus nutrient cycling, returning the nutrients of the wood back into the soil, that in turn maintains productivity of the soil system. And note how the wood pieces are of a variety of sizes, meaning that they will decay into the soil at different rates, like a nutrient time-release function.

(Photos taken on Bureau of Land Management land, Medford, Oregon USA.)

It might also open cavities and hollows in the logs for other creatures -- invertebrate and vertebrate alike -- to occupy, thus creating habitat for other species.

(Photo taken on Bureau of Land Management land, Medford, Oregon USA.)

In previous EPOW episodes, we have explored what other species do that can affect their ecosystems. These are all examples of wildlife acting as "ecosystem engineers," where what they do can have an influence on the physical, nutritional, habitable ecosystem for other species.

So, a tip of the field cap to what black bears do!

(Photo taken in forest outside MacKenzie, British Columbia, Canada.)

EPOW - Ecology Picture of the Week