Cascading Effects

The Gray Wolf is back and is having a positive effect on the grizzly population in the Greater Yellowstone Ecosystem by boosting an important food source for them. When the wolves returned after a 70 year absence they began to prey on the elk population which had exploded and over-browsed berry producing shrubs, a favored food for grizzlies to fatten up on for hibernation by eating the berries. I think this information caught my attention because I spent so many years teaching about the food chain and food webs that it was nice to see a real world application. The big idea is that any disruption in the chain negatively affects everyone in the ecosystem and bringing back the gray wolf is helping restore balance once again in Yellowstone. In this case the predator (gray wolf) is helping the producers (berry producing shrubs) while helping himself to the elk and this is in turn a win-win situation for the berry loving grizzlies.

Strangely enough this reminded me of a childhood memory of the time I used a rubber band to hang a glow in the dark skeleton (cereal box prize) on a hanging light fixture (light bulb and chain basically) in my bedroom and a fuse was blown. Somehow I had managed to short the electricity out in our entire house. Instead of fessing up and helping to quickly restore the balance (and electricity) to our home I watched my dad check every outlet and fixture starting from downstairs. Just like when you finally get to stop looking when you find what you were looking for he finally found the problem in the last place he looked, my room. And as, like the fate of some of the elks, the results didn’t seem humane at least to me, yet balance and the electricity was restored.