Friday, March 29, 2013

Climate of Fear Comic

Time for another geeky comic!

If you missed my first one, check out my Mesopredator Release Comic.

This one probably requires a little science lesson in order to put it into context.

One of the sexiest issues in wildlife biology today (by sexy I mean new, packed with buzz words, and full of controversy) is the concept of Trophic Cascades. "Trophic" refers to the food chain. Plants are on the 1st trophic level, herbivores are on the 2nd, predators on the 3rd, etc. When a predator (e.g. wolf) effects the abundance of the organisms in a lower trophic level (e.g. grass), by changing the abundance of an organism in an intermediate trophic level (e.g. deer), that's called a trophic cascade.

Basically, wolves don't directly control the amount of grass because they don't eat grass. But if wolves move into an area that has a ton of deer and very little grass (because the deer eat it all) and the wolves eat a bunch of deer, then the grass will come back (because there's not as many deer there to eat it). That's a trophic cascade. It's a form of "top down regulation". Predators (the top) regulate the bottom (the grass) by regulating the middle (the deer). The recovery of the grass is a type of "density mediated response". The deer population is less dense so the grass responds.

Still with me?

This is all well and good. I get all this. It works for me. The part I have an issue with is called the "Climate of Fear Response". This hypothesizes that the predators might actually effect the lower trophic level simply by scaring the middle trophic level away. Basically, the grass comes back because the deer are to scared of the wolves to stick around and eat, regardless of how many deer there are. It sounds fairly intuitive but the jury is still out about the science. I, for one, don't hold to it. 

That having been said, here is my Climate of Fear Comic!


Love to get comments!!!