Aaaaand action!

My first experiment is set up! Escape impediments positioned, grass measured, species identified, arms hurt, sweat drip, cameras work. And the meaning of all this?

The project I am working on is a part of the bigger programme about "the role of apex predators in the ecosystem" (basically why there must be large carnivores). Only recently have ecologists finally realized that large carnivores are not only one of the most charismatic species but that they are also essential for keeping the ecosystem healthy. What happened in Yellowstone was that wolves somehow modified the river behaviour. If they were absent, rivers suddenly changed their courses, meandering and eroding the banks. That was a disaster for the whole park and made managers’ hair turn grey and then fall out. And it happened when the wolves were not there (probably even hundreds of them digging wouldn’t be enough to change the way the river flows)! Magic!

Or maybe not. Wolves eat elk, elk eats plants, plants “eat” nutrients from the soil. The richest the soil, the tastier the plant, the rather the elk will feed on it. Areas where such plants grow are exactly the river flood plains. Because the elk find these so irresistible, they would keep feeding if they were if something wasn’t holding them back. These areas are open and you can get quickly spotted from a distance. Good for a tourist, not so good for the elk itself. Elk must keep scanning the area to see an enemy (the wolf) before it comes too close. So elk can’t eat as much as it wishes which means the plants get spared when it is on the look-out. Like that, vegetation by the river is not destroyed completely and can continue growing when elk decides it’s time to leave. See the trick? Wolves make elk scared, elk feeds less and plants stays imbedded in the river banks, holding them strong and keep the river flowing straight. This magic is called Trophic cascade.

This is the main concept of “my” programme as well, but only a basis of my project. I will investigate how predators change the behaviour of their prey (like wolves & elk), but in a different setting. For a start, it’s Africa, not The States. Also, there are predators all over the place and I cannot just take the lions and wild dogs out and see if impalas and nyalas eat the whole park. I have to do it in a scientific-small-scale way. I have to use poo and set up the experiment on the available rich spots, grazing lawns (not river banks). They are basically lawns, surrounded by the bushes. Ungulates are lovin’ them, because there’s yummie grass, which makes them a perfect place to test if the impala’s greediness goes beyond its fear. But the fear factor in this setting is not only predators. They could get nervous close to the bushes that can hide the danger, or by the elephant-broken trees and branches over which you can trample while you’re running for your life. Or the combination of both. So I will first check how afraid are they of bushes and the pieces of wood. Then, I will add the wild dog scat and see if that makes them (more) afraid. And all will be carefully monitored by the hidden cameras.

Plenty of work, but the first experiment is now set and the camera traps are doing their job. Let’s hope it works and that the impala gets terrified of them scats!