​Predators Group 1: Predator Loss at Lake Guri
“Deep in the wilds of Venezuela, the natural order is being turned inside out. Miles of verdant forest and savannah have given way to small and scattered islands. Some of these islands are now overrun by bands of voracious howler monkeys, a glut of iguanas and hordes of ravenous ants. What is driving this bizarre transformation? A team of scientists believes that life here has run amok in large part because its top predators are gone. Similarly, the majestic wilderness of Yellowstone National Park is also showing signs of change that some scientists trace to the depletion of natural predators. Familiar and revered forests have vanished. Researchers are linking these forest losses to the expulsion of the gray wolf some seventy years ago. In Venezuela and around the world, experts are learning that predators seem to play a crucial role in the structure and function of entire ecosystems. When the predators disappear, the consequences can be dramatic. If predators are so vital, should they — and can they — be brought back?”


· Describe the transformations in the plants and animals at Lake Guri.
· What event caused the loss of predators at Lake Guri and Caroni Valley Venezuela?
· What are some advantages and disadvantages to this event?
· Where in Arizona did this same event happen?

Predators: Lake Guri and Caroni Valley, Venezuela
Transformations in plants have been happening on Lake Guri. Some of these transformations are trees are dying and only the toughest plants have been surviving. It used to be a green land, but now it is broken into islands. Since the trees are dying, animals are too. On Lake Guri and in Caroni Valley there has been a loss of predators. The cause of this is because of a flood. By a flood happening, its killed trees, which animals need to survive. There are some advantages and disadvantages to this event. An advantage is it generates hydroelectricity. The water flows through generators and moves gears, which causes power. A disadvantage is it is killing off a lot of animals. This same event happened in Lake Powell, in Arizona.

Lake Guri and Caroni Valley have had a major loss in predators. This is occurring because of a flood. This is affecting the plants and the animals. Trees are dying, which is causing prey to die, because they have no plants to eat. In result, the predators are dying off now, because there is no prey to eat. The flood happened by building a dam, which created the man made lake. Today, it is barren, and has many trenches. No one knew how much damage the dam would create. People thought the animals would migrate, but they didn’t. They were dying because of drowning in the floods, and like we said earlier, scarce prey. But since predators almost disappeared, the prey came back with very large numbers. Now there wasn’t nearly enough resources to sup
port them all. It is still a big problem today, but has taught us many things, and the consequences of them.

In this Strangedays video, biologists were driving on a boat through Lake Guri. They were saving the animals who were in danger. They are saying that most predators will not be saved though. They're talking about Lake Guri, and how the dam is causing the lake and surroundings to change into islands, killing predators. Same thing is happening in a nearby place called Caroni Valley, Venezuela. Everytime Bioligist Turboard visits the places, he is seeing dramatic changes in the environment, and the trees and plants. What was once a large amount of land, with a riot of plant life and predators, got ruined by a flood. It is now a Lake, that was once loud with animal noises, that is silent, and you would never think that it once had a variety of animals living on it.


It is not really clear at first that a man-made dam was causing this event. You did not describe how the animals changed. There was a big change in the populations of howler monkeys. They were living at 50 times their normal density and do not make noise or groom like they normally do. All of the predators left as the flood moved in.
In Arizona Lake Powell was created in the 1960’s by filling in Glen Canyon with water. This probably had the same effect on the animals in the area. It also destroyed Indian ruins and what James Wesley Powell described as an even more spectacular canyon than the Grand Canyon.
65/75 Points