DRAFT: This module has unpublished changes.

Hayle Clark

24 September 2014

Chapter 4 #5



Predators in some cases can be good things for some types of food chains but in most cases predators are the bad guys who will eventually suffer in the long run. You have the predators and the prey who are similar because without one of them something is going to happen to a certain species. Predators are the ones who feed on the prey. Predators either feed on other animals or plants that are out in nature. Without them the prey will over accumulate and then finally they will die from starvation.

For example as giving in the book they talk about wolves and moose’s with the predator-prey relationship. This is a problem because the wolves are considered the predator and the moose’s are the prey. The wolves feed on the younger and sick moose for food but eventually as time goes on the moose population will decrease leaving the wolf population with not much to eat. The decrease in food leaves the wolves starving so most of them usually die which leads to a decrease in there population.

This is a big problem happening all over the world with the predator-prey relationship but this isn’t the only problem going on the main problem has to do with humans. Humans are killing the predators to keep the prey alive and to have a growing population with them but truly it is making it worse for the things they feed on. With this problem going on with humans people have come up with a name for the predators that they want to keep their population greater which is known as a keystone species. They believe these are the type of predators that we need to keep alive to lower the number of prey because the prey are making what they feed on worse. The keystone species is shown in the sea otter because without them eating away the sea urchins the number of kelp will decrease leaving an urchin barren which makes it worse for other animals who live in the sea. So as humans have seen over time is that killing predators or leaving them alive depends on what the predators prey is. It also depends on what the prey is doing to the habitat they live in or what they are feeding on.

Humans might have actions for removing the top predators but they also have actions for adding to the population of a certain species. Adding to a certain species causes there to be a overpopulation and for the prey it just means that there is more food for the predators, but for the predators to have an overpopulation it means that there will too many of that species without enough food for them to eat. In 1944 people saw this happening when they put the reindeer on St. Matthews Island where the overpopulation was so huge after 20 years that it went from 6000-42 surviving deer left. When the humans put the 29 reindeer on the island they believed that this would be a good idea because they had no predators but the thing people didn’t take into account was that they didn’t have enough food to survive for 20 years. Due to the lack of food the deer went from 6000-42 surviving over a 20 year period.

Humans have been adding and removing predators from our ecosystems for many years regardless of the problems that might occur from doing this to the predators. Killing some of them make it worse for other animals or plants because of the increase of prey. Adding more predators to one area finally will bring a decrease in a certain species because of starvation from the lack of food which in the long run will eventually lead to death. So what I believe should happen is that all species of animals and plants should be left alone to live a normal life there might be prey and predators but for the most part predators should be left alone.



DRAFT: This module has unpublished changes.