University:
Michigan State University
Course:
BS 162 | Organismal and Population Biology
Academic year:

2021
Views:

392

Pages:

1
Author:

Arielle Armstrong

Keystone Species - The American Alligator Ecosystem Dynamics, Functioning, and Resilience The American alligator was once thought to be a dangerous pest. Found in the southeastern U.S., they are the biggest reptile in North America – reaching 15 feet long and 1,000 pounds. They were showing up in people’s swimming pools and on golf courses. Fishermen worried that they were eating all the game fish that they liked to catch. People also valued their skin for making leather. So, they were hunted. They were hunted so aggressively, that by 1965, they became an endangered species on the verge of extinction. Then, as the alligators disappeared, something unexpected happened. People began to notice that instead of better fishing, all the game fish they liked to catch seemed to be disappearing. If the alligators where gone, what was eating them? Biologists confirmed that the alligators’ favorite food, a large fish, called a gar, had been having a population boom. With no alligators to eat the gar, their numbers were rising and they were eating all the game fish. The loss of the alligator had changed the ecosystem. Biologists now call the American alligator a “keystone species.” This means that it has a major influence on balancing its ecosystem. In 1967, the American alligator was put on the endangered species list and protected from all hunting. Over time, their numbers began to recover. As the alligator population came back, the number of gar decreased. Then the game fish came back. The balance had returned to the alligators’ ecosystem. By 1987, the alligator population had recovered so well, that it was removed from the endangered species list. It’s important to understand how a an animal affects its ecosystem if we want to protect our wild habitats over time.