Just like there are laws to protect people, there are also laws to protect animals. Some laws protect endangered species. Endangered means these animals are in danger of dying out. Some extinct mammals are the Badlands bighorn sheep, sea mink, and eastern elk. There are also many fish, insects, birds, and amphibians that have died out in the last 200 years.
Why have these species gone extinct? There are four main reasons why some species are disappearing. Many of the reasons have to do with humans.
Overhunting by men is what caused the passenger pigeon to go extinct. When settlers came to America, they loved the taste of these birds. They hunted them with no restrictions. The last passenger pigeon died at the Cincinnati Zoo in 1914.