reasons. Some become endangered naturally, however a majority of animals are listed as endangered species due to a variety of human causes such as habitat degradation, pollution, or hunting and fishing. There are certain levels to the endangerment scale going from healthy species to species that are extinct. The first category is “Least concern” and is reserved for animals that are doing well in their environment and have an abundant number of individuals. The second, “Near threatened” are species that have been identified as potentially having problems in the future. The next category is “Vulnerable species” and this is a species that is on the decline with regards to population, geographic range, and other restrictions. When a vulnerable population declines in these categories, it is then classified as an “Endangered species”. If the species declines even more, it becomes “Critically endangered” and if no action is taken, that species could reach the levels of “Extinct in the wild” or “Extinct”¹.
Once a species is identified as endangered, there is a lot of work that people must do to protect it. This protection is in place to give the species every chance of recovering, and a chance at thriving in nature once again. In fact, in some cases, our actions have worked and there are animals once considered to be endangered that have recovered.
The first group of animals are birds that become endangered due to widespread DDT use after World War II. After the war, the harmful effects on bird populations were still unknown and DDT was commonly used as a pesticide. However, it was later seen that DDT caused the egg shells to become extremely thin, easily breaking, which resulted in a decline in the reproductive abilities of bird populations. Bird populations that became endangered due to DDT include the peregrine falcon, bald eagle and brown pelican². Luckily, after the effects of DDT were realized, thanks to the work of Rachel Carson and her book Silent Spring, there was a ban on DDT use in the United States in 1972³, and the populations of these birds began increasing again².
Another bird that was once endangered but recovered is the Aleutian Canada goose. It is estimated that this species of goose decreased to only around 790 individuals in 1975. This decline was caused by non-native foxes introduced to the region by the fur industry. Foxes caused a lot of damage by eating the eggs and hunting for young geese⁴. After the removal of these foxes in breeding grounds, hunting restrictions, and habitat protection, the Aleutian Canada goose was removed from the endangered species list and in 2011, the population was estimated to have increased to nearly 111,000 individuals⁴.
The next two species are listed together because they both have very similar histories and reasons for becoming endangered. These animals are the American Alligator and Morelet’s crocodile². Although they occupy different areas, the American alligator living in the south eastern United States and the Morelet’s crocodile living in the countries of Guatemala, Belize and Mexico, they both were endangered due to overhunting and loss of habitat due to degradation². The American alligator recovered after regulations were put in place and removed from the list in the late 1980s and the Morelet’s crocodile was delisted in 2012².
The tiny Virginia northern flying squirrel living in the trees and forests in a small part of Virginia and West Virginia in the Unites States have come on the edge of extinction as well⁵. The primary reason for their endangerment was loss of habitat due to the timber industry. Once protections were enacted, the trees were able to grow again resulting in suitable habitat and the removal of these squirrels from the list in 2013².
It is important to know that these are not the only animals that have recovered due to protections and laws put in place to protect habitat and prevent the useless hunting and exploitation of wild animals. Other animals that have similar stories and have recovered include the American bison, Grizzly bears (Brown bear) and the Gray Wolf²,³. Furthermore, there are also other species that are in the process of recovering and making great progress, although they have not made a complete comeback. Other animals in the process of recovering include the California condor, the black footed ferret, the island night lizard and the Galapagos tortoise²,⁴,⁵. It is important for us all to work together to ensure that all animals have a chance of surviving in the wild. Recovery of these animals is possible, we just have to work together and believe we can make a difference.