Every spring, millions of people wake up in the morning and see and hear a seemingly endless amount of different birds singing, making nests, and fluttering about in the trees. Birds are so bountiful that they are all taken for granted. However, every year the number of bird songs may become fewer and fewer, until one spring, the people might find themselves listening to a sad, empty, silence. Although this is an exaggerated example of extinction, this can and does happen at the species level. Sadly, with enough time and the right conditions, even the most common animals can be wiped out of existence. When this happens, people often ask, “What happened?” There are hundreds of reasons why animal species become extinct. The top causes of extinction appear to be habitat loss, disease, and overhunting. If humans took conservation more seriously, these three reasons would likely be erased.
Habitat loss is the leading cause of animal extinctions produced by humans. Habitat loss occurs when the area an animal lives in is destroyed or altered so that they can’t live there anymore. Mass deforestation is an example of habitat destruction. Trees are cut down for countless reasons; to clear areas for agricultural use, to make paper products, to build frames for structures, to clear places for those structures, and for anything that has wood in its ingredients. Deforestation causes an animal’s natural shelters and food supply to become scarce because most of the trees and plants that provided them have been taken away. Without proper food and shelter, animals will either starve to death or try to find a new home.
Another type of habitat loss is pollution. Air, soil and water pollution all can be extremely deadly to animals and their habitats. For example, toxic pesticide and fertilizer runoff from farms can be harm animals if it is absorbed through their food, water, or skin. This is a major threat to frogs and other mash-dwelling species because they spend most, if not all, of their lives water. It can also contaminate the soil and cause plants to die, leaving a majority of herbivores without food. Yet another type of habitat loss is caused by invasive species.
Invasive species are any nonnative creatures or plants that have been introduced into an ecosystem and harm the native species. These invaders compete with the native species for food and space, often outnumbering the natives because there are no natural predators to keep their numbers in check. Burmese pythons are a great example of an invasive species. With its humid, grassy, wet, and warm climate, the Florida Everglades has become the perfect new home for these massive snakes. The unwelcome pythons have overrun Florida because people who couldn’t care for their scaly pets released them into the fragile Everglades environment. Ever since the first release, the snakes have been eating rare native birds and everything they can fit their mouths around. There are even some accounts of the pythons clashing with American alligators, who have just been brought back from near extinction. Although efforts have been made to eliminate the snakes, from capture and removal to all out-hunting contests, they have all ended up futile. The pythons have succeeded in their invasion and are here to stay. When there are new creatures, there are new diseases introduced along with them.
Deadly diseases are another reason why a species can become extinct. When a new disease infects an unprepared species, it will often kill enormous numbers of that particular animal if it isn’t contained. Humans, again, can cause easily avoidable outbreaks in animals that can make them go extinct. The White Nose Syndrome is a perfect example of how a disease made American bat species at risk for extinction. European bats are mostly immune to this disease because they have had time to adapt to it over the years. After exploring an infected cave in Europe, cavers transported the fungus from their gear into American bat caves. Because American bats had never had the chance to become immune, they started to die at alarming rates. Luckily, conservationists stepped in to help stop the spread of the deadly White Nose Syndrome, but not before the number of bats in America dropped severely. Although not always caused by humans, disease outbreaks that have the potential to wipe out an entire species are usually a lot easier to prevent before they spread than after.
Overhunting a specific species for food, profit, or just plain sport is one more major cause of extinction. Killing an animal species in large numbers will have an impact on the general population of that species over time, even if those animals appear plentiful. For example, passenger pigeons were so numerous in America a couple of hundred years ago that when they migrated, the sky would become black and noisy with the birds. People originally shot the passenger pigeons for food but, because there were so many, they started to shot them for sport without worrying about the repercussions. Soon, from the unregulated hunting, only a handful of the pigeons were left in the entire world. The extinction of the passenger pigeon became official when the last one died in a zoo. Another animal that is now on the doorstep of extinction from overhunting is the White Rhino. It was hunted almost to extinction by poachers who killed them just for their ivory horns. Only a couple of White Rhinos are left in the world and they are slowly approaching the same fate as the passenger pigeons unless a way to keep their species alive is discovered.
Knowing why animals become extinct helps conservationists to understand what they can do to keep a species from becoming extinct. Every animal serves an important purpose, no matter how small. Preventing animals from going extinct may save Earth’s fragile circle of life. If people don’t succeed in conserving plant and animal species vital to human life, the more likely humans themselves will become extinct in the future.