World governments and organizations consider more than 7,000 animal species to be endangered. The International Union for Conservation of Nature maintains the Red List of Threatened Species. The organization determines how species become listed when they fall under one of the following categories.
- The population decreased by 50 to 70% within the last decade.
- The total species population resides in an area of less than 1,930 square miles or 5,000 square kilometers. A local subset of the population resides in an area encompassing less than 193 square miles or 500 square kilometers.
- The total population of a species consists of less than 2,500 adults. Local populations have less than 250 adults.
- Statistics indicate that the species will become extinct within the next two decades.
Species become endangered for a variety of reasons. However, the majority of negative factors involve humans. Loss of habitat occurs when people encroach upon an area to live or acquire the location’s natural resources. Humans may cause pollution that contaminates a location’s natural resources, while also bringing disease. Pesticides contaminate the food and water of local populations, causing death and disease. Environmental factors caused by people may lead to losing the genetic ability to adapt and survive.
A foreign species might enter the area, which often occurs when people abandon an exotic pet or when an animal is otherwise inadvertently introduced to a destination. The newly introduced species on existing wildlife subsequently decrease the population.
People may consider hunting a particular species a sport. Poaching remains a problem in many world regions. The animal becomes prized for its body parts in alternative medicines. It might become the victim of the illegal exotic pet trade.
U.S. Fish and Wildlife criminalized the hunting of certain animals in the country. The use of DDT and other chemicals are known to endanger animals has also been banned. Local organizations may encourage the removal of non-native predatory species in order to protect native wildlife. Such is the case in Florida, which pays hunters for capturing pythons. Breeding programs in zoos are another example of conservation efforts to save various animal species.