Endangered species are those considered to be at high risk of extinction in the future. Such species can be considered endangered on a global level or classified by a region, state, or jurisdiction. Various factors can influence extinction rates and risk, and are unique to each species facing extinction.
In nature, there exists a balance between species and the environment. While many species are able to adapt over time to environmental changes, others are sensitive and unlikely to survive if their environment changes too drastically.
Species interact with each other and flora to create what is known as biodiversity. It has been argued that biodiversity is one of the most accurate ways to assess how healthy an ecosystem is operating. Biodiversity, by definition, means: the variety of life in the world or in a particular habitat or ecosystem.
In hopes to preserve global biodiversity and species classified as endangered, legislation has been implemented across the world to monitor endangered species populations, habitat, and threats. The goal of such legislation is to support monitoring systems which increase the likelihood of preventing species from extinction.
The most common factor between endangered species is habitat loss. Habitat is the spread of resources within an area that support the survival and reproduction of particular species that live within the area. Some species have not adapted to other environments; only thriving in specific conditions or areas. Loss in habitat may be caused by natural disasters, such as flooding, drought, or wildfires. Modern habitat loss, however, is mainly caused by human disturbances.
Human-caused habitat loss presents itself through logging, clearing, development, and agriculture. The act of cutting down trees or clearing forested areas for commercial, residential, or agricultural purposes has a direct impact on the habitat in the selected and surrounding areas. Other human disturbances to species include hunting, poaching, and introducing non-native or invasive species.
Species who are displaced from their habitats risk injury and starvation if unable to find suitable food, and will not prioritize reproduction. If unable to find suitable habitat or adapt in a timely manner, species are likely to lose strong genetic traits and variations, starve, fall ill, and ultimately, their populations will decline to endangered levels.
After implementing the 1973 act, organizations and individuals could petition for species to be added to the Endangered Species List. For a species to be added to the list, rigorous scientific evidence and research to back up claims are needed. After review of the data compiled for a certain species, it is ruled whether that species will be protected under the Endangered Species Act (1973), and added to the Endangered Species List.
For a species to be removed from the Endangered Species List, once again, science-backed evidence over a long period of time (five, ten, or more years) must be provided. For removal, the evidence must conclude that the species has recovered, and their populations are growing or stable.
The list ranks species based on concern for extinction. The categories include: least concern, vulnerable, near threatened, endangered, and critically endangered. Species ranked as critically endangered are depicted at the top of the list.
In The United States, many states have developed their own endangered species lists and protection programs. Species found to be endangered in a certain state may receive state protection, federal protection, or both.
A total of 726 species are currently listed on the Endangered Species List managed by The United States Fish & Wildlife Service.
The Endangered Species Act is known across the globe as one of the most successful pieces of legislation for the 
protection of wildlife. Within its first 30 years, less than one percent (1%) of listed plants and animals succumbed to extinction. And, over 100 species on the list showed a ninety percent (90%) recovery rate. Since the act began, over 200,000 acres of sensitive habitat have been protected from development or exploitation.
Through the act’s success, it inspired other nations to implement similar monitoring systems and legislation, causing biodiversity to be preserved all over the world. Beloved species once on the brink of extinction have been brought back to healthy populations, protected under federal and global treaties and legislation.
Species saved by (yet not removed from the Endangered Species List) the Endangered Species Act include:
Endangered Species Act signed into law – HISTORY.
The US Endangered Species Act | Pages | WWF
Species List | Endangered, Vulnerable, and Threatened Animals | WWF
FWS-Listed US Species by Taxonomic Group – All Animals
5 Endangered Animals That Were Saved By The Endangered Species Act – THE ENVIRONMENTOR
