1. The species must be in danger of extinction throughout all or a significant portion of its range. This means that the species is facing a high risk of extinction in the wild due to factors such as habitat loss, hunting, climate change, or other threats.
2. The species must be one of the following:
* A native species of the United States
* A species that is found in the territorial waters of the United States
* A species that is found on the high seas and is either a marine mammal or anadromous fish (fish that migrate from the ocean to freshwater rivers and streams to spawn)
3. The species must be either "endangered" or "threatened" according to the following definitions:
* Endangered means a species is in immediate danger of extinction throughout all or a significant portion of its range.
* Threatened means a species is likely to become endangered in the foreseeable future throughout all or a significant portion of its range.
The United States Fish and Wildlife Service (USFWS) and the National Marine Fisheries Service (NMFS) are the two federal agencies responsible for implementing the Endangered Species Act. These agencies use a variety of factors to determine whether a species meets the criteria for listing under the Act, including:
* Population size and trends
* Habitat loss and fragmentation
* Threats from hunting, fishing, or other human activities
* Climate change impacts
* The species' role in the ecosystem
The USFWS and NMFS also consider the economic and social impacts of listing a species under the Act. If the costs of protecting the species outweigh the benefits, the species may not be listed.
Once a species is listed under the Endangered Species Act, it receives a number of protections. These protections include:
* Prohibitions against hunting, fishing, or collecting the species
* Restrictions on development or other activities that could harm the species or its habitat
* Requirements for federal agencies to consult with the USFWS or NMFS before taking actions that could affect the species
The Endangered Species Act has been successful in protecting many species from extinction. However, it is a complex and controversial law, and there is ongoing debate about how it should be implemented.