Threatened and Endangered Species


The FWS leads the Federal effort to protect and restore animals and plants that are in danger of extinction both in the United States and worldwide. Using the best scientific evidence available, FWS biologists identify species that appear to be endangered or threatened. After review, species may be placed on the Interior Department’s official “List of Threatened and Endangered Wildlife and Plants.” FWS biologists, along with other partners, then develop recovery plans for the species that include research, habitat preservation and management, and other recovery activities.

  • Ae‘o

    Hawaiian stilt150x118

    The population of ae‘o is estimated at 1200-1500 individuals throughout the islands. The species was listed as endangered in 1970 as wetlands were being altered. Although ae‘o can be observed in ephemeral pockets of water throughout the islands, their habitat for foraging and successfully nesting is limited to protected areas where predators (mongooses, rats, and feral cats and dogs) are controlled. 

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  • ‘Alae ke‘oke‘o


    There are no records of how many coots were in Hawai‘i before the 1950s. Research in the late 1950s and to the late 1960s indicated a population of only about 1,000. This led to the ‘alae ke‘oke‘o being listed as an endangered species in 1970. The population of ‘alae ke‘oke‘o ranges between 1,500 and 3,000 individuals and live in all the main Hawaiian islands, except Kaho‘olawe. O‘ahu has the largest population in the state and Maui the second largest. It is believed that the population fluctuates according to climatic and hydrological conditions. The primary cause of the decline of this Hawaiian native waterbird has been loss of wetland habitat. Other factors include introduced predators and alien plants, disease, hybridization, and environmental contaminants.

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  • ‘Alae ‘ula


    No historical population estimates are available for the endemic ‘alae ‘ula. Because they are such secretive birds, it is difficult to conduct surveys of this species. It is believed that they were common on the main Hawaiian islands in the 1800s but radically declined by the mid 1900s. Surveys in the 1950s and 1960s estimated no more than 57 individuals. However, the spread of aquaculture in the 1970s and 1980s helped boost their numbers by providing more suitable habitat for these birds. Today, ‘alae ‘ula can be found only on O‘ahu, Kaua‘i, and possibly on Maui and Moloka‘i. The primary cause of decline to this Hawaiian native waterbird has been loss of wetland habitat. Other factors include introduced predators, alien plants, introduced fish, disease, hybridization, and environmental contaminants. The ‘alae ‘ula was listed as an endangered species in 1967.

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  • Koloa maoli


    Koloa is endemic and used to be found on all the main Hawaiian islands except Lana‘i and Kaho‘olawe. People first noticed them to be rare around 1915. A koloa restoration program was initiated in 1962 by the World Wildlife Fund and the state through the Federal Aid to Wildlife Restoration Act. By 1979, 350 koloa had been released on O‘ahu and Hawai‘i as part of this program. In 2002, biologists estimated the populations to be 2,000 koloa on Kaua‘i-Ni‘ihau, 300 on O‘ahu, 25 on Maui, and 200 on the Big Island. The koloa was listed as an endangered species in 1967.  

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  • Honu


    Honu populations have declined dramatically in the Pacific islands. Overharvest of turtles and eggs by humans is by far the most serious problem. Other threats include habitat loss, capture in fishing nets, boat collisions, and a disease known as fibropapillomatosis. While this species is declining throughout most of the Pacific, in the Hawaiian Islands, honu are demonstrating some encouraging signs of population recovery after 17 years of protective efforts. Honu is federally listed as a threatened species in 1978. 

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  • Honu ‘Ea

    Hawksbill thumbnail

    Hawksbills are solitary nesters and, thus, determining population trends or estimates on nesting beaches is difficult. The largest populations of hawksbills are found in the Caribbean, the Republic of Seychelles, Indonesia, and Australia. In the U.S. Pacific, hawksbills nest only on main island beaches in Hawai‘i, primarily along the east coast of the island of Hawai‘i. The honu ‘ea was listed as an endangered species in 1970.

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  • ‘Ope‘ape‘a

    Hawaiian hoary bat

    Population estimates for all islands have ranged from hundreds to a few thousand, however, these estimates are based on limited and incomplete data. The magnitude of any population decline is unknown. Observation and specimen records do suggest, however, that these bats are now absent from historically occupied ranges. ‘Ope‘ape‘a populations are believed to be threatened by habitat loss, pesticides, predation, and roost disturbance. Its decline may be primarily due to the reduction of tree cover in historic times, and they may be indirectly impacted by the use of pesticides. The ‘ope‘ape‘a was listed as an endangered species in 1970.

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  • ‘Ilio holo I ka uaua

    Hawaiian monkseal

    Hawaiian monk seals were first recorded in 1825 at the Hawaiian archipelago's northernmost island, Kure Atoll. Scientist estimate about 1,100 to 1,200 monk seals live in the Hawaiian islands chain today. The abundance of Hawaiian monk seals in the Northwestern Hawaiian Islands is declining about 4% per year. Analyses indicate that juveniles are failing to thrive, and only about one of every five juvenile monk seals live to reach maturity. The population decline will continue indefinitely unless survival of juvenile monk seals improves. The ‘ilio holo I ka uaua was listed as an endangered species in 1976.

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  • Pueo

    Pueo thumbnail

    State listed as endangered on O‘ahu. Found on all the Main Hawaiian Islands from sea level to 2,450 meters (8,000 feet). Because of relatively few detections, the Hawaiian Forest Bird Survey did not estimate the population size of the pueo. Pueo were widespread at the end of the 19th century, but are thought to be declining.

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