Wildlife & Habitat
The Hawaiian Islands National Wildlife Refuge provides breeding sites for all but three of Hawai‘i’s 22 species of seabirds. Millions of central Pacific seabirds congregate on these islands to breed. They nest in burrows and cliffs, on the ground, and in trees and shrubs. For some species, it is their only breeding site. Although a few of the islands (notably Laysan Island) were decimated by introduced mammals, many of the islets and atolls have been relatively untouched by humans. As a result, this group of islands has a mostly intact seabird population and healthy insect and plant communities. The importance of seabirds was recognized with the refuge's establishment at the turn of the century. Since then, protection and active management have resulted in large, diverse, and relatively intact seabird populations. |
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Wedge-tailed shearwater - Photo credit Mark McDonald |
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Nihoa Island is one of the most biologically pristine islands in the Pacific, and probably most closely represents the original island appearance and native species found before humans arrived in the main Hawaiian Islands. Like the coral reefs, the islets are home to many plant and animal species found nowhere else in the world, including four land birds and 12 plants. Unfortunately, their limited habitats and small population size make extinction of the species a distinct possibility, and most of these species are already listed under the Endangered Species Act. Three bird species (the Laysan honeycreeper, Laysan millerbird, and Laysan rail) became extinct in the early 1900s. |
| Laysan finches - Photo credit Pete Leary/USFWS |
About 240 fish species were recorded in the Northwestern Hawaiian Islands during a comprehensive fish survey conducted by the State of Hawai‘i in 1984. In 2000-2005 surveys, reef fish populations were found to be healthy and the fish biomass higher than in the main Hawaiian islands.
Approximately 27 percent of the corals, 25 percent of the reef fish, and 30 percent of the invertebrates in the Hawaiian islands are found nowhere else in the world.
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The majority of endangered Hawaiian monk seals breed and feed within the refuge. The population has declined to about 1,100 - 1,200 animals, and numbers appear to be declining in the southern end of the refuge at Nihoa, Mokumanamana, and French Frigate Shoals.
Five endangered sea turtles occur within the refuge boundaries. Threatened green turtles frequently haul out on the beaches of the refuge, with approximately 90 percent of the Hawaiian population of threatened green turtles nesting at French Frigate Shoals. |
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Photo of Hawaiian monk seal
Photo credit Pete Leary/USFWS |
Green turtle hatchling
Photo credit Pete Leary/USFWS |
