Home > Islets > Oahu > Manana ISLETS: OAHU > MANANA Manana   Manana - Photo: F & K Starr Manana - Photo: F & K Starr   Manana - Photo: F & K Starr Manana - Photo: F & K Starr   Manana - Photo: F & K Starr Physical Features Manana is 67 acres in size, making it Oahu's largest offshore islet. It is also called Rabbit Island, not only because it resembles a crouching rabbit but also because rabbits once lived there. The islet reaches a height of 360 feet and lies one mile north of Makapuu Beach on the southeast coast of Oahu. Manana is a volcanic tuff cone built around two vents that erupted underwater. The vents are each marked by a crater, one intact and the other cut in half by wave action. Rains have cut deep gullies in the outer and inner slopes of the main crater. Regulations State regulations prohibit landing on Manana. The islet is a State Seabird Sanctuary managed by the Hawaii DOFAW. Regulations in Hawaii Administrative Rules, Title 13 Chapter 125, protect wildlife and plants and restrict human activities in seabird sanctuaries. Federal law also protects seabirds, shorebirds, and threatened or endangered species. Birds Manana has the highest number of seabirds of Oahu’s offshore islets and, along with Mokumanu, Kaula, and Lehua, is among the most important seabird islets in the main Hawaiian Islands. Six species are recorded as nesting on Manana, including Sooty terns, Brown noddies, Black noddies, Wedge-tailed shearwaters, Bulwer’s petrels, and Red-tailed tropicbirds. The largest numbers of birds are sooty terns, brown noddies, and wedge-tailed shearwaters. Estimates from the 1980s are that between 85,000 and 130,000 breeding adults of all species were present. Although the first recorded ornithological survey in 1937 reported many breeding seabirds, anecdotal reports indicate that there were no birds on Manana during the 1880s and 1890s. Plants Rabbits were introduced in the late 1800s and drastically altered Manana’s vegetation, a situation not improved by its use as a target range in World War II. Although the rabbits were removed and the shelling stopped, the native vegetation has not been able to recover and alien plants currently dominate. A 2005 survey recorded 42 plant species, only 11 of them native. Golden crown beard (Verbesina encelioides) and buffelgrass (Cenchrus ciliaris) are dominant alien ground covers. In 2003, the U.S. Fish and Wildlife Service designated critical habitat on Manana for two endangered plants, Chamaesyce kuwaleana and Vigna o-wahuense. Although these plants are not present, establishing populations on Manana is considered to be an important step towards species recovery. Insects Recent collections found only alien insect species, including several types of ants. More extensive collecting efforts could discover some native species. Marine Organisms Endangered Hawaiian monk seals haul out on Manana and have pupped there in recent years. Formal marine surveys are unknown, although anecdotal information suggests that sharks are fairly common around Manana. Human Uses During the late 1800's, John Adams Cummins, a local rancher and owner of Waimanalo Sugar Company, brought rabbits to Manana to raise them for hunting. If the old stories are true that no seabirds nested on Manana in the 1880s and 1890s, this presents the question of what human activities, aside from rabbit ranching, could have caused this. Perhaps seabirds or eggs were heavily harvested by humans at one point. During World War II, Manana was used for military target practice but was designated as a bird sanctuary in 1945. Currently, human uses are minimal or non-existent since landing is prohibited. Threats Invasive weeds and ants threaten native species, although little intact plant habitat and few native insects remain. Mice have been present on Manana for many years, are likely still there, and may be impacting seabirds. Rabbits were there for about 100 years but the last one was eradicated by Hawaii DOFAW in 1994. The main concern is to prevent rats or other predatory mammals from gaining access to Oahu’s largest seabird colony. > Back to top of page Home  Islets  Species  Projects  Outreach  Links  About Us