Nihoa (/niːˈhoʊ.ə/; Hawaiian: [niˈhowə]), also known as Bird Island or Moku Manu, is the tallest of ten islands and atolls in the uninhabited Northwestern Hawaiian Islands (NWHI). The island is located at the southern end of the NWHI chain, 296 km (160 nmi) southeast of Necker Island. Nihoa is the closest NWHI in proximity to the eight main windward Hawaiian Islands at approximately 240 km (130 nmi) northwest of the island of Kauaʻi. The island has two peaks, 272 m (892 ft) Miller's Peak in the west, and 259 m (850 ft) Tanager Peak in the east. Nihoa's area is about 171 acres (0.69 km2) and is surrounded by a 142,000-acre (57,000 ha) coral reef. Its jagged outline gives the island its name, Nihoa, which means "tooth" in the Hawaiian language.
The island is home to 25 species of plants and several animals, making it the most diverse island in the entire NWHI. Endemic birds like the Nihoa finch and Nihoa millerbird, and endemic plants like Pritchardia remota, Schiedea verticillata, and Amaranthus brownii are found only on Nihoa. The plant communities and rocky outcrops provide nesting and perching areas for 18 species of seabirds, such as red-footed boobies and brown noddies, terns, shearwaters, and petrels. Prehistoric evidence indicates Native Hawaiians lived on or visited the island around AD 1000, but over time the location of Nihoa was mostly forgotten, with only an oral legend preserving its name. Captain James Colnett rediscovered the island in 1788, and Queen Kaʻahumanu visited it in 1822. It was made part of the Kingdom of Hawaii by King Kamehameha IV.
In 1909, Nihoa became part of the Hawaiian Islands Reservation, a federal wildlife refuge established by U.S president Theodore Roosevelt. The Tanager Expedition surveyed the island in 1923, taking a comprehensive biological inventory of its many species. In 1940, it became part of the Northwestern Hawaiian Islands Wildlife Refuge and in 1988, it was listed on the National Register of Historic Places due to its culturally significant archaeological sites. In 2006, it became part of the Papahānaumokuākea Marine National Monument. Efforts are underway to ensure that endangered plant species are propagated beyond their limited range and represented in ex situ collections. Persons intending to visit Nihoa for cultural and scientific research purposes require a USFWS-issued special-use permit to land on the island so as to reduce the risk of introducing alien species to Nihoa's already fragile ecosystem.
|Location||Papahānaumokuākea Marine National Monument|
|Archipelago||Northwestern Hawaiian Islands|
|Area||0.69 km2 (0.27 sq mi)|
Nihoa is part of the Hawaiian – Emperor seamount chain of volcanic islands, atolls, and seamounts starting from the island of Hawaiʻi in the southeast to the Aleutian Islands in the northwest. It is the youngest of ten islands in the uninhabited Northwestern Hawaiian Islands (NWHI), having formed 7.2 million years ago; the oldest, Kure Atoll, formed 30 million years ago. Over the millennia, Nihoa has experienced significant erosion; along with Necker, French Frigate Shoals, and Gardner Pinnacles, Nihoa is one of only four islands in the NWHI that still has an exposed basalt rock substrate. Six valleys slant down from north to south, meeting at the south side of the island: West Valley, West Palm Valley, Miller Valley, Middle Valley, East Palm Valley, and East Valley.
Among features on Nihoa are Dog's Head Peak (358 ft or 109 m), named for its likeness, and Pinnacle Peak (626 ft or 191 m), a volcanic dike created when less resilient rock was eroded away and harder rock was open to the elements. The only flat area on the island is Albatross Plateau, just below Miller's Peak. The Devil's Slide is a narrow cleft descending 700 feet (210 m) irrespective of the surrounding elevation. Extending northward from Albatross Plateau, it ends at the vertical cliffs with a 190-foot (60 m) drop straight down to the ocean below. In this chasm, rare ferns grow, along with several endemic species, including a giant cricket.
Nihoa's inaccessibility and lack of major guano deposits made the island unattractive to humans, helping to preserve its endemic species from extinction. Because of Nihoa's small size, most of its endemic organisms are endangered, as one single disaster such as an island-wide fire or an introduction of invasive species could wipe out the whole population. One such invasive species is the gray bird grasshopper, Schistocerca nitens; from the period between 1999 and 2003, grasshoppers devastated much of the vegetation on the island and posed a real threat to the continued health of plants on Nihoa. The following year, the numbers decreased and the vegetation became lush again. The grasshoppers probably came to Nihoa by way of wind from Kauai.
Unique species include:
Nihoa Island Archeological District
View of Nihoa Island
|Nearest city||Kauai, Hawaii|
|NRHP reference #||88000640|
|Added to NRHP||June 13, 1988|
Nihoa was well known to the early Hawaiians. Archaeological expeditions found extensive prehistoric agricultural terraces and house sites. At least one site has been dated to around the 1st millennium AD, sometime between 867-1037. There is some doubt as to the number of people that lived on Nihoa, because while the large terraces suggest a considerable number, there is scant fresh water to be found. Archaeologists Kenneth Emory and Paul Cleghorn estimate that water could support as many as 100 people, although if the island were previously forested, this would have increased fresh water supplies relative to its current state. It is also thought that Nihoa may have been used only for religious purposes, which would have meant that ancient Hawaiians only visited here occasionally and did not stay for long. Because of the island's importance, the island was added to the National Register of Historic Places in 1988, and subsequently became part of Papahānaumokuākea Marine National Monument in June 2006.
Nihoa, along with Necker Island to the northwest, is among the most northern, isolated, smallest and driest of the Hawaiian islands, and receives the lowest dust and tephra input. All of these features were found to strongly predict deforestation among the Pacific Islands. The collapse of the Nihoa population may stem from this, similar to how Easter Island became inclement to its human civilization following deforestation and depletion of seabirds and other natural resources.
The first Westerner to discover Nihoa was Captain James Colnett of the Prince of Wales, on March 21, 1788. Due to Colnett's lengthy absence from England, including his imprisonment by the Spanish for his part in the Nootka Sound Incident, the discovery was once widely accredited to Captain William Douglas of the Iphigenia, who sighted Nihoa almost a year later.
By the end of the 18th century, Nihoa had been forgotten by most Hawaiians. In 1822, Queen Kaʻahumanu and her husband King Kaumualiʻi traveled with Captain William Sumner to find Nihoa, as her generation had only known the island through songs and myths. Later, King Kamehameha IV sailed there to officially annex the island as part of the Kingdom of Hawaiʻi. Finally, in 1885, Princess Liliuokalani made a pilgrimage to Nihoa with her escorts, but their luncheon was cut short when one of the party ignited a wildfire by accident. The group tried to flee the island, but the rising tides made it difficult and several boats were flooded, destroying some of the photographs taken.
Amaranthus brownii was an annual herb in the family Amaranthaceae. The plant was found only on the small island of Nihoa in the Northwestern Hawaiian Islands, growing on rocky outcrops at altitudes of 120–215 m (394–705 ft). It was one of nine species of Amaranthus in the Hawaiian Islands, but was the only endemic Hawaiian species of the genus. It was first discovered during the Tanager Expedition in 1923 by botanist Edward Leonard Caum. A. brownii differed from other Hawaiian species of Amaranthus with its spineless leaf axils, linear leaves, and indehiscent fruits.
It was one of 26 vascular plants on Nihoa, 17 of which are indigenous, six alien, and three endemic only to Nihoa, including A. brownii, the Nihoa fan palm or loulu, and the Nihoa carnation. A. brownii was considered the rarest plant on Nihoa and had not been directly observed on the island since 1983, and is now considered to be extinct. Past expeditions collected plant samples and seeds, but no specimens managed to survive ex-situ conservation efforts outside of its native habitat. There are no known plants or seeds from A. brownii in any botanical garden.
Conservation and recovery plans for A. brownii had been proposed by the United States Fish and Wildlife Service (FWS) which administers the island of Nihoa as part of the Hawaiian Islands National Wildlife Refuge in the Papahānaumokuākea Marine National Monument. In 1996, the plant was listed by the FWS as an endangered species. In 2003, the FWS designated the island of Nihoa as a critical habitat for the plant and it was classified as critically endangered on the IUCN Red List. Following a lack of sightings for over 35 years despite intensive surveys, the species was classified as extinct on the IUCN Red List in 2018.Hyposmocoma malornata
Hyposmocoma malornata is a species of moth of the family Cosmopterigidae. It was first described by Lord Walsingham in 1907. It is endemic to the Hawaiian islands of Necker, Nihoa, Kauai, Oahu, Molokai, Maui and Hawaii. The type locality is Olinda, where it was collected at an elevation of 4,000 feet (1,200 m).
The larva is probably a case-maker, and it may feed on lichen.Hyposmocoma nihoa
Hyposmocoma nihoa is a species of moth of the family Cosmopterigidae. It is endemic to Nihoa, Northwestern Hawaiian Islands. The type locality is Miller Canyon.
The wingspan is 6.3–7.6 mm.The larval case is burrito-shaped and 3.4–4.8 mm in length. It is large and rounded with a curved pointed distal end and decorated with lichens woven with silk filaments. The case background color ranges from green to gray.Adults were reared from case-making larvae. Larvae were collected on small bushes and rocks.List of birds of the U.S. Minor Outlying Islands
This is a list of birds of the U.S. Minor Outlying Islands. (A) means bird species is accidental / rare.
The Wake Island rail was a species endemic to Wake Island, but it is now extinct. The Laysan duck is endemic to the Northwest Hawaiian Islands (which includes Midway Atoll — Midway Atoll is part of the U.S. Minor Outlying Islands, not the state of Hawaii). The endemic and critically endangered Nihoa finch was extirpated from Midway Atoll.
Because the U.S. Minor Outlying Islands is a statistical area with no organized government, it has no official bird (unlike the states and four out of five of the inhabited territories).List of flora of Nihoa
This is a list of the flora of Nihoa, an island in the Northwestern Hawaiian Islands, part of the City & County of Honolulu in the U.S. state of Hawaii. Nihoa is listed in the National Register of Historic Places and protected under the Papahānaumokuākea Marine National Monument.List of species of the Northwestern Hawaiian Islands
This is a list of the species that inhabit the Northwestern Hawaiian Islands. Except for researchers and volunteers living on Midway Atoll, Kure Atoll, and Tern Island, the leeward islands are uninhabited by people but home to at least 7000 species ranging from marine mammals, fish, sea turtles, birds and invertebrates. Many of these species are rare or endangered and at least 25% are endemic to the Northwestern Hawaiian Islands. This list identifies which islands the species lives on, and whether the species is endemic to the NWHI.Millerbird
The millerbird (Acrocephalus familiaris) is a species of Old World warbler in the family Acrocephalidae. It has two subspecies, A. f. kingi and A f. familiaris. The latter, the Laysan millerbird, became extinct sometime between 1916 and 1923. The former, the critically endangered Nihoa millerbird, remains the only race left, inhabiting the small island Nihoa in Hawaiʻi, though it has since been reintroduced to Laysan. It is the only Old World warbler to have colonised Hawaiʻi, although there is no fossil evidence that the species ever had a distribution beyond these two islands.
Millerbirds form long-term pair bonds and defend territories over a number of years. Territories can be as large as 0.95 hectares (2.3 acres), although 0.19–0.40 hectares (0.47–0.99 acres) is more typical. Breeding occurs variably from January to September depending on food availability.Nihoa (spider)
Nihoa is a genus of South Pacific brushed trapdoor spiders first described by Tracey Churchill & Robert Raven in 1992. It is named after the island Nihoa, where the type species (N. mahina) is endemic.Male Nihoan trapdoor spiders (N. hawaiiensis) grow to almost 15 millimetres (0.59 in) long, including chelicerae. The females are larger, growing up to 21 millimetres (0.83 in).Nihoa conehead katydid
The Nihoa conehead katydid (Banza nihoa) is a species of katydid which is endemic to the Hawaiian island of Nihoa (Northwestern Hawaiian Islands). It is one of the ten species in the genus Banza, all of them native to Hawaii, although it is the sister species to the remaining nine, and may belong in a separate genus. It gets its food mostly from plant leaves, but because of the low population, it does not do significant damage. Unlike Main Islands' species, whose males leap on the females before mating, the Nihoa variants sing to them. It is listed as a vulnerable species on the IUCN Red List, and as a "species of concern" under the Endangered Species Act.Nihoa finch
The Nihoa finch (Telespiza ultima) is one of the two endemic bird species of the tiny Hawaiian island Nihoa, the other being the Nihoa millerbird. When it was classified in 1917, scientists thought that it would be the last endemic species named. This was later found untrue. The island's population is 1000–3000 birds. The Nihoa finch was added to the Endangered Species List by the U.S. Fish and Wildlife Service on March 11, 1967. An attempt to protect the species against extinction was made by starting a colony on French Frigate Shoals, another leeward island. This would ensure its continued existence in the event that the Nihoa population was wiped out. This attempt, however, failed. Nihoa is part of a group of islands that make up the Hawaiian Islands National Wildlife Refuge which provides protected land for the Nihoa finch to roam on.Nihoa millerbird
The Nihoa millerbird (Acrocephalus familiaris kingi) is a subspecies of the millerbird. It gets its name from its preferred food, the Miller moth. The 5-inch (13 cm) long millerbird has dark, sepia-colored feathers, white belly, and dark beak. Its natural geographic range is limited to the tiny island of Nihoa in the Northwestern Hawaiian Islands, and it is hoped that birds translocated to Laysan will help to ensure the survival of the species. The Nihoa millerbird is one of the two endemic birds remaining on Nihoa, the other being the Nihoa finch.
Only 200– 900 Nihoa millerbirds persist on the island, making the species seriously endangered. It is always at risk of extinction from environmental changes (droughts, fires, insect population irruptions), because flight away from the island would likely prove fatal. The Laysan millerbird, now extinct, was closely related.
The trinomial commemorates Samuel Wilder King, captain of the Tanager Expedition and later Governor of Hawaii.Nihoa trapdoor spider
The Nihoa trapdoor spider or Nihoa mahina is a trapdoor spider endemic to Nihoa, Hawaii. These spiders are hunters that dig a hole near rocks cover it with a concealed trapdoor. These burrows are excavated completely with the spider's jaw. When prey approaches or falls in, the spider pounces on it. Then its abnormally large pedipalps are used to take food into the mouth.
Prior to the 1980s, trapdoor spiders were not thought to exist in Hawaii. Upon their discovery, the genus was given the name Nihoa, because it was thought to exist nowhere else. Eventually, over 23 species across the Pacific were found. The species epithet, "mahina", means "moon" in the Hawaiian language, referring how Sheila Conant discovered the spider by the light of the moon.Northwestern Hawaiian Islands
The Northwestern Hawaiian Islands or the Leeward Islands are the small islands and atolls in the Hawaiian island chain located northwest (in some cases, far to the northwest) of the islands of Kauai and Niihau. Politically, they are all part of Honolulu County in the U.S. state of Hawaii, except Midway Atoll, which is a territory distinct from Hawaii and grouped as one of the United States Minor Outlying Islands. The United States Census Bureau defines this area, except Midway, as Census Tract 114.98 of Honolulu County. Its total land area is 3.1075 square miles (8.048 km2). All the islands except Nihoa are north of the Tropic of Cancer, making them the only islands in Hawaii that lie outside the tropics.
The Northwestern or Leeward Hawaiian Islands include:
Nihoa (Moku Manu) at 23°03′38″N 161°55′19″W
Necker (Mokumanamana) at 23°34′N 164°42′W
French Frigate Shoals (Kānemilohaʻi) at 23°52.134′N 166°17.16′W
Gardner Pinnacles (Pūhāhonu) at 25°01′N 167°59′W
Maro Reef (Nalukākala) at 25.415°N 170.590°W / 25.415; -170.590
Laysan (Kauō) at 25.7675°N 171.7334°W / 25.7675; -171.7334
Lisianski (Papaāpoho) at 26.064031°N 173.965802°W / 26.064031; -173.965802
Pearl and Hermes Atoll (Holoikauaua) at 27.927687°N 175.737991°W / 27.927687; -175.737991
Midway (Pihemanu) at 28°12′N 177°21′W - not part of the State of Hawaii
Kure (Mokupāpapa) at 28°25′N 178°20′WPapahānaumokuākea Marine National Monument
The Papahānaumokuākea Marine National Monument (roughly ) is a World Heritage listed U.S. National Monument encompassing 583,000 square miles (1,510,000 km2) of ocean waters, including ten islands and atolls of the Northwestern Hawaiian Islands. Created in June 2006 with 140,000 square miles (360,000 km2), it was expanded in August 2016 by moving its border to the limit of the exclusive economic zone, making it one of the world's largest protected areas. It is internationally known for its cultural and natural values as follows:
"The area has deep cosmological and traditional significance for living Native Hawaiian culture, as an ancestral environment, as an embodiment of the Hawaiian concept of kinship between people and the natural world, and as the place where it is believed that life originates and to where the spirits return after death. On two of the islands, Nihoa and Makumanamana, there are archaeological remains relating to pre-European settlement and use. Much of the monument is made up of pelagic and deepwater habitats, with notable features such as seamounts and submerged banks, extensive coral reefs and lagoons."Pritchardia remota
Pritchardia remota, the Nihoa pritchardia, Nihoa fan palm, or Loulu, is a species of palm endemic on the island of Nihoa, Hawaiʻi, and later transplanted to the island of Laysan. It is a smaller tree than most other species of Pritchardia, typically reaching only 4–5 metres (13–16 ft) tall and with a trunk diameter of 15 centimetres (5.9 in). It is the only type of tree on the island and used to be abundant. In 1885 a wildfire ravaged the island, destroying most of the palms. Only about 700 of these trees remain, making the species endangered but numbers are slowly increasing. The palm is being cultivated in botanical gardens.Though it is impossible to mistake P. remota for any other species in its natural habitat, it can be discerned from other Pritchardia species by its wavy leaves, its short and hairless inflorescences, and its tiny, spherical fruits.A similar undescribed species existed on Laysan, but was made extinct after Laysan was mined for guano.Schiedea verticillata
Schiedea verticillata, known as the Devils Slide schiedea or Nihoa carnation, is an endangered species of carnation, endemic to the island of Nihoa in the Northwestern Hawaiian Islands, where it was discovered in 1923 by the Tanager Expedition. It has been listed as endangered since 1996.
It has stems 40–60 cm (16–24 in) long, erect or sometimes trailing, and fleshy mint-colored leaves as long as 15 cm. The flowers are petal-less, have ten stamens and 4-5 styles. The plant estivates, dying back to the fleshy perennial roots during the dry season. Less than 400 individual plants survive in two of Nihoa's rocky valleys, but the population has remained stable. How this plant is pollinated is not known. Even though there are very few individuals surviving, the carnation can avoid inbreeding, a problem that threatens fellow Nihoan plant Amaranthus brownii, because this carnation has the highest genetic diversity of its genus.Sesbania tomentosa
Sesbania tomentosa, commonly known as Oahu riverhemp and ʻŌhai, is an endangered species of flowering plant in the pea family, Fabaceae, that is endemic to the main Hawaiian Islands as well as Nihoa and Necker Island. It inhabits low shrublands and, rarely, dry forests, at elevations from sea level to 2,500 ft (760 m). Associated native plant species include akiʻaki (Sporobolus virginicus), ilima (Sida fallax), naupaka kahakai (Scaevola taccada), and pili (Heteropogon contortus). Off-road vehicles, wildfires, grazing, and alien species competition have destroyed their habitat on the main islands, but they are still quite common on Nihoa and Necker. At least 2000 specimens grow on Nihoa, while there are far less on Necker.
ʻŌhai is highly polymorphic, exhibiting broad variations in color and shape. Plants that grow on Nihoa have reddish-orange flowers and young leaflets that are relatively hairless. Necker plants have salmon to orange colored-flowers, and leaflets that are very hairy. A form that grows as a standing tree exists on Molokaʻi.
ʻŌhai grows as a prostrate shrub with semi-glaucous leaves devoid of tomentum on the southernmost tip of the island of Hawaiʻi, Ka Lae.Tanager Expedition
The Tanager Expedition was a series of five biological surveys of the Northwestern Hawaiian Islands conducted in partnership between the Bureau of Biological Survey and the Bishop Museum, with the assistance of the U.S. Navy. Four expeditions occurred from April to August 1923, and a fifth in July 1924. Led by Lieutenant Commander Samuel Wilder King on the minesweeper USS Tanager (AM-5), and Alexander Wetmore directing the team of scientists, the expedition studied the plant animal life, and geology of the central Pacific islands. Noted members of the team include archaeologist Kenneth Emory and herpetologist Chapman Grant.
The expedition began with the goal of exterminating domestic rabbits that had been introduced to Laysan island by the guano industry in 1902. Since that time, the rabbits had devoured Laysan's vegetation and led to the extinction of several endemic species. The rabbits were eventually eliminated on Laysan, and the crew witnessed the extinction of the Laysan honeycreeper (ʻapapane). Throughout the expedition, new species were discovered and named, and unique specimens were captured and returned to laboratories for further study. Over 100 archaeological sites were found, including ancient religious sites and prehistoric settlements on Nihoa and Necker Island.Thaumatogryllus conanti
Thaumatogryllus conanti is a nocturnal species of cricket endemic to the island of Nihoa, where it is found in Devil's Slide, a narrow ravine. It is named after Dr. Sheila Conant, the scientist who discovered it in the 1980s. Including T. conanti, there are only four known species in the genus Thaumatogryllus, which is endemic to Hawaii. Another species is found only in lava tubes on the Island of Hawaii.
Island gigantism is mostly found in plants and animals on tiny, remote islands. This is because largeness provides a survival advantage. Usually, larger size makes it harder to escape from predators, but in these cases, there are none. This insect probably lost the capacity for flight in exchange for larger size. The average length is about 4 centimetres (1.6 in).