List of threatened, endangered and extinct species in the Mariana Islands

The following is a list of species (or subspecies) in the Mariana Islands, defined by the International Union for Conservation of Nature (IUCN) Red List or by the U.S. Fish & Wildlife Service (USFWS), as being extinct, critically endangered, endangered, threatened, vulnerable, conservation dependent, or near threatened. This article addresses species found in the geopolitical states of Guam and the Commonwealth of the Northern Mariana Islands (CNMI).

As of 2024, there were 32 species or subspecies in the Mariana Islands listed by the U.S. Fish & Wildlife Service as endangered or threatened. USFWS has cited threats to species from habitat loss and degradation; military activities; urbanization; recreational vehicles; nonnative animals such as feral ungulates (wild boar and sambar deer), water buffalo, rats, brown tree snakes, slugs, flatworms, ants, and wasps; nonnative plants; fires; typhoons; water extraction; and future climate change.

As of 2024, the USFWS and IUCN together listed 9 species or subspecies endemic to the Mariana Islands that have gone extinct: the little Mariana fruit bat (Pteropus tokudae); 5 birds (Guam flycatcher (Myiagra freycineti), bridled white-eye (Zosterops conspicillatus conspicillatus), Pagan reed-warbler (Acrocephalus yamashinae), Aguijan reed-warbler (Acrocephalus nijoi), the Mariana mallard (Anas oustaleti); and 3 snails (Partula desolata, Partula langfordi, Mount Alifana partula (Partula salifana)). Archaeological evidence has revealed another snail from Guam, the Partula desolata, to be extinct. Four undescribed and extinct bird species were excavated from Rota. Additionally, the Guam kingfisher (Todiramphus cinnamominus) is listed by the IUCN as extinct in the wild.

Mammals

Common nameScientific nameImageUS Fish & Wildlife conservation statusIUCN Red List statusGovGuamNotesLittle Mariana fruit bat, Guam flying fox (fanihi)Pteropus tokudaeExtinct (USFWS)Extinct (IUCN)Endangered (GovGuam, 1997)Native to Guam. Last seen 1968; declared extinct in 2020 by IUCN, and 2023 by USFWS.Pacific sheath-tailed bat (payeyi, paischeey, payesyes)Emballonura semicaudata rotensisEndangered (Marianas subspecies, USFWS)Endangered (IUCN)Endangered (GovGuam, 1997)Subspecies native to Guam and CNMIMariana fruit bat, Mariana flying fox (fanihi)Pteropus mariannus mariannusThreatened (listed as Pteropus mariannus mariannus, USFWS)Endangered (listed as Pteropus mariannus, IUCN)Endangered (GovGuam, 1997)Native to Guam and CNMI

Amphibians and reptiles Common nameScientific nameImageUS Fish & Wildlife conservation statusIUCN Red List statusNotesSlevin's skink, Mariana skink (gualik halumtanu, gholuuf)Emoia sleviniEndangered (USFWS)Critically endangered (IUCN)Native to Guam and CNMIMicronesia saw-tailed geckoPerochirus atelesVulnerable (IUCN)Possibly extinct from Guam and Marcus Island. Found in Federated States of Marshall Islands; Japan; Micronesia; Northern Mariana Islands.

Endemic birds

Significant losses of bird species have likely occurred in the Mariana Islands in the past few millennia. A 1990 excavation of a late Holocene archeological site on Rota revealed the presence of 21 bird species, 12 of which have since become extinct or extirpated from Rota. Four of the species were not yet described and extinct: a small probably-flightless duck (Anatidae species), a giant ground-dove (Gallicolumba species), a large parrot (Psittacidae species), and a large parrotfinch (Erythrura).

The endemic birds on Guam, the southernmost Mariana island, were severely affected by the introduction of the brown tree snake after World War II. It has been reported that 11 of Guam's 14 terrestrial birds have become extinct or extirpated from Guam. A new tally after taxonomic revisions and the establishment of a population of Guam rail on Cocos Island, indicates there are now 5 of 16 native terrestrial (non-migratory) birds that remain in the wild on Guam: the Micronesian starling, yellow bittern (not endemic), and three endangered birds (Guam rail, Mariana common moorhen and Mariana swiftlet). The Guam kingfisher exists only in captivity. Common nameScientific nameImageUS Fish & Wildlife conservation statusIUCN Red List statusGovGuamNotesPagan reed-warblerAcrocephalus yamashinaeExtinct (IUCN)Native to Pagan. Last seen in late 1970s.Mariana mallard, Oustalet's duck (ngånga)Anas oustaletiExtinct (USFWS)Native to Guam, Tinian and Saipan, possibly also Rota and Pagan. Last seen in 1979.Bridled white-eye (Nosa')Zosterops conspicillatus (listed by UWFWS as Zosterops conspicillatus conspicillatus)Illustration available at GuampediaExtinct (USFWS)Extinct (IUCN)Endangered (GovGuam, 1997)Endemic to Guam and considered one of the most common bird species between early 1900s and 1930s. Last seen in 1983; declared extinct by USFWS and IUCN in 2023Aguiguan reed-warblerAcrocephalus nijoiExtinct (IUCN)Native to Aguiguan. Last seen in 1995.Guam flycatcher, Guam broadbill (chuguangguang)Myiagra freycinetiExtinct (IUCN)Endangered (GovGuam, 1997)Native to Guam. Last seen in 1984.Nightingale reed warbler, Guam reed-warbler (gå'ga' karisu)Acrocephalus luscinius (spelling per IUCN); listed by USFWS as Acrocephalus luscinia)Endangered (USFWS)Extinct (IUCN)Native to Guam. Last seen in 1969.Guam rufous fantail (subspecies of Micronesian rufous fantail) (chuchurika)Rhipidura versicolor uraniae (or Rhipidura rufifrons uraniae)Illustration available from GuampediaExtinct (IUCN)Endangered (GovGuam, 1997)Guam subspecies extinct, last seen in 1984.Micronesian honeyeater (égigi)Myzomela rubrata saffordiIllustration available from GuampediaExtinct (IUCN)Endangered (GovGuam, 1997)Marianas subspecies extirpated from Guam (last seen 1986) but remains in the wild in CNMI.Guam kingfisher (sihek)Todiramphus cinnamominus (previously listed by USFWS as Halcyon cinnamomina cinnamomina)Endangered (USFWS)Extinct in the wild (IUCN)Endangered (GovGuam, 1997)Native to GuamGuam rail (ko'ko)Gallirallus owstoni (species name as listed by USFWS, and previously listed as Rallus owstoni; species name listed by IUCN as Hypotaenidia owstoni)Endangered (USFWS) Downlisted from extinct in the wild (USFWS) in 2019 due to established population on Cocos IslandCritically endangered (IUCN)Endangered (GovGuam, 1997)Native to Guam.Previously extirpated from Guam but then reintroduced to Cocos Island off the coast of Guam in 2010.Saipan reed-warblerAcrocephalus hiwaeCritically endangered (IUCN)Native to Saipan and Alamagan (CNMI)Rota white-eye (nosa' luta)Zosterops rotensisEndangered (USFWS)Critically endangered (IUCN)Native to Rota (CNMI)Mariana crow (åga)Corvus kubaryiEndangered (USFWS)Critically endangered (IUCN)Endangered (GovGuam, 1997)Extirpated from Guam; extant on Rota (CNMI)Micronesian megapode (sasangat)Megapodius laperouseEndangered (USFWS)Near threatened (IUCN)Native to Mariana Islands and Palau Extirpated from Guam. Extant in CNMI and Palau.Mariana common moorhen (pulattat)Gallinula chloropus guamiEndangered (USFWS)Endangered (GovGuam, 1997)Native to Guam and CNMIMariana swiftlet (yǻyaguak) (previously listed by USFWS as the Mariana gray swiftlet)Aerodramus bartschi (previously reported by USFWS as Aerodramus vanikorensis bartschi)Illustration available at GuampediaEndangered (USFWS) Vulnerable (IUCN)Endangered (GovGuam, 1997)Native to Guam and CNMI Now very rare on GuamMariana fruit-dove (totot)Ptilinopus roseicapillaNear threatened (IUCN)Endangered (GovGuam, 1997)Extirpated from Guam. Extant in CNMIWhite-throated ground-dove (paluman ǻ'paka, female: paluman fache)Pampusana xanthonuraNear threatened (IUCN)Endangered (GovGuam, 1997)Native the Mariana Islands and Yap (Caroline Island). Extirpated from Guam, except for rare sightings.Golden white-eyeCleptornis marcheiEndangered (IUCN)Native to CNMIMicronesian starling (såli)Aplonis opaca (listed by GovGuam as subspecies Aplonis opaca guami)Least concern throughout its range, but decreasing (IUCN)Endangered (GovGuam, 1997)Native to MicronesiaSaipan white-eye (nosa)Zosterops saypaniNear threatened (IUCN)Native to Rota, Tinian and Saipan

Migratory birds Common nameScientific nameImageUS Fish & Wildlife conservation statusIUCN Red List statusNotesShort-tailed albatrossPhoebastria albatrusEndangered (USFWS)Vulnerable (IUCN)Native to North Pacific Ocean, mostly breeding on islands near JapanFar eastern curlewNumenius madagascariensisEndangered (IUCN)Breeds in eastern Asian Russia and Mongolia, but extant in coastal eastern Asia and western PacificSiberian sandploverCharadrius mongolusEndangered (IUCN)Breeds in Australia, New Zealand and Russia, wintering in east Asia and western PacificWhite-necked petrelPterodroma cervicalisVulnerable (IUCN)Breeds in New Zealand, Norfolk Island and Vanuatu; extant in other Pacific islands, Australia, and MexicoJuan Fernandez petrelPterodroma externaVulnerable (IUCN)Breeds in Chile; extant in French Polynesia, Guam, Mexico and HawaiiStejneger's petrelPterodroma longirostris Vulnerable (IUCN)Breeds in Chile; extant in French Polynesia, Guam, Japan, Marshall Islands, Federated States of Micronesia, CNMICommon pochardAythya ferinaVulnerable (IUCN)Widespread in Europe, Asia and northern Africa; non-breeding in Guam and CNMISharp-tailed sandpiperCalidris acuminataVulnerable (IUCN)Breeds in Russia; extant in Asia and western PacificLeach's storm-petrelHydrobates leucorhousVulnerable (IUCN)Native throughout the oceans, non-breeding in the Mariana IslandsMatsudaira's storm-petrelHydrobates matsudairaeVulnerable (IUCN)Breeds in Japan; migrates from eastern African coast to western PacificBar-tailed godwitLimosa lapponicaNear threatened (IUCN)Breeds in Russia and Alaska, extant in numerous other areas, including Guam and CNMIGrey-tailed tattlerTringa brevipesNear threatened (IUCN)Breeds in Mongolia; extant in Southeast Asia, Oceania and western Pacific Ocean

Gastropods

Three of the 7 partulid snails described from the Mariana islands are extinct, and the remaining 4 are imperiled. Partulid populations have been affected by invasive snails such as the North American Euglandina species and the New Guinea flatworm (Platydemus manokwari). Common nameScientific nameImageUS Fish & Wildlife conservation statusIUCN Red List statusNotesMount Alifana partulaPartula salifanaExtinct (IUCN)Native to the Mount Alifana region of southern GuamPartula desolataExtinct. Known only from an archeological site on Rota (although no indication that there was any human consumption of the snails). The species survived until at least c. 1000. The describing authors chose the specific name "desolata" due to the desolation brought about upon the Partulidae populations in the Pacific.Langford's tree snail (akaleha, denden)Partula langfordiEndangered (USFWS) Extinct (IUCN)Native to AguiganSuccinea quadrasiSpecies was being evaluated for protected status by USFWS in 1994.Endangered (IUCN)Native to GuamSuccinea piratarumSpecies was being evaluated for protected status by USFWS in 1994.Endangered (IUCN)Native to GuamFragile tree snail, akaleha dogas, dendenSamoana fragilisEndangered (USFW)Endangered (IUCN)Native to Guam and RotaHumped tree snail (akaleha, denden)Partula gibbaEndangered (USFWS)Endangered (IUCN)Native to Guam and CNMIGuam tree snail (akaleha, denden) Partula radiolataEndangered (USFWS)Endangered (IUCN)Native to Guam

Gastropods proposed to have protected status Partula lutaensis - endemic to Rota; species first described in 2021 and the describing authors advised it be "listed as Endangered as soon as possible."

Insects