Two of the birds unique to Guam now survive only as a result of captive breeding: the Guam Rail (Smithsonian National Zoo) and the Guam Kingfisher Todiramphus cinnamominus cinnamominus (Lincoln Park Zoo), a subspecies of the Micronesian Kingfisher. Four additional endemic birds are recently extinct: the Guam Broadbill Myiagra freycineti (fws.gov), the Guam Reed Warbler Acrocephalus luscinius (Wikimedia Commons), a subspecies of the Rufous Fantail Rhipidura rufifrons uraniae (guamdawr.org), and the Guam Bridled White-eye Zosterops conspicillatus conspicillatus (fws.gov), a subspecies of the Bridled White-eye which has a second subspecies that survives in the Northern Mariana Islands.
Flying Fox (Andrew Isles) (IUCN
Red List) is also extinct.
Freshwater fish unique to Guam include an undescribed freshwater sleeper goby of the genus Eleotris that is a blind cave dweller (p. 6 of Univ. Guam pdf file) and an undescribed goby of the genus Stenogobius (p. 62 of guamdawr.org 5 MB pdf file). The Pencil Dottyback Lubbockichthys myersi (Native Fish Lab pdf file) and the Yellow-crowned Butterflyfish Chaetodon flavocoronatus (eol) are endemic marine fish.
Land snails restricted to Guam include Partula radiolata (ARKive), the extinct Partula salifana (Femorale), Quadrasiella mucronata (p. 13 of Bishop Museum pdf file), Lamprocystis misella (Hathi Trust), and the endemic genera Ladronellum (Internet Archive) and Himeroconcha (Internet Archive). Endemic insects include a katydid Salomona guamensis (OSF), a raspy cricket Niphetogryllacris marianae (p. 5 of Univ. Guam pdf file), a flat bark beetle Propalticus scriptitatus (4a on p. 17 of Bishop Museum 6 MB pdf file), a plant bug Peritropis guamensis (p. 7 of Bishop Museum 6 MB pdf file), a leafroller moth Alcina stenotes (Tortricid.net), and an extinct butterfly Neptis guamensis (BHL). Other endemic invertebrates include a centipede Mecistocephalus ocanus (Internet Archive), a shrimp Axiopsis pica (FLMNH), an amphipod Hadzia guamensis (p. 3 of CaveBiology.com pdf file), and several crabs: Dynomene guamensis (FLMNH), Dynomene kroppi (FLMNH), Labuanium navus (p. 10 of Raffles Museum 8 MB pdf file), Calappa karenae (Raffles Museum), and Olenothus uogi (FLMNH). The crab Conleyus defodio (FLMNH) is the sole species in the family Conleyidae.
Guam has about 11 species of vascular plants known from nowhere else (p. 4 of Univ. Guam pdf file) including Eugenia bryanii (flickr), Hedyotis megalantha (flickr), a pondweed Potamogeton marianensis (p. 71 of guamdawr.org 5 MB pdf file), Phyllanthus mariannensis (Pensoft) (flickr), an orchid Bulbophyllum guamense (JSTOR) (flickr), Psychotria malaspinae (JSTOR), Psychotria andersonii (p. 108 of Smithsonian pdf file), Elatostema stenophyllum (JSTOR), Dianella saffordiana (flickr), and the ferns Cyclosorus (or Christella) guamensis (eol) and Ceratopteris gaudichaudii (flickr).
Guam is a territory of the United States of America, part of the Marianas Tropical Dry Forests ecoregion (EoE), and is included in the Polynesia-Micronesia biodiversity hotspot (CI). For an overview of Guam's marine biodiversity see the special issue of Micronesica (Univ. Guam) and for a general overview of Guam's biodiversity see the "Guam Comprehensive Wildlife Conservation Strategy" (guamdawr.org 5 MB pdf file).