Native Guamanian birds, seven are extinct, two are extinct in the wild (the Guam Rail, pictured left, and the Micronesian Kingfisher survive only in captivity), six are rare, and three are uncommon.
Distribution. The Mariana Fruit-dove is endemic to the Mariana Islands of Guam, Rota, Agiguan, Tinian and Saipan. The Mariana Fruit-dove was last seen on Guam in 1985. The only snake species native to Guam is a small harmless creature the size of an earthworm. On Guam, brown tree snakes found dense forests that were teeming with the birds and small lizards that are their natural foods. No enemies slowed their spread, and their numbers mushroomed. The snake populations moved steadily north at a rate of a mile per year from their southern landfall. The limestone and ravine forests of Guam have historically supported fourteen species of terrestrial birds. Two of these fourteen birds are endemic to Guam at the species level. Five bird species are endemic at the sub-species level. One of the endemic species is now extinct. Seven have been extirpated from the island. The loss of these birds is believed to be largely a result of habitat alteration and the effects of the introduced brown treesnake. Three species are still living in the wild. Three species are being held in captive breeding programs on Guam and zoos in the United States mainland. This snake became Guam's new top predator and ate its way through a buffet of the island's bird community. As a result, 10 of the island's 12 forest bird species are now extinct on Guam and the two surviving forest bird species remain only in tiny, localized populations where snakes are controlled. Guam's now silent forests currently hold about 13,000 snakes per square mile.  By the 1980s, 10 of 12 native bird species had been wiped out, and the starling and swiftlet are hanging on only in small areas protected by intense snake-trapping. “The lack of songbirds also make Guam’s forests eerily quiet during the day,” said Rice University scientists Haldre Rogers. (Photo: Isaac Chellman). By Rex Graham. U.S. and Guam scientist have begun a $600,000, four-year study of the devastating aftermath of bird extinctions on Guam due to the introduction of the brown tree snake on the island in the western Pacific Ocean. From Wikipedia, the free encyclopedia. This is a list of the bird species recorded in Guam. The avifauna of Guam include a total of ninety-five species, of which two are endemic, two have been introduced by humans and one is rare or accidental. Four species listed are extirpated in Guam and are not included in the species count. Six species are globally threatened. Introduced and accidental species are included in the total counts for Guam. The following tags have been used to highlight several categories. Not all species fall into one of these categories. Those that do not are commonly occurring native species. ( 1 A) Accidental-a species that rarely or accidentally occurs in Guam. Of 18 species of native Guamanian birds, seven are extinct, two are extinct in the wild (the Guam Rail, pictured left, and the Micronesian Kingfisher survive only in captivity), six are rare, and three are uncommon. On Guam, brown tree snakes found dense forests that were teeming with the birds and small lizards that are their natural foods. No enemies slowed their spread, and their numbers mushroomed. The snake populations moved steadily north at a rate of a mile per year from their southern landfall. The predominant population affected by the snake's introduction was that of native bird species such as the Mariana fruit dove, the Guam flycatcher, the rufous fantail and the Micronesian myzomela. The introduction of the brown tree snake into Guam has resulted in extinction of twelve native bird species in total. The Guam National Wildlife Refuge is attempting to prevent the extinction of additional bird species endangered by the snake. Fifty species ofpasserines have been introduced in Hawaii, and those birds make up most of theland birds present today. At least 30 species of birds native to Hawaii arefederally listed as threatened or endangered. One bird species native to Guam,the gray swiftlet, is established on Oahu (Moulton and Pimm 1986). Of the 14reptile species present in Hawaii (all introduced), 8 are known as native orintroduced species on Guam. Many of these introduced species are locallyabundant and attain high population levels in Hawaii To date, there has only been one report of a snake on Rota, though there is concern that the snake could spread to the island. Nearly 75% of t he native, resident bird species found in the CNMI are similar to those found on Guam before the snake's introduction. 
http://nationalzoo.si.edu/Animals/Birds/Facts/fact-guambirds.cfm http://www.guampedia.com/a-native-forest-birds-of-guam/ http://www.livescience.com/7638-guam-birds-forest-survive.html https://birdsnews.com/2013/891/ https://en.wikipedia.org/wiki/List_of_birds_of_Guam http://nationalzoo.si.edu/Animals/Birds/Facts/fact-guambirds.cfm https://en.wikipedia.org/wiki/Brown_tree_snake http://ftp.ma.utexas.edu/users/davis/375/LECTURES/L24/snake3.pdf http://depts.washington.edu/rabep/birds.html
what are the native bird species of Guam?