[4] In 2019, they became the second bird species to be reclassified by the International Union for the Conservation of Nature from Extinct in the Wild to Critically Endangered.

[7] Guam rail numbers fell drastically due to predation by invasive brown treesnakes.

Rothschild announced the specific name owstoni was "in honour of Mr. Alan Owston, of Yokohama, whose men have collected for me on the Marianne Islands.

Today, the rail is still found on Guam, though in captivity, with wild populations introduced on Rota and Cocos Islands.

[citation needed] The rails were once distributed widely across most habitats on the island, including mixed forest, savanna, grasslands, fern thickets, and agricultural areas.

Individuals observed by the Guam Division of Aquatic and Wildlife Resources were noted as preferring edge habitats that provided good cover.

It is a year-round ground nester and lays 2–4 eggs per clutch, and both parents share in the construction of a shallow nest of leaves and grass.

Guam rails are omnivorous foragers known to consume gastropods, insects, geckos, seeds, and vegetable matter.

[6] A large part of their diet consists of giant African snails, which were introduced to Guam around 1945 and became an easy food source for the birds.

Pieces of snail shell and coral have been found in the stomach and gizzard contents of Guam rails, suggesting use as grit.

The snake was likely passively introduced to the island as a stowaway in a military cargo ship after World War II.

[20] The snake is an opportunistic feeder, and on Guam has been observed to consume lizards, birds, eggs, insects, small mammals, and human trash.

[22] Invasive ungulates, including feral pigs and Philippine deer, destroy native forests and consequently, Guam rail habitat.

In addition to this, feral pigs wallowing and deer thinning the forest canopy contribute to the ecosystem's disruption.

Following the reintroduction of Guam rails at Andersen Air Force Base in 2006, feral cats killed all of the introduced birds within eight weeks.

Most native forest species, including the Guam rail, were virtually extinct when they were listed as threatened or endangered by the U.S.

[26] Beck was also a driving force in establishing Guam rail breeding programs in zoos throughout the mainland United States.

Fish & Wildlife Service have worked in collaboration with the Department of Defense and territorial government since the 1990s to control and mitigate the brown tree snake population and assist in efforts to reintroduce the rail and other bird species to Guam.

This will provide a model environment to develop strategies for future reintroductions, as well as expertise in rodent and snake detection, eradication, and bio-security measures.

[29] Ko'ko' Road Race Weekend is hosted every year on Guam to raise awareness of the species and conservation efforts.