What is the brown treesnake?

The brown treesnake is native to parts of Indonesia, the Solomon Islands, New Guinea, and Australia. The snake was first sighted on the island of Guam in the 1950s, probably after stowing away on cargo ships coming from New Guinea.

The snakes feed on lizards, birds, small mammals, and eggs. Since the treesnake has no natural predators or other controls on Guam, it multiplied rapidly and has virtually wiped out Guam’s native forest birds. The snakes also crawl on electrical lines and cause expensive power outages and electrical damage.

Brown treesnakes are mildly venomous. While the snakes are not considered dangerous to an adult human and no known deaths have occurred, young children can have reactions to tree snake bites.

While many techniques have been discussed to eliminate the brown treesnake in Guam, there is no known way to remove them entirely.  The best management strategy is to keep them from becoming established at new locations while continuing to do research on tools such as improved traps, fumigants, toxicants, and attractants; and on control options such as parasites and viruses.

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Date published: March 3, 2016

Brown Treesnake Rapid Response Team Deployed to Saipan after Two Snake Sightings

Two recent reports of two brown treesnakes on Saipan is prompting federal and state officials to urge citizens of Hawaii, Guam and other Pacific Islands to report any sightings of these invasive snakes to authorities. Snakes can be reported by calling (671) 777-HISS or (670) 28-SNAKE.

Date published: November 7, 1997

Snake Barrier On Rota is Important Step Toward Preventing Future Spread of Brown Tree Snake

A new way to prevent brown tree snakes from invading was unveiled yesterday by scientists working for the U.S. Department of the Interior’s U.S. Geological Survey and Ohio State University.

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A brown treesnake on frangipangi blossoms, by Bjorn Lardner, USGS.
2011 (approx.)

A brown treesnake crawls on some frangipangi blossoms in Guam. 

A brown treesnake in a Streptopelia bitorquata (island collared dove) nest. Yona, Guam, 2009.
2009 (approx.)

A brown treesnake in a Streptopelia bitorquata (island collared dove) nest. Yona, Guam, 2009. Photo by James Stanford, USGS.

A brown treesnake in a tree in Guam. Photo by Bob Reed, USGS, 2009.
2009 (approx.)

A brown treesnake in a tree in Guam. Photo by Bob Reed, USGS, 2009.

A brown treesnake in a tree in Guam. Photo by Bob Reed, USGS.
2009 (approx.)

This is an image of a brown treesnake in a tree in Guam, taken in 2009.