Brown Treesnake Project
Managing an invader hiding in plain sight
The brown treesnake is an invasive species that decimated many of Guam’s native vertebrate species. Under the leadership of the Pacific Island Ecosystems Research Center (Hawaii) and co-located with U.S. Fish and Wildlife Service at the Guam National Wildlife Refuge, the brown treesnake team works to prevent snakes spreading to other islands, develop and test tools for control efforts on Guam, and conduct research to inform resource managers so that they can restore native species.
Current USGS priorities with this species include:
Control and containment of the snake
Facilitating native species recovery goals
About the snake
The brown treesnake (Boiga irregularis) is a nocturnal, arboreal, and mildly venomous snake that is native to Papua New Guinea, Indonesia, the Solomon Islands, and Australia. It is a brown snake with a long, thin body and large eyes. Hatchlings are usually just over one foot long, and the average snake on Guam is 3–4 feet, but snakes over 7 feet in length are encountered occasionally.
Brown treesnakes are generalist predators that will eat almost all vertebrates that are small enough to ingest. They have shifting prey preferences as they grow in body size. Small snakes prefer to eat frogs, geckos, or other lizards, and large snakes continue to eat lizards but prefer birds and small mammals when they are available. They will readily eat carrion.
Its arrival and effects
Brown treesnakes were accidentally introduced to Guam from the Admiralty Islands probably soon after the end of World War II. After their introduction, they spread throughout the island and caused widespread ecological change.
Their introduction resulted in the extirpation of most of Guam’s native birds and likely contributed to declines of bats and lizards. In addition to causing species loss, they are responsible for millions of dollars of damage to the island’s power infrastructure and increased human health concerns from infant bites. They are expected to cause major economic and environmental harm if introduced to new locations, including the Hawaiian Islands.
Given the extensive effects of brown treesnakes on the local community and ecosystem, U.S. Geological Survey has worked closely with federal, state, territorial, and other partners to plan and conduct science that supports their improved management. Research has focused on development, testing, and validation of control tools; improving detection and population estimation; reducing the impact of snakes on Guam power infrastructure and native species recovery; and developing and maintaining an interagency Rapid Response Team.
The USGS Brown Treesnake Laboratory and Rapid Response Team
Route 3A Spur Road
GNWR Ritidian Unit
Yigo, Guam
Brown Treesnake reporting hotline: 1-671-777-HISS (4477)
Brown treesnake research
Brown Treesnake Rapid Response Team
Developing and evaluating a point-of-use environmental DNA test for rapid field detection of highly invasive brown treesnakes
Guam power lines and brown treesnakes are an electric mix
A citizen science program for brown treesnake removal and native species recovery at a National Historical Park in Guam
Invasive Species We Study: Brown Treesnake
The brown treesnake is an invasive species that decimated many of Guam’s native vertebrate species. Under the leadership of the Pacific Island Ecosystems Research Center (Hawaii) and co-located with U.S. Fish and Wildlife Service at the Guam National Wildlife Refuge, the brown treesnake team works to prevent snakes spreading to other islands, develop and test tools for control efforts on Guam, and conduct research to inform resource managers so that they can restore native species.
Current USGS priorities with this species include:
Control and containment of the snake
Facilitating native species recovery goals
About the snake
The brown treesnake (Boiga irregularis) is a nocturnal, arboreal, and mildly venomous snake that is native to Papua New Guinea, Indonesia, the Solomon Islands, and Australia. It is a brown snake with a long, thin body and large eyes. Hatchlings are usually just over one foot long, and the average snake on Guam is 3–4 feet, but snakes over 7 feet in length are encountered occasionally.
Brown treesnakes are generalist predators that will eat almost all vertebrates that are small enough to ingest. They have shifting prey preferences as they grow in body size. Small snakes prefer to eat frogs, geckos, or other lizards, and large snakes continue to eat lizards but prefer birds and small mammals when they are available. They will readily eat carrion.
Its arrival and effects
Brown treesnakes were accidentally introduced to Guam from the Admiralty Islands probably soon after the end of World War II. After their introduction, they spread throughout the island and caused widespread ecological change.
Their introduction resulted in the extirpation of most of Guam’s native birds and likely contributed to declines of bats and lizards. In addition to causing species loss, they are responsible for millions of dollars of damage to the island’s power infrastructure and increased human health concerns from infant bites. They are expected to cause major economic and environmental harm if introduced to new locations, including the Hawaiian Islands.
Given the extensive effects of brown treesnakes on the local community and ecosystem, U.S. Geological Survey has worked closely with federal, state, territorial, and other partners to plan and conduct science that supports their improved management. Research has focused on development, testing, and validation of control tools; improving detection and population estimation; reducing the impact of snakes on Guam power infrastructure and native species recovery; and developing and maintaining an interagency Rapid Response Team.
The USGS Brown Treesnake Laboratory and Rapid Response Team
Route 3A Spur Road
GNWR Ritidian Unit
Yigo, Guam
Brown Treesnake reporting hotline: 1-671-777-HISS (4477)
Brown treesnake research
Brown Treesnake Rapid Response Team
Developing and evaluating a point-of-use environmental DNA test for rapid field detection of highly invasive brown treesnakes
Guam power lines and brown treesnakes are an electric mix
A citizen science program for brown treesnake removal and native species recovery at a National Historical Park in Guam