Impact of invasive exotic animals on native reptiles and amphibians -- Brown tree snake

One reptilian invader of note is the brown tree snake (Boiga irregularis). Originally native to the New Guinea area, the brown tree snake was introduced to Guam, previously a snake-free island, around 1950 in a shipment of military cargo. In the absence of natural enemies and an abundance of prey, the brown tree snake spread throughout the island, reaching population densities that probably exceeded 100 snakes/hectare. Following the loss of native forest birds and drastic declines in the abundance of other vertebrates, including reptiles, brown tree snake populations fell to about 20-50 snakes/hectare. The coincidence of the arrival and proliferation of brown tree snakes on Guam and the loss of most of the island's indigenous forest vertebrates strongly support the snake's predatory role in the extirpation of many birds (Fritts and Rodda, 1995). In addition to concerns about native species, brown tree snakes also disrupt electrical power when they short out electrical systems, pose human health risks due to their venomous nature, and prey on domesticated animals. The herpetofauna of other states, including Hawaii and Florida, would be at great risk if the brown tree snake is intentionally or accidentally introduced.

SOURCES

• Fritts, T. H. and G. H. Rodda. 1995. Invasions of the brown tree snake. Pages 454-456 in Laroe, E. T., G. S. Farris, C. E. Puckett, P. D. Doran, and M. J. Mac, editors. Our living resources: a report to the nation on the distribution, abundance, and health of U.S. plants, animals, and ecosystems. U.S. Department of the Interior, National Biological Service, Washington, D.C. 530 p.