Skip to main content

Brown Tree Snake

Brown tree snake

The brown tree snake (Boiga irregularis) has caused major ecological and economic damage in Guam, the largest of the Mariana Islands. The snake is native to New Guinea and northern Australia . It has also been introduced to some Pacific islands in addition to Guam.

Brown tree snakes in their natural habitat range from 36 ft (0.91.8 m) in length. Some snakes in Guam are more than 10 ft (3 m) long. The snake's head is bigger than its neck, and its coloring varies with its habitat. In Guam, the snake's brown-and-olive-green pattern blends in with foliage.

The tree snake was accidentally brought to Guam by cargo ships during the years between the end of World War II (1945) through 1952. On Guam, there were no population controls such as predators that eat snakes. As a result, the snake population boomed. During the late 1990s, there were close to 13,000 snakes per square mile in some areas.

The snake's diet includes birds, and the United States Geographical Survey (USGS) said that the brown tree snake "virtually wiped out" 12 of Guam's native forest birds (three of which are now extinct). Furthermore, snakes crawling on electrical lines caused more than 1,200 power outages from 1978 through 1998.

The USGS and other agencies were working to contain snakes on Guam and stop their spread to Hawaii and other islands.

[Liz Swain ]

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Brown Tree Snake." Environmental Encyclopedia. . 20 Apr. 2019 <>.

"Brown Tree Snake." Environmental Encyclopedia. . (April 20, 2019).

"Brown Tree Snake." Environmental Encyclopedia. . Retrieved April 20, 2019 from

Learn more about citation styles

Citation styles gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, cannot guarantee each citation it generates. Therefore, it’s best to use citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

The Chicago Manual of Style

American Psychological Association

  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.