Extinction of Birds on Guam
Introduction:
Guam is a 541 square kilometer
island in the western South Pacific,
equidistant from Japan to the north,
the Philippines to the west, and New
Guinea to the south. In the 1960s
wildlife authorities noticed that birds
were entirely absent from the southern
one-third of the island; by the 1970s
birds were missing from two-thirds of
the island; and by 1985 most birds
were in isolated pockets at the northern
tip of the island, or completely
gone. The accidentally introduced
brown tree snake, Boiga irregularis, was responsible not only for the
extinction of the birds but also the
decimation of the island’s lizards,
mammals, and small domestic animals.
By October 1996 only three of
Guam’s twelve native forest bird
species still survived in the wild, and
most forests of Guam are empty of
bird life. Two of the three native bat
species have also vanished in the last
few years.
Thomas Fritts is a research
biologist and chief of the Biological
Survey Program with the U.S. Geological
Survey. A lifelong student of
reptiles, he received a Ph.D. from the
University of Kansas with a specialty
in tropical herpetology. In a recent
paper in BioScience he explained the
effects of the brown tree snake on the
wildlife of Guam. We spoke with Dr.
Fritts about how the brown tree snake
arrived on Guam and its effects on the
wildlife there.
