The Risk to Hawai'i from Snakes

Abstract

We assessed the risk to Hawai'i's native species and human quality of life posed by the introduction of alien snake species. An examination of Hawai'i Department of Agriculture records from 1990 to 2000 indicated hundreds of credible snake sightings in the state, mostly of free-roaming animals that were not recovered. These snakes arrived primarily through smuggling of pet animals, but some snakes are accidentally introduced as cargo stowaways. Most recovered specimens are of species potentially capable of inflicting substantial harm to native birds and the poultry industry if they become established. Some may affect native freshwater fish. An analysis of the frequency with which snakes are smuggled into the state, the suitability of the local environment to snake welfare, and the ecological threats posed by recovered snake species leads us to conclude that snakes pose a continuing high risk to Hawai'i. Mitigation of this threat can only be achieved by altering the human behavior leading to their widespread introduction. There are a variety of reasons why this behavior has not been successfully curtailed heretofore, and we propose a series of measures that should reduce the rate of snake introduction into Hawai'i. Failure to achieve this reduction will make successful establishment of ecologically dangerous snakes in Hawai'i a virtual certainty.