Potential Economic Damage from Introduction of Brown Tree Snakes, Boiga irregularis (Reptilia: Colubridae), to the Islands of Hawai‘i

The Brown Tree Snake (Boiga irregularis) has caused ecological and economic damage to Guam, and the snake has the potential to colonize other islands in the Pacific Ocean. This study quantifies the potential economic damage if the snake were translocated, established in the state of Hawai‘i, and causing damage at levels similar to those on Guam. Damages modeled included costs of medical treatments due to snakebites, snake-caused power outages, and decreased tourism resulting from effects of the snake. Damage caused by presence of the Brown Tree Snake on Guam was used as a guide to estimate potential economic damage to Hawai‘i from both medicaland power outage–related damage. To predict tourism impact, a survey was administered to Hawaiian tourists that identified tourist responses to potential effects of the Brown Tree Snake. These results were then used in an input-output model to predict damage to the state economy. Summing these damages resulted in an estimated total potential annual damage to Hawai‘i of between $593 million and $2.14 billion. This economic analysis provides a range of potential damages that policy makers can use in evaluation of future prevention and control programs. The Brown Tree Snake, Boiga irregularis (Merrem), arrived accidentally on Guam, an island in Micronesia, shortly after World War II, probably as a stowaway on U.S. military cargo ships from the New Guinea area (Fritts and Rodda 1998). Without any natural predators or parasites on Guam, and with an abundant prey base, the snakes increased in number dramatically. The Brown Tree Snake is a mildly venomous generalist predator with grooved, venom-conducting fangs at the rear of the maxillae (Fritts et al. 1994, Fritts and Rodda 1998). It is abundant in many habitats in both urban and rural areas and is successful in maintaining high densities near human populations (Fritts and Chiszar 1999, Engeman and Vice 2001). The Brown Tree Snake has caused human health concerns, power outages, and the extirpation of 10 of 13 native bird species on Guam (Savidge 1987, Fritts 1990, Fritts et al. 1994, Rodda et al. 1997, Fritts and Rodda 1998, Fritts and Chiszar 1999, Fritts and McCoid 1999, Fritts 2002). Although extensive research has been conducted on the biology and habitat of the snake and on efforts to control the movement of the snake (Fritts and Chiszar 1999, Rodda et al. 1999, Savarie and Bruggers 1999, Engeman and Vice 2001, Burnett et al. 2008), few studies have measured the economic damages (except for power outages) caused by the snake on Guam (Fritts 2002). The only study that estimated the potential damage of the snake in Hawai‘i (Burnett et al. 2008) utilized preliminary results from the study reported here. Islands are especially vulnerable to biological invasions because their human populations import large amounts of food and other Pacific Science (2010), vol. 64, no. 1:1–10 doi: 10.2984/64.1.001 : 2010 by University of Hawai‘i Press All rights reserved 1 This study was funded by the U.S. Fish and Wildlife Service and Office of Insular Affairs. Manuscript accepted 25 March 2009. 2 USDA/APHIS/WS, National Wildlife Research Center, 4101 LaPorte Avenue, Fort Collins, Colorado 80521-2154 (phone: 970-266-6150; fax: 970-266-6157). 3 Department of Accounting, Economics, and Finance, Texas A&M University-Commerce, Commerce, Texas 75428. 4 Corresponding author (e-mail: Stephanie.A.Shwiff@