Development of artificial bait for brown treesnake suppression

Abstract

The brown treesnake (Boiga irregularis) was accidentally introduced to Guam in the 1940s from the Admiralty Islands. A native of Australia, Papua New Guinea, and the Solomon Islands, the brown treesnake (BTS) continues to threaten the economy and ecology of Guam and is currently the subject of a cooperative program to control snake populations on the island and prevent its spread throughout the Pacific Rim. Delivery of toxic baits is a primary component of population suppression efforts. While many food items tested as baits for toxicant delivery provide relevant food prey cues leading to investigatory behaviors in BTS, only a few items tested in the past two decades have adequately promoted reliable consumption. Chief among them is the dead neonatal mouse (DNM). A series of chemical and bioassays were performed to identify materials with similar sensory qualities as DNM. Among the many items tested in a series of field experiments with free-ranging BTS in Guam, a processed meat product treated with an artificial mouse fat mixture was found to be removed from bait stations at rates greater than previously tested DNM substitutes and approaching removal rates of DNM. Furthermore, the test baits demonstrated excellent