2012 Annual Report 1a.Objectives (from AD-416): The brown tree snake is a harmful invasive species that was accidentally introduced to Guam by the military in the 1950’s. Snake control measures include the use of baited traps. The most effective known bait is the pelt from a neonatal mouse. This bait material is expensive, inconvenient and short-lived. The objective is to identify an inexpensive, easily prepared and readily available agricultural animal by-product that will serve as an effective substitute for mice pelts. 1b.Approach (from AD-416): The scientist will work with operators of slaughterhouses, hatcheries, rendering plants, hide processing facilities and fur farms to identify by-product materials likely to serve as snake attractants. He will acquire these materials and perform processing steps necessary to stabilize the materials and make them suitable for the production of bait cubes. Since the stabilization of the experimental bait material may impact its effectiveness, multiple stabilization techniques will be explored, including freezing, various methods of dehydration, and addition of humectants or preservatives. 3.Progress Report: The Brown Tree Snake is an invasive species causing significant ecological damage to the island of Guam. The most effective bait for these snakes identified by past research is the pelts from newly-born mice. ARS scientists at Wyndmoor, PA are collaborating with scientists at the National Wildlife Research Center to better understand the sensory cues that attract the Brown Tree Snake and design more effective baits for trapping it. ARS scientists supplied animal processing by-product materials that may serve as alternatives to mice pelts. Three types of material have been identified, obtained and processed for testing as experimental baits. These materials included the skin from both early and late stage fetal pigs, and culled hatchery chicks. These materials have been used to complete laboratory-based studies on their composition and indirectly on their attractiveness to the snakes. These studies identified skin from late stage fetal pigs as the most promising candidate material. ARS scientists have now prepared larger amounts of this material to be used in upcoming field-testing in Guam.