Guam, brown treesnake and non-target species takes of baits based on the presence of ants, 2020-2024

Toxic baiting is a primary method used to suppress many invasive species, including the brown treesnake (Boiga irregularis) in Guam. Based on limited alternative approaches to assess tool efficacy in snake removal, bait take is often used as a proxy for snake removal, despite evidence that non-targets remove baits in a spatially heterogeneous manner. Using photographic validation, we tested take rates of mouse, chick, and rat baits by brown treesnakes and non-targets including invertebrates at three sites undergoing snake removal for vertebrate conservation. We also identified the ant species present on baits for a subset of baits.