Vertebrate pests are a major environmental and economic threat in New Zealand. One of the species that has high potential threat is possum (Trichosurus vulpecula). The direct environmental impacts of possum are in defoliation of native flora and predation of native birds (Montague 2000). The direct economic impact is a result of their role as vectors of bovine tuberculosis (Tb). New Zealand spends $70m annually on possum control, largely undertaken by the Animal Health Board (for Tb management), Regional Councils (for plant, animal and environmental protection) and Department of Conservation (for environmental protection)... In this report, two low-cost commercially-available thermal sensors are evaluated for imaging a brushtailed possum in different environmental conditions, and at increasing distances, with the goal of gathering practical information on the utility of such sensors for handheld field use. The sensors were also considered for use in lowlevel survey from unmanned aircraft.