USING THERMAL IMAGERY IN THE AERIAL SURVEY OF ANIMALS

We investigated the use of aerial thermal imagery to survey animals in southwest Florida. Thermal signatures, in the 3- to 5-micron spectral range, of deer (Odocoileus virginianus) were recorded on video tape d uring flights along transects flown at 180-200 m altitude and at 74-93 km per hour. Our thermal imagery survey counted 42% more deer when co mpared with standard visual aerial survey methods. Using thermal image ry we successfully located radiocollared panthers (Puma concolor coryl ). Previous studies using imagery in the 8- to 14-micron spectral rang e experienced difficulties differentiating objects of small thermal co ntrast. We found the detectability of thermal contrast (Delta t) betwe en biological objects and their background was sufficient to permit sp ecies identification. These findings suggest that the use of 3- to 5-m icron thermal imagery can be employed successfully to locate and count animals.