Watching Nocturnal Animals by Infra-Red Radiation

Abstract
Most nocturnal vertebrates cannot be watched during the greater part of their normal activities and successful photographs are often a matter of chance. By means of infra-red radiation and a special telescope it is now possible to make continuous observations on nocturnal spp. which generally have poor sensitivity to light of the longer wavelengths. This technique has been successfully used to study and photograph the brown rat (Rattus norvegicus).