Camera-traps are remotely operated digital cameras triggered by motion and temperature. The commercial availability of affordable camera-traps since the early 2000s has revolutionised surveys and monitoring for many species of terrestrial mammals and birds. Camera-traps reduce the cost and effort required to detect wildlife compared to many traditional survey methods. This is particularly the case for remote areas and for nocturnal or otherwise elusive species. Modern camera-traps have evolved from basic film cameras with separate sensor units to robust digital models, designed to operate for months in all but the most extreme of climatic conditions, with trigger speeds of less than half a second and infrared flash to detect animals at night with minimal disturbance.
The Whitley Wildlife Conservation Trust (WWCT) first became involved with camera-trap surveys in 2005. Our first focal species were duiker antelopes in east African forests. Duikers are difficult to detect using most survey methods as they are shy and live in dense undergrowth. Dung piles are the most frequently encountered signs of forest antelope but in areas where multiple species co-exist it can be difficult to distinguish different antelopes just by looking at their dung. To test this in the Udzungwa Mountains of Tanzania we extracted DNA from dung collected in the field and used genetic sequences to verify the species. We found that neither identification in the field nor classifying dung piles based on pellet length provided accurate species identification. In contrast, camera-traps normally provide species-specific records, which also come with an accurate time and date.
WWCT and partners are currently using camera-traps to monitor or study wildlife populations in five different countries (Tanzania, Zimbabwe, Nigeria, Indonesia and UK). Important discoveries include new populations of Abbott’s duiker in the Udzungwa Mountains and servaline genet in the Uluguru Mountains, Tanzania; the first photographs and the first evidence for more than ten years that chimpanzees survive in the Omo Forest in Nigeria; and the first published photographs of Critically Endangered Aders’ duiker in the wild and confirmation that the largest remaining population of this species persists in northern coastal Kenya.