Crocodile by Camera Trap

Photograph by Michael Nichols

A remotely operated camera trap captures the tail end of a crocodile slinking to its den in Zakouma National Park, Chad. Triggered by infrared sensors tripped by the movement of a passing animal, camera traps have evolved from the trip-wire photography George Shiras pioneered in the late 1880s to high-tech digital traps with greater storage and memory capacity.