What Are Camera Traps?
A camera trap is a device that is programmed to take a picture automatically, without a person clicking a button. Some scientists use cameras that take pictures when something moves in front of the camera, and others use cameras that only take pictures when something warm moves in front of the camera. Both of these types of cameras have sensors that detect changes and trigger the camera to take a photo. The motion sensor cameras detect a change in light, while the heat sensor cameras detect a change in heat, or infrared energy.
Cameras are usually run on batteries and store their pictures on an SD card, just like a regular camera. Scientists can program the cameras to take photos as often or as infrequently as they want, and some cameras can be programmed to take video, too!
How are camera traps used for science?
Just like any science, camera trap science is driven by the scientific method. Scientists develop a question and a hypothesis, design a study, and test it using data from their cameras. What makes camera traps special is the kinds of data they can collect: a single scientist can deploy dozens of cameras for a month or more at a time, allowing the scientist to collect many more observations than they could otherwise, both spatially (i.e. covering a bigger area) and temporally (i.e. covering a larger time span) than the scientist could on his/her own. Cameras are always alert and ready to collect data at any time of day and in any weather. Also, cameras are inanimate objects, so animals are often much more likely to act naturally around them than they would around a human observer.