Night images can often be blurry and lacking in sharp focus, but still hold a viewer's attention.
Many of the cameras were attached to trees, but didn't stay put. Others didn't survive their encounters with curious, hungry or aggressive wildlife - with some getting chewed on, tossed about or destroyed.
Alexandra Swanson, a researcher, suspects that the cameras carried a human odor, which made some animals more aware of them than others, leading them to be inspected or scent-marked.