To answer some of these questions, and to find information that could stem population decline, National Geographic's Crittercam team joined forces with the Scripps Institution of Oceanography in southern California and the Manta Trust in the U.K. to attach cameras to wild mantas. 

Recent trials in the Revillagigedo Islands off central Mexico's Pacific coast marked the first time cameras were ever successfully attached to the animals, which can reach widths of up to 23 feet (7 meters). (Learn about new protections for manta rays in South America.)

We spoke with Scripps and Manta Trust researcher Joshua Stewart about the Crittercam project.  

The biggest technical challenge was finding a way to attach the cameras. Mantas are basically big flat disks. Unlike