The New Way to Track Animals Is Tagless

There's good news for scientists who study animals that are too small to carry a GPS monitor, or that spit ID tags back out through their arms. A setup using an off-the-shelf camera can precisely capture an animal's path in three dimensions--without anyone touching the animal. Emmanuel de Margerie, who studies animal behavior at the University of Rennes 1 in France, says there are several reasons to seek new animal-tracking technologies. To put a GPS or other kind of tag on an animal, you