Stefano Unterthiner from Italy observed two Svalbard reindeer battling for access to females, in a photo that won top prize in the Behavior: Mammals category.
We'll give you a hint: It lives underwater, but it doesn't swim. At least, not as an adult.
Winning shots from the Capturing Ecology competition highlight the complex relationships that shape ecosystems.
Astronomers, ecologists, and other scientists from around the world submitted mind-bending images representing their fields.
From secret mushroom worlds to extreme close-ups of cell motion, these photographs represent how, in science, things often aren't what they seem on the surface.
From Moon-gazing rattlesnakes to caterpillars with bizarre headgear—this year's winning photos will surely take your breath away.
Travel the universe from your seat with our picks from the annual ZWO Astronomy Photographer of the Year competition.
