While flying, frigatebirds can sleep one half of their brain at a time, and northern elephant seals can nap for 10 or 15 minutes at a time during deep dives, for example.But chinstrap penguin ...

While flying, frigatebirds can sleep one half of their brain at a time, and northern elephant seals can nap for 10 or 15 minutes at a time during deep dives, for example.But chinstrap penguin ...

While flying, frigatebirds can sleep one half of their brain at a time, and northern elephant seals can nap for 10 or 15 minutes at a time during deep dives, for example.But chinstrap penguin ...

It's a challenge for all new parents: Getting enough sleep while keeping a close eye on their newborns. For some penguins, it means thousands of mini-catnaps a day, researchers discovered.Chinstrap ...