National Geographic explorer and wildlife filmmaker Bertie Gregory gets up close and personal with the 'Grizzly Bear' of the sea... the leopard seal. Learn how these gentoo penguins catch their breakfast whilst avoiding this hungry predator. Watch Secrets of the Penguins on National Geographic WILD UK. Also streaming on Disney | National Geographic UK

Gentoo penguins are the fastest swimming penguins in the world 🐧 💨 They're also highly intelligent. Watch as they swim together to evade tough predators like this leopard seal. National Geographic Explorer Bertie Gregory spent two years discovering the secret behaviours, surprising intelligence and close-knit societies of penguins from Antarctica to the Galápagos. Much of what he discovered has never been filmed before. Watch Secrets of the Penguins this Earth Day. Tuesday April 22nd from 7pm,