Life, Mammals

S1, E3: Mammals dominate the planet. They do it through having warm blood and by the care they lavish on their young. Weeks of filming in the bitter Antarctic winter reveal how a mother Weddell seal wears her teeth down keeping open a hole in the ice so she can catch fish for her pup. A powered hot air balloon produces stunning images of millions of migrating bats as they converge on fruiting trees in Zambia. A gyroscopically stabilized camera moves alongside migrating caribou, and a diving team swim among the planet's biggest fight as male humpback whales battle for a female.