David Attenborough looks at how mammals dominate the planet through having warm blood and caring for their young, including Weddell seals, caribou and humpback whales.
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, and slow-motion cameras reveal how a mother rufous sengi exhausts a chasing lizard. A gyroscopically stabilised camera moves alongside migrating caribou, and a diving team swim among the planet's biggest fight as male humpback whales battle for a female.
Timings (where shown) are from the start of the programme in hours and minutes
The Weddell seal must teach its newborn to live in the Antarctic. Also, the sengi creates pathways to help catch and escape prey and the aye-aye can only use its hearing when hunting in the dark.
Barren land forces eight million reindeer to move north, finding food as they travel. The fruit bats, however, take to the sky, where they can fly up to a 1000km in a few nights.
A wounded hyena calls to her clan to help her challenge a pride of lions, and families of polar bears fight each other for food.
Strength in Numbers
There's some sibling rivalry when the coatis go hunting for the first time, whilst the meerkats are more organised and disciplined.
The Female of the Species
An inexperienced elephant mother must learn quickly so she can protect her young and the female humpback whale makes her presence known when looking for a mate.
Life on Location - The Heat Run
The team attempt to film the humpback whale's mating contest; this requires local knowledge, hours on the water and a big slice of luck.
Role Contributor Narrator David Attenborough Executive Producer Michael Gunton Producer Ted Oakes