IT’S MANATEE TIME!

Filming the sea cow, or manatee, around the warm Florida springs proved a problem – because the inquisitive, docile creatures were just so darn friendly. ‘Manatees sense the world through their long whiskers, so they wanted to come right up and nuzzle,’ says assistant producer Sarah Whalley. ‘They chewed on our hair and even on the airpipes of our breathing apparatus. But they’re a protected species and we weren’t allowed to touch them, not even to push them away. Usually you wish you could get closer to wildlife when filming, but this time we were trying to get further away!’

At the other extreme, the team watched polar bears hunting beluga whales in Canada’s Hudson Bay. In the summer, when the whales are calving, they’ll swim into the shallows to rub their bellies on the shingle. The bears wait for them on the rocks above, but they have to time their pounce to perfection – the belugas can turn tail in an instant.

Some animals rely on other species to chase away their predators. The prairie dog, or gopher, is vulnerable to attack from the American badger, which snatches infants from its burrows. But burrowing owls hate the badgers too. To protect their chicks on the ground, the owls divebomb the badgers, making the owls and gophers unlikely but effective allies.

One creature that knows how to maximise its feeding opportunities is the North American black bear. At low spring tides it will venture from the forests on the West Coast to the vast boulder fields revealed by the retreating water where a feast of eels and shellfish awaits – all the bear has to do is flip over the boulders.

In winter manatees are drawn to the waters around Florida’s hot springs. Inset: in the Rockies, a male calliope hummingbird imitates an alpine flower with his colourful throat feathers to attract a female

On America’s Great Plains, a burrowing owl chases away a badger – much to the relief of the local gopher population, which badgers prey on

In many of North America’s rivers in spring, the river chub can be seen building impressive pebble mounds to attract a mate. There can be 7,000 pebbles in a mound – and the little fish positions them all with his mouth!