BBC 'Life' - Mammals

21/10/2009 12:25:04 Mammals dominate our planet and can be found in every habitat, except the very deepest ocean. Their success lies in more than just the unique physical traits of fat, fur, and warm blood. What makes the mammals stand out is the care they lavish on their young.

Weddel seal - Only animal that can survive Antarctic ice winter
Only one mammal can survive the punishing temperatures on the Antarctic ice during winter - a Weddell seal. As the spring comes, a lone seal gives birth to a single pup and it manages to survive.

Polar bears feeding on whale carcass
At the other end of the globe, polar bears also cope in the freezing cold. Female polar bears and their cubs face

Polar bears feeding on a Bowhead whale carcass in Alaska. Copyright Ted Oakes.

starvation during the summer and autumn when the sea ice - their hunting platform - melts beneath them. They are forced onto land, where they can do no more than scavenge for scraps. Faced with the unexpected bounty of a huge bowhead whale carcass lying on the beach, polar bears have to suppress their instincts to fight or run and actually join in with other polar bears to share in this feast.

Super quick
Having warm-blood means that mammals are much faster than their reptilian predators. When filmed in super-slow motion, the rufous sengi - a small gerbil-like creature - demonstrates the extreme speed and agility of mammals. The sengi builds and maintains an intricate network of trails in its territory, the details of which it fortunately remembers when being chased by a hungry monitor lizard.

10 million fruit bats
Being warm-blooded also gives giant straw-coloured fruit bats the endurance to migrate from all over the Congo to a mega-roost that scientists have only recently discovered in Zambia. Over ten million giant bats gather to spend a few weeks at Kasanka. At night, they stream off to feed on fruit, devouring over a billion pieces in a few weeks. 

Being able to track the camera alongside animals as they move gives a potentially wonderful sense of being right with them. The problem is that animals have a tendency to head off where they want to go rather than where we have set up our cameras! The solution was to devise a much more flexible way of getting a camera to them that was both smooth and easy to position. The answer for tracking on ground was the invention of ‘yogi-cam'. This uses the same ‘Heli-gimbal' camera system used so spectacularly in helicopters to get amazing eye-in-the-sky views of landscapes and animals from above, but instead it is rigged to a 4x4 vehicle. The camera is gyroscopically stabilised to smooth out any vibrations and it's then attached to a counterbalanced arm that smoothes out the big bumps. The result means for the first time the camera appears to be running shoulder to shoulder with caribou across the tundra and to be amongst an elephant heard as it marches across the savannah, all without disturbing them. Although helicopters can get amazing results from the air there are occasions when they are impossible to use - when flying very low through trees or very slowly or amongst flocks of flying animals. The amazing migration of straw coloured fruit bats in Zambia was a perfect opportunity fly amongst a flock. So a powered balloon was used to fly with them at bat speed. The bats completely ignored the slow moving and very quiet balloon as it flew alongside them - something they would have never have done with a helicopter!

Meerkat teachers
Meerkats have taken social living to a high level and live in truly co-operative family groups. It has recently been discovered that some adults will tutor novice youngsters in finding and dealing with difficult prey.

Teaching their young is a key mammalian talent.

Granny elephant to the rescue
And nowhere is this more apparent than in elephants. An old matriarch can have 70 years' worth of learning which she shares with her herd. A newborn elephant gets stuck in the mud under her inexperienced mother, who simply makes matters worse. It is her grandmother who comes to the rescue.

Humpback whale mating
In Tonga, humpback whales gather to breed and, in another TV first, Life captures the complete sequence of the 'heat run'. Females must make sure they secure the strongest and fittest male to mate with, so they incite a battle. She releases a scent into the water and then makes her presence known by slapping her pectoral fins down hard on the surface. The males respond and begin to gather. She moves off ahead and the following males fight for prime position. These massive creatures slash their tails, collide and force each other under water in their efforts to be the winning male.

It was filmed from the air, surface and underwater to give the full picture. This was a dangerous assignment for underwater cameraman Roger Munns. A team of free-divers placed themselves in position to film a fast moving train of fighting whales, each weighing up to 40 tonnes.

For the first three weeks all they found was an inquisitive and playful calf. When the heat run began, Roger placed himself in a precarious position to capture the action. Holding his breath deep underwater, he filmed seven male whales as they battled for position behind a female. Roger was confronted by the most remarkable underwater experience of his life as the males charged past. It was like "standing in a stream of traffic", he said.