The Ark Files - Fussy Eaters

Eating only one kind of food can be very convenient for animals. But being a fussy eater also results in some rather strange behaviour.

LIQUID DIET

One very specialised bat, the Vampire Bat, has a completely liquid diet - and a rather gruesome one at that. It drinks blood and only blood.

Sleeping mammals are the bats' victims and they are particularly partial to pigs, cows and even the odd human. Their front teeth are triangular and razor sharp, enabling them to quickly puncture skin. Once a small wound has been made, an anti-coagulant in the bats' saliva ensures that the blood continues to flow without forming a clot. With its meal thus sneakily prepared, the Vampire Bat then sits down and begins lapping at the blood.

LEAF THIS ONE ALONE

Woolly monkeys in the South American rainforests eat mainly leaves, sitting way up in the canopy and stuffing handfuls of them into their mouths. They must be careful, though, as the leaves on many of these trees are poisonous. The monkeys have to check each leaf before they eat it, smelling it and turning it over in search of signs of ageing. They select only the youngest leaves that have had the least amount of time to make poison, and reject the older, toxic ones.

Even so, the monkeys can't avoid taking in some poison and will eventually have to stop eating a particular type of leaf and try another tree whose leaves will have a slightly different type of poison. Their stomachs will tolerate these leaves until it is time, once more, to vary their tree-top menu.

SUCKED IN

Pangolins (African scaly anteaters) relish ants and termites which they gather up with the help of their extremely long and sticky tongues. The biggest Pangolin has a tongue that can reach as far as 40 centimetres! But how can the Pangolin fit such a lengthy tongue back in its mouth? When not in use the tongue is kept within a tube that reaches all the way down inside the animal's chest.

Once collected, the Pangolin swallows the ants and termites whole since it has no teeth and its jaws are so weak it cannot chew. But it makes up for this with a strong, muscular stomach which grinds up the ants and termites. Sometimes the animals swallow pebbles to help crush the food.

MORE BAMBOO? YES, PLEASE!

Giant Pandas are bears and, like all bears, have teeth quite capable of dealing with meat as well as plants. But instead of killing and ripping into their dinner, they prefer to feast on the shoots of bamboo plants. Since their digestive system is short like a meat eater's, much of the bamboo passes straight through. So to get enough nutrients they must eat lots and lots of food (up to 18 kilograms of bamboo a day) and spend up to 16 hours a day doing nothing but feeding. Large molar teeth and strong jaws are ideal for crushing the tough bamboo to extract the nutrients.

The Giant Panda does not need to hibernate in the winter as bamboo forests flourish throughout the year. This is just as well, as the energy-poor bamboo doesn't allow them to build up the large amounts of stored fat they need to keep them alive for such a long time.

KRILL ROUND-UP

At 30 metres long and weighing four times as much as the largest dinosaur, the Blue Whale could probably eat anything it wants to that would fit inside its mouth - which would be just about everything! But this particular whale dines exclusively on tiny sea animals - krill - which gather in huge herds in the sea.

To make a decent meal of these shrimp-like creatures, the whales don't need any teeth. Instead they filter the shrimp out with baleen, which hangs from the roof of their mouth in stiff sheets, feathered at the edges. Blue Whales, Right Whales and Humpback Whales all feed in this way.

The whale rounds up its meal by quietly approaching a large patch of krill and then diving below and spiralling upwards beneath them, blowing bubbles so the krill are herded close to the surface. Then it gulps a vast mouthful, partly closes its jaws and shoots out the water by pressing its tongue forward - the krill are caught in the sheets of baleen and can then be swallowed.