The Ark Files - Table Manners

What animals eat and how they eat it can be enough to turn your stomach.

No left-overs

Hyenas are living garbage disposal units. Although they are skilled hunters, killing animals as large as a wildebeest, they will also scavenge carcasses, even stealing them from lions. There's lots of competition out there on the savanna, so they have learned to eat quickly and their amazing digestive systems make sure they get every bit of goodness they can from the meal. The meat and most of the bones are digested completely and the other parts, like the hooves, horn, bone splinters and hair, are regurgitated in pellets. The waste material in these pellets is often matted together with grass, which the hyenas eat to help them get rid of these indigestible bits.

Koala cuisine

Everyone knows koalas eat gum leaves! However, they sometimes eat non-eucalypt leaves at well, including wattles, tea trees and paperbarks. Their favourite food, though, is definitely eucalyptus leaves but they can be very choosy and their preferences can vary with the season, region and "mood" of the tree. Under certain circumstances, eucalypts are believed to produce a defence compound to discourage creatures eating their leaves and this may put the koala off that tree or that type of leaf for a while. Only a few animals are able to eat eucalyptus leaves because they are full of toxic oils and phenol which would be fatal to humans.

Chewing it over

Most animals with hooves eat tough grass and leaves containing cellulose, a substance found in the walls of plant cells. Breaking down cellulose is hard work, so these animals have developed different ways of digesting their food such as specialised fermentation areas in their guts, large, flattened molar teeth, and jaws that grind from side to side.

Ruminants such as cows, sheep, goats, giraffes and camels, have a four-chambered stomach for cellulose fermentation. They can gobble up a lot of food in a short time and digest it later in safety. After a quick chew, food passes into the first stomach chamber or "rumen" where it is partially broken down. Cellulose is formed into small balls called "cud" which are then regurgitated and chewed again. After this it passes through the other stomach chambers for further digestion.

Some animals such as horses, rhinos and tapirs, have only a single-chambered stomach for protein and sugar digestion and an enlarged "caecum" where microorganisms split and ferment cellulose. Their food is chewed only once. It's not as efficient as the ruminant method of digesting cellulose as you can see by the undigested plant material in their droppings.

Egg heads

Have you ever watched a snake eating? The food is often bigger than the snake's head but it is able to swallow it whole because the two halves of the lower jaw are not solid and fused together like ours, but are joined at the front by an elastic ligament. This helps the jaws to stretch very wide apart and allows different bones to move separately. African egg-eating snakes eat large birds' eggs. Thick folds of gum tissue act like suction cups on the hard eggshell and help the snake draw the egg into its mouth. Once the egg is swallowed, the snake bends its neck quickly, pushing the egg against a series of sharp, downward pointing spines that pierce the shell. These spines are a modified part of the snake's backbone. The snake then swallows the egg&'s contents and other blunt vertebrae further down its throat crush the empty shell and form it into a small bundle that can be regurgitated.

Tiddly toddy

Palm civets like a mixed diet. While almost any type of fruit is high on their menu, they will also eat rodents, birds, snails and scorpions. The common palm civet has a particular liking for fermented palm sap. (This sap is tapped from the tree in bamboo tubes and made into a sweet liquor called toddy, popular all over South East Asia.) A little too much toddy has the same effect on the civet as it does on humans - they get drunk, and have been known to fall out of trees! That's why they are nicknamed "toddy cats".

Toddy cats are also fond of coffee cherries (fruit of the coffee bush) and are often found dining in coffee plantations. However, they are not considered pests by plantation owners, in fact quite the opposite. The civets only digest the outer fruit pulp so the valuable coffee beans (the seeds) pass unharmed through their digestive systems. The beans are easily collected because the civets usually have regular toilet spots. At some plantations, workers collect these beans separately so they can be roasted and then brewed into "kopi luwak"- civet coffee. This is reputedly the Rolls Royce of coffees because palm civets eat only the most perfectly ripe coffee cherries. One report says that roasted kopi luwak beans sell for $175 a pound in gourmet coffee shops in the USA!