Sunday, November 4, 2001		Nature

The ant-eater gobbles 140 ants in a minute
Nutan Shukla

THE ant-eater is a magnificent animal that feeds on small insects, specially on ants. The giant ant-eater has powerful forelimbs and tough, digging claws that can tear into the nests of ants. Colonies are found by smell. It has been proved by experiments that this mammal can detect an odour four-thousandths of the natural odour at an ant’s nest. Ant-eaters, after finding the nest, excavate it with their large claws, but feed only for a short time, probably no more than a minute, during which they eat about 140 ants. The most significant thing is that the digging does not destroy the nest and the cropping is well short of over-exploiting the resource. So, in order to gain a fair day’s food, the animal visits many different nests in its home range, taking a little from each.

The ants are extracted by the tongue, which can be 24 inches long. Muscles regulating the movement of the tongue are attached to the breastbone and can push and pull the tongue in and out a remarkable 150 times a minute. Huge amounts of thick saliva coat the tongue and trap the ants. In the mouth, they are scrunched first against the nobbly roof of the month and cheeks and then squeezed in the muscular stomach. The animal must visit a 100 or so nests to satisfy its daily nutritional requirement.

There are several species of ant-eaters, found in many countries. One such animal is echidna of Australia which is a proof of the fact that mammals have evolved from reptiles. Despite being a mammal it still has the reptilian habit of laying soft-shelled eggs.

To lay her single egg in the pouch on her abdomen, a female lies on her back and extends her genital area. The egg shell is covered in the sticky slime, and this may help hold it in the pouch as the mother moves around. After about 10 days, the young echidna cuts its way out of the shell with its egg tooth and a horny patch on the end of its snout. Although the mother has no nipples, the baby feeds on milk that seeps into her fur from patches on her abdomen. Not until it is seven weeks old do the infant’s spines begin to develop. At this stage, it leaves the pouch, but is suckled for several months more and stays with its mother until about a year old.

Apart from the echidnas -of which there are two species, the Australian short-beaked echidna and the long-nosed echidna of New Guinea -the only other mammal that lays eggs is the Australian duck-billed platypus. The platypus, unlike the echidnas, has no pouch.

Also known as the spiny ant-eater, the back of echidna has sharp quills, which protect it from predators, giving it an appearance of a porcupine. It is a very shy animal. When disturbed, it digs itself into the earth within a minute, leaving sharp, pointed spines protruding through the loosened soil. It will keep buried until it is sure that the danger has passed.

Armadillos of America and pangolin of old world tropics are two scaly ant-eaters that have heavy armour on their bodies. In the event of attack, instead of trying to run away from their predators, these slow-moving animals roll into a ball, presenting the attacker with an impenetrable surface of tough, bony plates or leathery scales. A pangolin clamps itself closed with its broad, muscular tail, and can not be forced open.

Another member of the group the silky ant-eater, a squirrel-sized inhabitant of South America, is also a slow-moving creature that spends most of its days asleep in trees. If threatened by owls or harpy eagles, however, it holds its front paws in front of its face, displaying a single huge, curved claw on each paw. These claws are formidable weapons, capable of disemboweling a dog, and are certainly enough to discourage any predator.

This feature was published on October 28, 2001