Forest Preserve District of Cook County, Illinois
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Guinea Pigs and Hamsters
Nature Bulletin No. 747   March 14, 1964
Forest Preserve District of Cook County
Seymour Simon, President
David H. Thompson, Senior Naturalist

Many of us share our homes and family life with four-footed, warm- blooded pets. Dogs and Cats are most common but, occasionally, rabbits, rats or mice of various domesticated races are house pets. This select list also includes the guinea pig and a fairly recent addition, the hamster, which has become very popular in the United States.

The Syrian or Golden Hamster has come to be known as "The hamster" although many other wild species and varieties of these rodents are found in Europe and Asia. Because of their habit of hoarding food they get the name "hamster" which, in German, means a selfish or greedy person.

Somewhat smaller than a rat, the golden hamster is a fat chubby little animal with thick, soft, golden brown fur, short legs and a little bobbed tail. It is active only at night. A pair of large cheek pouches are used to carry food to its burrow which is a deep network of tunnels. It includes a grass-lined nest chamber and storerooms that may contain as much as a bushel of wheat or other grain. In its native Syria these food caches often are robbed for human food.

The naked, pink, blind young are born in litters of seven or more. At two weeks of age their eyes are open, they are completely furred, and are beginning to forage for themselves. In another week they forsake their mother and each digs a burrow of its own. Other litters follow at monthly intervals. Young females can start bearing young at six weeks. Two years is old age. Because of the hamster's high rate of reproduction it is a pest in agricultural lands where it is native.

In 1930 a man from the Hebrew University of Jerusalem captured a litter of young from which a male and two females survived in captivity. This Adam and his two Eves were the ancestors of all the golden hamsters now in homes, pet shops and laboratories. The first ones were brought to the United States in 1938.

As a pet, the hamster is clean and reasonably gentle. Adults fight if caged together and sometimes nip a finger if handled roughly. However, there is no danger from rabies since they are reared in captivity.

The Guinea Pig grunts but it is not a pig. It does not come from Guinea in Africa but from South America. From there, the Dutch and English slave traders (nicknamed Guineamen) brought it to Europe in the 16th Century. Its wild ancestor, the cavy, belongs to a group of about twenty species in South America. One of these, the capybara, reaches the weight of a hundred pounds and is the world' s largest living rodent. The Inca Indians of Peru domesticated the guinea pig and used it for food long before the discovery of America.

The guinea pig is a chunky, one-pound animal with a large head, short legs, and no tail at all. It walks flat-footed like a man or a bear. The fur of different breeds may be long or short, silky or coarse, smooth or in odd whorls -- with a bewildering array of colors and color patterns. They are widely used in the study of heredity.

Females give birth to four or more young two months after mating. Well developed from the first, with eyes open and a coat of fur, the infants can scamper within a few hours and begin to nibble greens next day. They mature in a few months and can live to be eight years old. Friendly and harmless, they grunt when hungry and converse in musical whistles.

The guinea pig is import ant in medicine where they are used for testing the potency of vaccines, serums, antitoxins and the virulence of disease germs. In research laboratories it has been partially replaced by the hamster.

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