The 81 known species of gerbils are found in desert areas throughout Africa, parts of Europe, and across Asia and China. The Mongolian gerbil is the gerbil species most often kept as a pet. The Mongolian gerbil is also known by the names of Mongolian desert gerbil, clawed gerbil, and clawed jird, but its scientific name, Meriones unguiculatus is always the same. The Mongolian gerbil is native to the desert and semi-desert areas of Mongolia and northeastern China. Mongolian gerbils are social animals and live in family groups or related individuals. However, they are territorial and will attack an unrelated or unfamiliar gerbil that tries to enter their territory.
Wild gerbils are colored so that they blend into their desert habitat. The dense fur on their back is a golden sandy color and the fur on their belly is pale gray. Like a kangaroo, gerbils have long muscular hind legs that enable them to hop and leap quickly. Their front legs are shorter and are used to hold food and to dig. Gerbils measure about 9 inches in length, including their long, fur-covered tail, which helps them keep their balance when they sit up. This tail also helps them to leap and turn when pursued by a predator.
Gerbils were first available as pets in North America in 1964, and they have been increasingly popular as pets since then. Their inquisitive nature, calm demeanor, and clean habits have made them appealing to potential pet owners.
Gerbils are ideal small pets. They are cute, easy to care for, and practically odorless. Even though they are lively and agile, gerbils are docile, gentle pets. Unlike other small pets, such as hamsters, they are not timid and nervous. Brave and curious, instead of running away from something unknown, an alert and inquisitive gerbil will often advance and investigate.
One of the most interesting things to observe in gerbils' behavior is their curiosity. They are absolutely fearless; a finger extended into a cage is instantly observed and explored. They will run and hide if not used to your presence, but will soon come out to see what is going on.
Digging seems to be an instinctive need, for gerbils will spend hours scratching into the corner of their cage in a seemingly endless effort to dig out. This is quite a violent movement as it is rapid and vigorous, causing sawdust, food, bedding, babies, everything, to go flying. After a while it stops and the animal returns to normal activity. Digging is a frequent form of exercise occurring every 2 or 3 days.
Gnawing also seems to be a necessary activity. Any wood or plastic object will be chewed to pieces after a few weeks. If the cage wires are far enough apart, the animal will continually gnaw on the wire causing damage around their nose and head as they rub against the next wire. Loss of fur and a bloody nose are the net results. Many breeders place a block of hard wood in the cage to keep the animals busy gnawing on it, rather than the cage or food. Some animals need other things to do; an exercise wheel, runways or bridges keep them busy. Otherwise, the animals often chop up the food for bedding or floor litter, pulling it out of the holders and spreading it around. Baby gerbils will squeak when they are first born and up to weening. Adults will thump with their hind legs with a thump, thump, thump rhythm. Gerbils are nocturnal animals; they sleep all day and are most active at night.
The breeding period lasts all year and starts at 10 to 12 weeks of age. Litters are from 1 to 12, and take about 24 days to arrive. Immediately after the birth, the female is again in heat. This means that the female can be bred again at this time. Close to 60% of the females can be bred or drop a new litter 25 days after the first litter. Heat periods last about 4 days and occur approximately every 6 weeks. The female will continue to breed for almost 2 years.
Dominant females around 6 months old will often kill a new male introduced into the cage. For this reason, mating must be started early. Take 2 females for each male, the male being from a different litter. After weaning, hold the sexes separate and pair at 9 weeks. At this age they accept each other readily and get along just fine. However, at sexual maturity (age 10 to 12 weeks) if animals are mixed up or mated, they will occasionally fight to the death. The female is so selective of her mate at a later age that she very seldom accepts a male. If something happens to her first mate she may not breed, even though she will live with and not fight another male. Young males and females, 25 to a cage, weanlings, get along quite well for a while. Even then as they get older, individual aggressive fighters can be spotted and removed before they damage other animals. Injuries suffered in fighting tend to heal themselves once the fighters are removed to another cage. But often the gerbils, if not separated, will mutilate or kill one another.
Gerbils are slow breeders probably because of in-line, or closed colony, brother and sister mating carried to extremes. Outbreeding is the mating of unrelated stock, and is the best for maximum stock production. However, in this process the gerbil loses its genetic similarity. Inbreeding tends to develop greater similarities in the animals. Another main reason for failure to breed is excessive weight in the male. A fat male gets lazy and refuses to get involved in breeding. If the male looks like a cute little teddy bear, he is too heavy to breed. A lot of sunflower seeds can put on weight in a short time. Feeding low-fat commercial diet will hold the weight down well.
New babies are little pink balls. They look like bugs; no teeth, no furs, no ears, and eyes closed. At 5 days dark fur is observed. In 17 days teeth form, and ears form, and eyes open. They will eat solid food at 17 to 21 days. On the 24th or 25th day weening is necessary to make room for the next litter.
Once babies are born wait 3 weeks before cleaning the cage. Most deaths of newborn babies seem to be from the new mother's excitement or the mother packing the babies or moving them from one corner of the cage to the other, seemingly trying to hide them. Also, the burrowing or frantic digging into the corners often sends babies flying and buries them in the shavings, sawdust or bedding.
When a mother dies, is killed, escapes or abandons a litter, a litter may be foster-mothered by placing the babies in the care of another mother with a small litter or almost the same age.