Gobi jerboa
The gobi jerboa (Galemys gobio), also known as the Mongolian giant rat, is a species of rodent in the family Muridae found in Mongolia and China. They are sometimes called “Mongolian hamsters”. Their name derives from the fact that they resemble the Chinese water deer, also called the “gobi”, due to their similar size and coloration.
The gobi jerboas live in rocky areas where there is plenty of food, such as grasses, herbs, shrubs, seeds, roots, bulbs, tubers, fruits, and berries. They eat mostly plants. They dig burrows into the ground and use those tunnels to sleep during the day. They tend to avoid people, preferring to remain hidden underground.
They are active throughout most of the year, except during cold weather, when they hibernate underground. During the winter months, their diet consists mainly of roots and stems. In summertime, they feed on leaves, flowers, buds, fruit, and seeds. As their name suggests, they spend much of their lives digging and tunneling in search of food.
Gobi jerbos are nocturnal animals; however, they do come out during daylight hours to drink water. They are capable swimmers and can even dive underwater to escape predators.
Gobi jerboas mate in spring and give birth to one litter per year. Females usually bear litters of four to six young, though litters of up to ten young have been recorded. Each female gives birth to two or three litters each year. After weaning, the pups begin to explore the world around them. Pups born later in the season grow larger than earlier born pups.
This animal is listed as Least Concern by the IUCN Red List because it is widespread across its range and appears to be adaptable. However, some populations are declining, possibly due to habitat loss caused by overgrazing and mining.
Range
The Gobi jerboa is a small rodent species within the genus Dipodomys. This species is native to Central Asia. Its distribution includes Mongolia, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan and western China (including Xinjiang), where it lives in deserts, steppes, grasslands and rocky mountains. It inhabits dry habitats such as sandy desert dunes, salt flats, saline marshes, shrub lands, grasslands, stony slopes, semi-deserts and xeric scrubland.
The Gobi jerboas are omnivorous; they eat seeds, insects, plants, fungi, berries and roots. They use their long claws to dig burrows and nests in loose soil, sand and gravel. They hibernate during winter. Their gestation period lasts about 30 days, and females give birth to one litter per year.
They reach sexual maturity at 12 months old, and live up to seven years in captivity.
Habitat
The Gobi jerboa is one of five species of jerboas native to Asia. They are small mammals about the size of a house mouse, with long legs and tails, and short, rounded ears. Jerboas are named for the sound they make while grooming themselves; it sounds like “jerky”. This name is derived from the Old English word jerr meaning “to scratch.”
Jerboas are diurnal animals, spending much of the day outside in open areas such as deserts, grasslands, and prairies. In the wild, they prefer dry environments where vegetation is abundant, especially saltworts, ephedras, and desert shrubs. However, some populations exist near water sources.
These animals are solitary, living alone in underground tunnels called burrows. Burrows usually consist of several interconnected chambers, each large enough for a single animal. A typical tunnel is about 15 centimeters deep, 8–12 centimeters wide, and 20–60 centimeters long. Each chamber contains a nest consisting of a pile of dried leaves and twigs covered with a thin layer of soil. The nests are used to protect the animals during winter hibernation.
Diet
Jerboas eat many types of plant material including seeds, roots, tubular structures such as bulbs and corms, and insect larvae. They feed mainly at night, eating mostly seeds and rootlets. During the daytime, they rest and groom themselves.
In captivity, jerboas often consume artificial diets composed primarily of cereal grains, vegetables, fruit, milk products, and meat substitutes.
Breeding
Gobio jerboas reproduce between May and August every year, and can have up to three litters during this period. A single female gives birth to a litter of four to eight young, usually within about 12 days. The gestation period lasts from 30 to 60 days, depending on temperature and food availability. Females typically give birth to two litters each summer. Males do not participate in breeding activities.
The young are born naked and blind, and remain completely dependent upon their mothers for several months. They begin to walk at about 10 weeks old, and start eating solid foods at about 15 weeks old. Their eyes open at about 16 weeks old, and sexual maturity occurs at about 20 weeks old. After mating, females lay eggs in shallow burrows dug into sandy soil. In captivity, males mate with multiple females over a period of several months.
Physical attributes
The Gobi jerboa is very similar in appearance to the Allactaga sibericus. They are both small rodents found in deserts and grasslands in China, Mongolia, Pakistan, Afghanistan, Iran, Iraq, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan, India, Nepal, Bhutan, Bangladesh, Sri Lanka, Myanmar, Thailand, Laos, Cambodia, Vietnam, Malaysia, Indonesia, Papua New Guinea, Australia, and the southern part of Japan. In addition to being smaller, the Gobi jerboa is darker than the Allactaga sibirica, with a mostly dark brown coat, rather than the greyish buff coat of the latter species. Both species’ coats are long, reaching nearly half the length of the body; however, the Gobi jerboas’ tails are shorter and less bushy than those of the Allactagas. The Gobi jerboa’s ears are longer than those of the Allacataga sibirica. Their tails are generally thicker and heavier than those of the Allcataga sibirica and Allactaga balikuncii. The Gobi jerboa’s legs are much shorter than those of the Allcata gabriellae, and its feet are larger. The Gobi jerboa’s teeth are wider than those of the Allctaga sibirica; it has four incisors, one canine, three premolars, and three molars per side. As opposed to the Allcataga siberica, the Gobi jerba does not have a third maxillary tooth. The Gobi jerba’s eyes are large and round, whereas those of the Allcatagas are relatively small and oval. The Gobi jerboa has a lower number of chromosomes than the Allcatagas, having 2n 50, and therefore fewer genes. However, it has a higher percentage of heterozygous loci than the Allcatagases. The Gobi jerboa’s heart weighs about 0.2 grams, compared to the Allcatagas’ heart weight of 0.3–0.5 grams. The Gobi jerbao’s kidneys weigh about 10 times as much as those of the Allcatage sibirica.
