The midday jird (Meriones meridianus), also called midday gerbil
Appearance
The midday jird (Meriones meridianus), also called midday gerbil, is one of the smallest: body length 9-13 cm, tail length up to 13.5 cm (usually equal to body length). The back colour is sandy-yellow, with an admixture of brownish-brown, less often greyish tones; rings around the eyes and cheeks are light; the belly is white; the tail is the same colour as the back, covered with rather long hair, which makes the tassel (broom) at its end stand out weaker than in other gerbils.
Meriones meridianus inhabits sandy deserts and "islands" of sands from Manych to Central China. The area of more or less continuous distribution in Russia covers the sands of the Tersko-Kumsky interfluve, in the north reaching Astrakhan and east Volgograd regions. From the Volga River, the northern border of the range of this species goes to the Orenburg Region, from where it goes to Kazakhstan along the valley of the Ural River. In the south Meriones meridianus is distributed as far as Iran, Northern Afghanistan, Western and Southern Mongolia and China. It can also be found in southern Transcaucasia and Tuva.
Habitat
Meriones meridianus is a typical inhabitant of sands, especially those overgrown with semi-shrubs (including isolated sand massifs in the steppe zone). In the Caspian region it is common around shrubby sandy hillocks, avoids free barchan sands and places with compacted soil and homogeneous wormwood thickets, and in the south of Tuva it settles in sand dunes, in Central Tuva - along field margins. In the desert zone, this rodent is found in small residential and abandoned settlements; in the east of its range - on cultivated sandy loam lands. In Tuva and Mongolia it can be found at altitudes up to 1600 m.
Social behaviour
Meriones meridianus is active: in spring and summer in the evening and at night; in autumn in the period of fodder preparation and in winter - round the clock. It does not move far from burrows and tries to feed under the cover of shrubs. Burrows of Meriones meridianus are usually located under shrub roots, on elevations. Foraging, spring-summer (temporary) and wintering (permanent) burrows are distinguished. The latter have the most complex structure: their depth is 80-200 cm, their length is up to 4 m, there are several storerooms and 1-2 living chambers. From 5 to 15 Meriones meridianus hibernate in such a burrow. Simpler burrows serve as day or temporary shelters; there may be from 1 to 4 of them in a family plot. Meriones meridianus are colonial, especially during the breeding season and winter. They feed mainly on seeds; they also feed on insects in small quantities. In September-October Meriones meridianus make stocks for winter, which may weigh up to 300-500 g (not more than 2 kg). The reserves are eaten by animals hibernating in the same burrow under particularly unfavourable weather conditions.
Breeding
The breeding period of Meriones meridianus lasts from February-March to early October in the south of its range, in favourable years - year-round; in the north - from April to September, with peaks in spring and autumn. Overwintered females usually bear 3 broods per year; young 1-2. Pregnancy lasts 22-24 days, with an average of 6 (up to 11) cubs in a brood. At 20-30 days of age they become independent, and from 2 months of age they are able to reproduce on their own.
Status
The midday jird is a common species in suitable habitat across its wide range. It is capable of large population swings depending on the harshness of the winter weather and the availability of food. No special threats have been identified, and the International Union for Conservation of Nature has assessed its conservation status as "least concern".
