1. Origin
  2. Classification
  3. Biological and physiological features
  4. Housing conditions
  5. Main health problems

Origin

The first gerbils were imported into the United States in 1954. They came from Mongolia. Their original colour is grey-brown, but many mutations exist: black, yellow, cream, albino, two-tone.

Classification

Class: Mammals
Order: Rodents
Suborder: Sciurognaths
Family: Muridae
Subfamily: Gerbillinae
Genus: Meriones
Species: unguiculatus
Common name: Gerbille de Mongolie, Mongolian gerbil, clawed jird.

Other species of gerbil are found in captivity, notably the Egyptian gerbil, or sand rat, and the Libyan jird.

Biological and physiological features

  • adult weight: male: 65-100g and female 55-85g.
  • body length (including tail) 21-24.5cm

Biological parameters

  • way of life: diurnal and nocturnal, mainly crepuscular. Builds simple burrows.
  • social system:
  • the gerbil is very sociable and gregarious by instinct, and must be kept in a group. Keeping one on its own is prohibited!
  • natural hibernation: no
  • respiratory rate: 70-120 movements/minute
  • heart rate: 360 beats/minute
  • lifespan: 3-4 years (maximum 5 years)
  • temperature: 37-38.5°C

Reproductive physiology

  • age at sexual maturity: male: 70-85 days, female: 65-85 days
  • breeding season: all year round
  • pairing system: monogamous or harem before weaning at 7 weeks of age
  • cycle length: 4-6 days
  • cycle type: polyoestrous
  • type of ovulation: spontaneous
  • gestation length: 24-26 days
  • newborn characteristics: altricial (eyes opening at around 15 days)
  • number of young per litter: 1-12 young, but 5 on average
  • birth weight: 3g
  • weaning age: 21 days
  • number of litters per year: 7-8 (some pairs can produce a litter a month)

Females are no longer fertile at 18 months, and males at 2 years.

Living environment

The cage must be at least 100 cm x 50 cm, ideally a minimum floor area of 0.8m2 for 2 to 5 gerbils, with an extra 0.05m2 per additional animal. Minimum height: 60-100cm. You can also use a terrarium tank with a lid. Hiding places are needed, as well as material to build nests and branches to gnaw (beech, hazel, untreated fruit trees). The bedding must be 40-80 cm thick and changed every 1 to 2 weeks. A sand bath will also be needed to remove the excess sebum on the skin.

  • ambient temperature: 20-22°C
  • humidity: 30-40%
  • lighting duration: 12 hours
  • ammonia level: <8ppm

Feeding

  • Vegetarian diet, tending towards omnivorous
  • A cereal-based ration provided as commercial pellets for gerbils or rodents at 18-22% protein, plus a seed mix
  • Supplementary foods: vegetables, fresh and dried fruit
  • Careful: fruits rich in vitamin C (citrus, kiwis) should be avoided

Handling

This rodent is sociable and friendly; it rarely bites unless it is frightened. It is not very timid and is naturally curious, readily coming to eat from the hand.

To pick it up, take it by the base of the tail or between the index and middle fingers. Sudden movements should be avoided, as they can trigger epileptic fits.

Main health problems

Skin disorders

  • Mange and fleas
  • Mycoses
  • Nasal dermatitis, facial eczema: this infection is unfortunately of poorly understood origin. It results from an abnormal secretion of a gland called the Harderian gland, sometimes with secondary bacterial infections. The perinasal skin lesions can spread over the face, the limbs and the rest of the body.
  • In gerbils housed in an aquarium with insufficient ventilation, high humidity (> 50%) and bedding that is not changed often enough, a change can be seen in the animal's coat; it becomes rough.

Digestive disorders

  • Enteritis: bacterial (and contagious) or parasitic.
  • Dental malocclusion

Eye disorders

  • Conjunctivitis

Nervous disorders

  • Epileptiform seizures in the Mongolian gerbil: spontaneous and of genetic origin, they are more frequent in certain selected lines. They are brought on by handling or by stress.
  • Convulsions: these may be due to encephalitis, trauma, poisoning, or an ear infection.

Respiratory disorders

  • The gerbil can suffer from colds, pneumonia or an upper respiratory tract infection.

Reproductive disorders

  • Infertility: this may be due to an incompatible pair, immaturity, an environmental disturbance, ovarian cysts, or tumours.
  • Abandonment of the young and cannibalism: this can be seen in cases of environmental disturbance, a lack of milk from the mother, and inflammation of the teats.
  • Miscarriages: these can occur in cases of nutritional deficiency and environmental stress.

Zoonoses

  • Salmonellosis, gastrointestinal parasites (tapeworms).