The jerboa is allegedly one of the creatures that God forbade the children of Israel to eat. In more recent times, the jerboa was used as the emblem of the British 7th Armoured Brigade, who were known as the Desert Rats during their successful campaigns against Rommel's Afrika Korps in the Second World War1. But what on earth are these enigmatic little rodents?
Officially, a jerboa is:
- Kingdom - Animalia
- Phylum - Chordata
- Class - Mammalia
- Order - Rodentia
- Suborder - Sciurognathi
- Family - Dipodidae
- Subfamily - Dipodinae
- Genus - Jaculus
What this actually means is that a jerboa is a rat-like mammal that lives in the deserts of Africa, Asia, and south-east Europe. It is similar to the kangaroo rat2 in that it has large, powerful hind legs that can propel it faster than a human can run. The hind legs are approximately four times longer than its forearms, which are primarily used for burrowing and eating. The body of a jerboa is approximately 18cm long, with another 24cm of tail. They are a tawny yellow colour, rather like that of dried lemon-peel. The fur is very smooth and soft, eyes are full and round, and the head is much like that of a young rabbit. When a jerboa eats, it manipulates food with its forepaws, in common with many rodents. The two main European species are often kept as pets, and are closely related to the gerbil.
The gestation period of the species varies but the average is about 40 days. They give birth to three to four altricial3, one to three times a year.
Why Jerboas Are Amazing
With a single leap, a jerboa can travel ten times its own body length forwards and 12 times as long upwards. This extraordinary prowess enables it to escape the jaws of hungry predators as well as avoiding too much contact with the burning desert sands. These athletic endeavours have been made possible by the fusing of the three main, centre, and foot bones into one large 'Canon Bone' which is extra strong, enabling the jerboa to propel itself further with less risk of injury upon landing. Jerboas also have tufts of hair on the undersides of their hind feet to stop them slipping on soft material and help them kick sand backwards when they burrow.
Jerboas use their heads and strong noses to create tunnels that can be between 1.5 and 2.5 metres long, and which they then live in. These tunnels have only one entrance but several exits. They often create emergency exits that consist of an exit lightly plugged up with sand so that it can force its way out in an emergency. In the summer however they may block up all of the entrances and exits, probably to prevent snakes and warm air from getting in, keeping the burrow cool and safe.
Solitary, nocturnal animals, with a low tolerance for heat, jerboas spend the day in individual burrows off the main tunnel, with plugged entrances. In nothern climates, they often hibernate. Their diet consists of plant matter, especially seeds, and insects. Astonishingly, the jerboa does not drink, but survives on water obtained from food or produced by their own metabolism. It is also believed that moisture is recycled from exhaled breath.