Food in the desert

Heat usually produces a loss of appetite – so do not force yourself to eat. Protein foods increase metabolic heat and increase water loss, and liquids are needed for digestion. If water is scarce, keep eating to a minimum and then try to eat only moisture-containing foods, such as fruit and vegetables.

Food spoils very quickly in the desert and any stores, once opened, should be eaten straight away or kept covered and shaded. Flies appear from nowhere and settle upon uncovered food.

Vegetation, away from oases and waterholes, is likely to be little more than scrub and grasses – even in the semi-desert – but grasses are edible and sometimes plentiful. The acacia tree in the scrub provides edible beans. Beware of the acacia’s thorns but try all its soft parts: flowers, fruit, seeds, bark and young shoots.

The grasses of the Sahara and Gobi are neither nutritious nor palatable, but in the Sahara and the Asian deserts you may find the desert gourd, a member of the squash family. Its vine can run over the ground for 4.5m (15ft). Chew its water-filled shoots and eat its flowers and orange-sized fruits, the seeds of which are edible roasted or boiled.

The mescal plant of the Mexican desert (an agave, from which tequila is made), grows with a rosette of thick, tough, sharp-tipped leaves. Its central stalk, which rises like a candle to a flowering head, can be eaten. Cut the ends of the leaves to suck out water.

Deserts often support a variety of animal life which burrows into the sand or hides in any available shade during the day, including insects, reptiles, small rodents and specially adapted mammals such as the fennec fox of North Africa, the Australian bandicoot, a hedgehog in the Gobi and the jack-rabbit of North America – all of which have big ears to act as cooling aids. Most large mammals are an indication that there is a water supply within daily reach of their grazing areas.