The Przewalski Horse

The Przewalski's horse is the last real wild horse, and the only ancestor of the domestic horse that has survived to the present day. It is certain to be extinct in the wild . The Przewalski horse is the sole surviving genuine wild horse in the world, not to be confused with, for instance, the mustang, a descendent from domestic breeds gone wild. (Bouman 1986) It is also unique that after their extinction from the wild in the 1960s and after more than thirteen generations in captivity the Przewalski horses were successfully reintroduced into their natural environment in Mongolia. The name refers to the Russian explorer Nikolai Przewalski who first discovered the subspieces in the 1870s. Przewalski horses are among the most threatened wildlife species in the world. The entire world population consists of no more than 1,435 individual animals (Studbook Prague, 01.01.2000).

The wild horse has a stocky body with strong, short legs, a short neck and a powerful jaw. Its color is beige-brown, becoming lighter towards its belly. They have erect manes which stop between the ears. The lower part of the tail is covered with long black hair; the upper part has shorter, light colored hairs. Przewalski's horse mostly feeds on grasses, grains and other plants. Most of the day is spent foraging, as it feeds on food with a low nutritional content.

In the wild, Przewalski's horse occurred in family groups led by a dominant stallion, juveniles were ousted and the males formed their own groups before attempting to take over a horde of females. In captivity, births occur in April/May but in the wild the season is later and more likely to be May/June. (Bouman 1986) Gestation takes between eleven and twelve months and foals are able to stand as soon as one hour after birth. A week after giving birth, females come into heat and will mate again.

In summer they daily wander to their favorite spots to graze. They relax against the mountain ridges, high rockeries or in the woods. In summer they preferably graze during the early morning and in the cool of the evening to escape from the heat and insects. At the hottest part of the day and in the middle of the night they rest. At night they are very vulnerable, so one of them will keep vigil to alarm the others in case of danger. In spring, winter and autumn they need more time finding the right food. During those seasons food quality diminishes considerably, so horses have to eat more to survive. Life gets dangerous in the snow. The snow that fills the clefts is deep and the Przewalski's have to be very careful because their hoof may get stuck between the rocks.

Przewalski horses are social creatures. They know one another face to face and keep up individual friendships. They live in groups composed of six to seventeen animals. There are harem groups consisting of a leading stallion, mares, foals and one to two years old juveniles, and there is also a bachelor group. When they are about one and a half to three year of age the juvenile stallions and mares are ousted from the native group.

Social behavior

Przewalski horse behavior is remarkably synchronized in a harem. They all graze and rest at the same time. When some of the horses start to nibble one another, the others will follow suit. Frolicsome foals or rolling older ones instantly invite others to join in with the fun. Skin care is very important. They like to scratch themselves against rocky surfaces, shrubs or to roll in the sand. Yet, they cannot reach their own backs. The help of others is needed. Standing head to tail they nibble one another's skin. This is called mutual grooming, which not only has a pure practical function, but also furthers mutual bonding and works as a stress relief for the whole group.

Dominance hierarchy is essential for the ordering of social contacts. While social hierarchy ascertained each individual knows his position in the group, which leads to lesser aggression and to more harmony. Internal fighting results in a loss of energy and increases the chance of getting wounded. Survival in the wild requires much energy. Wounds attract parasites and can be the cause of dangerous if not lethal infections.

The leading stallion is often the most dominant one in a harem, followed in this order by the mares and the younger members in the group. The older and most aggressive mares rank highest in the hierarchy. The stallion expresses his top rank position by herding his mares, using a characteristic ' snaking' posture with his head held low and ears flat back. The mares set their mutual disputes by lowering their ears in the neck and intimidating the other with bite threats or kicks with the hind legs.

Dung piles serve a different cause. There will certainly be more of them alongside the most popular migrating routes when there are more Przewalski groups in the area. Communal dung piles are a means of communication between the different harem stallions. By marking it with his own dung a stallion signals his presence. A passing stallions 'reads' the pile in a ritualized manner by sniffing the scent, walking over it, dropping his own dung and finally sniffing his own freshly deposited scent markings. In this way the stallion learns whether other stallions did pass this spot recently or did so at an earlier moment. The dung piles accomplish not only a social function in the contacts between the various groups, but they also function as some kind of orientation mark.

An encounter between two leading stallions takes also a ritualized course. The two dash into each other. Once they are close, they approach one another with crested necks and sniff noses. Mostly this will elicit a squeal and one or both may strike out with a front leg. Thereafter they sniff at each other's genitals and noses. When a fight seems unavoidable, the opponents will rear and box with their front legs and bite one another fiercely in the flanks and legs. The hostilities will go on until the weaker party is chased away and the victor has rejoined his mares. However, most encounters between family stallions rarely end in violence. Encounters with mature bachelor stallions are far more hostile. Such confrontations are very violent and often lead to severe injury. In the course of many encounters the stallions learn to respect each other's force. This helps them to decide whether they should avoid a particular harem stallion or just take the chance to dispute a drinking place or even mares.

Sources:

Particulars About The Przewalski Horse by Jan Bouman (1986)

http://www.treemail.nl/takh/index.htm