Mustang Horse

By the late eighteenth century, mustangs were well established in nine western states and numbered between two and five million. Then, as settlers moved west and began to cultivate the land, the mustangs were driven off and killed by the thousands. The greatest destruction of the mustangs has occurred in this century; huge numbers were captured and used in both the Boer War and World War I. Others were caught and used as cow ponies, and many more were shot to be used as pet food and fertilizer. By the mid-1960's, their numbers were estimated at between 18,000 and 34,000, and by the early 1970s, there were less than 10,000.

Unfortunately, there are no detailed studies on olfactory communication. Horses spend a great amount of time sniffing or smelling objects, but nothing is known about the information they gather or transmit. As with other ungulates and carnivores, horses exhibit flehmen, retracting their nostrils while in- and ex-haling and analysing the scent in their vomeronasal organ which is packed with olfactory nerve cells. This behaviour is present in foals a few hours old when they suddenly are confronted with a strange scent like smoke, and specially developed in stallions when they smell the urine or faeces of mares at the onset of oestrus, a state or period of heightened sexual arousal.

The foals are able to stand within several hours of birth. After 2-3 days, mother and foal join the herd and remain with it for a year or more. When the male colts reach about 3 years of age, they are driven from the herd by the stallion. The colts are too young to attract females, so they form a herd of their own with which they roam for several years. They occasionally challenge the leader of other herds, until they are successful in establishing a herd of their own.