There is some evidence that before the arrival of the camel, which was introduced into Africa via Egypt at the time of the Arab conquest, bullocks were used either as pack animals or to draw carts from the northern countries across the Sahara to the gold-producing areas of the ancient Sudan. From the 16th century onward the Portuguese developed transport inland from the coast at Mozambique, and from the 17th century first the Dutch and then British settlers from the Cape trekked northward and northeastward with their wagons. Except in such highland areas as Ethiopia, where pack animals were and still are used, the tsetse fly often prevented the use of animal transport. With the steady progress in the development of transport infrastructure in many African countries, the use of bullocks in Southern Africa, donkeys in western and North Africa, horses in northern Nigeria, and camels in western and North Africa and the Horn of Africa has been reduced, but the extent of this reduction cannot be accurately gauged.
