Zebra black and white at birth. Plains and mountain zebra foals are protected by their mothers, as well as the head stallion and the other mares in their group. Grévy's zebra foals have only their mother as a regular protector, since, as noted above, Grévy's zebra groups often disband after a few months. Attempts have been made to train zebras for riding, since they have better resistance than horses to African diseases. While occasionally successful, most of these attempts failed due to the zebra's more unpredictable nature and tendency to panic under stress. For this reason, zebra-mules or zebroids (crosses between
Plains zebra The striping pattern of the zebra is unique among sympatric ungulates. One suggested function for the stripes is to provide crypsis for the animal in tall grass or in the dappled shade beneath bushes and trees. However, cryptically coloured species, such as the kudu and bushbuck, tend to be quiet and stealthy. They freeze during danger and flee only at the last moment. By contrast, the zebra is active and noisy, and makes no attempt to hide itself. Another suggestion is motion camouflage, that the stripes affect a predator's judgement of the zebra's size, distance, and what direction it is