Knowing the zebra’s ancestor is similar to the horse and the donkey, both very calm animals, one might wonder how aggressive are zebras. They are known to run away at the first sign of trouble or danger. This does not seem like the behavior of an aggressive animal. However in the right situations zebras can show aggressive behaviors. One such situation being if a predator comes near the herd. The herd works together to protect the more vulnerable, especially the young. The stallion, male zebra, who is keeping watch will go on the offensive and attack any predator that gets close enough. This gives the rest of the herd a chance to get away. Female zebras, mares, with become extremely aggressive if they feel like their offspring are threatened. They will kick violently at any perceived threat. This kick has the potential to seriously harm or even kill predators such as lions or wild dogs.
Mating is another time when zebras show an aggressive nature. The stallions fight to add new mares to their harems. Mares within the same harems fight to be alpha female, and therefore the first to mate with the stallion. This behavior does not get nearly as aggressive as when fighting off predators. These behaviors are used to show social status and keep others in line.
Zebras have never been domesticated. This tells us something about the nature of this animal. Humans have been able to domesticate horses and donkey, both are related to zebras. However the zebra is to unpredictable and tends to panic if it feels stressed or frightened. They will bite or kick their hind legs at any sign of danger.
So while zebras are not considered an excessively aggressive animal, people still need to understand that they are a wild animal and have not been domesticated the way horses have. There is no way to predict how they would react to a human approaching them. Any person wanting to approach one should be cautious and know that zebras have very powerful kicks and will bite.