ABOUT GREVY'S ZEBRA
Ears standing to full attention, neck arched, muscles tensed, 450kg of alert zebra ready for action. Watch a Grevy's zebra adult male presiding over his territory and one begins to understand the majesty of this species. Indeed in 1882, Menelik II, Emperor of Abyssinia (now Ethiopia), thought the zebra was so regal that he presented one as a gift to the President of France, Jules Grévy. And so the name Grevy's zebra was coined.
What's the difference?
Grevy's zebra was the first of the zebra species to evolve after asses. Taller, narrow stripes, a white belly, black dorsal stripe, large rounded ears and a brown muzzle the Grevy's zebra is easily distinguished from the more common plains zebra. These two species overlap in the southern range of Grevy's zebra and the northern range of plains zebra.
Habitat and diet
Grevy's zebra occupies the niche between the water-dependent plains zebra and the arid-adapted wild ass, living in arid and semi-arid habitat comprised of grass and shrubland with permanent water available. Predominantly grazers, Grevy's zebras live on forbs and grasses but during extremely dry periods they also browse. Grevy's zebra can go without water for up to 5 days however if lactating, the females must drink at least every other day in order to maintain milk production. With land degradation worsening each year, the distance between available grazing and water increases, meaning that Grevy's zebra mums have to make long and more frequent journeys, resulting in high foal mortality, which is one of the major threats to the survival of the species.
Closer to an ass than a horse, their social system is adapted to their arid and semi-arid ecosystem. Breeding males reign over territories of up to 10 km2 in size, which they have established with the interests of the females in mind: water, forage, and the strength and power of the male to watch out for her safety. What more could a female ask for? Depending on her breeding condition, a female has different resource requirements. When she is lactating, she needs to be closer to water and therefore those males who have water within their territory will be more successful at breeding. Grevy's zebra males who haven't yet reached breeding age hang out in bachelor groups. Only if females are not in breeding season within a territory, will the bachelors be tolerated by the dominant territorial male. A territorial male can keep his territory for up to seven years before he will be defeated by a younger, stronger bachelor male who will challenge him for the territory. Males make the boundaries of their territories known by vocalising loudly and by creating dung piles which they mark regularly to let everyone know they are present.
After being inside their mothers for 13 months, Grevy's zebra foals are born all legs and ears. Births are usually timed with the onset of rains with peaks observed in May/June (long rains) and November/December (short rains). When resources become scarce with a resulting drop in body condition, females may not come into oestrus.