The Grevy’s zebra, Equus grevyi, is the largest of the equids as well as the most critically endangered. This was one of my target species that I wanted to observe and photograph during my recent trip to Kenya. To do so I had to travel into northern Kenya to see the Lewa Conservancy, a conservancy that deserves a post of its own which will be a topic I work on after this, and the Il Ngwesi group ranch. I had feared that this species may be hard to find as there are so few of them left in the world. However, Lewa is home to one of the largest populations of this species and we managed to find a small herd of them shortly after leaving the airstrip.

The Grevy’s zebra is an interesting creature which looks like a cross between the plains zebra, Equus burchellii, and the wild ass, Equus hemionus. In fact, they fill a narrow ecological niche between the wild ass, which is more desert adapted, and the plains zebra, which is heavily dependent on water (Estes 2012). During dry seasons the Grevy’s will migrate to better-watered highlands. However, this species is not overly limited by food. It can eat grasses you tough for cattle and when these are gone it will shift to browsing. Without the need to find better grazing as long as water is available it will not migrate. They have even been known to dig waterholes in stream beds which they fiercely defend rather than migrate (Estes 2012).

Grevy's Zebra

Grevy’s Zebra

These zebras are highly territorial. Stallions maintain dung middens to mark the boundaries of their territory. A stallion will not tolerate the presence of another dominant male in his territory when a female is in estrous, although subordinate males are still allowed within the territory but at a distance from the dominant stallions females. However, the territorial stallion will often mingle with subordinate bachelors and even other territorial males when the females are not in estrous (Estes 2012). Females will breed as young as 3 years old but stallions never before the age of 6. The foals become more independent after 6 months but still follow their mother up to 3 years. When females are forced to travel during droughts they often leave their young unguarded or in a crèche (Estes 2012). Lacking the instinct to hide, the foals just stand around as easy prey for any predator in the area.

Historically this species ranged throughout most of Kenya, Somalia, and Ethiopia. With only 750 mature individuals left, and only 2,000 total including juveniles, this species is almost entirely restricted to the Laikipia region of Northern Kenya (Moehlman 2013). As of 2010 the Ethiopian population was estimated around 126 individuals, a 90% decrease from the 1,900 estimated in 1980, and the species has been extinct in Somalia since 1973 (Hollingshead 2010).

Grevy's grazing

Grevy’s grazing

In Kenya it was believed that hunting for skins was a large part of the decline of this species throughout the 1970s. However, even after the closing of all big game hunting in the late 70s this species has continued to sharply decline. More recent data suggests that possibly the biggest factor in the decline is low juvenile recruitment, that is to say that very few of their offspring are surviving to adulthood, due to competition with pastoral people and livestock for access to food and water (Moehlman 2013).

There are many efforts in place now to save this unique species. They are a CITES Appendix I species and are being upgraded to the designation of “protected animal” in Kenya. Kenya has taken steps to create a national conservation strategy. The aforementioned Lewa Conservancy has been a shining example of the dedication of Kenyan’s to saving this iconic species.

Literature Cited

Estes, R.D. 2012. The Behavior Guide to African Mammals. 2nd ed. Berkeley: University of California Press. 240-242. Print.

Hollingshead, A. 2010. “Equus grevyi” (On-line), Animal Diversity Web. Accessed August 30, 2013 at http://animaldiversity.ummz.umich.edu/accounts/Equus_grevyi/

Moehlman, P.D., Rubenstein, D.I. & Kebede, F. 2013. Equus grevyi. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1. <www.iucnredlist.org>. Downloaded on 30 August 2013.

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