ZEBRA “ON THE ROLL” AT THE NAIROBI NATIONAL PARK

Year after year the plains zebra faithfully return to the Nairobi park to seek fine pasture. In recent years this feat is becoming more and more challenging with the pressures of human encroachment. So it is again amazing that they returned in such numbers this year, totalling quite a few thousand.

It has always been a favourite habit of mine to approach a herd of zebra, slowly idle and edge the vehicle closer and closer until virtually in the middle of the herd and then switch off the vehicle and observe them. A particularly strange activity that they do is to find a patch of dust and then repeatedly roll in it, effectively dust bathing their coats. Often the herd seemingly waits in line to all roll on exactly the same dust spot. There are various possible reasons for this behaviour including a protective dust layer that results in minimizing parasites and thermo-cooling their coats in the African heat. Maybe the action could also be linked to communal scent marking of the herd? Whatever the reasons it is always interesting to watch the zebra when they are “on the roll”!! they all have a unique marking pattern with no zebra being the same, much the same as human fingerprints.

There are two sub-genus of zebra, namely Hippotigris & Dolichohippus. There are 5 subspecies across Africa in the genus Hippotigris of which the plains zebra in East Africa is classified.

The name zebra comes from the old Portuguese word “ZEVRA” meaning “wild ass”, and in Swahili, they are known as Punda Milia. Sometimes it can be very rewarding to just sit quietly near a herd of zebra and watch them for a while. Zebra tend to be quite habitual in their daily habits, so waiting at a dam can be special when zebra and other species come and drink. Interestingly zebra often walk deep into the water, perhaps because it is cooling and easier to drink. However, their deepwater drinking habits can expose them to the dangers of becoming a crocodile meal. We recently observed a zebra with a severe leg wound that had most likely been the result of a life & death “tug of war “ with a large crocodile.

They are quite observant and very sensitive regarding predator awareness. For decades and decades, scientists have wondered why zebras have stripes. One prevailing theory held that the stripes confused predators, making it harder for, say, a lion to pick out an individual zebra from a stampeding herd.

Lately, more intriguing theories have emerged. Some scientists think that stripes keep zebras cooler. The dark stripes soak up more sunlight than the light ones, and this stirs up eddies of wind that swirl heat away. Other researchers discovered that biting flies avoid striped patterns. And the two theories might be linked: Biting flies prefer hot temperatures, so they may be less likely to bite a cooler zebra.

For fussy grazers such as Thomson’s gazelles and wildebeest, zebras are their unlikely feeding friends. Those striped heroes have special digestive systems that can quickly process lower-quality forage.  Plains zebras are often the first to enter a un-grazed grassy area. They’ll munch on older, harder, less nutritious plants that other grazers can’t eat. Once the old stuff is cleared out, tender new growth pops up. More fussy selective grazers will then wander in and eat the good stuff.

I have seen many encounters with lions by just sitting still with the herd. Try it someday, just remember to take your camera and binoculars.