"I Thought There Was Only One!"; of zebras, ostriches and more

The year is winding down, but there seems so much to do still. Accordingly this will be a fairly low-key post, based on a comment I heard with regard to our African adventure earlier this year, both while there from our companions on the East African tour, and since getting home. "But I thought there was only one zebra (ostrich, giraffe etc)!"

Fair enough too; we usually just refer to such animals in one-word terms, strongly implying that this is exactly the case. 'Zebras' for instance; even if we're aware of the more formal name of Plains or Common Zebra we usually tend to just go for friendly informal 'zebra'.

Plains Zebras Equus quagga, looking Africa-postcardish in the magnificent Ngorongoro Crater in Tanzania
(one of the most satisfying days of my natural history life by the way).  And you might like to entertain yourself
by thinking of how many other names there are with a 'q' in both genus and species name.

This is quite understandable; almost any zebra that you're likely to see either in captivity or in the wild in Africa will probably belong to this species. This post is intended as an introduction to a few often unsuspected animals, not an in-depth study, but a couple of questions probably need to be asked about this one. Why 'zebra', and why the stripes? Unfortunately if you really wanted to know the definitive answer to either of these questions, you've come to the wrong place. My trusty old big Oxford Dictionary reports that it appeared in English for the first time in 1600, in a work translated from Portuguese. It suggests that the word originated in a Congolese language and appeared in similar forms around the same time in Italian, French and Spanish too. However I understand that other sources suggest a possible Latin origin, though the nexus seems pretty vague. I'm inclined to go with the Oxford, based on a long relationship.

Plains Zebra and foal (and bonus Yellow-billed Oxpecker), Tarangire NP, Tanzania.
The foal's stripes will darken age.

And the stripes? There is an array of suggestions, the most popular of which relate to camouflage, either referring to broken shadows or the 'dazzling' effect of swirling patterns of fleeing animals. Social aspects have been mooted, wherein stripes stimulate a zebra to groom other zebras, or the unique patterns of individuals assist in recognition. A couple of more recent suggestions, both evidence-based, are interesting. One shows that biting flies, which rely on homing in on polarised light, are confused by the stripey patterns. Another demonstrates that black stripes can be up to 10 degrees C hotter than adjacent white ones, which sets up small air convection currents which in turn assist in evaporative cooling. Have fun working your way through all those options!

We do know about the quagga part of the name though. This is a Khoekhoe word (once referred to as Hottentot) from South Africa, referring to an abundant sub-species which was hunted to extinction by 1880. Only one photograph exists (from an animal in London Zoo), plus 20-odd skins. Curiously the Quagga lacked stripes over most of the back half of its body. Which brings us to the point of this post; there isn't just one 'zebra' and this isn't just true at the subspecies level. Before we look at the other two zebra species, let's see what differentiates the Plains Zebra from them.

Plains Zebra, Lake Mburo NP, Uganda.
The key factor is the stripes (unsurprisingly!); in the Plains Zebra they run right under the belly,
and body stripes are much wider than those of either of the other two. There are no small transverse stripes
across the rump and top of the tail, and no stripe along the spine.

While the Plains Zebra is found in much of eastern Africa, and across northern Namibia to the Atlantic, the Mountain Zebra Equus zebra is limited to scattered mountain populations in southern South Africa and western Namibia. In the 1930s there were perhaps only 100 left, but numbers have increased with sustained conservation programs.

Mountain Zebra, Goegap NR, South Africa. They seem to like it rocky, hot and dry;
Goegap, near Springbok in the north-east of the country, meets these requirements well!
Notice the white belly and narrow body stripes, which suddenly get dramatically wider on the hips.
The little stripes across the spine above the tail and on it, and the obvious throat dewlap are also distinctive.

The third zebra species lives in the opposite corner of the continent, scattered in a few reserves in northern Kenya and Ethiopia, while it has has been extirpated in Djibouti, South Sudan, Eritrea and Somalia. Grevy's Zebra E. grevyi is the largest living wild horse, and rangier than the other zebras. This was the hippotigris ('tiger horse') which appeared in Roman arenas and parades. It is listed as Endangered, though populations seems to have stabilised.

Grevy's Zebra, Buffalo Springs NR, northern Kenya.
It has narrow body stripes and white belly like the Mountain Zebra, but no broad bands on the hips,
and a dark stripe down the spine bordered by a white strip on either side, plus noticeably bigger ears.

But ostriches? Surely there's only one ostrich?! No, there are actually two. The Common Ostrich Struthio camelus has two quite separate big ranges, across southern Africa, up from northern South Africa, and across a huge swathe of the Sahel from the Red Sea to the Atlantic with a 'tongue' of occupation down through Kenya and Tanzania.

Common Ostriches, Tarangire NP, Tanzania. The two ostriches are the world's largest birds;
a male can be nearly three metres tall and weigh over 150kg. Females and immature birds are
very similar.

The Somali Ostrich S. molybdophanes was described as a separate species back in 1883 but this was rapidly rejected, and until this millennium it was regarded as a sub-species of Common Ostrich. Only in 2014 was it reinstated as a full species, based on various physical and genetic characters, and the fact that the two live side by side in Ethiopia.

Somali Ostriches, Shaba NR, northern Kenya. The most obvious distinction from Common Ostrich
is in the blue-grey (not pinkish) legs and necks. The male is also 'very' black, as opposed to sort of 'off black'.

There are other differences too. 

Male Common Ostrich (Lake Nakuru NP, Kenya) above; male Somali Ostrich (Shaba NR, Kenya) below.
The Common has mostly dark irises, and a smooth crown with bristly hairs;
Somali has pale irises and a bare crown with a little horny protrusion.

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At Shaba we encountered another Horn of Africa relative of a widespread and well-known species too. The Common Warthog Phacochoerus africanus is a familiar pig across much of sub-Saharan Africa.

Common Warthog, Ngorongoro Crater, Tanzania. It really is a remarkable creature.

In northern Kenya, Ethiopia and Somalia is a closely related warthog, an arid land specialist, the Desert Warthog P. aethiopicus. It's been known for a long time, but it's not a part of the world that most nature-watchers tend to visit.

Desert Warthogs, Shaba NR, Kenya. They are very similar to Common Warthogs, but have very
different dentition, lacking incisors entirely and with muscles that allow considerable side to side movement.
Presumably this assists with mastication of hard tubers and roots.

And finally I mentioned giraffes. No, it's OK, there really is only one Giraffe species Giraffa camelopardalis. Well, so far anyway; a number of reputable recent studies strongly suggest there are more. The eminent - and sadly recently late - Colin Groves in a 2011 publication believed there were eight species! We'll stick with the orthodoxy for today though, which generally recognises eight subspecies. Here are some of them; they are really quite distinctive.

Cape Giraffe G. c. giraffa, Augrabies Falls NP, northern South Africa.
The spots are dark and not as angular as others, and extend to about the knees.
From north and north-eastern South Africa and into Zimbabwe and Mozambique.

Masai Giraffe G. c. tippelskirchi, Serengeti NP, Tanzania.
The spots here are very 'splintered' and go right down to the hoofs. Tanazania and southern Kenya.

Reticulated Giraffe. G. c. reticulata, Shaba NR, northern Kenya. Arguably the most striking giraffe,
with big angular chestnut spots on a white background.
An arid land giraffe, from north-eastern Kenya and adjacent Ethiopia and Somalia.

Rothschild's Giraffe. G. c. rothschildi, Lake Nakuro NP, Kenya.
Its large dark spots often contain paler lines, which can be seen on the male on the left
(though you may have to click on the photo to enlarge it).
From a small area here in south-western Kenya, plus northern Uganda and adjacent South Sudan.

As I said, these very different giraffes are still regarded as the one species, but I have a feeling that that may not be the case for much longer. 

Well, not for the first time that's probably more than I meant to say, but I hope you've found something to interest you here. If nothing else you may have met some special animals whose existence you may not hitherto have known about. Either way they're worth considering.

Enjoy the last days of 2019, and may 2020 bring you lots of natural history adventuring! I'll be back once more before the end of the year, for my annual year's highlights, via one photo per month.

NEXT POSTING TUESDAY 31 DECEMBER
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