The quagga Equus quagga quagga is nowadays famous for two very different reasons. Firstly: it is – or was – the only semi-striped form of zebra, its striping being confined to its foreparts. Secondly: although once common in its South African veldt habitat, it was hunted into extinction there during the second half of the 19th Century, with the very last captive specimen's death in Amsterdam Zoo on 12 August 1883 marking the tragic disappearance of this highly distinctive equid from the face of our planet – though The Quagga Project continues its aim to recreate this vanished creature's characteristic phenotype (external appearance) via back-breeding, using striping-deplete specimens of other Equus quagga subspecies to produce quagga facsimiles.
Speaking of which: today, the quagga is classed as a subspecies of the plains zebra Equus quagga, but back in the mid-1800s when still very much alive it was deemed to be a valid, distinct species in its own right, and was dubbed Hippotigris quacka (hippotigris being the name given to zebras by ancient scholars who believed these exotic-looking striped equids to be the product of matings between horses and tigers!) – see later for further taxonomic details. But that is not all.
For a time during that same period, a second, very remarkable quagga species was also recognized, despite being known from just a single specimen – a poorly-preserved skin formerly held at the British Museum in London. This unique, extraordinary-looking animal became known as the isabella quagga, but today the skin is long lost and the isabella quagga itself is long forgotten. Consequently, I felt that what (very) little is known about this beautiful if baffling enigma of an equid richly deserved to be collated and presented in article form in order for modern-day readers to become aware of its erstwhile existence. So here is the hitherto-obscure history of the long-overlooked isabella quagga – a ShukerNature exclusive.
I first learned of the isabella quagga Hippotigris isabellinus many years ago, when I chanced upon the following previously-obscure yet fascinating excerpt from a quagga-themed communication by famous British zoologist Richard Lydekker that had been published by the scientific journal Nature on 10 January 1901. The excerpt alluded to a supposedly separate, second species of quagga, again extinct:
...the British Museum formerly had the skin of a young quagga, in very bad condition, which was presented by the traveller William Burchell [after whom Burchell's zebra is named], and was subsequently described by Hamilton Smith as a distinct species, under the name of Hippotigris isabellinus.
Two points to note here. Firstly: the above-mentioned Hamilton Smith was Charles Hamilton Smith (1776–1859), a lieutenant-colonel in the British Army. He was also a naturalist who scientifically described and named several equine species and subspecies. In two 1841-published tomes referred to later here, he dubbed this enigmatic animal the isabella quagga. Secondly: whereas all zebra species and subspecies are nowadays housed in the genus Equus (alongside horses and asses), back in Lt-Col. Hamilton Smith's time several were housed in their own separate genus, Hippotigris, including the normal quagga, which was formally deemed back them to be a valid species in its own right (rather than merely a subspecies of the plains sebra, as it is classified today) and was duly known as Hippotigris quacka.
Lydekker's communication then continued with the following text, but it is unclear whether this text was still referring to the isabella quagga or (as I suspect) had returned to the communication's primary subject, the normal quagga:
Apparently London museums possess no other relics of this lost species, of which, however, we believe there is a specimen in the museum at Edinburgh. As the animal yielded no trophies worthy the attention of the sportsman, it is unlikely that there are any specimens in private collections, unless, perchance, a skull or two may be in existence.
The remaining text in Lydekker's communication unequivocally referred to the normal quagga, so it needn't be quoted here.
What exactly was the isabella quagga, I wondered, when I first began researching this curious creature, and what did it even look like, bearing in mind that Lydekker provided no description of it in his communication and the British Museum no longer has it?
Back in pre-internet times, it was by no means easy to research anything as unimaginably obscure as the isabella quagga, so after various attemptss to solicit more information concerning it all proved futile, I placed Lydekker's intriguing communication on file and directed my attention to other subjects. Notwithstanding these failures, however, I never forgot about it, so when I was checking some details recently while completing some other researches and noticed it again, still on file, I decided to reinvestigate its elusive subject, but now assisted enormously by the vast wealth of data readily accessible online. And this time, finally, I was successful, as now revealed.
Originally, my only clue had lain in its moniker. For in this instance, isabella refers not to a woman's name but instead to a colour, known in full as isabelline, and which constitutes this mystery quagga's species name, isabellinus. It is variously defined as pale grey-yellow, pale fawn, pale cream-brown or parchment colour, and is primarily utilised in relation to mammalian coat colour and bird plumage.
Presumably, therefore, I mused, this shade was the background colouration of the coat of this unique specimen (a male, incidentally), meaning, if so, that it was paler in appearance than normal quaggas and probably with fainter stripes too. Whether such a difference warranted Hamilton Smith naming it as a separate species, however, when it was surely nothing more than an aberrantly pallid (possibly leucistic?) specimen of the normal quagga (see later), was another matter.
During my recent researches, I uncovered two beautiful vintage illustrations depicting the isabella quagga, both of which represent it in the living state. One of these illustrations is a hand-coloured engraving in very pale shades with minimal background colouration. The other illustration is in full-colour, so it is much more vibrant.
I traced the pale engraving back to a couple of tomes from 1841, which upon close examination turned out to be identical in content but bearing different titles. One is entitled Horses, and constitutes Volume 20 of the massive 40-volume series edited by Sir William Jardine and entitled The Naturalist's Library. The other tome is exactly the same but is retitled as The Natural History of the Horse and constitutes a stand-alone volume. In both tomes, the author is given as Charles Hamilton Smith, and a concise section documenting what he specifically refers to as the isabella quagga is included, containing the pale engraving of this specimen. In both tomes, it is designated as Plate 25, and is credited to Hamilton Smith.
In his duplicated 1841 tomes, Hamilton Smith began his brief coverage of the isabella quagga (pp. 332-334, and which constitutes this claimed species' formal scientific description and naming) by stating that although this animal's body shape (including its head) compared closely with that of the normal quagga, he had separated it from the latter equid because it differed by virtue of its smaller size (barely 10 hands, i.e. 40 in, tall) and even more so by the forms and colour of its stripes.
He then referred to an unidentified equid seen by travelling French naturalist François Le Vaillant (1753-1824), presumably in South Africa's Cape as this is where he had spent time collecting animal specimens, and which he'd named the zebre but was apparently different from those zebras already known from there. Some zoological authorities, including Dutch zoologist Coenraad Temminck (whose father was Le Vaillant's employer) had considered the isabella quagga to be Le Vaillant's zebre, but Hamilton Smith disagreed with their opinion.
The remainder of Hamilton Smith's account consisted of a verbal description of the isabella quagga skin (augmenting the engraving of this animal portrayed in the living state), which included his belief that it was an adult rather than a juvenile specimen despite its small size, and was not albinistic. Conversely, when concluding his account by mentioning that a Dr Leach had believed the skin (which still existed at the British Museum at this time) to have originally come from the Cape, he conceded that Leach had considered its pale colouration, especially its white stripes, to be due to the animal's 'nonage' (young age).
Moreover, it should be noted here that back in Hamilton Smith's time, there was a somewhat naïve but very prevalent tendency among taxonomists to over-emphasise the significance of individual variation within species, leading to the splitting off and naming of many spurious animal species that in reality were nothing more than freakishly-coloured/patterned individuals of already known, confirmed species. Eventually, however, such shortcomings were rectified by lumping these unsubstantiated species back together – as happened with the isabella quagga, subsequently being subsumed by zoologists into the normal quagga species (now subspecies).
As for the full-colour isabella quagga illustration: it is an undated watercolour painting, again by Hamilton Smith, and is contained with various others of his watercolours in an unpublished manuscript by him held in the library and archives of London's Natural History Museum. Moreover, this beautiful painting remained unpublished until as recently as 2010, when it appeared in a Zeitschrift des Kolner Zoos article on quaggas by Lothar Schwahle and Wolfgang Wozniak.
Hamilton Smith's two illustrations readily confirm my early deductions as to the isabella quagga's likely appearance – namely, an aberrantly pale, isabelline-coloured quagga with only very faint, white striping.
Having viewed several comprehensive lists of quagga material currently housed in museums worldwide, I can confirm Lydekker's statement that the isabella quagga skin deposited by Burchell at what is now London's Natural History Museum is no longer there, and is therefore lost. Presumably it was discarded due to its very poor condition, but a tragic loss nonetheless of such an exceptional, unique specimen, and which nowadays might well have yielded much useful information via DNA tests conducte3d upon samples of this skin's tissues.
Yet despite the isabella quagga having long since been reduced in status from a taxonomically-discrete species to a non-taxonomic mutant oddity, its delicate pallid beauty deserves to be remembered and celebrated. So I am very glad that I discovered this elegant animal hidden away as the briefest of footnotes within the dusty archives of the past, and have been able to revive it, even if only in words and pictures, within this present article, written up at last.
