The supposedly extinct 'Cape hartebeest': not a real subspecies, but just individual variation in Alcelaphus caama
Roberts (1951) recognised two subspecies for the red hartebeest, namely
- Alcelaphus caama caama (G. Cuvier, 1816), and
- Alcelaphus caama selbornei (Lydekker, 1913).
He regarded the former, with its southwesterly distribution, as extinct in pure form.
The stated difference is that the various dark markings are better-developed in the nominate (extinct) than in the surviving ssp. The latter, ostensibly adapted to the semi-deserts in and around the Kalahari, was widely introduced in South Africa after Roberts' time.
The postulated subspecies-distinction may seem to make sense, given a common pattern, among many animals, of relative pallor in arid climates.
It also seems plausible in view of the biogeographical patterns shown by Raphicerus campestris (https://www.inaturalist.org/observations?taxon_id=698704) and Sylvicapra grimmia (https://www.inaturalist.org/observations?taxon_id=698822) - both of which have dark nominate sspp. in Western Cape province of South Africa.
The following specimens conform approximately to the description of selbornei:
https://www.inaturalist.org/observations/61764302.
However, J M Dolan, as long ago as 1964, concluded that the type specimen of selbornei is nothing more than a pale individual of Alcelaphus caama (https://eurekamag.com/research/023/288/023288726.php and https://www.zobodat.at/pdf/Zeitschrift-Saeugetierkunde_30_0179-0181.pdf). This was based on specimens in zoological gardens at that time.
Dolan also pointed out that Lydekker acknowledged that he had erred - although never correcting his error in the literature.
R H N Smithers (1971, The Mammals of Botswana), using a sample collected in Botswana, independently tested Dolan's conclusions, and came to the same conclusions.
Smithers, on page 248, quotes and compares the type descriptions in detail in tabular form. He then spends three whole pages (249-252) discussing the problem.
He concludes: "On this basis one is led to the conclusion, as arrived at by Dolan (1965), that A. b. selbornei Lydekker is a synonym of A. b. caama G. Cuvier and that Lydekker must have based his description on a specimen that, while apparently adult, fell at an extreme of variation of colour and other characters normal in a population of A. buselaphus (sic)"
And there, half a century ago, the notion of a subspecies called 'selbornei' should have been discarded once and for all.
However, this notion has, somehow, persisted. Some still believe that the reintroductions of the red hartebeest to most of South Africa (https://www.researchgate.net/figure/Early-historical-incidence-of-the-red-hartebeest-mappable-written-and-supporting_fig6_283211067) have been of 'the closest thing' (selbornei), rather than 'the real thing' (nominate caama).
Examples of subspecies selbornei still being (incorrectly) cited to this day are:
https://www.imago-images.com/st/0149292940
(The following not only is mislabelled as selbornei, but is a particularly worthwhile photo in its own right: https://www.agefotostock.com/age/en/details-photo/red-hartebeest-alcelaphus-buselaphus-selbornei-mountain-zebra-nationalpark-south-africa-africa-group-of-adults-group-at-waterhole/JHS-S07818.)
So, I have made my own effort to join Dolan and Smithers, in dispelling the lingering notion of a pale subspecies called selbornei. In my case, I have taken advantage of the thousands of photos now available on the Web, to test the hypothetical subspeciation.
I have recently scrutinised about 4,000 photos of A. caama, partly to sort out how much of the variation in colouration is owing to age and sex (see https://www.inaturalist.org/journal/milewski/71244-age-and-development-in-the-red-hartebeest-alcelaphus-caama-from-photos#), and how much is owing to individuality.
Like Dolan and Smithers, I have found so much individual variation that I, too, doubt the validity of any subspecies.
INDIVIDUAL VARIATION
I have noticed that individual variation affects the various dark markings to different degrees.
The following lists these in order of decreasing variation on an individual basis (after controlling for age, i.e. ontogenetic effects):
Darkness most consistent among mature individuals: tail-tassel (caudal flag), lower lip-chin (buccal semet), and eye-mask (the latter never black)
Darkness moderately consistent among mature individuals: nuchal stripe, posterior surface of pedicel, patch on shoulder, patch on ventral part of haunch, rostrum, temple, forehead, anterior surface of upper foreleg
Darkness least consistent (perhaps particularly among mature female individuals?): lower legs, both fore and hind (https://stock.adobe.com/au/search?filters%5Bcontent_type%3Aphoto%5D=1&filters%5Bcontent_type%3Aillustration%5D=1&filters%5Bcontent_type%3Azip_vector%5D=1&filters%5Bcontent_type%3Avideo%5D=1&filters%5Bcontent_type%3Atemplate%5D=1&filters%5Bcontent_type%3A3d%5D=1&filters%5Bcontent_type%3Aaudio%5D=0&filters%5Binclude_stock_enterprise%5D=0&filters%5Bis_editorial%5D=0&filters%5Bfree_collection%5D=0&filters%5Bcontent_type%3Aimage%5D=1&k=%22red+hartebeest%22&order=relevance&safe_search=1&limit=100&search_page=12&search_type=pagination&get_facets=0&asset_id=414565863).
VARIATION WITH AGE, from adolescence to full maturity
The following shows that the dark patches on the forehead, the shoulders, and the ventral part of the haunches remain incomplete even when the horns have achieved their main curvature: https://www.shutterstock.com/video/clip-11340560-red-hartebeast-4k-footage-namibian-savannah.
SEXUAL VARIATION
Mature males may be darker than mature females (https://www.inaturalist.org/observations/107746869).
Skinner and Chimimba (2005) state, about the ground-colour on the back and rump: "The saddle is less obvious in females than in males and in some females it is barely perceptible".
So, among adults, the main variation seems to be on an individual basis, rather than by age or sex.
In summary, I provide further, independent confirmation of Dolan's 58-year old refutation of the validity of subspecies selbornei.
After all the wanton killing of the 1800's, in which we lost the quagga to extinction, the red hartebeest came through fully intact, and has been so widely reintroduced that it provides one of the most encouraging success-stories of wildlife conservation on Earth.
We can, therefore, be glad that
- no subspecies has been lost, and
- the form of the red hartebeest seen today by virtue of reintroduction, in and near the original localities ('Cape of Good Hope' in Western Cape province, and 'Agter Bruintjes-Hoogte' in Eastern Cape province), is indeed the same as what hunters exterminated from the whole of the previous Cape Province, south of the Kalahari.
Comments
The nominate has to be valid. By definition.
You mean that selbornei is not a valid subspecies.
The specimen originally described by Sparrman was been obtained in what is now Eastern Cape province:
https://en.wikipedia.org/wiki/Bruintjieshoogte_Pass.
There is also a locality of similar name in Namaqualand (https://mapcarta.com/19084218), but I take this to be irrelevant.
@tonyrebelo Yes, many thanks for the correction.
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