How long will the most widespread type of wildebeest remain unnamed?

Wildebeests (Connochaetes) can be divided into the species C. gnou (black wildebeest or white-tailed gnu) and the rest.

A problem with the rest is that it is a stretch to call them mere subspecies of one species, namely Connochaetes taurinus, as is currently done in iNaturalist.

They are too different-looking from each other, as might be expected given that the distributions of at least four of them were naturally isolated. But on the other hand they are similar-looking enough that most naturalists shrug their shoulders, assuming that experts are aware of the problem and subspecies-status is good enough. 'We all know what we mean', at least for now.

The problem that keeps flying under the radar is a different one.

Not only does a whole subspecies of Connochaetes taurinus (https://www.alamy.com/stock-photo-profile-of-a-blue-wildebeest-pictured-in-etosha-national-park-namibia-77058608.html) remain without a name (either scientific or common), but this is actually by far the most widespread of all the forms of wildebeest.

The type in question occurs all the way from the Northern Cape of South Africa across the Kalahari (https://www.alamy.com/blue-wildebeest-connochaetes-taurinus-kgalagadi-transfrontier-park-south-africa-image355236582.html), Okavango (https://www.dreamstime.com/herd-wildebeest-island-okavango-delta-near-maun-botswana-wildebeest-okavango-delta-image141699574) and Etosha (https://www.123rf.com/photo_46595093_blue-wildebeest-in-the-etosha-national-park-namibia.html) to southeastern Angola and western Zambia (https://www.alamy.com/cooksons-gnuwildebeest-connochaetes-gnou-cooksonni-in-busanga-plains-kafue-national-park-zambia-image264898393.html and https://indafrica.co.nz/listings/western-zambia-safari/).

This range is far greater than the combined ranges of all the other forms of wildebeest. The nameless one spans five countries and remains common in at least four national parks. And it still makes its ancestral migration into Liuwa Plain National Park (https://www.safaribookings.com/liuwa-plain/wildlife-photos).

How has this subspecies continued to be overlooked as an entity worthy of a title?

A confusing appearance is hardly the reason. The type in question is recognisable, in any of thousands of photos on the Web, owing to its upright mane, long blackish beard, and minimal brindling. In fact, these diagnostics make it more distinctive than any other subspecies of 'blue wildebeest', because they etch a characreristic silhouette even at a distance (https://www.inaturalist.org/observations/41748464 and https://www.inaturalist.org/observations/80522527 and https://www.inaturalist.org/observations/84725640 and https://www.istockphoto.com/photo/group-of-four-blue-wildebeest-or-gnu-herd-walking-through-drought-land-surrounded-by-gm1213909211-352986493).

The main problem seems to be a kind of circularity: it can be hard to see the unlabelled.

Sometimes it is only when something has a name that one can even form a search-image for it. And the failure to identify the most widespread of wildebeests seems to be a quirk of history and geography. The first scientific specimens of Connochaetes taurinus happened to come from the Kuruman-Vryburg area, which is in the intermediate zone between the western and eastern subspecies.

Later this name was applied fully to the 'blue wildebeest' of Kruger National Park and Zululand, without noticing the more lax mane, shorter beard, and more intense brindling (https://www.alamy.es/foto-el-nu-azul-fotografiado-en-el-africano-arbusto-28203516.html and https://www.alamy.com/stock-photo-blue-wildebeest-brindled-gnu-white-bearded-wildebeest-connochaetes-76132063.html and http://www.joelinnphoto.com/africa/xmrwckt8ri8yocv7kwy1dl7ny0ynu1 and https://www.alamy.es/el-nu-azul-de-pie-en-el-cesped-en-el-parque-nacional-kruger-sudafrica-image333968871.html and https://www.alamy.es/foto-el-nu-azul-en-el-parque-nacional-kruger-sudafrica-87295200.html) of that type.

And this unwitting slide of identity eastwards left the western type a name-orphan.

Can naturalists not do better than this? Is it not time to rectify what is ultimately just a habitual oversight?

Let me set the ball rolling by proposing names. How about the 'western wildebeest', Connochaetes taurinus mattosi?

Posted on July 13, 2021 08:35 PM by milewski milewski

Comments

This immature individual, from the intermediate zone in easternmost Botswana, combines the upright mane of the western form with the intense brindling of the eastern form: https://www.alamy.com/stock-photo-blue-wildebeest-connochaetes-taurinus-tuli-block-botswana-25908156.html.

Posted by milewski over 2 years ago

You will need to spell this out better.
Obviously you are suggesting that C. t. taurinus be split. By the sounds of it, into separate Thornveld and Bushveld subspecies/species. Given the features above for the Thornveld or Arid (or 'western') form, what are the features for the Bushveld (or Lowveld) form?

Basically, you are also saying that we should be managing the Kalahari, Botswana and Namibian populations separately from the Kruger-KZN populations. Do we know where the populations in the other national parks (Mokala, Mapungubwe, Pilansberg, etc., and also way out of range: Addo, Karoo, etc.) originated from? Likewise, the extensive populations of private rangelands would probably have been obtained from auctions from a variety of sources, perhaps even with emphasis on "sport" stud bulls (different coats, larger size, horn shapes?). And what about the introduction of other subspecies by the hunting industry?

or to sum up: you have told us what to look for for the Kalahari Wildebeest, now how when I look at a picture do I recognize the Kruger Wildebeests?
Or how blue is Blue?

https://www.ewt.org.za/wp-content/uploads/2019/02/6.-Blue-Wildebeest-Connochaetes-taurinus_LC.pdf

PS: where is the type from?

Posted by tonyrebelo over 2 years ago

@tonyrebelo Many thanks for your comments and questions. My aim in this Post is to point out a taxonomic lapse in an important (indeed the most numerous in the wild besides mearnsi of the Serengeti) form of wildebeest. As you know, everything in Biology is based on taxonomy, i.e. phylogenetic classification and nomenclature. The eastern (blue wildebeest) and western forms are not ecotypes, they are taxa. The western wildebeest, as I propose we call it, occurs in the widest possible range of climates for a wildebeest, from the arid southwestern Kalahari to the mesic grasslands (adjacent to rainforest patches) in northwestern Zambia. The two subspecies intergrade in Hwange and Tuli and presumably likewise (formerly) at the type and lectotype localities at Kuruman/Vryburg.

Posted by milewski over 2 years ago

Perhaps the first step is to determine if the type is one or the other or an intermediate.
I was not suggesting ecotypes, although clearly this has some role to play.

Perhaps the most important question, given that you suggest that there is integration, is how wide that zone of integration was?, and if the two subspecies are not just extremes on a continuum?, in which case, the idea of two subspecies may be problematic.
You have made a case (half a one anyway, for the W form) for a difference, now you need to unpack the where and the problems.
You have flown your kite, now you need to put it to bed.

Posted by tonyrebelo over 2 years ago

Basically, the current problem arises from the following two understandable historical errors/lapses. Firstly, Burchell had no way of knowing that the type location for taurinus was compromised by being in an intergradation zone between a western and an eastern subspecies. Later, after Blaine named mattosi from Angola, Shortridge (1934 vol. 2 page 467) and Ellerman et al. (1953 page 205) assumed this subspecies was synonymous with taurinus - whereas in fact it differs in its mane, beard and brindling. In principle, the solution would be to adopt mattosi for the western subspecies and to change the name of taurinus to reflect a type location well east of the intergradation zone. However, it is probably far too late for the latter disruption. Instead, let us accept taurinus as the nominate despite the lectotype being subspecifically compromised, and let us adopt mattosi, which has always been appropriate for the western subspecies but is still unrecognised as such, a century after Blaine named it.

Posted by milewski over 2 years ago

The distribution of Connochaetes taurinus in southern Africa consists of an eastern area and a western area, connected in easternmost Botswana and, formerly, the Kuruman-Vryburg area. There is intergradation, much as there is between the bush duiker subspecies caffra (east) and steinhardti (west). Intergradation is normal for subspecies and the area occupied by the western wildebeest beyond any zone of intergradation is vast: the whole Kalahari, Etosha, Zambia in both the Liuwa Plain area and Kafue, and southeastern Angola.

Posted by milewski over 2 years ago

Has there been any DNA work?

Posted by tonyrebelo over 2 years ago

The genetic analyses so far seem to have focussed on the problem of hybridisation with the black wildebeest, and the selective breeding of new morphs in the hunting industry. As far as I know there has been no genetic comparison of the eastern and western subspecies of 'blue wildebeest', and this is for the simplest of reasons: there seems to have been no question in anyone's mind about such a distinction. This lack of awareness will, in hindsight, seem odd given that a) there have for so long been so very many photos from Kruger Park and Etosha to compare, and b) any supposed type claimed to occur unvaryingly all the way from Zululand to the edge of the Congo Basin should have been suspect. Of course, genetic comparisons of western and eastern C. taurinus would be welcome, but they would not be necessary for the splitting of the subspecies-names, any more than they have been for subspecies of e.g. the bush duiker living in the same areas. As I see it, no new description by any taxonomist seems to be needed; all we need to do is take Blaine's name mattosi from a location in Angola, and start using it.

Posted by milewski over 2 years ago

So a short note in a peer reviewed journal should do it.

Posted by tonyrebelo over 2 years ago

Add a Comment

Sign In or Sign Up to add comments