Wednesday 21 August 2013

The Indian Aurochs: breeding-back with Zebus?


UPDATE: I consider my life reconstruction of the Indian aurochs a bit outdated. For my current opinion, see my 2017 post

When we speak about the aurochs, we mostly refer to the Eurasian subspecies, B. p. primigenius, the wild type of taurine cattle. The two other subspecies, the African and Indian aurochs, are almost forgotten because they died out way earlier, there are no written accounts of them and there is much less skeletal material to work on. The distinct Indian subspecies, Bos primigenius namadicus, is in the focus of this post. This subspecies has a number of living descendants too, the zebuine cattle or zebus, arising from a different domestication event. Zebus usually are avoided, even banned, from effigy breeding because their ancestors separated from those of taurine cattle during the middle or late Pleistocene. Also their phenotype is rather awkward and derived, and they are adapted to very arid habitats and none of them has the same cold-tolerance or thick winter coat as European cattle. So they are considered to serve no good for creating a proxy for the European aurochs. But how about using less-derived Zebus for breeding a suitable stand-in for the Indian aurochs in its native range? Before going further into this idea, we have to see what we do know about Bos primigenius namadicus.

Skeletal remains of the Indian aurochs are scarce, only fragmentary postcranial material and few skulls are known. These tell us that the Indian aurochs probably was smaller than the Eurasian subspecies (I don’t know how much smaller, but 150-160 cm for bulls might be realistic) and had proportionally larger and more wide-ranging horns [1]. There are no unambiguous depictions that show the Indian aurochs, nor are there historic accounts describing them [1]. Therefore, much of its phenotype is actually unknown.
But phylogenetic bracketing which is based on parsimony is a useful tool to infer some traits of its appearance because features present in both zebus and sister clades such as taurine cattle, the banteng, kouprey and gaur must have been present in the Indian aurochs as well. I think it is very likely that the Indian aurochs too had a long-legged and athletic body like the Eurasian aurochs, and also Koupreys had similar proportions. The dorsal spines of the 1st - 13th dorsal vertebrae are elongated in Eurasian Aurochs, Bantengs, Gaurs, Koupreys and Bison (also in primitive cattle such as Lidia), forming the typical “hump” of wild cattle. Therefore it is very likely that the Indian aurochs also had this feature. The colour of the Eurasian aurochs displaying black bulls with an eel stripe and reddish or brownish cows and a mealy mouth in both sexes is also present in some Bantengs (except for the light eel stripe in bulls) and is indicated in some gaurs as well. It is even displayed by some primitive zebu cattle. Therefore the same basic colour must have been present in the wild Indian aurochs as well. The so-called “zebu tipping gene” causes a lightly coloured area between the legs cows and (some) bulls of zebus, and apparently the same gene is present in the Banteng, so the I. aurochs must have had it as well. The hair of the area between the horns is lightly-coloured in many primitive taurine cattle bulls and also in Gaur bulls, therefore some Aurochs populations must have had this feature. Because the same is found in some zebu, I apply it to namadicus as well. The hair between the horns in the Eurasian aurochs were said to be curly and frizzy, but this isn’t the case in any zebu or Gaur/Banteng, so I assume this feature to be absent in the I. subspecies. The pelvis in zebus is oriented more vertically than in taurine cattle, resulting in a more horse-like rear. When taking a closer look at wild cattle, it becomes obvious that actually all of them have the same feature – Bantengs, Gaurs and Bisons. So it must be a plesiomorphy (a “primitive” feature) and must have been present in the Indian aurochs as well.
Putting everything together, it turns out that although we actually do not know much about this subspecies’ appearance directly, we can infer a lot of things when approaching it systematically. Based on this, I created this reconstruction:


I also gave my Indian aurochs a slightly longer dewlap, because bovids tend to have long dewlaps for display and cooling in warmer habitats (and hairy appendages like beards in colder ones). There is the possibility that the Indian aurochs also had a kind of hump that is visible in its zebuine descendants, it could have served as an additional tool for cooling down and also for storing fat (the Indian aurochs probably dwelled more arid environments than the Gaur or Eurasian aurochs). But the zebuine hump mainly consists of a hypertrophied rhomboideus muscle that actually serves no visible purpose and has no effect on thermoregulation or food reserve [2]. Unambiguous depictions of the Indian aurochs might help solving that question. I think the zebuine hump is too speculative for me to include it in my drawing and I am not convinced of its presence, but I cannot rule it completely out yet. There is an engraving in the Bhimbetka rock shelters from the Pleistocene which may show the aurochs and has no zebu hump. The depicted animal definitely has an eel stripe, but because this eel stripe is dark it could also show a Banteng, or a Kouprey (the horn tips look a bit bristled).

The phenotype of modern zebuine cattle is very derived and gives them a quite weird appearance. Apart from the fleshy hump and the long dewlap, they have hanging ears, a floppy body and horns of various shapes and sizes. Clearly there is no known zebuine breed that resembles their wild type as much as some southern European taurine breeds resemble their respective wild type. The first depictions of zebu-like cattle were date back 6000 years ago, but it is possible that more-primitive zebuine cattle still were around at that time. I have no likely explanation for why there are no truly primitive zebus left; they were not domesticated significantly earlier than taurine cattle. Perhaps the disappearance of primitive zebus was due to conscious selection or simply coincidence. However, there still are some zebuine breeds that preserve some aurochs-like features.

Miniature zebus with aurochs-like coat colours (photo: Markus Bühler) 

Some miniature zebus have a coat colour very reminiscent of the aurochs, even displaying sexual dichromatism. But this breed is quite small, stubby, has tiny horns with a deviant curvature and many of them have taurine introgression.

 
Watussi cow with remotely aurochs-like horns (Photo: Marc Thevenard)
Watussi cattle are taller and slenderer, but do not have the wild colour. Their horns sometimes have an excellent curvature, and their huge dimensions are useful for compensating the small horns of other breeds. Very likely Watussi is no purely zebuine breed as well.

Gudzerat zebu (Photo: Marleen Felius)
Kankrej zebu
The Gudzerat/Kankrej (both breeds are nearly identical) have a grayish wild colour with a reduced sexual dimorphism (much like Steppe cattle). Their horns are very upright, but apart from that, have a useful curvature and also decent dimensions. This breed has no taurine introgression as far as I know.

Although quite satisfying results might be achieved by crossing and selective breeding with breeds like these three, it is clear that the most suitable animals for effigy breeding with zebus are yet to be found. What such a “Wild zebu project” needs before actual breeding starts is: research!
In fact, we don’t know much more about the Indian aurochs and primitive zebus than the Heck brothers knew about the European aurochs and primitive taurine cattle ninety years ago. To ensure that such a project is a success, one has to

1. Collect more material of Bos primigenius namadicus
Be it bone material that tells us more about the morphology, habitat preference and extinction of this subspecies or artistic depictions that could provide clues about its external appearance.

2. Research on zebuine breeds, locating the most primitive breeds
While those three breeds I took as an example may provide some useful features, most zebus outside India are mixed with taurine cattle and looking for good Indian breeds that are hardly known in Europe may uncover not only pure (I am no fan of the purity cult anyway) but also more primitive zebus than those we usually see.

I think that only after such research is done the actual breeding should be started. I am sure that virtually all Indian zebus are hardy, robust and heat-tolerant landraces, but it would be best if such a “Wild zebu project” would also be carried out in India, in order to keep the animals in a semi-feral state in the habitats they are supposed to be living later on.
Although some native Indian zebu breeds may be more primitive and aurochs-like than those breeds usually known in Europe, it may turn out that zebus do not preserve enough phenotypic features to reconstruct the appearance of their wild type completely. I consider that likely because all zebus we know of lack the athletic body that is displayed by at least some taurine cattle, most have very derived horns and almost none of them have a long, aurochs-like skull. Also all zebuine breeds that we know of have a the typical, hypertrophied rhomboideus muscle. However, not all zebus have a really huge hump, actually the hump is quite small in some Indian and south-east Asian zebus. Another idea which is worth considering that some breeds which previously were considered taurine cattle or taurine hybrids in southern Asia might actually represent primitive, humpless zebus. This would need to be genetically tested and would be the third task of the research that yet has to be done.
 
This is what the "wild zebu" could look like
This photographic reconstruction by Jochen Ackermann on Wikipedia illustrates what I think is achievable with selective breeding with zebus. It would be interesting to see how these “Wild zebus” would look like after living several generations in the wild, perhaps even with pressure from predators. They’d certainly get more swift and athletic, their zebu hump might get smaller until it disappears while the neck and shoulder region gets developed stronger and the horn shape would also be refined.

Actually there are Zebu populations living feral, such as in the Kuno Wildlife Sanctionary. These cattle have been reintroduced recently, are a mix of several zebus and serve as “buffer prey” for the big cats until viable populations of genuine large herbivores are available for them, making them the only domestic descendants of the aurochs that are exposed to large felines. Let’s hope they are not short-sightedly removed after that stage because they will develop into a fascinating dedomestication example and one of the few (or even only?) feral zebus to date.
 
Feral zebu in the Kuno wildlife sanctuary 
But what is the point of creating an aurochs-like zebu breed at all? Well, it’s the same reason why authentic proxies for the European aurochs are desirable. The aurochs was a native large herbivore in India and fulfilled a niche that others do not (f.e. it likely inhabited dryer and more open habitats than the Gaur). The Kuno Wildlife Sanctuary, Gir Forest or the Rhanthambore National Park are suited wildlife refuges which might be a good place to reintroduce and dedomesticate the “Wild zebu”.


Literature

[1] Cis van Vuure: Retracing the Aurochs - History, Morphology and Ecology of an extinct wild Ox.
[2] McDowell, McDaniel, Hooven: Relation of the rhomboideus (hump) muscle in zebu and European type cattle. 1958. 

5 comments:

  1. About the possible habitat of African Aurochs:
    The Sahara Desert was once green, this desert climate changes twenty thousand in twenty thousand years due to oscillations of the Earth's axis. There are large underground lakes in this desert.

    ReplyDelete
    Replies
    1. How The Was Made Season: Sahara:
      http://www.youtube.com/watch?v=7PuBCFVPZpw

      Delete
    2. How The Earth* Was Made Season: Sahara:
      http://www.youtube.com/watch?v=7PuBCFVPZpw

      Delete
    3. (HD) How The Earth Was Made Season 2: Sahara:
      http://www.youtube.com/watch?v=1OxyOMqasYk

      Delete
  2. Here's some zebu breeds we could use for such a project.

    Ongole - For the size and aggression
    Kangayam - Horn shape
    Hallikar - Coloration and sometimes horn shape
    Javari - Coloration
    Kenkatha - Coloration and adaptability

    ReplyDelete