Saturday, 25 April 2015

Using extant wild cattle to create an aurochs replica?

I have been asked by several people if crossbreeding with existing, extant wild cattle is a good idea for creating a bovine that resembles the aurochs and is suited to live in Europe’s wilderness. I have been wondering that myself already, and indeed it is tempting. As so many aspects in “breeding-back”, rewilding or “de-extinction”, this question is subjective. But I am going to try to list some of the pro’s and con’s and draw my personal conclusion.

The thoughts behind this idea are that domestic cattle have lost certain wild animal traits, what they undoubtedly did, and that wild bovines could bring them in, otherwise the cattle would have to redevelop them by dedomestication. And apart from that, they would be able to contribute morphological and external traits resembling the aurochs at least as good as primitive domestic cattle could, or even better. For example, Java banteng have a strong, well-marked sexual dimorphism and the tone of their coat colour is reminiscent to that of the aurochs (light brown in cows, black in bulls). Gaurs have an impressive size, bigger than any living cattle. Some wild yaks have horns that perfectly resemblethose of the aurochs, and they would contribute excellent cold tolerance. Yaks are closer to bison than cattle, and the males of the first generation have fertility problems. But that would disappear as the breeding progresses. The wisent would contribute aurochs-like proportions with a well-pronounced hump, but there are even more pre- and postzygotic isolation mechanisms, and wisent and aurochs were sympatric, so I would not use them. Actually, all of those wild bovines would add high processus spinosi in the shoulder area. The undesired traits they contribute, such as the overlong coat of the yak, the upright horns or white “socks” of banteng and gaur would be selected out just as any other undesired trait.

So using those wild bovines seems advantageous for optic traits and probably also cold resistance. But there are other aspects that must be considered. First of all, they are not just different varieties of one and the same species, but completely different species. They diverged more than two million years ago (the age of the oldest aurochs remains), so there are considerable differences not only in morphology but also genetics and ecology. The argumentation that an aurochs replica made by “breeding back” would be ecologically equivalent to the aurochs because domestic cattle are a domesticated variation of this species would be gone, and it is likely that the other species differ ecologically from the aurochs. The gaur for example was sympatric with the aurochs and prefers dense forest, live on higher altitudes and browse more than cattle. This distinguishes it from the aurochs in the same way as the wisent. The banteng on the other hand, whose range did not overlap with the aurochs but with the gaur, dwells in dryer and open landscapes and is therefore comparable to the aurochs. Yaks definitely are grazers. According to Wikipedia, they need less food intake than robust cattle and survive a couple of days without water and food, and they cope with way colder temperatures than cattle usually do.
While I don’t know of fertility problems between the closely related Bos members gaur, banteng and aurochs, cattle and yak do have some as stated above. Yak are closer to bison, which might be problematic – it could increase the chance of hybrid cattle interbreeding with wisents. But this is just an assumption, I do not know if yak and bison readily interbreed at all.

From the ecological point of view, yak and banteng shouldn’t be that problematic. The yak would probably even be beneficial. Morphologically/optically, they would be advantageous as well: banteng contribute size, high shoulder spines and a well-marked sexual dimorphism, and (wild) yaks add perfectly aurochs-like horns. So why not using them, at least in small doses?

There are people who are opposed to the usage of breeds with visible zebuine influence (like Watussi) because zebuine and taurine cattle diverged in the late Pleistocene, but still are B. primigenius, so they would totally reject the usage of extant wild bovines in the first place. The argument that dedomesticated, aurochs-like cattle have a legitimation as native wild animals in Europe because they belong to the same species as the aurochs would lose its credibility since such a population would consist of hybrids, at least to a certain degree. This would be problematic for their academic and public acceptance. Considering the controversies around releasing endangered animals even with subtle introgression of another subspecies, I would be surprised if the majority, or even a third, of serious scientists would be in favour of releasing a population consisting of domestic stand-ins for an extinct species mixed with species that are certainly not native – which is understandable. And I can imagine headlines in crappy tabloids like “Hybrid monster cattle to be released into nature!”. Of course I am aware that hybridization is a part of evolution and takes place anywhere closely related species neighbour each other, and regular readers of my blog will know that I am not averse against bison introgression into controlled wisent herds as diversity donors. But primarily I think that man should try to conserve or reconstruct nature as it is or was, and not to try playing evolution if not necessary. Regardless of how strong the hybrid influence would be, the population will probably display a mosaic of not only morphology but also ecology and behaviour. I have not mentioned yet that yaks also live on higher altitudes than cattle, and banteng have a different combat behaviour. They have a higher profile and display it to their opponent, raising their head to look as large as possible. They do not fight nearly as often as cattle do, what explains their upright horn shape. Who knows what kind of effect it will have on the behaviour of the population.

So there are arguments for and against using wild cattle to breed an aurochs substitute. My personal opinion is that I probably would not do it, because of the scientific and public response and a weaker argumentation basis as outlined above. Nevertheless it would be interesting to see hybrids between Yak, Banteng and primitive cattle. A “test herd” could be an idea.


  1. With the articles I've been reading about George Church gene editing Asian elephant DNA for smaller ears, and thicker longer hair, makes me think it should be possible to modify cattle DNA to have aurochs features.

  2. Hello and thank you for an interesting blog.
    Afterall the gaur and banteng derive from the Indian Aurochs, which itself was closer related to the Aurochs than modern domestic cattle so there is obviously shared ancestry where these breeds may have perserved some genes and traits from the Aurochs that is not preserved in modern domestic cattle, which their morphology and colour pattern indicates, meaning they carry a piece of the puzzle which legitimizes them in the means of restauring the aurochs, utilizing selective breeding to exclude undesireable traits, which probably wouldn't make a strong protrusion after a couple of generations of introgression anyway.
    It begs to question how big the problems versus the benefits of such introgression would bring. It also somewhat puts to question why watussi cattle, a hybridization with zebu cattle which differs even more from the aurochs have been used in the project, when a gaur or banteng the same way could be selectively introgressed emphazising desireable trairs, which are more evident than in the Watussi.
    I don't think it is a higher gamble, or a more controversial inclusion than some other breeds that have been used in the program. Rather oppositely the fact that they developed in a different branch might just mean they carry heritage that has not been preserved in taurine cattle.
    Just throwing it out there, could for example toro de lidia balance up the reduced fighting behaviour of the banteng?
    Even the yak at some point share a common ancestry hence also genetics, with some traits that are evidently highly desireable for the end goal.
    BUT, taken in mind the points in your article it might be wise not to use them in the official program right of the bat, but for a separate test herd. Since they would have to be slowly introgressed either way. I am confident you could and would produce specimens desireable for further use in the program. Maybe you could produce a stud breeding bull for example that exhibits fine aurochs traits without much of the undesireable. And the genetic diversity would surely not be of harm.
    Following the progress with intrigue.

    1. Just to add further; IMO, it would just sort of broaden the palet of all bovines related to the aurochs to some degree, reasonably using those closest relating to aurochs in a higher degree in controlled breeding to achieve the correct traits.
      One could almost see it as breeding this ancient beast from two separate ways, you would be breeding it back from it's descendants and breeding it forth from a line that separated from it before the aurochs era in for example the yak, used to a lesser extent due to smaller relationship, introgressed upon desired traits. This makes perfect sense in recreating the original, ancient version of the aurochs.
      If you by utilizing gaur, yak, banteng and the like could produce a specimen that was closer morphologically, arsthetically and to some degree behavioural like to the ancient aurochs than if only using modern cattle. Now isn't that more legitemate than ONLY using domestic cattle?
      I also want to bring up the behavioural issue, now since it's domestication and original separation from wolves, mans best friend the dog, have lost almost the entire front lobe responsible for instinctive behaviour, and their brain has been effectively reorganized to adjust them for human need, and their behaviour significantly changed. Now, i know it is not the entirely same deal but to use as an example, if you would assume the wolf was extinct, you could use modern wolf like breeds like the malamute and husky to create a closely resembling, even identical specimen like this GSD-malamute cross but you could never return the lost behavioural centras in the brain solely from using modern breeds, and they would probably not survive in the wild. Would it be reasonable to use for example a dingo or jackal, which is less related to a wolf than a husky, but has been forced to preserve independent and instinctive behaviour? Hence traits lost in the domesticated closest relative to the wolf, the dog, yet preserved in them. Now, they might aquire additional and differing behaviour from the grey wolf yet it would be more apropriate for a wild animal and probably still closer to the wolf than if solely using modern dog breeds.
      I am wondering how much of the same the case could be for aurochs? Meaning how much is documented and known from their original behaviour for modern cattle to be apropriate as a reference to aurochs characteristics.
      If you are really bent on recreating the aurochs it makes sense to go wide and far to pick as many pieces of the puzzle as possible from an as wide range of specimens as possible, and now so happens to be that wild extant relatives exhibit traits hard to muster out from the aurochs domesticated descendants. Why is it any more controversial? It only means a more advanced effort. More controversial seems to recreate an extinct, ancient beast from animals highly domesticated and dulled out for human purpose, why not stretch the horizon to extant, wild even if distant relatives?

  3. And the kouprey?

    1. Where did you get the idea from that Gaur and Banteng descendet from the Indian aurochs? There is no hint for that and it is implausible.
      And it is questionable if the kouprey still exists at all, and even if, nobody would come up with the idea of crossbreeding them first instead of conservational breeding.

  4. Hi i didn't suggest kouprey but wrote that the banteng and gaur descended from the indian aurochs which i was probably wrong about. They do obviously however share common ancestry even if distant. It was a personal assumption, i should have read your entry more thoroughly too, not educated in these things i follow it as an interest.
    I think these things are highly interesting and it's amazing from a time where mankind has exploited nature from hundreds of thousands of years and left such a meager biological diversity, which i think most people have a certain longing for, that we now have become so rich and developed that we are at a turning point where we can start to redevelop nature to it's previous state, even have at our hands to return animals who's extinction we were responsible tens of thousands of years ago. It's going to be really fun and interesting to see nature recuperate and arise again all around the world. And if they could speak how much would they thank us? :P I think the restauration of species and nature that has just started is one of the most exciting things that goes on in our time right now.

  5. Hi,

    I think the question of using "wild Cattle" ist not to cross Cows with Banteng ore Gaur. The question is why not use feral cattle, wich live all over the world. The Beginning is done in using old and free ranging cattle-races from south europe. But there are other races of feral cattle ( f.e. longhorns) and some races on islands. Some of them first have to be found.

    mfg Hans

  6. Just a quick not to say that this post and your whole blog are great. I've just finished a short piece about aurochs and the ancient Greeks, and I've linked to this blog.

    The attempt to back breed the auroch is cool, but you don't really end up with an auroch, anymore than if you glued hair to an elephant and called it a woolly mammoth.

    The only way to make a real auroch is through cloning from ancient DNA

    1. Yes, I repeatedly stated this on my blog.

  7. Hey!

    Did you know that the Dutch True Nature foundation is attamepting to breed back the European water buffalo?
    Could you please do a post about that subject? not much info is provided about breeding back european waterbuffaloes on the internet.

    Many thanks in advance!

    J. K.

    1. They are not actually trying to "breed back" Bubalus murrensis but to create an ecologic proxy from living wild and domstic water buffaloes. I actually intended to write a post on that for ages, but I never got to it... thanks for the reminder.