Sunday, 30 March 2014

Teaser: Wild horse looks, dedomestication, cattle behaviour and more!

Busy days at the university, so I do not have the time to write long posts at the moment. Therefore only a teaser today. A post collecting and analyzing primary references on western wild horses is in preparation, as much as one on the Sayaguesa and Tudanca at the Veluwe in the Netherlands. A post on historic Heck cattle, including the extinct Berlin lineage, is completed already, but the illustrations are not ready yet. I also plan to do a well-pictured post on the social and reproductive behaviour of cattle. My most extensive posts will be a series on the role of dedomestication in restoring "wild" horses and cattle. 
Please stay tuned! 

Thursday, 27 March 2014

Newborn calf at the Lippeaue

UPDATE: Part of the numbers in this post were wrong, they should be correct now. 

OK, there are probably numerous calves that get born in the population counting approx. 90 animals at the Lippeaue per year. But I report this one because it is of an interesting combination. 

See here for the bull calf

This bull calf was born in a recently formed herd at Kleiberg, which counts 5 adult and subadult individuals yet. Her mother is one of the first cross animals of Taurus cattle, a 13 years old Chianina x Heck cow named Ludovica, fullblood sister of the bull Luca. The breeding bull is named Linnet, son of a pure Sayaguesa bull and a 37,5% Heck, 50% Sayaguesa and 12,5% Chianina cow (not a half-Sayaguesa though) - and therefore the bull is 18,75% Heck, 75% Sayaguesa and 6,25% Chianina and of the fourth cross generation. There are no photos of Linnet as an adult bull on the web, and I did not see him personally, but I saw him in a video on German TV, and he looked a bit like a larger version of a Lidia bull with thicker horns to me. The snout wasn't that long though. 

Why am I mentioning that calf? It is a fift-generation calf - there are surely much more - and I am curious on how that bull will work out. This calf is a 34,725% Heck, 37,5% Sayaguesa and 28,125% combination. Inheritance works by chance, but his father looks very good, and the half-Chianina mother is able to pass on a full Chianina chromosome set, so I hope this bull might become an even larger but still nicely aurochs-like bull. And if not this one, another calf of these parents might. It looks like it has no apparent dilution expressed, so its coat should become good (it still might develop a light saddle). 

UPDATE#2: That's what the bull looks like today

Tuesday, 25 March 2014

Video of the feral cattle on New Zealand

New Zealand has a population of cattle that have been living feral there since the 1920s, descending from ordinary farm cattle. They are another example of how the body shape and proportions of cattle get changed by the environment and natural selection, creating an optical resemblance to the aurochs - let alone their ability to survive hindrances such as diseases, weather, injuries and of course the display of their natural instincts. Those cattle's proportions and body conformation strongly reminds me of Lidia, and therefore resembles the aurochs. Some of them also have aurochs-like coat colours. Their horns are not special though. 
Here I found a video on the hunting of these cattle. If you can put up with the portrayal of the perverted joy and pride about needless cruelty against animals, you' probably enjoy the shots of these free-ranging feral cattle. 



Monday, 24 March 2014

Post #100! And: Is there a difference between effigy breeds and landraces?

This is my hundredth post on the breeding-back blog, and I am really happy how my blog has been growing – last week I cracked the 500 mark for views per day, and it seems that my blog is the second among the top Google results for “breeding back” already.  Thanks a lot to my awesome readers!!
I spent the last day clearing up older posts by correcting language mistakes, removing dead picture links and inserting a few updates.

Moving back to the topic, the question in the caption. As usual, I define an “effigy breed” as the result of breeding for the desired traits of the extinct animal you want to optically recreate à effigy breeding, a term I transferred from German Abbildzüchtung as a neutral alternative to “breeding back”.  I often thought about whether it is useful to make a sharp distinction between an effigy breed and a primitive landrace, and if we should consider an effigy breed “artificially/secondarily primitive” and a landrace “originally/primarily primitive” (note that by “primitive” I mean less-derived in a value-free sense. I am not happy with that term though, but I haven’t found a useful alternative yet). The arguments for such a distinction are
1) effigy breeds are aurochs-like or wild horse-like because they have been crossed and selected for uniting as much wanted traits as possible, while primitive landraces apparently remained in this state of primitiveness since the beginning of their domestication and therefore their resemblance with their wild types is the legacy of nature instead of artificial selection.
2) some effigy breeds/lineages are selectively breed for increasing the size of certain features without crossing by selecting within the breed only, for example large horns or long legs and snouts in some Heck cattle lineages, large horns in Watussi and large body size in Chianina. This might suggest that these traits should be considered secondarily primitive.

If that’s the case, what difference would it make, and are uncrossed primitive landraces more desirable than effigy breeds? I think this is a totally subjective question and everybody is free to form his own opinion, but I see problems with these two hypotheses outlined above.

1) Domestication is a process consisting exclusively of crossing and selecting over thousands of years. There are, above a certain level, no consistent lineages with a consistent set of features and purebreeding is a relatively recent phenomenon of the last few centuries. Phenotypic traits get transferred, altered or lost all over the phylogenetic tree of the domestic trait of a species (as long there are no isolated subclades). This explains why some cattle of central European dairy breeds like Braunvieh or Fleckvieh can show the upright, lyre-shaped horns of steppe cattle and zebus but also, surprisingly, horns with a perfectly aurochs-like shape. Or the Murnau-Werdenfelser, a central European dairy breed as well, is a morphologically unspectacular breed but yet has a quite aurochs-like coat colour. Each cattle breed has a history of being a mosaic of its neighbouring conspecifics, depending on how large the area of exchange and how intensive this exchange is.
The history of most Iberian primitive cattle is seemingly not very well-documented, but it is in some Italian and eastern European breeds. And it shows that aurochs-like landraces are no exception from having an origin of crossing and selecting and introgression of breeds differing to a varying extent. For example, Podolica was influenced by Braunvieh, Chianina, Romagnola, Maremmana, Simmentaler and other breeds during the 20th century. Boskarin from Croatia is a mix of Podolica, Maremmana, Chianina and others. Many of the small Italian aurochs-coloured breeds apparently are mixes of local landraces and Braunvieh-type cattle, just as many eastern European cattle breeds such as the Rhodopian shorthorn or Busha. Pisano looks quite aurochs-like with their primitive colour, the long legs and their – in some cases – aurochs-like trunk. If it was an Iberian breed with an undocumented history, an advocate of the distinction of original and artificial primitiveness probably would propose that this breed and its ancestors always possessed these features in this combination, and if their level of optic primitiveness had changed it more likely decreased rather than increased. However, we know that Pisano is a mix of Chianina, Braunvieh and Tuscan cattle – and since none of the breeds above has a slender, long-legged stature with an aurochs-like colour at the same time, it must be considered artificially primitive because it is the result of crossing and selection, just like f.e. Taurus cattle would be tagged this way. Whether it was the intention to breed aurochs-like cattle or not is irrelevant for the genetic make-up of the cattle and plays no role. The only thing the “genes care about” is whether or not the breeder selects for, say, long legs, or not and not what his intention behind is. There are more examples for this, like Sardo Bruna, and I bet that if we’d know more about the breeding history of the Iberian primitive breeds, we’d rub our eyes how many examples there are. Look at this Sayaguesa cow used in Tauros Project. It has a reddish brown back like an aurochs cow would have, while most other modern Sayaguesa cows are very dark brown to black all over their body. You might think we are looking at a case of a cow with a remaining sexual dichromatism that wasn’t diminished by selection yet, but in fact this cow is 25% Alistana-Sanabresa. Does that make this cow less aurochs-like? If we wouldn’t know, we wouldn’t even think that there is a difference. Another example: imagine Barrosa and Sayaguesa already existed 300 years ago, but not Maronesa. Some breeders had the idea to crossbreed these two for whatever reason, and the result after some selection is a new breed with horns intermediary between these two, sexual dichromatism (we know thanks to Taurus cattle that sexual dichromatism can surface in crosses between wildtype-coloured breeds of different tones), a short snout and comparably small body size. After a few genetic bottlenecks that always can occur, the modern Maronesa phenotype would have occurred. This is just an imaginary scenario and very likely totally incorrect, but considering that the creation of a new breed always is the mixing of other breeds, and that there is no reason to believe that there was less exchange between the breeders than in similarly civilized regions of Europe, we have to assume that each primitive breed is originally a mix from other more or less primitive breeds. The same goes for horses of course. And it is simply obvious that coincidental combinations of certain primitive breeds can result in cattle or horses that are either a) as much as, b) less or c) more like their ancestors in appearance than the founding breeds themselves. See the Barrosa-Sayaguesa example, or a mix of Maremmana-Pajuna. Whether it is a, b or c depends on the (coincidental) selection or bottlenecks as well of course. As an example, I wouldn’t be surprised if the very long snouts of some female Sayaguesa and perhaps some Pajuna are the results of in-crossing of Holstein-Frisian, which increasingly take place.
Furthermore, it is important to note that some wildtype traits simply cannot be reinvented just by selection. While this is true for quantitative traits like horn size, body size or leg length (which are influenced by environmental factors as well), it is simply impossible for certain colour aspects. Wild type base colour (E+) simply does not reappear in a population that doesn’t have it just because one “tries” to select for it somehow. It has to be present and become fixed, and it stays the same allele as in the founding breeds you got it from. You can’t “create” dun horses either. So a wholly aurochs-like or wild horse-like colour in an effigy breed that is the result of crossbreeding and selection is as authentic as in a primitive landrace, which itself was very likely originally a stabilized mix, and there is no evidence that all ancestors of that landrace always possessed the same colour setting.

2) It gets more complicated in features such as horn size and curvature, leg length or body or hump size – these traits probably are the result of the interaction of many genes we can’t track down yet, and are influenced by environmental factors and phenotypic plasticity as well.  But what we can say is that if you cross a large-horned with an aurochs-coloured breed and unite those traits in one herd, both the features are not anymore artificial than those of its founding breeds, because they passed on exactly the same genes to this herd. And whether or not the genes responsible for large horns are the same as in the aurochs we just can’t tell. Therefore I use “aurochs-like” instead of “primitive” when referring to phenotypic traits, because the latter word automatically implicates that it is a unchanged, genetically identical trait of the aurochs, which is baseless except in the case of colour, while “aurochs-like” simply is more neutral.
Not to forget, there are primitive southern landraces which were in fact selected for traits unintentionally resembling those of the aurochs – such as Barrosa, which has artificially large horns evidently created by selection within a population without crossing in other large-horned breeds (just compare modern Barrosa with those on that old photo UPDATE: I just realized that the link did not direct to an old photo of Barrosa cattle but to a Russian Death Metal song, sorry.). Does that make their large horns less desirable for breeding-back? I don’t think so. It is the goal to create an optical and functional imitation of the aurochs not only for fanciers and education but in fact primarily for its function and value as a native animal in natural areas, and nature does not care about such bagatelles we don’t even have a convincing clue about.

 To put it in a nutshell, I don’t think it is useful to regard effigy breeds as artificially aurochs-like and landraces as originally aurochs-like. After all, it sounds like an inconsequence in itself – a product of crossing aurochs-like breeds and selecting them for uniting their aurochs-like traits should be less original in the end? The history of modern domestic breeds is very dynamic and so probably was that of their phenotype. Before race breeding came up, farmers probably were very pragmatic and used those animals accessible to them and selected them on traits they needed for certain purposes. Either large udders for milk production, or a strong and large-humped body for draft work. The history of many of the Iberian breeds is undocumented, and that of Italian and neighbouring landraces shows that they are themselves mixes of a several breeds, so we should assume that the Iberian cattle breeds are of mixed origin like any other domestic breeds as well, and that their phenotypic resemblance to the aurochs is mostly coincidental. As a consequence, I don’t think that the aurochs-like phenotype of a good Taurus bull is less original than the phenotype of an aurochs-like Pajuna.



Thursday, 20 March 2014

Aurochs model WIP pt.II

As some of you might remember, I am working on two aurochs models, bull and cow, at the moment. Here's another WIP photo: 


The bull model measures 19 cm at the "withers". It's based on the Braunschweig specimen and I am pretty happy with how it worked out. However, I am not sure if it might be actually too athletic. If any of you notices inaccuracies or imprecisions, I'd be grateful if you point it out to me, because after it is burnt I can hardly change it. I might do the dewlap a little longer between the forequarters. 
After the first burning, I am going to add the tail tuft and - of course - the horns and the horns will be sticked into their place as well. The wire forming the base of the horns doesn't represent the final shape, by the way. 


Wednesday, 19 March 2014

Taurus cattle in Hungary

I already gave some basic information on the Taurus cattle in Hungary in this post, but in the lack of recent photos showing what the current population looks like and without more background information I didn’t have much to say. However, about three weeks ago, I contacted Claudia Zimmermann and István Sándor who are directly involved in the grazing project in the National park Hortobagy, where the Taurus cattle are bred. They provided me with very helpful information and a lot of beautiful photos, and I got permission to use them for the blog and Wikipedia. Many thanks!

The grazing project was started with Przewalski horses in 1997, for which the Puszta surely is an ideal habitat. Now they number about 250 individuals. One year later cattle were released, mostly Heck cattle from Austria (more on Austrian Heck cattle in a future post), and Germany f.e. Lippeaue, Wörth and Munich but also Neuwied and Karlsruhe. Steppe cattle and Steppe cattle x Holstein were added because a large number of cattle was needed for the large area of about 2500 ha (little less than half the Oostvaardersplassen). The total number of the cattle currently is higher than 150, making it the largest population in a grazing project and probably one of the largest herds of aurochs-like cattle of that quality in Europe.
I was told that several bloodlines within the herd can be distinguished that are respectively influenced by the following breeds: Watussi, Taurus/Sayaguesa, Heck, Grey cattle and Holstein. As far as I know, there are Lidia-influenced individuals as well. I suppose that these bloodlines are not strictly separated and that the population is basically panmictic.

The horns of this Watussi-influenced cow may not be that thick, but it might carry the genes for larger horns and there must be Watussi-crosses with larger horns as well. I think this cow might be influenced by Sayaguesa as well. What I find particularly interesting is the strong wine red Watussi seems to add. Watussi is advantageous for its large horns and their adaption to dry habitats. Using Watussi is often criticised because of their half-zebuine nature, but Steppe-type cattle are massively zebu-influenced as well and yet they were and are part of each aurochs effigy project.

The bull above is called Rimu (Grey x Watussi) x (Sayaguesa x Heck). He’s one of the largest bulls. The horns are quite impressive and the colour is accurate, but his trunk is rather long and the hump small. Would be interesting to see more results of such a combination.

The Holstein-influenced bull down below is called Zeusz, I think he has a quite cool aspect:


The use of Holstein seems counteracting at first, but it depends on how you select the offspring. The Holstein crosses tend to result in rather large and long-legged animals. Both the black colour and the spots of Holstein are dominant, so it shouldn’t be all too difficult to select those traits out. 

Now some classic Taurus individuals:



Toldi (above) and Szepes (middle) are fullblood brothers (75% Heck, 25% Sayaguesa). Toldi unfortunately was slaughtered before reproduced because of his temperament, but Szepes is a breeding bull and looks pretty good in my opinion (look at all the birds flying around him on the photos, like in Europe's old days!).

I suspect this bull has Lidia in its ancestry (EDIT: wrong suspicion. This bull is actually half Grey x Holstein and half 75% Heck and 25% Sayaguesa. Unexpected looks)

There is a number of un-crossed Heck cattle in Hortobagy as well, including a bull from the Insel Wörth herd. That bull is called “Anno” and used as a breeding-bull.



The Heck x Gray cattle crosses are hard to distinguish from usual, not-well selected Heck cattle (which are grossly influenced by Gray cattle anyway): 

Phenotypically they consequently are not convincing to me, but I think steppe cattle is advantageous because it is a local landrace that is adapted to the Puszta, improving the cattle’s suitability to the region. Furthermore, they are needed to build up the quantity necessary for the ecologic landscaping. But of course Gray cattle enlarges the portion of individuals having the dilution alleles that cause the beige and gray colours we see in usual Heck cattle.

This cow is an interesting animal:

What looks a bit like a usual Heck cow here is in fact a first-generation crossbreed of Holstein x Gray cattle. I puzzled around a bit why this combination resulted in an accurate aurochs colouration. Grey cattle is homozygous for E+, wildtype base colour, while Holstein has Ed, black, which is dominant – so the cow actually should be black. But perhaps the Holstein parent was E+//Ed and passed on the wildtype allele. Grey cattle have a dilutor allele on their Agouti locus (at least), resulting in their fawn colour, but perhaps Holstein has the wildtype alleles allowing the production of red melanin, hidden under their solid black colour. This is the only way I can explain this outcome.

Like the Tauros Project would say, there has been a “breeding for quantity” phase, and now the “breeding for quality” phase is about to start. They have a large population, but numerous individuals do not show a satisfying phenotype yet. So they want to produce a large number of young bulls and select the best ones to increase the aurochs-likeness of the whole population. The selective process runs under the goal of producing a complete aurochs effigy, and when I look at the individuals on these photos, I think this is definitely feasible. The largest bulls like Rimu and Zeusz measure up to 160 cm.
They have all the aurochs features the Lippeaue population has, plus large horns thanks to large-horned Hecks, Watussi and Grey cattle. Indeed their horns are obviously larger on average than those of German Taurus cattle. In the reserve they are going to select on hardiness and resistance to cold as well, so that the cattle do not need supplementary feeding. The Heck cattle, Sayaguesa and a whole range of other breeds proved that they cope very well with the circumstances of central and western Europe, but the Puszta is a particular challenge for the cattle because it is an exceptionally cold and dry area.
Previously, supplementary food was given because the cattle calved during winter as well, what is usually problematic for both cow and calf under natural circumstances. The reproductive cycle of cattle adapts to that if exposed to natural selection, but this is incompatible with the animal welfare for domestic animals (also in grazing projects). So they separate the bulls from the cows for a part of the year to prevent calves being born during winter for now, and also tend to select out cows that calf during this season to mimic the natural selection. 2011 was the first winter the cattle spent without supplementary food.

The cattle are legally classified as domestic animals, like in all other grazing projects, and therefore have to be checked for certain bovine diseases like all cattle in Europe (including those of Tauros Project or other grazing projects). I don’t know if it is legally possible to treat them fully as wild animals (perhaps an arrangement like in Oostvaardersplassen could be made), but I think it might certainly be possible to let them breed freely after a sufficient accuracy of the phenotype is reached. This would mean that we could expect similar phenotypic changes concerning proportions, body conformation and horn shape like in Oostvaardersplassen because of intraspecific fights (dominance of the cows, reproductive success of the bulls etc.).

It is really enchanting to see how really aurochs-like cattle are reconquering natural areas around whole Europe, not just less than mediocre Heck cattle in Zoos. I am talking about all those Taurus cattle, Tauros cattle in three, soon four, areas, and now also the Uruz Project. As a last photo, here is a herd of cows along some Prezwalski horses:

For the Taurus cattle at the Lippeaue, Germany, see here: 



Sunday, 9 March 2014

New photos of the Tauros Project on Rewilding Europe

Finally we get a sneak-peek on cattle of the Tauros Project we haven't seen before, like some second generation animals, but also of older individuals we are familiar with already. You can find those photos on the gallery of Rewilding Europe: http://rewildingeurope.photoshelter.com/gallery-image/TaurOs-project/G0000FBhfa8_okhw/I00001IhTqcO7NQg
These are very aesthetic photos in my opinion. Unfortunately all the images are gifs so no-one can insert them. But I'll link some of the more interesting photos here:

The all known Maremmana x Pajuna "Manolo Uno"
http://rewildingeurope.photoshelter.com/gallery-image/TaurOs-project/G0000FBhfa8_okhw/I00001IhTqcO7NQg

A Limia cross calf, it's not apparent which combination it is, but obviously it has Highland in it:
http://rewildingeurope.photoshelter.com/gallery-image/TaurOs-project/G0000FBhfa8_okhw/I0000MlPjnxPIfAw

Maremmana x Limia
http://rewildingeurope.photoshelter.com/gallery-image/TaurOs-project/G0000FBhfa8_okhw/I0000YwU9ilpYRj8

(Maremmana x Pajuna) x Maremmana
http://rewildingeurope.photoshelter.com/gallery-image/TaurOs-project/G0000FBhfa8_okhw/I0000.tTJyDMZ7dc

"Manolo Uno"
http://rewildingeurope.photoshelter.com/gallery-image/TaurOs-project/G0000FBhfa8_okhw/I00002_y27VOBxdk

Limia
http://rewildingeurope.photoshelter.com/gallery-image/TaurOs-project/G0000FBhfa8_okhw/I0000bjjMo2pR23Q

http://rewildingeurope.photoshelter.com/gallery-image/TaurOs-project/G0000FBhfa8_okhw/I0000iR6HDRS99HM

Sayaguesa in Campanarios de Azaba
http://rewildingeurope.photoshelter.com/gallery-image/TaurOs-project/G0000FBhfa8_okhw/I0000r3HBaepNJCs

http://rewildingeurope.photoshelter.com/gallery-image/TaurOs-project/G0000FBhfa8_okhw/I0000Q.wCzYQ2mSo

Maremmana with whatever cross calf:
http://rewildingeurope.photoshelter.com/gallery-image/TaurOs-project/G0000FBhfa8_okhw/I0000d0G.el0SycQ

Another Highland cross calf, exact combination not stated. Obviously is e//e, so I really wonder which combination it is.
http://rewildingeurope.photoshelter.com/gallery-image/TaurOs-project/G0000FBhfa8_okhw/I0000WWwU2yYi1.Y

Pajuna
http://rewildingeurope.photoshelter.com/gallery-image/TaurOs-project/G0000FBhfa8_okhw/I0000RRHTGVHJYBw


What I - and I am sure a lot of other people too - really would like to see a document revealing all their crossbred animals (or at least the breed combinations that exist already) and qualitative photos showing what they look like, so that we know which crossbred animals we are looking at. This would be simply awesome, and certainly helpful for the Tauros Project's information flow.

Saturday, 1 March 2014

Tudanca - grey, numerous and beautiful

The ABU described the Tudanca as “small, but displaying a lot of aurochs features” in their guidelines [1], and in my opinion this is accurate. My very first aurochs reconstruction done by photo manipulation was based on a Tudanca bull:

Modified Tudanca bull from Wikimedia Commons,
horns of a Maronesa bull 
Wikipedia states that Tudanca cows reach 135 cm at the shoulders and a weight of 320 kg, what sounds plausible, and bulls 150 cm and 420 kg. The height of 150 cm is plausible as well, but 420 kg are very likely too light for bulls with this body conformation. For comparison, a Heck bull with 145 cm shoulder height weights between 600 and 900 kg [2,3]. According to the DAD-IS (Domestic Animal Diversity Information System), Tudanca grow 165 and 160 cm at the withers and 650 and 450 kg (male, female, respectively). The shoulder heights are likely exaggerated, but the weight data sounds plausible.
Tudanca is one of the very few aurochs-like breeds that is still numerous, counting 12.230 individuals in 2011 (DAD-IS). This is four times the number of Heck cattle. Tudanca live in the Cantabria uplands, where they cope with a humid and cold climate.


The bulls are not long-legged and therefore look heavy, and their snout is shortened. But the have a well-developed hump and an S-shaped backline, and they have prominent forelocks – a feature that I appreciate very much, it is historically well-supported that European aurochs had them, and they give a kind of wild and masculine appearance. The cows have longer legs, though their hump is not as well-developed. The horns of Tudanca are comparably long, but their tips curve outwards in a corkscrew-like manner, resembling those of some Maronesa cows. A lot of Tudanca cows have horns facing strongly outwards, like a lyre pulled apart. The colour of Tudanca lacks phaeomelanins and therefore is grey. The sexual dimorphism is reduced, but bulls are darker than cows in general. Cows have a prominent ocular ring, which is most likely is a juvenile feature.

The ABU once did a Tudanca x Heck cross, but were not impressed by that combination. I also think that Tudanca doesn’t add anything to Taurus cattle except more undesired features. The breed, on the other hand, is used by the Tauros Project. There are Highland x Tudanca cows (photo) covered by a Sayaguesa, and Sayaguesa x Tudanca cows covered by a Limia (video).



Now, be delighted by some nice photos of beautiful Tudancas:







Literature

[1] Margret Bunzel-Drüke, Carsten Böhm, Peter Finck, Gerd Kämmer, Rainer Luick, Edgar Reisinger, Uwe Riecken, Johannes Riedl, Matthias Scharf, Olaf Zimball: ''„Wilde Weiden“. Praxisleitfaden für Ganzjahresbeweidung in Naturschutz und Landschaftsentwicklung.'' 2. Auflage. Arbeitsgemeinschaft Biologischer Umweltschutz im Kreis Soest, Bad Sassendorf-Lohne 2009, ISBN 978-3-00-024385-1.
[2] Julia Poettinger, 2011: Vergleichende Studie zur Haltung und zum Verhalten des Wisents und des Heckrinds.
[3] Cis van Vuure: Retracing the Aurochs - History, Morphology and Ecology of an extinct wild Ox. 2005.