Wednesday 31 July 2013

The Aurochs' head


© Life restoration of a lost Aurochs cow skull from Berlin

The head of the aurochs is another one of those features that clearly distinguish it from many modern cattle breeds. Most domestic cattle skulls are paedomorphic: they retain juvenile traits all their life, such as a concave profile, a short snout and front head, larger eyes et cetera. Consequently, the skull bone of the aurochs was much more elongated than in many cattle breeds, with a long snout and front head and comparably small eyes sitting in prominent sockets.

© Berlin skull
Over the last year I did a lot of life restorations based directly on photos of a lot aurochs skulls, about 20 or so. Some of the better ones are presented above. These reconstructions confirm what is implied by the actual skull bones. There are, however, skulls that are shorter than in average aurochs individuals (f.e. the Cambridge cow from the early Holocene), but the snout profile is always either straight or slightly concave.

© Skull from Lund, Sweden
@ Aurochs from Copenhagen
© Skulls from Germany, Cambridge and Poland
Note that the different horn shapes on my drawings are either an result of perspective or orientation relative to the skull – the basic curvature of aurochs horns was always the same. I’ll do a post on the aurochs’ horns some time as well.

The skull of most, if not all, Heck cattle is considerably shorter than in the aurochs and more or less paedomorphic, therefore its skull differs from the wild bovine but is much like that of other domestic cattle.



Heck cattle usually have a paedomorphic
skull much shorter than in the aurochs (Photo above: Wenzel)
Taurus cattle individuals usually have much better skulls, probably thanks to the influence of Sayaguesa. This Taurus cattle skull that I repost here, resembles the aurochs skulls to a large extent already (just slightly shorter):


Taurus bull skull (above) compared with a true aurochs skull (below)
In Sayaguesa, particularly the cows have a very elongated, straight-profiled skull. The same goes for some Pajuna individuals, and also some Maremmana primitivo.


 

Even some highly-derived breeds like Holstein and some zebuine breeds have very elongated skulls:
 
Holstein cow (Photo: flickr) 
A particularly interesting detail of the European aurochs’ head in life was the curly hair between the horns. Anton Schneeberger makes a reference about it in a letter published in 1602, and the copy of the “Augsburg painting” by Charles Hamilton Smith also shows it. It was a cult to cut the skin with the hair off the face of caught living aurochs during the middle ages, because it was thought that belts made from that skin could increase fertility [1]. Many cattle breeds show that curly front head hair, particularly the bulls. The exact colour of this portion is unknown. Historic evidence (text references and artistic depictions) suggest that it was coloured black or at least dark in European aurochs bulls, while a cow depicted at Lascaux clearly shows a lightly-coloured area between the horns. But many aurochs-like breeds show lightly-coloured hair between the horns in bulls as well. Cis van Vuure considers this to be a discolouration after domestication [1], but Gaurs also display lightly-coloured hair on their fronthead. Thus, parsimony implies that it must have been present in at least some aurochs populations if not in Europe. Because of that uncertainty, I think that it is possible that the colour of that particular area ranged from black over reddish-brown to blond in bulls, and probably always light in cows.


[1] van Vuure, Cis: Retracing the Aurochs - History, Morphology and Ecology of an extinct wild Ox.

Tuesday 30 July 2013

Ideal horses for rewilding: Exmoor, Konik or Przewalski?


In this post, I described a number of Tarpan-like horse breeds. None of these breeds is a complete stand-in for the Tarpan, but each of them is able to survive without human help and each of them resembles at least one colour morph of the Tarpan to a larger or lesser extent. That’s why most rewilding projects are convinced that no further breeding (more precisely, “breeding-back”) is necessary for "restoring" the wild horse in Europe. Speaking in terms of ecology and social behaviour, this might be true indeed. But in this post I want to share my thoughts on which kinds of breeds would give us an authentic picture of how the Tarpan looked like and behaved like, and what combination might be best for being rewilded.

As I explained here, the Tarpan did not have a uniform appearance. Although probably all Tarpans had a relatively small, strong and stocky body with a robust head and a short frizzy mane, there are five possible colour morphs known. Based on historic and genetic evidence, bay dun (like in the Przewalski’s horse) probably was the most common of these, followed by black dun. There is no evidence of a correlation of these morphs to a specific region (yet), so probably each of them were distributed all over Europe. Therefore I think that we have to consider more than one breed or type of breed if we want to create authentically Tarpan-like feral horse populations. One also has to consider that landraces usually show regional adaption to a specific habitat or climate and might do not as well in other regions. For example, the attempt to introduce Koniks into the Atapuerca mountains failed badly because the horses were not adapted to the mountainous habitat (and also the presence of wolves).
The Przewalski horse is, as we all know, the only living wild representative of Equus ferus. Its authentic wild horse features, be it phenotypic or behavioural, are certainly very desirable and their influence would compensate the domestic “maladaptions” of some otherwise authentic breeds. Surely some people would be against the influence of Przewalskis in the feral/wild European horse population because there are genetic differences (they have one more chromosome pair and separated from domestic horses during the middle Pleistocene), and they are adapted to a very cold, dry steppe environment. But pure Przewalskis are used in a number of grazing projects in Europe, and also semi-feral in Hortobagy (Hungary) and Atapuerca. Nevertheless, I am inclined not to use pure Przewalskis for releasing them into European wilderness among domestic horses because I think that a) it might be a waste as their native range is Asia and b) their different climatic adaptions might not be ideal in some regions. But F1 hybrids with suited, local primitive horses could be used instead. The use of crosses instead of pure individuals also has the advantage of not diminish the population of Przewalskis that are used for the conservation of this precious subspecies.

As I mentioned here, the ABU in Germany has Przewalski x Konik crosses which probably represent the most common phenotype of the Tarpan very well. They have the muscular stocky body that all these ponies have, a robust head, a short frizzy mane and a perfectly bay dun colour. They are most likely adapted fine to European climate. Since these crosses worked out well, imagine other combinations like Exmoor x Przewalski, or Hucule x Przewalski.
Konik x Przewalski on my flick album
The behaviour of Przewalski’s horses is, not surprisingly, very reminiscent of what is known about that of the Tarpan. They are difficult to handle or to tame and have a high potential aggression, and they are known to kill concurring domestic horses. But in the wilderness, they behave shy towards humans, and they also know how to defend themselves against predators. This is very desirable and needed, because tame released horses can cause problems in interaction with humans (according to some sources, Koniks remain tame even after living their whole life without human contact) and if the horses do not know how to defend themselves successfully against predators, you’ll get the same results as with the Koniks in Atapuerca. UPDATE: In Popielno and the Biesczcadzki Koniks defend themselves successfully against predators - even bears; they form a defensive circle around their foals and stallions try to chase away wolves. See f.e. here. On the other hand I might mention that there are domestic/feral horses which know how to defend themselves as well, such as Exmoors (f.e. they form a defensive circle around their foals, and they tend to be shier) and Garrano from Portugal (feral Garrano deal with wolves).

I agree that actual breeding-back is not really necessary in the case of the horse, because the suited breeds are very close to the desired archetype already. Instead, releasing a bunch of suited breeds together in an area so that they interbreed and letting mother nature do the rest might be sufficient already.
Therefore, my proposal of breeds and breed combinations is:

Iberia:
Garrano, Asturcon (used to predation, phenotypic closeness to the Tarpan but lack the dun factor), primitive Pryor Mountains mustangs and Przewalski crossbreeds (bring in the dun factor). This combination would result in a population that is experienced in living feral, dealing with predation, suited to the climate and contains all desired wild horse features.

Garrano during winter
Pryor Mountain Mustang

Northern Europe:
Exmoor (feral ancestry, phenotypic closeness to the Tarpan, but lacking the black gene and dun factor), Fjord horse (brings in the dun gene), Konik (brings in dun and black), Przewalski crosses. This population would be perfectly cold-adapted, have all the Tarpan features and contain animals that can deal with predators (not only the Przewalski is adapted to predation, but also Exmoor ponies were exposed to predators in previous centuries). The lack of dun is actually not a negative feature, because the presence of the dun factor within Holocene wild horse populations is not evaluated yet, and non-dun wild coloured horses like the Exmoor are perfectly camouflaged in wooded habitats.

Semi-feral Exmoor ponies
Fjord horses
Western, Central and Eastern Europe:
Exmoor, Konik, Hucule and Noriker (used to mountainous habitat), Przewalski crosses.

Noriker horse
Koniks
I am sure that everyone has a different opinion on this, and some might not agree with me at all and prefer regionalism, existing feral populations or the exclusive presence caballine horses. Until now it seems that each project uses its own breed, and I think this is good. It might lead to exactly the diverse horse population that contains all known Tarpan features as I am proposing it here. Only time will tell. But in my opinion, the fact that the Tarpan had a number of different colour morphs and that modern breeds have different local adaptions should be considered when compositing a new semi-feral horse population for a specific region.


Saturday 27 July 2013

The Heck horse: a bred-back Tarpan or a washy Konik?


Heck horses are the only horse breed that actually is the result of breeding-back (the Konik is not, as I explained here), except for the Hegardt horse (as far as I know, this breed is merely a bunch of mustangs that were selected for a black dun colour, that’s not enough in my view, and there aren’t any photos of this breed avaiable). Often Heck horses are referred to as “bred-back Tarpans”, especially in Germany. But is this labelling justifiable? Does the Heck horse resemble the European wild horse better than other horse breeds?

The Heck horse was created by (big surprise) the Heck brothers during the 1930s and 1940s. The Hecks crossed Icelandic horses, Gotland ponies and Dülmen ponies with a Przewalski stallion, and subsequently Koniks from Poland were crossed in. After WWII, more and more Koniks were merged into the breed, so that there is only little difference between the Konik and many Heck horses [1]. However, Heck horses are more heterogeneous and tend to have a larger and more gracile phenotype. Towards the 1970s Heck horses were crossed with Przewalski horses again in a zoo in North-Rhine Westphalia. As a result, some Heck horses have upright manes today [1] (this trait, however, is unlikely for Holocene European wild horses [2]).
Just like the Konik, the Heck horse is a black dun breed, and thus representative of one of five possible colour morphs within European wild horses. Bay dun, just as authentic, does not appear as far as I know. Many Heck horses have a quite light expression of their basic colour, resulting in a very light gray that is not very likely for genuine wild horses because it is never mentioned in historic references. Also, some Heck horses have typical riding horse proportions and a long mane. Take a look at this Heck horse from the Munich Zoo which barely has any wild horse features:


Nevertheless, thanks to the high amount of Konik influence, there are Heck horses in grazing projects which do have a wild horse-like stocky body and a brownish colour, the Przewalski influence contributed a large robust head and a short mane. These individuals are prime examples for what black dun Tarpans probably looked like (I can't link the first photo directly):




But, considering the multifaceted origin of this breed, some individuals with a bit weird appearance can show up as well (the colour in that one is OK, but it is too slender and the head shape is awkward):



To address my question in the first paragraph: No, the Heck horse is not more Tarpan-like than other primitive horse breeds, even if we look at the phenotype only. Its population misses the other colour morphs of the Tarpan (bay dun, leopard spotted, possible non-dun individuals) and both authentic and not authentic individuals are present in this breed. Basically, modern Heck horses are Koniks with introgression from other horse breeds, they is not necessarily more authentic than the Koniks are. What does that mean for creating a wild horse substitute: one has to pick the best individuals out of that pool, just like in any other suitable breed.

By the way, there is no breeding book for the Heck horse, and German breeders often either consciously or unintentionally mix Heck horses and Koniks, so that the two breeds probably will be one pool in the future [1].

Literature:

[1] Bunzel-Drüke, Finck, Kämmer, Luick, Reisinger, Riecken, Riedl, Scharf & Zimball: „Wilde Weiden: Praxisleitfaden für Ganzjahresbeweidung in Naturschutz und Landschaftsentwicklung“. 2010
[2] Baker, Sue: Exmoor Ponies: Survival of the Fittest – A natural history. 2008.

Heck cattle at Munich Zoo

The Heck cattle at Tierpark Hellabrunn, Munich, were the first Heck herd I ever saw. This herd is particularly interesting not only because they live in exactly the Zoo where Heinz Heck created that breed and had considerable influence on many other Heck herds, including the wonderful Wörth lineage, but also because they are among the very few Heck cattle herds that have a nearly perfect Aurochs-like coat colour: 



As you see, the bulls are dark brown to black without a prominent saddle, the eel stripe and mealy mouth are present. The cows are reddish-brown becoming darker towards neck, head, legs and tail tip. Actually, it is almost surprising to see purebred Heck cattle with a coat that strongly reddish, because many lightly-coloured Heck cows tend to have either a pale brown or beige-coloured coat. But in this herd, the colour genes seem to be puzzled together correctly. 
But as we know, coat colour is only one aspect of the aurochs' outer appearance. The body of the Munich herd is very bulky and domestic, very similar to "usual" cattle breeds and unlike the aurochs. Same goes for the small and short head. The legs are considerably shorter than in the aurochs, while the trunk is elongated. There is little to no hump. Their body size isn't remarkable, probably they are within Heck cattle's usual size average of 140 cm for bulls and 130 for cows at the withers, and therefore, much too small. The horns have a correct basic curvature, but they are oriented too vertically and the tips do not face as much inwards as in the aurochs. Also the horns should be slightly larger. 
Apart from that, there are black cows in the herd. There were black aurochs cows too, but probably only very rarely, while in Heck cattle they might make up more than the half of the cows in a herd.  
Quite frankly, this cow should be selected out
So, when taking a closer look, the Munich herd resembles the aurochs only in colour closely. In some Iberian breeds the coat colour also matches that of the aurochs very well, such as Maronesa (I will cover Maronesa in a later post), or some of the few "primitive" Lidia herds left. 

Nevertheless, the Hellabrunn Heck cattle are still nice to look at. Cows from that herd have recently been transported to the national park in Hortobagy, Hungary, where they contribute to a large herd of Taurus/Heck cattle. 

Thursday 25 July 2013

The Quagga and the Quagga Project



The Quagga, Equus quagga quagga, got some attention during the last decade because of a selective breeding project in South Africa that tries to “rebreed” the appearance of this Plains zebra subspecies. The Quagga project is different from those concerning the aurochs or wild horse, particularly because there are no living descendants of the Quagga to work on. The identity and evolutional history of the Quagga has been a matter of debate for a considerable time, but let’s have a look at the history of the equines referred to as zebras as a whole, because we have to look at the complete picture in order to understand it better.

Surprisingly, a study by Orlando et al. 2009 [1] found zebras to be a polyphyletic arrangement, with the Mountain Zebra E. zebra being more closely related to the African ass E. asinus, the Grevy’s zebra E. grevi within hemionine asses and the Plains zebra as an outgroup to these two clades. According to this study, zebras are an umbrella term for heavily striped wild asses, if you will. But the paper itself states these conclusions are to be taken with caution, and mtDNA analyses might be necessary for better resolving the non-caballine Equus tree. Another 2009 study finds zebras to be monophyletic, but oddly the onager outside E. hemionus [2].
The phylogeny of zebras is essential for understanding the evolutional cause of their striped coats, in order to deduce which coat pattern is a plesiomorphy and which is an apomorphy. If the plesiomorphic state of the clade formed by zebras and their most recent common ancestor is a bay dun coat colour, it means that the striped zebra coat pattern evolved several times independently within Africa (E. simplicidens from the Pleistocene of America is often claimed to be a zebra-like animal, but I think this is highly speculative based on skeletal morphology alone). If the plesiomorphic state is the striped coat, it must have been lost several times again and re-developed into a bay dun coat of the asses nested within that group according to Orlando et al. 2009. Several hypotheses try to explain why zebras developed their unique coat, and if it evolved several times independently within Africa, a connection to a special environmental condition is very likely. The hypothesis that it evolved in order to remain undetected for tsetse flies and horseflies is the most popular one, and indeed it has been shown that polarized striped patterns is less attractive to tabanid flies [3]. According to the hypothesis, zebras needed this protection because their relatively recent arrival on the African continent did not give them the time to evolve efficient immune defence against diseases transmitted by these parasites. And that is how we finally come to the Quagga: far in the south, where the tsetse fly is not present, the stripe pattern allegedly got useless and therefore these zebras reduced it again. But I have several problems with this scenario. First of all, there is no real correlation between the range of the tsetse flies and that of the zebras. The modern range of the Mountain zebra’s range is totally outside (and it actually occurs as southwards as the Quagga did), as is a large part of that of the Plains zebra, and I wouldn’t be surprised if the former range of the African wild ass and that of the tsetse fly also overlapped. Furthermore, I don’t know of studies suggesting that zebras are more vulnerable to trypanosomiasis than other African herbivores, making the passive protection through their striped coat necessary. I think the “fly hypothesis” is plausible, but not yet really convincing for me (please correct me if my criticism is erroneous).

Regardless of why the Quagga had reduced stripes, they were its most remarkable feature (there is the possibility that this condition actually is a basal one, but I’ll address that later on). Sometimes the quagga is described as looking like half zebra and half horse, but I don’t think that is an ideal portrayal of its appearance. I would rather describe it as a brown zebra with white legs and tail and stripes fading away at the posterior half of its body. On its brownish rear, the Quagga displayed an eel stripe just like phenotypically bay dun wild equines. Most stuffed specimen show brownish stripes, but that’s likely due to discolouration because all of them are more than hundred years old. Based on contemporaneous paintings and photographs of one individual, I think that the lighter space between the stripes on the neck and head area were white or whitish, in some individuals maybe brownish. With this (baaadly rendered) drawing, which is also featured on the Quagga Project’s website, I tried to portray the individual variation within the Quagga:
 

The preserved specimen of the Quagga, which are all listed here, might give you a good idea of the variation within the population as well. Considering the unique pelage characteristics and also alleged craniometric differences between the Quagga and the Plains zebra [4]*, it is understandable that it has been regarded as a separate species for a long time. However, genetic studies found the Quagga to cluster within the Plains zebra (thus indicating that its ancestors were fully striped) and having little genetic diversity. It is likely that the Quagga split from other lineages between 290.000 and 120.000 years ago, possibly due reproductive isolation during the last glacial, what also provides a possible scenario for the radically different pelage colour (genetic drift) [3]. Most importantly, the Quagga does not share any haplotypes with other Plains zebras according to this study, indicating that there was no genetic exchange after their isolation [4]. This means that the Quagga is a genetically distinct subspecies rather than a mere colour variant, although more material might be needed.


* Some have disputed the craniometric differences because available horse or donkey skulls were used for some mounted zebra skins instead of genuine skulls. However, I know that there is at least one preserved Quagga skull (on the only mounted Quagga skeleton); I wonder which material those cranimetric comparisons are based on. If you want to judge it for yourself, here is the confirmed Quagga skeleton with the skull in profile view, and a Plains zebra skull.

However, the Quagga’s outer appearance was not homogeneous, there actually was considerable variation concerning the degree of striping among the mounted Quagga skins. Some museum specimen show a very brownish coat with stripes only recognizable at the shoulder, neck and head area, others display stripes that go right to the hips and a comparably light background colouration (as far as we can tell from those skins). Interestingly, the living plains zebras also show a degree of striping varying from north to south, with those in the north having the most polarized stripe pattern (E. q. boehmi) and those in the south showing a tendency to reduced striping on the rear and legs (E. q. burchelli). Concerning the pelage characteristics, the quagga might represent the end of a cline, although it seems to be genetically distinct.

Because of the obvious variation in modern Burchell’s Zebras striping, Lutz Heck proposed that selective breeding could rebreed the Quagga’s outer appearance (phenotype) in a book published in 1955. Eventually a project with this aim was formed by zoologists, veterinarians and museum personnel under the initiative of Reinhold Rau in 1987 [4]. They selected wild zebras, mostly from the Etosha national park and exclusively from the burchelli subspecies that already showed a promising-looking amount of stripe-reduction. The current herd has 83 of zebras resulting from this selective breeding programme living in several locations near Cape Town. The youngest individuals are from the fourth generation. Keep in mind that zebras have a longer generation span than domestic horses so breeding with them takes longer. The project selected for a reduced striping and a more brownish background colour by crossing the chosen wild zebras and choosing the offspring with the least striping for further breeding. Surprisingly, some animals also showed stronger striping, but those were selected out. The breeding progressed surprisingly fast, already the third generation showd considerable reduction of stripes on the legs and rear, a white tail and a slightly more brownish background colour. The fourth generation (some of them were born in 2012) show an even greater approximation towards the Quagga’s pelage characteristics. The project developed a counting system in order to quantify the progress, and the results show that the reduction of striping is happening fast, but the darkening of the background colour progresses only slowly (this aspect is especially hard to quantify because of dust, sun et cetera). Here are some photos and a video of some of these “Rau zebras”**:

Individual "Freddy", F4
Individual "Henry", F3
Individual FM12, F4



** Funnily, I independently came up with the idea of calling these animals “Rau zebra”, the Quagga Project itself wants to name their results “Rau Quagga”, but I think calling them zebras is more objective.

If you are interesting in seeing more photos of these Rau Zebras, you can have a look at the homepage www.quaggaproject.com or the project’s facebook page. In contrast to aurochs or wild horse projects, where all desired phenotypic features are present in living animals (which descend from the desired archetype) and “just” have the be united, the Quagga Project wants to achieve features that are not present in any living zebras (which do not descend from the Quagga). If you’d imagine a bell curve, the Boehm zebra is on the one end and the Quagga is on the other end, and the Burchell zebras are somewhere in between. Nevertheless, the optical resemblance that already has been achieved is impressive to me. Some of these individuals have show a significant resemblance to the Quagga already, like “Freddy”, “Henry”, DJ10 and FM12. The stripes on the legs are greatly reduced or absent, the stripes on the rear are reduced, and the background colour is more brownish than on average Bruchells zebras. Imagine how Quagga-like the F5 and F6 generation might become. But can the project truly rebreed all the Quagga’s phenotypic features, or even the Quagga as a whole?
The Quagga’s appearance often is equalized with its coat, but there are other features that yet have to be evaluated. For example, there is no osteometric study working with that one complete skeleton and that of living Plains zebras, and since the use of skulls from stuffed skins is questionable, one should compare the genuine Quagga skull with that of living zebras in order to verify the statement that there are no osteometric/craniometric differences between the Quagga and other members of that species. I think it is well plausible that there are, because of the apparent founder effect during its evolution, but this simply requires testing.
Furthermore, there is more that defines a subspecies than just a differing phenotype. The argument “the Quagga was merely a subspecies, so it can be rebred” that is sometimes brought up in connection with the project is erroneous. Some of the Youtube commenters seemingly have a very simplified idea of species and little clue about population genetics. Species that are divided into several subspecies are not genetically homogenous, connected populations but more like a branched tree, with each subspecies being an evolutionary distinct clade, defined by whatever differences that are laid down in the genome. And apparently there was not much genetic exchange between the Quagga and other Plains zebra populations for at least 120.000 years (although more evidence might be needed). This means that E. q. quagga was genetically different from E. q. burchelli just like burchelli is from E. boehmi and so on. To make a comparison on a similar level, you cannot rebreed the Polar wolf by selecting white Timber wolves. Also, you cannot rebreed the Boehm Zebra by selecting those Burchell’s Zebra with the heaviest striping. Different subspecies mean a different genetic make-up (although not as marked as on species level, of course) and therefore a different animal. Consequently, the Rau zebra will always differ from the Quagga because the populations have a different ancestral history. These differences are at least genetically, and perhaps also in ecologic, behavioural or phenotypic respects that are either unknown or not evaluated, although I personally think these aspects are overall roughly the same the within the Plains zebra.
We probably cannot say anything about the exact ecologic role of the Quagga because there are no living representatives left to study. But probably, since they belong to the same species, they were largely similar if not ecologically identical to other Plains zebras. I read in some sources that South Africa’s flora has a higher degree of endemism than farther in the north, but I don’t know if that is true (does anybody have literature on that?). The Quagga project claims that the flora is not significantly different from that of the habitat of living members of the species. I think that many conservationist would be in favour of reintroducing the Plains zebra into its former range in South Africa, as subspecies are obviously no barrier for reintroduction projects, especially when the native type is lost (as the reintroduction of Przewalski horses in some parts of Europe or recent projects with big cats have shown). The ecologic functionality and physical characteristics of the Rau zebras are the same as in other plains zebras, but they are the only lineage that resembles the type that once was native in that region. If the Plains zebra is to return into this area – what would surely make sense from a conservational view – the Rau zebras from the Quagga Project certainly are the most desirable option (just like the project says on their web page).
I think it is very helpful that the Quagga Project methodologically quantifies their selective breeding progress; also, it’s the only breeding-back project that has published papers explaining their “materials and methods”, making the whole process much more scientific and transparent (see here and here). Apart from that, I am also curious to see other effects on these zebras because of the selective breeding, and perhaps also new mutations will show up. 

Although the Quagga itself is lost, I am very happy that the Quagga Project is trying to establish zebras resembling this remarkable subspecies. It will be interesting to see how far they can get and indeed the similarities that already have been achieved are astonishing. Some of these Rau zebras already show an amount of stripe reduction that is shared by some Quagga mounts, and if they had the same brownish background colour they would be virtually indistinguishable. Because the progress in stripe reduction has been fast but not the change of the background colour, the project decided to put more focus on that feature [5].
Also, the Rau zebra would be a very useful tool if it will be possible to clone one or more Quagga individuals one day, however unlikely that scenario is. But these few cloned Quaggas could constantly be merged into the Rau zebra’s population that provides a genetic base, coming as close to the Quagga as technically possible. However, this is a fantasy scenario of mine (yet?).

Literature


  • [1] Orlando et al.: Revising the recent evolutionary history of equids using ancient DNA. 2009
  • [2] Samantha A. Price und Olaf R. P. Bininda-Emonds: A comprehensive phylogeny of extant horses, rhinos and tapirs (Perissodactyla) through data combination. 2009.
  • [2] Knight, Kathryn: How the Zebra Got its stripes. 2012.
  • [3] Leonard et al.: A rapid loss of stripes: the evolutionary history of the extinct quagga. 2005
  • [4] Eric Harley et al.: The restoration of the Quagga: 24 years of selective breeding. 2013.
  •  


Saturday 20 July 2013

The Tamaskan Dog as a test for "breeding back"


Luckily the wild types of most of the species that were domesticated are still extant. But imagine the wolf was extinct because of human persecution. Conservation could try to substitute their ecologic niche with other wild canines, or create an effigy that can be released into nature in order to redevelop surviving strategies and social behaviour patterns typical for that species, Canis lupus. Interestingly, there was some kind of “breeding-back” effort for the wolf, the Tamaskan dog. It is a crossbreed of less-derived dog breeds with the target to resemble the wolf in appearance but without crossing-in any true wolves. And just like cattle and horses, domestic dogs were domesticated in the middle east but likely experienced introgression by European wolves, making the situation of the Tamaskan very similar to that of other breeding-back attempts. The fact that living wolves still exist makes it possible to see how successful classical "breeding-back" can be. 
The breeding was started with a number of sled dogs that were crossed with Siberian Huskies, Alaskan Malmute and German Shepherds in the 1980s. The similarity that has been achieved in some individuals is indeed impressing. Tamaskan dogs have size and proportions very reminiscent of some wolf populations, and also the colouring is very similar to their wild type, with some subtle differences. Regardless of that, Tamaskans still have a number of domestic features. For example, a fifth toe on the hindquarters appears in some individuals, and the face of the Tamaskan differs from that of wolves in being more paedomorph by having a broader snout, larger eyes and a more domed front head, and I am pretty sure the brain volume is reduced as well. These are typical domestication features evident in virtually all dog breeds, just like enlarged udders or dewlaps, a reduced brain volume and snout length are found in most domestic cattle breeds. 

www.fotocommunity.de
www.dogwallpapers.net
www.hundeseite.de
Without doubt the Tamaskan is a domestic animal and not a wolf, although it does resemble its wild ancestor. It would be interesting to see a genetic comparison of several dog breeds (including the Tamaskan) with the several wolves from different subspecies, to see if there is any significant difference between the relationship of the dog breeds to the wolf. However, I do not expect the Tamaksan to be closer to the wolf than its founding breeds, for the simple reason that it was selected for a few key genes for phenotypic features, but the whole genome of a wild type consists of more than that.
It would be interesting to see how a population of Tamaskan dogs would do living in the European or North American wilderness. There are a lot of examples of dogs surviving in the wild, so I think the Tamaskan would do so as well. They’d probably evolve hunting strategies and complex social behaviour just like, for example, Dingoes. One could start a dedomestication experiment releasing a population of Tamaskan dogs in a large area with deer and other prey animals and watch evolution doing its work. After some amount of time, we could compare these wild Tamaskans to true wolves. (I don't know if such a project is legally possible, I think it isn't). 
What would be the point of that? First of all, such a project itself would be interesting enough. Furthermore, the history of the Tamaskan is surprisingly similar to primitive cattle and horse breeds designed to be aurochs and tarpan proxies. It shows that no matter how authentic an effigy breeding result will get, it will always be different from the genuine wild type. But if man can achieve both “bovine Tamaskans” and “equine Tamaskans” that resemble their wild type just as good as this dog breed does and survive in nature in a similar manner to their wild types, it would be awesome. And several projects are trying to do so. Such cattle and horses would be a prime basis for dedomestication, for letting nature refine them and develop surviving strategies and social behaviour necessary for survival so that they can re-occupy the vacant niche of their extinct ancestors. 

Thursday 11 July 2013

Visiting Taurus cattle at Lippeaue, Germany



The Lippeaue is a reserve in North Rhine-Westphalia, Germany, that is managed by the ABU (Arbeitsgemeinschaft Biologischer Umweltschutz). During the last decades, the ABU transformed the area from a former agricultural area into a natural floodplain again that is home to a diverse avifauna. The Lippeaue also is the most important Taurus cattle breeding site in Germany and is where it all started in 1996. Actually, the first Heck cattle arrived in 1991, but 1996 marked the beginning of Taurus cattle by including Chianina cows, and Sayaguesa cows in the following year. I met with Magret Bunzel-Drüke and Matthias Scharf from the ABU and discussed about the cattle and lots of other things; I learned a lot and it was a very enjoyable trip.  

Breeding bull "Lamarck": 50% Sayaguesa, 25% Heck, 25% Chianina

The cattle in the Lippeaue are separated into different herds in Hellinghauser Mersch, Klostermersch and Disselmersch. The Taurus cattle in the Lippeaue number up to 90 individuals (the number is dependent on how many individuals are removed each year). In the current population, Sayaguesa is the dominating breed in the crossbreeds with 47 %, followed by Heck 29%, Chianina 20% and Lidia 4%. So the Taurus cattle actually are more like improved Sayaguesa than improved Heck cattle today. The influence of Lidia, the Spanish fighting cattle, has been reduced recently because of their small size and their behaviour that is very difficult to handle. There are also no pure Heck cattle anymore, so that the cattle keep having a large size and a long-legged body.

"Laola", 50% Sayaguesa 25% Chianina 25% Heck

75% Sayaguesa, 12,5 % Heck, 12% Chianina

Most of the adult individuals are of the second cross generation (F2), some of F3, and there is their offspring as well. The breeding bull in the Hellinghauser Mersch, “Lamarck”, is 50% Sayaguesa, 25% Heck and 25% Chianina and has a very aurochs-like overall appearance. The other bulls are good too; long legs, an athletic body with an S-curved back, large skull and good horns. One young bull has Lidia influence. The dewlap also is not all too long in Taurus cattle. I also like most of the cows, some had really good and comparably large horns, and especially the very Sayaguesa-influenced ones have long snouts and a shiny dark colour with a reddish saddle. The colour of the cows seems to be more variable than that of the bulls, ranging from beige to light brown, reddish brown or the colour described above. Black cows appear too, but these still look very nice overall. Unfortunately some individuals can have white spots on the belly. The colour of the bulls is uniformly dark brown to black, either solid black or with a kind of saddle on the back. The horn shape bears a good resemblance to that of the aurochs in many individuals, probably thanks to the good influence of the Sayaguesa cows and the Neandertal Hecks. The body of the cattle is surprisingly muscular and athletic, the bulls really look like large, long-legged and large-horned fighting bulls without having any in their ancestry. The cow “Larissa” descends from a good half-Sayaguesa bull and is 62,5% Chianina; I’m curious on how large her male offspring will get.
It would be interesting to know the exact size of Taurus cattle. But as you can imagine, it is not easy to measure them. One F1 bull was measured to be about 165 cm tall at the withers and weighting 1400 kg. Other large bulls might be about the same size. Judging from what I saw, I think the cows might be around 145 cm tall, but that’s only a guess.

"Lamarck"
50% Sayaguesa, 25% Chianina, 25% Heck
I was also shown a number of skulls from cross individuals. One of these (the upper one) was really huge with a horn span of about a meter or so. The skulls resembled Aurochs skulls, but slightly shorter.


The herds also include pure Sayaguesa and Chianina cows. My favourite Sayaguesa cow is named “Dona-Urraca”, she has a very good horn curvature and is fairly large, and during her 17 years of life she produced a lot of aurochs-like offspring. She is also the only cow that behaves dominant over the horses they share the reserve with. Another Sayaguesa is very interesting because she has a beautiful, red coat colour (a rarity in modern Sayaguesa, unfortunately). I also liked the Chianina cows. Every breed has its pro’s and con’s, and Chianina is better than I initially thought. Their small horns and the white diluted colour are disadvantages indeed, but their slim, long-legged and very large body can produce good results as Taurus cattle demonstrates. And apparently, their hardiness was largely underestimated, they do just as well as Sayaguesa and Heck cattle.

Red pure Sayaguesa cow
"Donna-Urraca", pure Sayaguesa cow
Pure Chianina and a Taurus cow
Sayaguesa x Chianina
The Taurus herds are fed supplementary during winter, for the simple fact that the reserve is not large enough for such a large population during the cold season, especially because it gets partially flooded during the year. Interestingly, the pure Lidia cows (not present in the current herds anymore) seemed to be the least dependent from supplementary food. Because of the legal situation in Germany it is not possible to dedomesticate cattle. The death of individuals would cause a public outcry that is a danger for the project. Therefore it is not possible to let weaker animals starve (just like it would happen in nature) to increase the hardiness, but cattle obviously doing bad still can be selected out. Furthermore, as I explained in previous posts, numerous cattle breeds survived in the wilderness in different regions on this world, so probably Taurus cattle would do so as well.

Old F1 cow "Lerida", Heck x Sayaguesa
62% Sayaguesa, 25% Heck, 12,5% Chianina
75% Sayaguesa, 18,75% Heck, 6,25% Chianina
62,5% Sayaguesa, 31,25% Chianina, 6,25% Heck
68,8% Sayaguesa 18,7% Heck, 6,25% Chianina, 6,25% Lidia

The behaviour of the cattle was interesting. As I mentioned above, the Lidia influence was reduced to avoid animals too difficult to handle. Of course all cattle living semi-feral develop a kind of wilder behaviour, so do Taurus cattle. The behaviour is varying from individual to individual. Some bulls are very gentle and tame, others might behave shyer and get feisty when caught.  Like most semi-feral cattle, they have a clear herding instinct as well. When running, they appeared comparably swift and agile, much more like oversized deer than usual sluggish Heck cattle. They can jump over barriers up to 160 cm high, which is quite impressing. 

"Larissa", 62,5% Chianina cow
We also went to Pöppelsche (not one of the ABU's herd), where there was a herd composed of Taurus crosses and usual Heck cattle. One of the bulls also was Lidia-influenced. This herd shares the reserve with some beautiful Exmoor Ponies.

Lidia-influenced bull and usual Heck cattle at Pöppelsche

The ABU interestingly has pure Koniks as much as Przewalski x Konik crosses, and one pure Przewalski mare. I think that these crosses might represent the phenotype that most European Tarpans displayed: bay dun colour, mealy mouth, short but falling mane. Of course these crosses do not have the purpose to get Konik genes into the Przewalski population, but other way round, and I think this is good (actually, Koniks even might have Przewalski influence already). The 75% Konik and 25% Przewalski horse looks very interesting because it has the typical reddish bay dun colour of Przewalskis, but no pangare and mealy mouth. Life in a wild-living horse herd is tough, there are constantly fights between the stallions. The dominant Konik stallion killed its father, and wild Przewalski horses in Mongolia are known to be even more aggressive.

Konik-Przewalski crosses
75% Konik 25% Przewalski + Konik x Przewalski
Konik stallion
To put it in a nutshell, I really like the Taurus cattle from Lippeaue. Their behaviour appears natural to me, it is neither overly aggressive nor sluggish or tame, and their surviving capacity probably is the same as in usual Heck cattle. They are very elegant animals. The phenotype of some of the individuals, as you see on the photos above, resembles the Aurochs to a large extent already. Surely the right colour and the right horn shape/dimensions have yet to be stabilized, and (although the size is good and much better than in Heck cattle already) the animals could be bigger on average. With good selection, a very, very aurochs-like population can be established, but it will take its time because inheritance is very coincidental in heterozygous crossbreeds. Two very good individuals might produce disappointing offspring and vice versa. The breeders from the ABU are aware of that, therefore it is complicated to find out which individuals should be selected out. Is a cow with good horns but the wrong colour less good than a cow with bad horns but the right colour? Are long snouts and legs more important than large and well-shaped horns? An individual that does not look that good might produce good offspring combined with the right partner … that sort of stuff. With more breeding locations and cooperation between the breeders the progress can be speeded up, and not to forget that nature itself would shape the cattle the way it is best if released in a large natural area where they can live more independently.


 I really enjoyed my trip, it was cool to go directly to the source and see the cattle. I am curious on the future development of Taurus cattle, and I hope that such cattle will play a crucial role in improving Heck cattle as a whole. The cattle at the Lippeaue are surely the most aurochs-like animals in Germany, and in my opinion might be better than many other primitive breeds on this worldon average

If you want to see more of the photos I took there, you can go to my flickR stream