Saturday, 18 November 2017

Wild horses pt. IV: The Przewalski's horse - is it still a wild horse?

This title is surely a bit provocative – it is of course zoological consensus that the Asiatic Przewalski’s horse, Equus ferus przewalskii, is the last living genuine wild horse that is extant today after the last western wild horses disappeared. However, advocates of a number of horse breeds that they purport as living remnants of the European wild horse or at least being strongly influenced by original wild horses, sometimes put the status of the Przewalski’s horse as a genuine wild animal into question. They argue that decades of breeding in captivity and introgression from domestic horses has altered the nature of the Przewalski’s horse, and claim that the situation is comparable to what has happened to their favoured “wild” breed: an original wild population has been influenced by domestic horses and artificial selection. As a consequence, they argue that if the Przewalski’s horse still deserves status as a genuine wild horse, which is zoological consensus, then so does their breed of choice. However, the often purported background stories for those breeds being “near-wild horses” are not tenable after objective examination for a number of reasons (see here), but what about the arguments against the original, wild status of the Przewalski’s horse?

The lineage of the Przewalski’s horse separated from that of domestic horses several millennia ago. The exact point of separation varies from study to study, depending on the molecular chronometer and its calibration. The maximum I found was 160.000 [1] and the minimum 38.000 [2] years ago. This comparably long reproductive separation resulted in a different karyotype, the Przewalski’s horse having 23 pairs of chromosomes and the domestic horse 24 due to a fission or fusion (depending on what is the plesiomorphic state), but they intermix readily and without fertility problems. In the millennia of living side by side in the Eurasian steppe, the Przewalski’s horse contributed genetically to the domestic stock (which is not only genetically [3] but also optically apparent, f.e. see some Mongolian horses), and vice versa. The Przewalski’s horse gene pool was introgressed by domestic horses, especially in the 20th century. Photographs of wild herds from 1954 showed individuals of divergent colours (Wikipedia), indicating admixture. The whole modern population descends from 13 founding individuals, one of them was a domestic Mongolian stallion [4]. Does this mean that the original, genuine Przewalski’s horse is lost and the modern population is an altered result of intermixture?
Orlando et al. 2015 made a genomic study compromised of a large sample of Przewalski’s horses, post and prior to the bottleneck (including the holotype specimen), domestic horses plus a late Pleistocene wild horse as outgroup. The result is that although there are genetic traces of intermixture, also including such having an effect on the phenotype such as an allele associated with increased withers height, there are still lineages in the population that are virtually free of admixture[3]. Also, height is a highly multifactorial trait, therefore it cannot be claimed that Przewalski’s horses are taller now due to admixture because of one allele – the average withers height is still between 122-142cm according to English Wikipedia, between 120-146 according to German Wikipedia (note that there is also sexual dimorphism in size). Przewalski’s horses are still uniform in their typical colour, sturdy build, robust head shape, erect and short mane, short-haired tail basis, a very lightly coloured almost white winter coat, and other typical morphologic differences to domestic horses such as thicker hooves (Wikipedia). I would even say that domestic cattle left a bigger trace on modern American bison than domestic horses did on the Przewalski’s horse, yet nobody is questioning the bison’s status as a wild animal. Also I found no source stating that Przewalski’s horses with a domestic karyotype have been observed.

Yes, the Przewalski’s horse seemingly intermixed with domestic horses continuously after their point of separation, but I see no compelling evidence that this fact altered the genetic integrity of this wild subspecies. Furthermore, domestic animals introgressed the gene pool of their wild counterparts everywhere they shared the habitat – this evident in European wild boar that show deviant, domestic colours and there is also the hypothesis that American wolves inherited black and other colour variants from domestic dog introgression several millennia ago (this might also explain blue-eyed wolves). Yet nobody is calling their wild animal status into question.

If Przewalski’s horses indeed lost part of their wild animal nature due to domestic introgression and being bred in captivity for a number of decades, it might be helpful to look at a checklist of aspects typical signs of domestication:

- Morphological paedomorphy
- Behavioural paedomorphy
- Reduced brain volume
- novel morphological/optical traits (very typical: colour variants, particularly white spots)
- Earlier maturity and increased litter size (the latter aspect is not true of domestic horses either, so let us ignore it for now)

Przewalski’s horses do not show any signs of morphological paedomorphy, not even if you compare photos of the early 1900s to modern individuals. Przewalski’s horses still always have the robust, donkey-like skull with small eyes and their proportions do not seem to be altered as well. I have not found any remarks in the literature stating that Przewalski’s horses as a whole lost brain volume; domestic horses have about 14% less brain volume than Przewalski’s horses [5]. Captive Przewalski’s horses also have 14% less brain capacity than wild counterparts [5]. Since there are no separate genetic lineage between wild and captive Przewalski’s horses, this should be applicable to phenotypic plasticity. According to Wikipedia, earlier maturity in captive Przewalski’s horses has been reported, but explained with better nutritional conditions in zoos than in the wilderness and as far as I know the same phenomenon can be observed in other zoo animals. The behaviour of Przewalski’s horses and domestic horses is well comparable, but Przewalski’s horses have a way higher aggression potential than domestic horses, especially the stallions. This is universal for this subspecies and evident in zoos as well as grazing projects. I once was told that zookeepers are more afraid of Przewalski’s horses than lions. Przewalski’s horses can be tamed and ridden to a certain degree, but this is also true for zebras, including the quagga.
There are not any novel traits found in any Przewalski’s horse, such as a new colour variant, or fur modifications. There are occasionally individuals showing a white streak along the face or white socks, which is applicable to introgression from domestic horses.
Looking at some deer populations which have been kept in game parks for many generations, we see incipient signs of domestications, such as new colour variants or typical domestic spotted patterns, or beginning paedomorphic skull shapes – you can find this in some roe deer, red deer and fallow deer in European game parks and this is what I would call an early state of slow domestication. But we do not see that at all in Przewalski’s horses.
All in all I think there is not one compelling reason to claim that the original Przewalski’s horse is gone, that it has been altered by man and hybridization, or that it is on the edge of domestication. I see nothing that calls their status as a genuine wild animal seriously into question, especially when we look at other wild animals. And even if the critics were right, it would not make any of the domestic horse breeds praised as near-wild horses “wilder” than they are (or not are, actually).


[1] Ryder et al.: A massively parallel sequencing approach uncovers ancient origins and high genetic variability of endangered Przewalski’s horses. 2011.
[2] Orlando et al.: Recalibrating Equus evolution using the genome sequence of an early Middle Pleistocene horse. 2013.
[3] Orlando et al.: Evolutionary genomics and preservation of the endangered Przewalski’s horse. 2015.
[4] Bunzel-Drüke, Finck, Kämmer, Luick, Reisinger, Riecken, Riedl, Scharf & Zimball: „Wilde Weiden: Praxisleitfaden für Ganzjahresbeweidung in Naturschutz und Landschaftsentwicklung“. 2010
[5] Röhrs, Ebinger: Are zoo Przewalski’s horses domesticated horses? 1998.

Friday, 27 October 2017

New aurochs bull reconstruction

About three weeks ago, I presented a recent drawing I did of Europe's megaherbivore fauna of the Holocene. I promised that I am going to present the aurochs of the drawing on a separate, refined version which is what I am going to do today. I do that because I think it is one of the most accurate aurochs artworks I did recently. 

It is not a reconstruction that is based on an actual skeleton, but it is based on such reconstructions. Actually, the basis for the drawing were the bull reconstructions that I did in June 2017. I did them by tracking out mounted skeletons (I corrected anatomical flaws in the mounts at first) to assure maximum precision: 
For my recent life illustration, I used the Vig bull and Kopenhagen bull (c and d) as a model, and decided to do it in a running pose. Here is the result (I decided to watermark it as I repeatedly made the experience that my drawings have been used without permission and crediting, which is not pleasant): 
While body shape and proportions are dictated by the skeletons and wild cattle anatomy, there are a few aspects that allow subjective decisions. For example, I could have given my aurochs larger horns. But as the horns of Holocene aurochs were smaller on average than those of Pleistocene ones (see here or here), I gave it medium-sized horns. The snout is slightly convex and the nose curves downwards a bit, which is a trait found in many Lidia bulls but also displayed by a skull of a British aurochs. Colouration also leaves room for speculation or subjective decisions (see here), such as the colour of the eel stripe, forelocks and extent of the lightly coloured muzzle. I gave my aurochs a yellowish eel stripe, as it is the most frequent colour in wildtype coloured bulls and written sources are not clear (they just speak of a "lightly coloured" stripe). The lightly coloured mouth is never mentioned in contemporaneous texts, and cave paintings show them only for cows. In wildtype coloured cattle, this trait is very prominent in almost all cows and also widespread in bulls, but aging bulls often have it reduced. In gaurs and bantengs, this trait does occur, but not in all individuals. So perhaps it was not that prominent in grown aurochs bulls as well. As for the colour of the forelocks, I decided to draw them black, as this is better supported by the evidence (see the post linked above). 

All in all, I am very happy with this aurochs drawing as it really shows a 100% of what I imagine a typical Holocene European aurochs bull to have looked like. Perhaps not surprising as it was me who did this drawing, but this is not always the case. The result also bears great similarity to many Lidia bulls (Spanish fighting bulls), but more on that on an upcoming post. 

My recent aurochs reconstructions and illustrations all have been rather bull-based, which is why cows are about to follow. 

Wednesday, 25 October 2017

The Heck bull at Lembruch, Germany

I have several posts in preparation at the moment, but for today, I have a short post. It is about a Heck bull I found recently on the web, and I think he is interesting for a number of reasons. It is or was (the article is from 2014, so I do not know if it is up to date) the breeding bull of a herd at Lembruch, Germany, owned by the breeder Martin Kockmeyer. At first I want to present some photos of the bull (photos owned by the Presse-Bild-Agentur Nokem Martin Kemper, I got them from this article): 
First of all, the upper two photos show nicely how Heck cattle is a mosaic of its founding breeds: the body and skull shape of a Highland bull (not desirable from an "aurochs point of view"), the colour of a Werdenfelser or Corsican bull, the horns very reminiscent of Watussi. 
Secondly, the bull's name is "Arak", thus I suspect he might be from the Wörth lineage, which is/was remarkable for being the only closed breeding line within Heck cattle and having established large, thick, comparably well-curved horns. The bull also resembles those of the lineage, like "Albatross" or "Aretto" quite well. It is always good to see bulls from that lineage being breeding bulls on other herd, as it means that they are spreading the genetic make-up for good horns among the population. As it is apparent from the photos, the bull is seemingly not very large, which is unfortunately true of many un-crossed Heck bulls. 

On the VFA's sale site, there is currently a bull for sale from the same herd, named "Delika", born in 2014. The horns are of a very useful dimension and curvature, it might be a son of Arak: 

Thursday, 19 October 2017

Wild horse series Pt.II: The Konik, Exmoor and Sorraia myths

In my 2017 wild horse summary I had a look at what the evidence suggests regarding the life appearance, extinction and population genetics of European wild horses. There are some open questions, but also some things that we can say with certainty. One of those things is that European wild horses are as extinct as the aurochs. Nevertheless, there are three horse breeds that are often referred to either as surviving wild horses or near-wild horses, having a special status among European horses in being particularly close to the original wild form. Those three breeds are the Polish Konik, the English Exmoor pony and the Portuguese Sorraia, and each one of those has its own proposed background story that is supposed to link them closely to European wild horses. Those stories, however, are only purported and believed by advocates of those breeds, people involved in various projects, and are spread exclusively in non-scientific text books, public relations articles, or on signs in zoos while nothing of them is replicated in scientific literature, and none of those breeds are considered zoologically special among domestic horses. Advocates of the breeds blame a “conservative scientific mainstream” that is biased against the idea that the European wild horse might still be extant in some form, while the truth is that the background stories for the purported special status of the Konik, Exmoor or Sorraia are largely based on wishful interpretations, Chinese whispers and fabrications, actually making those stories myths that do not withstand objective examination.
Here I want to present and subsequently dismantle those myths. When not relying exclusively on sources that repeat the same stories over and over, but actually provide a deeper background knowledge, backed up by more evidence than usually delivered, it becomes rather obvious that the usually purported background stories for those breeds are not tenable. Yet those stories are pretty persistent and widespread, and I hope this post might become a little contribution to clear things up. 

The Konik myth: The Polish game park at Zamosc was the place were Europe’s wild horses survived longest. In the year 1806, these wild horses were donated to local farmers of the Bilgoraj region and incorporated to their farm horse stock. In the 1920s, the Polish agriculturist Tadeusz Vetulani started a breeding-back project using wild horse-like individuals from the Bilgoraj region and bred them selectively for a wild horse-like nature, eliminating the domestic influence their genome experienced in the hundred years before. He called the result “Konik”.
The truth behind it: Whether or not the supposed wild horses at Zamosc were truly wild and not feral, it is unlikely that they left a noticeable trace in the local farm horses. This claim is based on a notion by Julius Brincken in a book from 1826, but this book is full of errors, misinterpretations and fabrications, so it is not a reliable source. Furthermore, the Zamoski family was at war with the local farmers due to social unrests in the 1780s and 1790s, so it is unlikely that they would have provided them with generous gifts in the form of livestock. And even if they did, it is unlikely that the farmers tolerated a strong wild influence in their horses as it would have been a throwback in their productivity and suitableness for agricultural work, as wild horse hybrids used to show intractable behaviour [2]. And even if they incorporated wild horses, and perhaps only mares, into their stock, not much would have been left after 100 years. So it is very unlikely that the horses of those particular rural regions of Poland had a notable wild horse influence in the 20th century [1,2].
In Poland, there was/is a landrace called Panje horses. Those horses were very robust, of a small and stocky body and varying in colour between black dun, black, sorrel and bay. In an 1921 article, Panje horses were considered as possible wild horse descendants (which is to be refuted for the reasons stated above) by the researchers Gabrowski and Schuch. This drew the attention of Polish agriculuturist Tadeusz Vetulani to the Panje horse as “wild horse relict”, he tried to back up this suspicion with cranial measurements (that have been questioned [1]), and coined the name “Konik”, which successively replaced the name Panje horse. Private and public studs were created in order to preserve and spread the landrace. In 1927, Vetulani started an experiment that is often considered a “breeding-back” experiment, but was actually more of a dedomestication attempt, using Konik/Panje horses that he considered wild horse-like. But Vetulani’s herd was only one of many Konik lineages back then, and the Second World War created a lot of confusion, as many Koniks were moved all over Poland and Germany during and after the war. After the war, the stud at Popielno was the most important Konik breeding site. They performed two separate ways of breeding: one to continue Vetulani’s way of few human interference, and one of traditional indoor breeding and commercial sales. Popielno was one of many breeding sites, and when other countries started to become interested in this breed, they purchased from any stud available [2].
Thus, neither was Vetulani’s experiement an experiment of selective breeding, nor was it the ancestral stock of the modern Konik population but merely one of many lineages [2]. He did not create the breed, but merely coined the modern name of the breed. The fact that 10-5% of the modern Konik still show a black or sorrel colour or white streaks on the forehead (respectively) reveal the mixed origin of this landrace [2], and there is no compelling, not even plausible, evidence that their ancestral stock was strongly influenced by wild horses [1,2].
The Heck horse, which is often presented as a “recreated Tarpan” in Germany and also other countries, is in a sense a washy Konik – it was created by the Heck brothers in the 1930s and 1940s by crossing Icelandic horses, Gotland ponies and Dülmen ponies with a Przewalski stallion. Later on, Koniks were used massively as breeding stallions on Heck horses, so that they are heavily influenced by that breed, hence the large optic resemblance [8]. The same was the case in the Dülmen pony, which is why the three breeds sometimes are regarded as the Konik group [8]. The Liebenthaler horse can also be regarded as a member of this group.

The Exmoor Pony myth: The Exmoor Pony is a remnant population of a wild horse type or at least a feral type of very original western European horses that once ranged on the entire British island. Several other populations of this primitive British horse type have been intermixed with derived horse breeds, creating the modern British pony breeds such as the Welsh Pony, New Forest Pony, Dartmoor Pony and others. The Exmoor Pony however is the only population that retains a stable, wild horse-like appearance with a brown colour, countershading + white muzzle and a sturdy body. The similarity to other northern ponies such as the Gotland or Faroe Pony, and especially some primitive Iberian breeds such as the Garrano and Pottoka, endorse the hypothesis of a north-western European wild horse/primitive horse type that once was found in this region and is most authentically represented in the form of the Exmoor pony.
The truth behind it: At first, this scenario sounded convincing to me. But what is most important to note first is that equines disappeared from the archaezoological record of the British isle at the end of the Mesolithic until domestic horses were introduced by the Celts [3,4,5]. Therefore, the Exmoor pony cannot be a remnant wild horse population or wild horses with domestic introgression, they have to be of domestic origin. But this alone does not rule out that they are the last representative of a homogeneous, feral and primitive horse population that once ranged across the entire British isle. One argument is their homogeneously small body, comparably short mane, the brown colour with countershading plus white muzzle. However, careful examination suggests that the population at the Exmoor never was homogeneous after all[4]. There are no helpful references prior to the 18th century on the colour variants found in the Exmoor population. Between 1805 and 1809, 81 Exmoor ponies were sold from the moor. Their colour was documented and included black, grey, bay, dun, chestnut and one piebald individual. There is no evidence that purposefully “non-pure” Exmoor ponies were caught in this case. Two illustrations in the Illustrated London News from 1835 clearly show horses with a long mane, their colours are probably implemented to be brown with a white blaze and sock, grey and a black one [4]. A notion by Worthley Axe in the year 1906 is even more revealing: “… the majority of the so-called Exmoors are simply mongrels” [4]. The Acland herd, which made a considerable contribution to the modern Exmoor population, also included a number of greys and blacks in 1900. There is a record that suggests that black Exmoor ponies were selected out because they lacked the expression of the white muzzle, indicating that artificial selection started back then. Furthermore, the Exmoor pony population went through several bottlenecks, the most severe in course of the Second World War. A stud book for the breed was set up in 1921, at first black and grey individuals were tolerated but selected out later. It is thus far more in line with the evidence that artificial selection and genetic bottlenecks created the homogeneous external appearance we see in the modern Exmoor pony, and there is no evidence that it was homogeneous prior to 1906. Most likely the Exmoor pony that is always brown in colour with countershading, a white muzzle and no white markings is an invention of the 20th century [2]. It would therefore also be more parsimonious to assume that other British pony landraces like the Welsh pony, Dartmoor pony or New Forest pony never were homogeneous either. Furthermore, the use of British ponies including the Exmoor pony on Iberian breeds like the Pottoka in the 20th century is well-documented[2], which is at least partially responsible for the optical resemblance. Thus there is no empiric basis for a once feral, primitive free-ranging horse type that looked like the Exmoor and ranged across Great Britain or even whole western Europe.
Also, which is important to note, Exmoor ponies most often display a colour variant that is called seal brown, At. This is an allele that has not been identified in wild horses yet, in contrast to the two wildtype alleles bay A+ and black a [6,7], and therefore most likely is a domestic colour. The black individuals, which have been actively purged from the population, however, would have displayed a wildtype colour variant [6,7].

The Sorraia myth: The Portuguese agriculturist Ruy d’Andrade spotted a herd of strongly striped, free-ranging horses in a remote region in Portugal. He considered them to be a remnant population of the zebro, a strongly striped Iberian wild horse type. He was unable to find them again, but collected a number of farm horses from that region that he considered to be closest to those horses, and started to breed them. This is the modern Sorraia horse, by some even communicated to be identical to the zebro and thus a wild horse.
The truth behind it: The claim that the Sorraia is a surviving Iberian wild horse is flawed by the story itself – d’Andrade did not catch any wild horses and started breeding them, but merely collected farm horses he considered to be reminiscent of the horses he spotted. He collected four local stallions and seven mares, and a Criollo stallion was added later on. Therefore, the Sorraia is a descendant of domestic farm horses. But is it possible that is particularly strongly influenced by an optically identical Iberian type of strongly striped wild horses, the zebro? First of all, there are not any references suggesting a survival of wild horses on Iberia into the beginning of the 20th century. C.H. Smith reports free-ranging horses of black dun and bay dun colour with wild markings that ranged from the Camargue, parts of Spain to the Ardennes, Great Britain and Scandinavia (see here), but also describes them as “sturdy mountain-forest ponies”, and it is not clear if those are wild or feral horses anyway. Regarding the actual zebro, it seems that this population of equines vanished in the 16th century [8] and many authors tend to consider them feral donkeys instead of horses. Indeed a genetic test of the skeleton of the supposedly last zebro turned out to be a donkey [9]. The strongly striped ashy grey colour of wildtype coloured donkeys is very reminiscent of the black dun colour scheme in horses.
The allegedly strong stripe pattern of the Sorraia is often purported as its trademark and an indicator of particular primitiveness that links it to the zebro. However, stripes are part of the bay dun and black dun colour scheme and found in many horse breeds. Therefore, it does not give the Sorraia any special status (see a very strongly striped Hucule here, for example).
Ferus-type wild horses are usually assumed to have been comparably small and sturdy in build. The Sorraia, however, is comparably large (140-150cm at the withers) and lanky. As there is no comprehensive archaezoological record of predomestic wild horse skeletons that has been osteometrically examined (only some single fragmentary specimen) it can neither be proven nor ruled out that Iberian wild horses were larger and more gracile in build than other Eurasian wild horse types, but it would be necessary to have evidence at hand for making such a claim.
More importantly, genetic information has revealed the Sorraia as a domestic horse [10].

I am going to come back to genetic studies more extensively in the next part of the wild horse series 2017. A closer look at the respective history of those three breeds that are often supposed to be wild horse relicts, near-wild horses or recreated wild horses alone is sufficient to show that there is actually nothing of substance that suggests that these three breeds deserve a special status among robust landraces of European domestic horses. But this of course provokes the question which horse breeds are best suited to be used as a substitute for the European wild horse in ecologic restoration. Thus, the upcoming post is on this question as much as on the domestication of the horse in general.

Similar but older posts: 


[1] Cis van Vuure: On the origin of the Polish Konik and its relation to Dutch nature management. 2014.
[2] Tadeusz Jezierski, Zbigniew Jaworski: Das Polnische Konik. 2008.
[3] Baker, Sue, 2008: Exmoor Ponies: Survival of the Fittest – A natural history.
[4] Peter Green, 2013: The free-living ponies within the Exmoor National Park: their status, welfare and future. A report to the Exmoor moorland landscape partnership. 
[5] Bunzel-Drüke, Finck, Kämmer, Luick, Reisinger, Riecken, Riedl, Scharf & Zimball: „Wilde Weiden: Praxisleitfaden für Ganzjahresbeweidung in Naturschutz und Landschaftsentwicklung“. 2010
[6] Pruvost et al.: Genotypes of predomestic horses match phenotypes painted in paleolithic works of cave art. 2011
[8] Bunzel-Drüke, Finck, Kämmer, Luick, Reisinger, Riecken, Riedl, Scharf & Zimball: „Wilde Weiden: Praxisleitfaden für Ganzjahresbeweidung in Naturschutz und Landschaftsentwicklung“. 2010
[9] L. Orlando et al.: Revising the recent evolutionary history of Equids using ancient DNA. 2009.
[10]  Lira et al.: Ancient DNA reveals traces of Iberian Neolithic and Bronze Age lineages in modern Iberian horses. 2009

Friday, 13 October 2017

Some more photos of Watussi x Maremmana

Claus Kropp from the Auerrind project recently published a post on the use of Watussi in the project on the Auerrind blog, including a recent photo of Thando and his half-Maremmana offspring. 
Thando (©
Apollo (©
Ambra (©
I think that Apollo might approach the age of reaching its final colour, but it is obvious that he is darker in colour than its halfblood sister. This is likely mostly due to its Maremmana ancestry, but sometimes also Watussi cattle show a tendency of sexual dichromatism. The zebuine hump seems to be either lacking or very weakly developed yet, but this is irrelevant as those individuals are F1. Surely the hump might or might not reappear in future cross individuals, depending on coincidence. One always has to pick the right individuals once the genes become split up and distributed among the offspring. Regarding the colour, I think this combination bears the potential for very dark or even black bulls (probably with a colour saddle) in F2 and subsequent combinations. Watussi might pass on alleles for very dark bulls, but is unable to express it since their coat colour seems to lack the black pigment eumelanin. Maremmana enables that, but carries dilution alleles that remove red pigment, pheomelanin. Watussi, however, contributes the wildtype alleles that enable the expression of pheomelanin. Thanks to the 2. Mendelian rule, it is possible that true F2 individuals might end up showing the right wildtype aurochs colour setting. 

I am confident that it is possible to boost the horn size of the Auerrind crossbreeds using Watussi without adopting the negative traits of the breed using careful selection and also a bit of luck. It worked successful with Heck cattle of Neandertal descent, and in Hortobagy there are a couple of qualitatively aurochs-like Taurus cattle with Watussi influence. 
Thus, I am looking forward to watching those individuals grow up and to see their respective offspring with great interest. 

Monday, 9 October 2017

Drawing: Central Europe's Holocene megaherbivores

I recently did another drawing showing Holocene Europe’s megaherbivores of the nemoral mixed-forest zonobiome, drawn to same scale. It shows, from left to right: fallow deer, Dama dama; wild boar, Sus scrofa; red deer, Cervus elaphus; elk, Alces alces; roe deer, Capreolus capreolus; aurochs, Bos primigenius primigenius; wisent, Bison bonasus; European wild horse, Equus ferus ferus.

I know of course that wild boar are actually omnivores. One might ask why I included fallow deer, as it was introduced in historical times just like the mufflon. In contrast to the mufflon it has a Pleistocene interglacial record in Central Europe, which is why I included it here. The question is whether Dama dama would have recolonized Europe without human influence. In order to answer the inevitable question “but where are elephants and rhinoceroses?”, my drawing intends to illustrate only those herbivores which had a solid presence in Holocene Europe. It is not known for certain that the European continental elephant species Palaeoloxodon antiquus as much as the two rhino species of the genus Stephanorhinus have been driven to extinction by men and would still be extant without anthropogenic influence today. It is plausible, I even consider it likely, but not proven. One might also ask where water buffalo and Equus hydruntinus, the European wild ass, are. There is only one Holocene remain for the genus Bubalus in Europe (Austria, to be precise) which has been tentatively assigned to this genus by Erich Pucher in 1993, nowadays he would reclassify it as Bos (personal communication). Bubalus murrensis might have been hunted to extinction (although its record is really rare and I do not know of literature mentioning its association with kill sites), but here goes the same as for elephants and rhinos. Europe being recolonized by extant members of Bubalus without anthropogenic influence is speculation. Equus hydruntinus has a solid Holocene evidence in Neusiedl, Austria (Pucher, pers. com.), but as part of a different biome – the Puszta steppe.
When I refer to a mixed-forest zonobiome I do not intend to imply it was naturally all forested. I consider the classical hypothesis of this biome being one closed canopy forest falsified by a number of facts. However, I also consider it an exaggeration to speak of a European savannah, as there is also evidence pointing against such a hypothesis. To me it is most likely that this biome was a mosaic of open, semi-open and closed landscape, depending on a variety of factors also including such as latitude, precipitation, flooding and humidity, natural disasters and so on. This a complex, big and (needlessly) heated debate that is way to extensive for this post and my drawing. I could have drawn my megaherbivores on a grassy background, which would be only one of several habitats we might have encountered those animals, but sporadic oak trees and hazel bushes are certainly a realistic background as well considering they have been pushed in those habitats as civilization progressed and the space for wild herbivores became increasingly limited.

I decided to give my wild horse a bay dun colouration, as bay dun is suggested to have been most frequent in Holocene wild horses by genetic evidence. Historic evidence, which is dubious, would have favoured black dun, but both colour variants plus the non-dun variants are proven for ferus-type wild horses. For details, see my wild horse summary 2017.

And here a close-up view of the aurochs:

I am very happy with this one, I managed to get it exactly the way I imagine Holocene European aurochs bulls to have looked like. It is based on my reconstructions of several skeletons that I published in July 2017 and I think it bears a striking similarity to many Lidia bulls. I am going to post a refined version of that close-up drawing soon.