Wednesday, 30 December 2015

Did the Heck brothers good work or not?

Heck cattle is not a revived aurochs, that’s no secret to those who are familiar with this subject. It is also far from being a perfect optic copy. In the past, I heavily criticised the work of the Heck brothers because of that – but how bad or good was their work really? Did they do their best their possibilities allowed back then, or where sloppiness, a lack of knowledge and care the reason why Heck cattle “failed” the goal to mirror the aurochs in optical sense? In this post, I try to evaluate if the Heck brothers could have done better considering their time and abilities, if they made some crucial mistakes and what is positive from modern perspective.  

First of all, we have to define what the Heck brothers had to do executing their project, and then analyse how well they did it and if they could have done better.
For the ideas, thoughts, statements and actions of the Heck brothers given in this text, see Cis van Vuure 2005 and Walter Frisch 2010. The latter source also includes original texts written by the Heck brothers in German, if you want to have a look at direct quotes.

1) Getting a clear idea of the morphology and external appearance of the aurochs. That is its size, bodily build, horns, coat and colour of the coat, and differences between male and female.
2) Researching on which cattle breeds have those traits and getting their hands on them for breeding.
3) Doing efficient breeding to unite those traits desired in order to create a complete picture of the aurochs. #2, getting the right breeds, is essential for that of course.
Painting based on a photo of "Nordland", a third-generation crossbull of Heinz Heck. All rights reserved. With highest probability, all living Heck and Taurus cattle have this bull in their ancestry. For more illustrations of historic Heck cattle, go here
One of Lutz Hecks' stock. Photo found somewhere on the web, with no copyright or owner mentioned.
The Hecks original goal was to truly revive the aurochs. They thought this would be possible by just uniting all optical traits this wild animal possessed, under the assumption that all morphological/optical traits of the aurochs are still present in modern day cattle. Other biological aspects like habitat preference, food choice and behavioural aspects were not of interest for the Heck brothers. Most likely they either assumed these factors were identical in cattle and aurochs, or that would re-appear correctly once optical match has been achieved, or they simply did not care. So their goal was an optical match, what they considered sufficient for a revival of the wild type.

What kind of sources and material did the Hecks have to go on in order to get an accurate impression of what the aurochs looked and was like during the 1920s and 1930s? Well, actually everything that we have today. Although the quantity of skeletal remains increased, probably multiplied, they did have more or less complete skeletons, crania, horn cores and preserved horn sheaths. Also, the cave paintings (except for Chauvet), stone engravings, Charles Hamilton Smiths painting, Schneebergers and von Herbersteins reports all were known back this time. So the Heck brothers had the possibility do know as much about the aurochs’ morphology and external appearance as we do today. How well did they do their homework?

Heinz Heck noticed correctly that the size of the aurochs varied from region to region and he was aware of the fact that the aurochs was considerably larger than most cattle today, and considered its maximum size to be 2m at the shoulders. His brother Lutz, however, seemingly totally underestimated the size of the aurochs and postulated a size of only around 350kg (!) for bulls. I do not know how this is possible, especially because I assume that he had seen aurochs remains himself, which unambiguously tell you that the aurochs was a fairly large bovine (he did, however, realize his obvious mistake in 1952, when his breeding project was already over).
Regarding body build, Heinz describes the aurochs as elegant and high on the legs in 1980. I do not know whether he was aware of that when he did his breeding attempts in the 1920s-30s or not. Lutz Heck must have been aware of the aurochs’ “elegant” and athletic build, as he appreciated that trait very much in Lidia, Camargue and Corsicana. However, both brothers seemed to have worried about the exact weight more than body shape, so they maybe assumed that bodily build does not play an important role.
Heinz Heck claimed the aurochs did not have a hump formed by high processus spinosi as the Wisent does, which is evidently wrong as each more or less complete skeleton shows. He also believed the aurochs had a slightly raised pelvis, for reasons unknown to me.
The distinction between female aurochs and male aurochs in the subfossil record back then might have been not as precise as today (and I do not think that we can tell both sexes apart for sure in each case as well today), but the Heck brothers should have known that there was considerable size dimorphism alone because it is mentioned in Schneeberger’s report. How much attention the brothers paid to it is another aspect.

Concerning the horns, Heinz Heck described them curving sideways, then forwards, then up and therefore did not recognize the very clear inwards-curve that all aurochs horns had. He claims that there was considerable variation regarding horns, which is not true of the general curvature and orientation relative to the skull. Lutz’s description is more vague, he merely compares them to those of breeds such as Lidia, Camargue, Watussi, Longhorn, English Park cattle and others – a set that also includes horn shapes that were not present in the wild animal. Despite the fact that the basic curvature of the horns of the aurochs was recognized and described in the scientific literature and numerous well-preserved crania were known back then already, the brothers also used the various and imprecisely illustrated horn types of the paintings in the Abrigo de los Toros cave – a source that is highly unreliable for traits like horn shape.

As regards to colour, both Heinz and Lutz Heck knew the basic traits of the aurochs’ wild type colour: very dark brown to black bulls, light-coloured muzzle ring, reddish-brown cows, dorsal stripe. Heinz Heck assumed this stripe could have also been broad (historic evidence only speaks of a narrow stripe), while Lutz believed it was of red colour (historic and artistic evidence suggest a light or greyish colour instead). Lutz also believed in a reddish colour saddle for bulls, for which there is no evidence in Europe at least. Heinz Heck considered brown or blond forelocks a wild type character, a trait that is widespread in aurochs-like coloured cattle but for which there is no evidence in the Central European aurochs. Heinz further states that their breeding-back attempt revealed the “previously unknown” fact that aurochs were born being of a brown colour and subsequently grew a darker coat. He seemingly overlooked that Schneeberger in Gesner 1602 reports exactly this, and that it is a general characteristic of wild type-coloured cattle, i.e. those that show an E+ expression. He further states that the head of cows was lightly coloured, which is contradicted by artistic evidence (cave paintings) and the colour scheme of extant E+ coloured cattle. Heinz Heck also believed that both sexes had white eye rings as adults, for which there is no clear evidence for, as well as for Lutz’s baseless statement that there also were cows with of a lighter, greyish tone. Lutz also assumed the presence of black cows, which is confirmed by cave paintings and Schneeberger’s report on the other hand.
They both presumed that the winter coat was longer than the summer coat and dense. This was undoubtedly the case. The fact that aurochs had, like other wild bovines, a barely visible udder must have been apparent to the Heck brothers as well.

As you see, the Heck brothers did their homework, but it could have been more in-dept. It also seems that they barely studied the scientific literature that had already existed back then. They did have an idea what the aurochs’ morphology and appearance were like, but it included inaccuracies, imprecisions and misconceptions as I outlined, and they made some more or less baseless speculations. Also, they completely forgot about the cranial morphology that differed from most domestic cattle, at least I do not know of any notes on that. Therefore an animal that would end up exactly like they described would necessarily not be entirely authentic and might also have some definitive flaws.

The next step for the Heck brothers was to locate and get their hands on the most suitable cattle breeds for crossbreeding. The Heck brothers’ father, who had been director of the Berlin Zoo as well, build up a large cattle breed collection during his time. But this collection did not include cattle with all the traits the brothers wanted, so they had to start a quest for particularly aurochs-like cattle.
This was during a time when it was not only uncertain where the aurochs was domesticated and how many times, but there was also no internet, barely any breeding associations to contact, and rural cattle populations very often had not been categorized in distinct breeds yet and consequently there was no compelling literature either. So, where to start? Scandinavia, Iberia, the alps, Balkan, Near East? The Heck brothers researched in the literature and went on field trips in other countries to locate suitable cattle – besides their jobs as zoo directors. I think that’s laudable. And those cattle that they found to be suitable also had to be purchased and imported. So if two men alone did not find the absolutely most aurochs-like cattle in whole Europe, sloppiness is probably an unfair explanation – it simply was not nearly as easy as it is these days.

Lutz Heck discovered that there are a lot of Southern European cattle that bear striking similarity to the aurochs. He was particularly impressed by Lidia, which he considered the most aurochs-like cattle of all, as well as Camargue and Corsicana. During the first years, he bred exclusively with those three breeds because of their aurochs-like colour, elegance, horn shape and “wild character” that he considered fitting. From the modern perspective, this combination would lack body size and horn size, which both were traits that were not of much importance for Lutz Heck. Later on, he incorporated also crossbreeds containing Highland, Norwegian Fjäll, Hungarian Grey and English Park cattle; but he was not impressed – Highland cattle contribute horns protruding sideward, Park cattle ad Fjäll cattle both have a “wrong” colour that causes spots in heterozygous state (we would classify that pattern as “colour-sided” today). Furthermore, the latter has a dominant lack of horns, which Lutz did not like (dominant traits, however, are easy to breed out).
Heinz Heck used a Southern European breed as well, Corsicana. But he included a wider set of breeds than his brother. Additionally to Corsican cattle with their aurochs-like colour and forwards-facing horns and Grey cattle with their good horn size and shaggy winter coat, he also included more derived and often large-uddered Murnau-Werdenfelser, Angeln, Highland, black-pied lowland cattle (original German: Schwarzbunte. Similar to Holstein-Frisian but smaller and not as high-legged) and Braunvieh. Murnau-Werdenfelser have a typical domestic body shape and their horns are not aurochs-like either, but some of them have a useful colour. Angeln have, at least today, more or less long snouts (and in some cases also useful horns and colour), but since neither of the Hecks ever made a remark on that trait of the aurochs, it is probably not the reason why Heinz included it. Braunvieh was used because of its comparably slender build and is E+//E+ as well. Paradoxically, Highland, black-pied and maybe also English park were included to “add mass”, on the other hand. Heinz Heck was aware of the fact that a number of the breeds he chose barely contributed anything if nothing in terms of optical similarity. But he regarded them as necessary to get as much aurochs traits as possible, because he believed these breeds could add “invisible traits” of the wild form that would surface from alone when the breeds and their “old genes” are combined. A suspicion that, considering the state of the art knowledge on heritage and genetics in the 1920s to 1930s, might have been legitimate back this time.

After the war, Heinz Heck noted that their experiments told them that a “bred-back aurochs” is achieved at fastest by using Podolian cattle, Highland cattle, Southern European cattle and Texas Longhorn (the mention of the latter is curious because neither of the two used this breed). Speaking of the cattle’s optics only, the inclusion of the derived breeds was a mistake – Heinz’ hope for hidden ancient traits surfacing did not fulfil. But, retrospective, it created a wider genetic base for the new breed than it would have been possible using the primitive breeds they chose only.
Counting the brother’s breed choices as one, the set up contained many aurochs traits, with the exception of a truly elongated, not paedomorphic skull shape and body size at least. For the latter trait, the Chianina could have been an option back then – this breed was probably not an enigmatic one in the time between the two world wars, as it has a long breeding history and is remarkable for its size. So the Heck brothers should have, or at least could have, known about it. And even if not, Heinz Heck noted that some Podolian bulls get very large (he exaggerated it to up to 2m) – so either he was not able to get his hands on the very large ones, or he did not consider it that important and was confident with what he had. In 1980, he responded to the criticism that their cattle are too small by calling this criticism false because the breeding-back attempt is or was working against this size dimorphism – which is incorrect, because it is evident that large size was not one of the goals of the Heck brothers experiments, and it was not until 1996 that someone actively bred for large size by crossing in larger breeds (Taurus cattle).

The Heck brothers did not keep track of their crossbreeding precisely, at least there are no such documents known and many of their reports are only vague. As an example, Heinz Heck example stated in 1934 that he intended to further cross-in English Park and to exchange bulls with his brother. Whether it happened or not is unknown. Because of the lack of precise records, the exact descent of Heck cattle post 1945 is nebulous. This was certainly sloppy, and one can consider it another mistake. But technically it makes no difference, because it is about the traits that are present in the population.

Nevertheless there are other things to criticise. First of all, it starts with the often  imprecise, sometimes speculative and partly inaccurate idea of the aurochs the brothers had, that also neglected certain traits (f.e. body size, build, udder size) or not even recognized (f.e. skull morphology), as outlined above. With that as a base, their breeding products just had to have flaws. Cis van Vuure, in his 2005 book, diagnoses “a lack of basic knowledge, broad selection criteria and complacency”. There were numerous such undesirable traits because of the diverse set of breeds they used. Due to their very loose selection criteria, the Heck brothers seemingly permitted non-aurochs-like traits such as all kinds of horn shapes and sizes, a greyish tone in the coat colour of cows at least, colour saddle in bulls, and other traits that are either incorrect or not supported by evidence. These “wrong” traits accompanied with the neglected traits body size, build and skull shape. Furthermore, it is not clear how much they cared about sexual dimorphism. Also it seems that udder size plaid no role in their experiments as well.

Taking the year 1945 as the benchmark to compare with, the result was not an optically reconstructed aurochs, but ended up being a population of cattle that contained a number of aurochs-like traits, but also a number of undesirable ones, and traits such as horns, body size or build never were present in a satisfying way. Therefore, the Heck brothers’ results were criticised early on in scientific circles based on exactly these reasons. The Heck brothers, on the other hand, seemingly were immune to criticism and failed to recognize deficiencies. Partly because they did not know better (as outlined above), but perhaps also because they did not want to see. They also wanted to see things that were not there, such as the alleged optical match between the Berlin stock and the Munich stock that should proof the success of their project – albeit there were obvious differences between both stocks. They failed to scrutinize. On the contrary, they were very confident, even euphoric, about their work and claimed almost full success, what further contributed to ridicule made by more down-to-earth colleagues. They certainly were not frauds, but perhaps victims of self-deception to a certain degree. Their experiments were a lot of work, surely also exciting and fun – so maybe their enthusiasm hindered them to see and correct deficiencies. It was also this enthusiasm and complacency that caused ridicule in zoological circles. And I think this is understandable, since their basic idea (recreating a true aurochs by breeding with domestic cattle, solely on optical grounds) is a gross oversimplification and impossibility in the first place in any case.

So, how well did the Heck brothers do their work?  
- Their idea of the aurochs was half correct; it was partly imprecise, took some needless speculations for granted and contained some flaws. This would not have been the case if they had researched more in-debt, (they had all the contemporaneous literature and most of the contemporaneous art we have today, plus the scientific literature on the aurochs that had existed back then) and if they had taken a closer look at the skeletal material that was sufficient back then already.  
- A number of traits were simply neglected, such as body size and build, udder size, or the elongated skull shape that they failed to recognize. Consequently, these traits were also neglected in their breed choice and selective breeding.
- As a consequence, their selection criteria were too loose regarding a number of traits. For example, they tolerated a way too large range of horn types – looking at the bones would have told them. Another example is their conceptions about fur colour, which included needlessly speculative variants. It also seems that they did not worry about udder size as much as they did not worry about body size, build and skull shape.
- Within their possibilities, the set of breeds they collected was not that bad. It had aurochs traits such as a correct fur colour, sufficient horn size and an acceptable curvature. Lutz Heck’s breed choice also included slender and elegant cattle – a trait that his brother did not care that much about. What was generally lacking was a breed that would have contributed large size. Either such breeds/individuals were not available for them, or they (i.e. Heinz, since Lutz was assuming a way too small size for the aurochs) did not care enough. Based on their statements and confidence, large size was definitely neither a priority nor goal in their experiments.
The breeds chosen by Heinz Heck, which are most likely the sole basis of the modern Heck cattle population (except the brothers did exchange some individuals), included such with many less than desirable traits; he chose them for reasons outlined above, and back these days his assumption of invisible traits that might surface again was probably not unjustified. It did not come true however, and introduced a lot of undesirable traits.
- The lack of precise notions on the crosses carried out, as well as if they exchanged individuals, was sloppy and leaves open question on the cattle’s exact descent. But, on the other hand, this does not alter the traits that were and are present in the population. - Due to their lack of will to scrutinize their work as much as their immunity to fact-based criticism, they did not see or accept the deficiencies pointed out by other contemporaneous zoologists and therefore made no efforts to correct them.

All in all, the Heck brothers could have done their work better given the time and possibilities they had. More careful research would have resulted in an idea of the aurochs’ morphology and appearance that is identical to other modern one. Stricter selection criteria would have limited the number of undesired traits, and they also should not have ignored or neglected certain traits and taken a closer look at the bones. With that as a base, their results probably would have been better. On the other hand and to be fair, even if they had an ideal set of breeds, the fifteen to twenty years of time they had would have probably been not sufficient stabilize an aurochs-like appearance in a fully satisfying way (as we know from breeding today).

Although the Hecks did make mistakes and did some tasks not thoroughly enough, their effort of looking for suitable breeds, purchasing and importing them on their own is laudable. And however unsatisfying the end result was, it was the Heck brothers’ project that started the whole breeding-back idea. I wonder if, hadn’t there been the Hecks’ experiments, there would be the modern aurochs-projects at all – only if someone else came up with that idea.
In spite of their failure to create an optical aurochs, the Hecks reached one of their goals: to rescue the aurochs from oblivion and get it into the mind of people again. Probably a lot less people would know about this animal today if not zoo visitors from the 1930s onwards were seeing those cattle wrongly tagged as “aurochs”. I was also surprised how many non-scientific animal guides include this animal.
Their cattle (again, taking 1945 as a benchmark) were actually useful animals to work on. Despite of all its deficiencies, the population did contain a number of aurochs traits and had potential. All the optically useless breeds that Heinz Heck included added genetic diversity: His set of breeds included cattle from southern Europe, Northern Europe and Central Europe. This genetic diversity was apparently enough to allow a population growth from less than 50 in 1945 to more between 3000-2000 animals nowadays without having any signs of inbreeding depression. In fact, thanks to their genetic diversity and the use of hardy, healthy and cold-resisting breeds Heck cattle turned out to be a very useful breed for natural grazing, and these traits are also very useful for further “aurochs” breeding. No matter how much one might dislike that breed for its general lack of traits like size, inwards-curving horns, and their small, stubby body with their short, calf-like heads, one cannot alter this fact.

In the end, we, in 2015, might even have to be thankful to the Heck brothers and their experiment, even though they could have done their work better.


  1. Nice work on that essay.

    As a side not I've, I've found a pic of a Highland-zebu cross with some aurochs-like features. https://scontent-ord1-1.xx.fbcdn.net/hphotos-xat1/v/t1.0-9/11224055_1034490666564224_494732105994040338_n.jpg?oh=548165b6b764c436bb04e65d57e2d120&oe=570AE4BD

  2. i breed some black highland cattle one bull in particular could be of interest to the back breeders. a very close match in shape to the charles hamilton smith image. my email ian.duncan@outlook.com i will send a picture i can't paste on here for some reason. he is now five years old. i have 2 full brothers of him as well, one born last year and one the year before.