Lions prefer killing piebald cattle

In my dedomestication series from 2015 I speculate on the selective pressures acting upon the genetic structure of feral domestic animals that will eventually turn the feral animals into wild animals adapted to their environment. I made the prognosis that the animals will show a regression towards wildtype traits because these provide a greater evolutionary fitness since they are the product of past natural selection. Colour would be one of the examples. I speculate that predators would influence the colour of the animals, because some variants are well-camouflaged and others are not, such as piebald individuals. This would, after a sufficient amount of generations in the wild, lead to an eradication of alleles producing piebald colours which are typical of domestic animals and to a genetic fixation of non-piebald (wildtype) alleles. 

My dedomestication hypothesis has empirical problems, as there is no feral population of domestic animals in the same habitat as their wildtype under the same ecologic circumstances that has been reproductively isolated for a sufficient amount of time. But recently there was a study that might provide empirical support for some of my prognoses postulated in the dedomestication series. 

The prey behaviour of lions preying on cattle in Botswana has been analyzed in 2020 by Weise et al.. What they found was not only that lions prefer to kill cattle that are easier prey such as hornless individuals (which is not surprising, as hornless cattle have a much harder time defending themselves against predators than horned cattle), but also that piebald cattle have a higher risk of being attacked by lions. Lions seem to prefer piebald cattle over solid coloured cattle [1]. The authors speculate that a piebald colour makes identifying movement easier for the lions, and therefore they are attacked more often than solid coloured cattle [1]. I think that it is also possible that it is simply the fact that piebald patterns stand out more than solid colours, so that these individuals are attacked more often.  

The authors also found that short-horned cattle were preferred over long-horned cattle, which were mostly avoided by the lions. 

These findings are very interesting. In my view, they clearly suggest that at least some wildtype traits (solid colour, long horns) provide a selective advantage over domestic traits (piebald colour, short or no horns). The authors indirectly say the same by pointing out that cattle lost adaptions of the aurochs against predators [1] (this is a generalization that is not actually true, as there are cattle which still have large forwards-facing horns, significant body size, an athletic long-legged stature and wildtype colour et cetera). This implies that in a heterogeneous cattle population, where some individuals have these wildtype traits and others do not, this will lead to an increase in the frequency and eventually the fixation of the wildtype alleles, and therefore a regression towards wildtype traits, when exposed to selective pressure caused by large predators. 

This shows that the selection criteria of "breeding-back" are not pure cosmetics as some critics repeatedly claim, but actually contribute to the survival of the population of the animals once returned into an ecosystem with predators. 

Literature 

[1] Weise et al.: Lions Panthera leo prefer killing certain cattle Bos taurus types. 2020. 

Transforming Lerida the Taurus cow to an aurochs cow

A while ago I did a post on the Taurus cow Lerida in the Lippeaue, Germany. She is a Sayaguesa x Heck cow, and has always been among my favourite Taurus cattle individuals. Recently I used a photo of Lerida and used the program GIMP to modify her morphology so that she fits a European aurochs cow. The result is down below. The photo was provided by Matthias Scharf from the ABU. 

original photo (bottom) © Matthias Scharf

The changes I made include: 

- horn size increased 

- horns slightly elevated viewed from frontal view 

- visible udder removed 

- trunk shortened 

- dewlap size decreased 

- hump size increased

A real aurochs cow would probably be slightly more muscular, as wild bovines usually are. But apart from that, I think the manipulated photo compared to the original shows the differences and commonalities between Lerida and an aurochs cow very well. The differences are reflected by the changes on the photo that I made, the commonalities include the colour, which is flawlessly wildtype, the skull shape, the leg length, the horn shape except for the fact that they could be more raised in frontal view producing that < >-shape, and also the body size is probably right as Taurus cows are usually around 150 to 155 cm in withers height. 

Australian scrub bulls and their aurochs-like morphology

There are feral cattle in Australia called scrub bulls. Those scrub bulls are noteworthy for their morphology. They are long-legged, slim but not too gracile. They are part zebu, and I think the zebu influence is responsible for their morphology, as primitive zebus are very short-trunked with long and slim legs. It is also possible that the fact that they live feral contributed to the morphology of the scrub bulls, but I do not know if they have been living feral for enough generations so that natural selection influenced their skeletal morphology.  

Here you have a video of some interesting scrub bulls in Australia: 

The morphology of scrub bulls, in my opinion, endorses the idea of using primitive zebus for achieving aurochs-like proportions in "breeding-back". An F2 of well-selected Taurus x (Taurus x primitive zebu) could be very interesting. 

Is "breeding-back" too much looks-based?

Originally, when the Heck brothers started their breeding experiments, their intent was merely to show what the aurochs looked like, i.e. they only cared about the animals’ looks. Nowadays, “breeding-back” aims to produce animals that are fit to ecologically fill the empty niche of the extinct aurochs. Cattle that work ecologically like aurochs are a valuable contribution to conservation and rewilding, as they represent a species once native in Europe. 

This is the modern purpose of “breeding-back”. But isn’t it too much looks-based for this purpose? Shouldn’t the breeding focus on the animals’ ecology, health, natural instincts and ability to defend themselves against predators if the cattle are supposed to survive without human help in nature? Wouldn’t existing feral cattle populations be a better substitute for the aurochs, because they proved to survive without human help? 

 

These objections against the concept of “breeding-back” occur from time to time, and I do not consider them valid. To avoid this kind of criticism, “breeding-back” projects emphasize that they do care about the cattle’s ecology. But that seems to be unheard by those who consider “breeding-back” too much looks-based. 

I think that those who criticise “breeding-back” as too superficial imagine that the desired aurochs traits are evenly distributed among the cattle world, so that aurochs-like traits desired are coincidentally found in breeds that might or might not be robust in ecological terms, and that the breed choice of “breeding-back” is based only on those optic criteria, so that the selection of breeds used might consist of breeds that have the desired optic traits but may lack the ability to survive and thrive in nature and the subsequent breeding focuses only on those optic traits, so that the robustness of the cattle would fall by the wayside while feral cattle prove to be robust and able to survive in nature. 

This, however, is a wrong assumption. In fact, optically aurochs-like cattle are always at the same time robust, hardy landraces because they are less-derived as a whole, and often live free all the year round. That means that the animals that “breeding-back” works with are hardy and robust right from the beginning. Heck cattle are a very good example for this. As mentioned above, the Heck brothers only cared about the looks of the cattle. Yet the resulting breed turned out to be healthy, hardy and robust, because the breeds it was created from were healthy, hardy and robust. Heck cattle proved to be able to survive without human help in the Oostvaardersplassen reserve. If the assumption of those considering “breeding-back” too much looks-based was correct, Heck cattle – originally only selected for looks – would not have ended up as a hardy and robust breed that is able to survive in nature. The same inevitably goes for more aurochs-like “breeding-back” cattle like Taurus cattle, because those projects also exclusively work with hardy and robust breeds. I have to admit that I do not know of a single breed that is truly aurochs-like but is susceptible to diseases, not able to cope with weather or to live free all year round and can only live on easy-digestible food provided by humans. 

It is also not true that “breeding-back” does not care about the ecologic capacity of the animals. For example, “breeding-back” cattle in Central, Northern and Eastern Europe need a thick insulating winter coat in order to cope with harsh winters. Watussi is used in some “breeding-back” projects which is a subtropical breed and not very winter-resistant, and the winter coat of Chianina is not the longest and thickest either. The breeders are aware of that and included breeds which have a thick insulating winter coat, f.e. Hungarian Grey cattle in Hungarian Taurus or Auerrind cattle. Yes, “breeding-back” focuses on a lot of optic traits, but the ecologic capacity of the animals is an additional criterion in all modern projects. 

Regarding the behaviour of the cattle, I think that many people underestimate the natural instincts of cattle. Cattle of any breed redevelop a natural shyness after a few weeks in the wild [3]. Heck cattle are known to form defensive circles around their offspring when they consider it threatened, they will defend calves and cows retreat to a shelter when giving birth, where they hide the calf during the first days of their life [1,2]. All free-roaming cattle populations show herding behaviour, this also goes for “breeding-back” cattle. No additional breeding for natural instincts is necessary, cattle still have the natural behavioural repertoire required by a life in nature. 

 

Furthermore, the assumption that feral cattle are more qualified as an aurochs substitute than “breeding-back” cattle is not really logical when the fact that many feral cattle populations descend from ordinary farm cattle is considered. For example, the exterminated population on the Ille Amsterdam which thrived in the wild for about 150 years, descended from the following breeds: Jersey, Tarentaise, Grey Alpine and Breton Black pied [4]. If just any cattle can build up and sustain feral populations in nature and redevelop wild traits, then so will “breeding-back” cattle. 

 

Another important aspect to consider is that an aurochs-like morphology also provides fitness advantages for the cattle. Small, hornless or short-horned cattle have a harder time defending themselves and their offspring from predators than large cattle with aurochs-like horns. Also, a short dewlap and a small udder mean less heat loss during winter. And as already mentioned, “breeding-back” cares about the winter coat. Wildtype colour is probably more suitable for a life in nature than a piebald colour, piebald calves are detected much easier by predators than the chestnut colour of wildtype-coloured calves. 

 

All in all, I do not think that “breeding-back” is too much looks-based and I am 100% confident that “breeding-back” cattle will fulfil the ecological niche of the aurochs very well if they were released into nature. 

 

Literature 

 

[1] Frisch, W.: Der Auerochs – das europäische Rind. 2010. 

[2] Poettinger, J.: Vergleichende Studie zur Haltung und zum Verhalten des Wisents und des Heckrinds. 2011. 

[3] Bunzel-Drüke et al.: Praxisleitfaden für Ganzjahresbeweidung in Naturschutz und Landschaftsentwicklung -  “Wilde Weiden”. 2008. 

[4] Rozzi & Lomolino: Rapid dwarfing of an insular mammal – the feral cattle of Amsterdam Island. 2017. 

 

 

 

Second generation Auerrind calves

Today, Claus Kropp posted new photos of second-generation Auerrind calves. They are the offspring of Alvarez, the Sayaguesa x Watussi bull. 

© Claus Kropp

This photo shows a young (Sayaguesa x Watussi) x (Sayaguesa x Chianina) bull. His colour is flawless as he is black with a dorsal stripe. I think he looks promising, he is quarter Watussi but does not have any of the obvious negative Watussi traits (zebuine hump, long dewlap etc.). If his horns get good and he grows large, he will make a prime new breeding bull. 

© Claus Kropp

This photo shows a (Sayaguesa x Watussi) x Chianina cow calf. It seems that she will be of a correct cow colour, and thus not too dark (as both Sayaguesa and Watussi do not have sexual dichromatism, this is a strong hint for the suspicion that Chianina has sexual dichromatism masked beneath the colour dilutions). Based on her breed combination, she would be the ideal cow to mate with the young bull linked above, as the result would have the potential to not only have a qualitative phenotype but also to be homozygous for some of the desirable traits inherited from the three founding breeds. 

Wild horses: getting the taxonomy right

I used to refer to the European wild horse as Equus ferus ferus, which may be wrong. This post deals with the issue of the taxonomy of the European wild horse(s), the domestic horse and the Przewalski’s horse. 

 

Some consider the domestic horse and the Przewalski’s horse different species, mainly because of the different chromosome number and morphological differences. However, we find differences in the karyotype also in other species, such as the Banteng (the Cambodian banteng has a chromosome number different from the other subspecies), and morphological differences are also found between subspecies, and both horse types interbreed without fertility problems. Thus, it is not unjustified to consider the domestic horse and the Przewalski’s horse members of the same species. The western subspecies of the Eurasian wild horse, which was the predecessor of the domestic horse, was definitely part of this species too, for once as many consider wildtypes and their domestic derivates members of the same species, and because they most likely could interbreed without fertility problems too and the morphological differences were likely smaller than between domestic horses and Przewalski’s horses. How to name this species, then? Wikipedia, and I too in the past, uses Equus ferus ferus for the western wild horse subspecies, Equus ferus przewalskii for the Przewalski’s horse and Equus ferus caballus for the domestic horse. I consider this problematic. 

At first we have to consider the priority rule of the ICZN. Equus caballus was described in 1758, Equus ferus in 1784 and Equus przewalskii in 1881. Following the priority rule, Equus caballus would definitely be the senior synonym and thus the name that should be used for the species. However, in 2003 a number of names of wildtypes that are synonymous with their domestic derivates, have been conserved by the ICZN, including Equusferus (and also Bos primigenius, by the way). Thus, the name to be used would be Equus ferus. But the main problem is: what type of horse is Equus ferus based on?

The original description of Equus ferus is a short description by Boddaert from 1784, lacking a holotype, but referring to free-ranging horses of the Russian steppe. According to most recent research as well as the fact that these horse populations included many individuals that might have been feral domestic horses or hybrids, these free-ranging horses (called “tarpan” by other contemporaneous authors), were most likely hybrids between native wild horses and domestic horses. Thus, Equus ferus is not based on the predomestic western Eurasian wild horses, but on hybrids with domestic horses. Hence, it does not describe the wildtype. Therefore, the reason to preserve this nomen in the ICZN falls apart. Also, the description lacks a holotype and is based on hybrids of two subspecies, thus the legitimacy of the taxon is to be questioned. 

Considering this, I no longer use Equus ferus as the name for the species of the western Eurasian wild horse, the eastern Eurasian wild horse (Przewalski’s horse) and the domestic horse. Rather, Equus caballus should be used: Equus caballus caballus for the domestic horse, Equus caballus przewalskii for the Przewalski’s horse and the western subspecies of the Eurasian wild horse is yet not scientifically described. 

The western Eurasian or European wild horse thus needs a proper description in the scientific literature. Someone should describe this subspecies, using a type specimen that is definitely a member of the Holocene western wild horse subspecies, f.e. bone remains predating domestic horses (so that they are predomestic for sure) found in Europe. I know of no such specimen that are mounted and on display, but there are remains that have been found. 

Another important aspect is that the Iberian wild horses probably deserve a subspecies status on their own. They are a genetically independent lineage that is less closely related to the domestic horse (and their predecessors) than the Przewalski’s horse and Equus (caballus) lenensis, respectively [1], and thus should not be regarded as a part of the western subspecies that gave rise to domestic horses and was found on the rest of Europe, because that subspecies is younger than the Iberian wild horse. As the European wild horse, the Iberian wild horse subspecies needs a proper description with a reliable type specimen. 

 

Literature 

 

[1] Fages et al.: Tracking five millennia of horse managment with extensive ancient genome time series. 2019. 

 

 

 

 

Why is the aurochs extinct while the wisent survived?

As everybody reading my blog will know, Holocene Europe was originally home to two native bovines, the wisent and the European aurochs. But only the wisent survived, while the aurochs eventually died out in the 17^thcentury, as a result of anthropogenic influence. But why did the aurochs die out while the wisent survived human activity until today? 

 

It was two anthropogenic factors that drove the aurochs to extinction: one was hunting, the other one habitat limitation due to the expanding civilization. Both factors also apply in the case of the wisent. The wisent was also hunted, and its habitat was also limited increasingly as the human population in Europe grew continuously. So why did the wisent survive and did not die out at the same time the aurochs did? 

One of the reasons might be that aurochs were hunted more intensively than wisent. Aurochs had larger, more impressively shaped horns and a colour that was more aesthetically appealing than that of the wisent (Sigismund von Herberstein wrote: “…the wisent is not as beautifully black as the aurochs…” in the 16^th century), so that it is possible that trophy hunting focused more on the aurochs than on the wisent. Julius Caesar wrote in De bello gallico that the Germanic people liked to hunt the aurochs for its horns, while he made no mention of the wisent, although this species must undoubtedly have lived in the Hercynian forest as well. 

Another possible reason why the wisent survived human activities while the aurochs died out lies in the ecology of both species. I outlined the ecologic differences between the two bovines in my post The ecologic niche of the aurochs. The aurochs was likely in direct competition with domestic cattle (and likely also horses) for feeding grounds. The aurochs was predominantly a grass eater, as are cattle and horses, and it is historically documented that aurochs grazed on the same places as the livestock of farmers, who chased the aurochs away if they encountered one on the pastures (see Anton Schneeberger’s report in Gesner 1602). During the last millennia and centuries of its existence, the aurochs retreated to wet habitats, such as swamps and marshes as isotope analyses show [1]. But also these areas were cultivated increasingly. The last historically documented population of aurochs, which lived in the forest of Jaktorow in Poland, disappeared because the space available to them became ever smaller and smaller as farmers continuously let their cattle and horses graze in the forests, so that the aurochs had to retreat even further and could not thrive [2]. 

The same problems also applied to the wisent. It, on the other hand, had the advantage that it could retreat to more mountainous regions (while the aurochs lived in even lowlands), which was less invaded by farmers or their domestic cattle and horses. Also, the wisent is more adapted to a forested habitat than cattle (and consequently likely also the aurochs), as they consume more wooden vegetation and need less grass in their diet [3]. The ecology of the wisent is probably the main reason why the extinction of the species in the wild occurred three centuries after the extinction of the aurochs, in 1919 [4]. We should not forget that the wisent survived the extinction in the wild only due to the fact that it was bred in captivity. Without the captive population, there would be no wisents today. The Caucasus wisent, B. b. caucasicus, did not have that luck and was fully exterminated in 1927. 

 

Literature 

 

[1] Lynch et al.: Where the wild things are: aurochs and cattle in England. 2008. 

[2] van Vuure: Retracing the aurochs - history, morphology and ecology of an extinct wild ox. 2005. 

[3] Bunzel-Drüke et al.: Praxisleitfaden für Ganzjahresbeweidung in Naturschutz und Landschaftsentwicklung – “Wilde Weiden”. 2008. 

[4] Krasinska & Krasinski: Der Wisent: Bison bonasus. 2008.