How aggressive was the aurochs?

As my readers will know, many of my blog posts on the aurochs focus on aspects of its morphology or appearance, because that is what we know most about. But I also made posts covering social behaviour patterns, like this one. Today I want to cover a behavioural aspect of the aurochs that I am sometimes asked about: its aggressiveness. More precisely, its aggressiveness towards humans. Was the aurochs an aggressive animal towards humans, or was it gentle and docile? 

Regarding the aggression of the animal, we have to differentiate between intraspecific aggression, aggression towards other animals (predators in particular), and aggression towards humans. That is important because domestication drastically changed the latter factor, while the other two factors seem to be somewhat independent from it. Cattle that are very agreeable and docile towards humans still can become rather aggressive against opponents in intraspecific combat or towards possible predators. The question how aggressive the aurochs was is also important for “breeding-back” as it raises the question what kind of behaviour the cattle need in order to survive in nature, or to be aurochs-like, and what to expect from dedomesticated cattle living in the wild. 

 

Historic evidence on the behaviour of the aurochs towards people

 

The most famous notion on the behaviour of the aurochs is in Caesar’s Commentarii de bello gallico, writing that aurochs “will spare neither humans nor animals at sight”. Caesar also wrote that aurochs never get used to humans, even if raised as calves. Also, Anton Schneeberger who visited the last Polish aurochs in Jaktorow wrote that aurochs will get very hot-tempered when challenged. Andrea Swiecicki reported from the 16^th century that aurochs will get very aggressive when being tormented and attack humans and horses, throwing them in the air with their horns [1]. Schneeberger further writes that aurochs are not afraid of people and will not run away if they stand in the way of the humans. As the Jaktorow herd was managed by humans and encountered people on a regular basis, it is possible that they were tamed to some degree [1]. These are the only general notions on the behaviour of aurochs towards people that have been preserved, at least as far as I know.

Caesar’s notion can be interpreted in a way that aurochs were generally aggressive animals, but Schneeberger’s and Swiecicki’s seem to be more differentiated, stating that they can become very aggressive when challenged or being hunted. Caesar’s impression that the aurochs will not spare any living being might come from the behaviour of the bovine in situations of threat. If one knows the animal only in the context of hunting it, one might assume it is generally a very dangerous animal. Schneeberger’s report clearly states that aurochs would not attack without a reason whenever they encounter a human, in fact he writes that one could easily approach it. If the aurochs at Jaktorow were indeed tamed to some degree, this could imply that the behaviour of aurochs towards humans was plastic and partly depended on socialization. However, Caesar’s notion that they never get used to humans even when raised as calves indicates that there were genetic limits to this. This is likely, as the difference in behaviour between domestic and wild animals is due to genetic differences to a certain degree. Curiously, Vergilius mentions that in the Po River area in Northern Italy aurochs were caught and tamed to be used as draft animals, in the lack of domestic oxen [1]. Either it was indeed possible to use grown, wild-caught aurochs for draft work or Vergilius was misinformed. It is even possible that these animals were not aurochs but feral cattle living in the region. Personally, I cannot imagine that it would be possible to use an undomesticated wild bovine for draft work, even if they were tamed to some degree. I think Caesar’s notion is more credible than that of Vergilius, both authors were basing themselves on second-hand information. 

 

The behaviour of domestic cattle 

 

For the social behaviour of the aurochs, cattle living under natural circumstances are a pretty good model. What we know of the social behaviour of the aurochs is congruent with that of cattle, and since domestication likely did not affect the social behaviour patterns of cattle, all the other aspects of their social behaviour are likely shared between aurochs and domestic cattle. One difference is, however, that cattle tend to mate all year round while the reproductive circle of the aurochs was adapted to that of the seasons, with a mating season during fall and the birth of the calves in spring. 

But that domestic cattle are a model for the aggression level of the aurochs is very unlikely. First of all, domestication likely drastically changed the hormonal system of cattle, particularly the corticosteroid hormones, what has an influence on the aggression and stress response of the animals. Furthermore, there are considerable differences between breeds in their behaviour towards humans. Highly derived breeds in particular are very agreeable, docile and have a very minor stress response. In some breeds the bulls can even be ridden. The Spanish fighting bull, on the other hand, is the complete opposite. Lidia have a very intense stress response and attack readily, although there is individual variation in “fighting spirit” within the breed. Most domestic breeds were artificially selected for agreeableness and less intense stress response, Lidia was artificially selected for an intense stress response, so that it may be the case that neither of them is a model for the behaviour of the aurochs towards humans. 

The potential for aggression, particularly towards humans, must have a genetic component otherwise it would not be heritable. The MAO-A gene seems to be different in Lidia compared to other taurine cattle breeds (go here). This gene plays a role in the endocrinology in the brain of mammals, and mutations on this gene are linked to increased aggression in other species, suggesting that this plays a role in the aggression of Spanish fighting cattle. It would be interesting to have a look at this gene in the aurochs. Since the full genome of the aurochs has been resolved, this should be possible. The MAO-A gene is probably one of many genes that influence the potential for aggression in cattle. 

 

To sum it up, aurochs likely would have had the potential to become very aggressive and energetic when defending itself, like other wild bovines. We do not know, however, how readily wild aurochs would have attacked if they encountered a human being that they consider threatening to them. Some aspects, like flight distance, might have partially depended on socialization. However, as Caesar writes, an individual raised under human custody likely would never lose its wild nature as they were undomesticated animals. 

 

All current “breeding-back” projects select against aggressive behaviour towards humans, which is understandable as they have to work with the cattle as the law dictates. As long as the animals have to be handled, it is better for the cattle and the people handling them that they do not have an extreme stress response. As we do not precisely know how aggressive aurochs were, I think it would be most sensible to let “rewilded” cattle develop their own aggression level that is formed by natural selection and thus what is best for them in order to survive in nature.

 

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