Monday, 24 June 2013

Wild behaviour in cattle and horses


As we all know, the behaviour of domestic cattle differs from that of their wild types because of artificial selection and a human-controlled life that does not give them the chance to display the natural behavioural traits of their species. But feral populations might represent a good model for the behaviour of the Aurochs and Tarpan. Additionally, there are historic reports describing the ethologic traits of these extinct animals and there are some surprising matches.

Cattle

Feral/semi-feral cattle form a number of different groups. There are matriarchic groups of cows of different generations, together with calves and young bulls (under the age of 1,5 years). During foraging, calves often group together and are guarded by either the young bulls or cows not having calves. Bulls above the age of 1,5 years form bull herds, composited of mature animals of different ages. Old bulls are solitary, territorial and do not reproduce anymore. Cow groups wander around and are circuited by bull groups. Because the cow groups constantly move, they mate with different bull groups, what is interpreted as a protection against inbreeding [1]. This interpretation makes it very likely that the same behaviour was found in the aurochs. In cattle herds, there is a constant struggle for dominance between the individuals. The pecking structure is tested by agonistic behaviour such as pushing the less-dominant individual aside during foraging or even chasing it if it doesn’t retreat fast enough. Display is a factor as well; the dominant individual shows its status by displaying its profile and raising its neck. Combat fights are common in both bull and cows. Cattle fight head-to-head by pulling and pushing each other with their horns [2]. Pregnant cows separate from the herd immediately before giving birth to the calf and seek a shelter on forest edges. After that, the cow leaves the hidden calf and joins the herd again for foraging (during this phase, the calf is extremely vulnerable to predators), but will visit it several times. When the calf is strong enough, cow and calf join the herd [3]. Some feral cattle form a defensive circle around their calves (Heck cattle released in East Prussia during World War II) [4]. This behaviour is widespread among wild bovids, so the aurochs probably did the same. Cattle get increasingly difficult to handle, shy and cautious the less contact they have with humans.

The most precise description of the aurochs’ behaviour is that of Anton Schneeberger in his letter to Conrad Gesner, published in Gesner’s Historia Animalum in 1602. Interestingly, he describes exactly the same behaviour for calving Aurochs cows as we know it from living cattle. Furthermore, Schneeberger notes that aurochs fed on twigs, leaves and acorns during autumn and winter. Cattle do so as well. Schneeberger says that rutting bulls often have severe fights (according to him, some “fell down dead” after these competitions), just like domestic bulls. Oddly, Schneeberger states that aurochs roam the wilderness solitary during summer. This is untypical for any bovine, which all live in herds all the year round. Perhaps this was a misconception. Interestingly, Schneeberger also describes mimics that might refer to the flemen gesture, and also mentions that aurochs sometimes throw hay up in the air with their horns. Rutting bulls often push their horns in the ground and throw piles of dust up in the air in order to show off their level of testosterone – likely, Schneeberger witnessed this kind of behaviour.

Was the aurochs an aggressive animal? Within cattle herds, bulls need aggressivity to achieve dominance. Once the dominant status is achieved, they get less aggressive towards conspecifics [5]. Regarding its relationships with humans, it is likely that it usually was a peaceful or at least not a ferocious animal, otherwise the aurochs would not have been domesticated [3]. However, historic references state that aurochs got very hot-tempered and dangerous when challenged (Schneeberger, Caesar) [4]. All domestic cows, no matter which breed, defend their calves by attacking whatever might be a treat. This is no sign of aggressivity, but is the natural protective instinct of female bovids. If you encountered aurochs in the wilderness, the first reaction of the animal probably was escape and not attack, just like in feral cattle and living wild bovines.

Horses

The social behaviour of numerous feral horses and also the Przewalski horse, the “sister subspecies” of the Tarpan, is well studied and roughly the same. So it is very likely that the Tarpan had the same social structure, and some historic references match this assumption. Adult horses form either harem groups that are led by one dominant stallion and a number of juveniles, or a stallion group. Within the herds, stallions frequently fight for dominance by kicking and biting [1].
Interestingly and in contrast to cattle, the tameness of domestic horses disappears only slowly.  Koniks that spent all their lives in reserves are still tame and enjoy contact with humans, especially their foals [6]. One exception is the Exmoor, possibly because of its feral ancestry – the horses of Exmoor have been used as hunting game and were prey of native predators in the past, so they either retained or re-developed natural instincts. For example, they are shier than usual horses that roam freely (I experienced it myself when I visited Exmoor and Dartmoor two years ago), and they show a clear herding instinct when escaping, while Koniks stray up. Furthermore, they protect their foals in defensive circles [7].

Historic references describe the Tarpan as very shy and fast, virtually untameable and they apparently often stole domestic mares and killed concurring stallions. Furthermore, they defended themselves harshly against predators [8]. This high aggression potential and dominant behaviour accords with that of the Przewalski horse. According to Charles Hamilton Smith, Tarpans formed herds of “several hundreds”, which is likely an exaggeration or describes a regional/seasonal phenomenon. He also reports that a dominant stallion leads a herd. Interestingly, Tarpans seemingly migrated seasonally, similar to the Przewalski horse. More on Smith’s text in a future post.  

All in all, the behaviour of feral cattle and horses probably resembles that of their wild types to a large extent. This seems logical because feral animals have the possibility to show the natural behaviour of their species and natural selection favours ethological traits and inherited instincts that increase the evolutional fitness (as you see in Exmoor Ponies forming defensive circles). For a number of reasons, I think it is likely that breeding back results (or any released proxies for the Aurochs/Tarpan) display a natural, wild animal-like behaviour after a sufficient time living in nature: a) while some behaviourial traits certainly are coded genetically[5], others apparently are environmentally influenced to a large degree, b) domestic animals still display modes of  behaviour very reminiscent of their ancestors when they need to or have the chance to do so, c) nature and experience will “refine” the behaviour of the released animals automatically and adapt it to the particular circumstances of their environment (presence/absence of predators, transhumance…).

Literature

  • [1] Meissner, Rene; Limpens, Hermann: Dedomestikation – Wilde Herden zwischen den Menschen. 2001.
  • [2] Perrey, Anette: Die Sozialstruktur einer Herde Auerochsen im Wildgehege Neandertal. 1999
  • [3] Frisch, Walter: Der Auerochs – das europäische Rind. 2010.
  • [4] an Vuure, Cis: Retracing the Aurochs - History, Morphology and Ecology of an extinct wild Ox. 2005
  • [5] Broucek, Uhrincat, Soch, Kisac: Genetics of behaviour in cattle. 2008.
  • [6] Bunzel-Drüke, Finck, Kämmer, Luick, Reisinger, Riecken, Riedl, Scharf & Zimball: "Wilde Weiden: Praxisleitfaden für Ganzjahresbeweidung in Naturschutz und Landschaftsentwicklung
  • [7] Baker, Sue, 2008: Exmoor Ponies: Survival of the Fittest – A natural history.
  • [8] Tadeusz Jezierski, Zbigniew Jaworski: Das Polnische Konik. Die Neue Brehm-Bücherei Bd. 658, Westarp Wissenschaften, Hohenwarsleben. 2008

2 comments:

  1. This is your best post!!!!!!! Congratulations!!!! An amazing article on behavior and ecology of feral herds, that should be two essential pillars of the breeding back projects!!!!

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    1. Thank you very much! I think feral domestic animals and dedomestication are a fascinating subject (evolution at work!), but it's a sadly understudied field.

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