Before human intervention upset the sustainable habitat of the African savannah, the American prairies and the steppes of central Asia, large numbers of herbivores grazed the pastures and browsed the shrubs and trees. Smaller numbers of carnivores killed and ate some of them. On the savannah, the initial beneficiaries of predation may be a pride of lions, followed by a flock of vultures to tidy up afterwards. In the Canadian wild, wolves manage the caribou population. The First Nation people have a wise saying: ‘It is the wolf that keeps the caribou strong’. This is a classic expression of Darwinism. Not only do the wolves control the numbers of caribou but by killing the weakest and slowest they promote the overall fitness of the population. Before the arrival of the Europeans, the predators that sustainably managed the huge population of bison on the American prairies were the indigenous human population.

Although the great majority of the herbivorous species are wild, their numbers are in steep decline because humans are taking away their habitat. Today, most of the animals grazing the open plains are semi‐domesticated species such as cattle, sheep and goats. Most semi‐domesticated herbivores of today are killed by us, in abattoirs. However, whether wild or domesticated, the environmental challenges to the herbivores free ranging on the open plains and the impact of these challenges on their minds, motivation and behavioural needs are much the same.

For about 99% of the span of life on earth, herbivores and carnivores coexisted in a balance of nature that maintained population numbers in both groups. Quick culling of herbivores by carnivores reduced the risk of overgrazing which could otherwise lead to their slow death from starvation. If the carnivores killed too many herbivores, they would go hungry, leading to a fall in their numbers from malnutrition and infertility. Human interference with this balance of nature has affected the animals in many ways, both good and bad. Semi‐domesticated sheep and cattle should enjoy a more reliable feed supply, but things can go badly wrong, for example, when too many animals are kept on too little land during conditions of prolonged drought. They will be less likely to experience the daily risk of predation, but the end of their life may be worse as they endure the stresses of handling and transport prior to slaughter.

Environmental Challenges

The big difference between the environmental challenges to domesticated and wild herbivores grazing the open plains is that the former should enjoy some protection from their human herders, the latter face the constant threat of predation. Populations of wild herbivores have adapted to this threat. I repeat: the impala is less at risk of extinction than the cheetah. Here, I think I should briefly reprise my thoughts on the mental processes involved in the survival strategies of herbivores exposed to predation from the big cats on the open plains (Chapter 4) All prey species have a hard‐wired programme that sets their flight distance from a potential predator. When the predator is outside their flight distance, they will be aware of its presence but see no need to take evasive action. As the predator approaches the flight distance they will, if unrestrained, move away in a controlled fashion in a direction determined by the angle of approach of the predator. If the predator encroaches within the flight distance, they will run off at speed. Survivors learn by experience that they can escape. Incipient threats may be picked up from a distance. Most signals are likely to come from members of the herd who spot the danger first and signal to the others.

For many wild animals that experience nature red in tooth and claw, tasks essential to survival may take up most of their time. It would be a mistake, however, to assume that their minds are exclusively hard wired to these primitive tasks. We can observe wild animals, both youngsters and adults, with time on their hands in the better, environmentally enriched zoos engaging in behaviour that looks to us just like play. I repeat what I wrote in Chapter 2. Some severe animal behaviourists reject the notion that non‐human animals engage in play. I cannot accept this argument. Anyone who has watched young lambs playing ‘king of the castle’ around straw bales would have to be very severe indeed to deny that they were having fun. Young animals, whether lambs or lion cubs have lots of energy and lots of spare time. Most behaviourists would concede that sentient animals are strongly motivated to seek pleasure as a means to feeling good if they do not conflict with the actions necessary for survival. Pleasure may take the form of rest or recreation. Hard working adults may take the chance to rest and luxuriate in the sun, energetic youngsters to play games. One of the reasons that signs of play behaviour are more common in carnivores is because they have more spare time. Otters, for example, who need little time to catch their daily ration of fish, sport on mud slides. Adult herbivores on sparse pastures are so occupied by the need to take in sufficient food that they have little time or energy for the pursuit of pleasure. However, cows can get satisfaction from time spent comfortably at rest, ruminating in the sun or shade. Groups of young foals regularly enjoy what my wife refers to as ‘their mad five minutes’: wild races, with their tails held high in the air, typically at sundown.

Animals of the Open Plains

The predominant animals of the savannah and plains are the bovidae, ruminant herbivores with cloven hooves. This family of more than 140 species includes a small number of domesticated species, cattle, water buffalo, sheep and goats. Wild species within this family include bison, African buffalo, antelopes (dik‐dik, impala and wildebeest) and musk ox. The males, and, in some species, the females have permanent horns growing out from their skull. Other families include giraffes and the camelidae (camels, llamas, alpacas, guanaco, vicunae), technically classed as pseudo‐ruminants. The cervidae, deer, elk (or wapiti), moose and caribou (or reindeer) are also ruminants but differ from the bovidae in having antlers, rather than horns, which develop each year from skin tissue rather than bone and are shed at the end of the breeding season. The Cervidae are principally creatures of the forests so will be considered in more detail in the next chapter. Other animals of the plains include zebras, feral horses and African elephants, all herbivores with the fermentation vat at the hind end of the digestive tract so adapted to take in food slowly by grazing or browsing for long periods.

The apex predators of the plains of Africa are the big cats, lions, leopards, and cheetahs. Apex predators in other regions include the jaguar, cougar and snow leopard. All these animals are obligate carnivores: they have evolved to subsist on a diet of protein and fat, have a limited ability to digest carbohydrates and almost no ability to digest fibre. They must kill or die. Behind the apex predators come the scavengers, such as hyenas. Omnivores like African hunting dogs, or bears (which are creatures of the forests) have a wider range of options but will eat meat when they can.

In the following discussion of the environmental challenges encountered on the open plains and the responses of the different species, it will rarely be necessary to distinguish between wild and domesticated. Inevitably however, more space will be given to semi‐domesticated species like sheep and cattle on range since we know so much more about them.

Sheep

Sheep, whether wild or semi‐domesticated, occupy environments where they must forage long hours to obtain enough nutrients to maintain good health and support their offspring. They are relatively small, slow‐moving animals, with limited ability to defend themselves so depend for their security on strength in numbers. To promote the success of their own family, within a large flock, they need to recognise who’s who.

Sheep quickly discover or learn from their mothers to avoid poisonous plants (41). In experimental studies, sheep have shown an aversion to the smell of the wolf, while apparently not disturbed by the smell of bear, which suggests that these aversions are expressions of innate fears, like the monkeys’ fear of snakes (58).

Healthy, nutritious plants vary in their proportions of protein and digestible energy (mostly sugars and cellulose). Growing lambs and lactating ewes need a higher ratio of protein to energy relative to adults that require food only for maintenance and adjust their feed selection to provide the protein:energy ratio best suited to their needs (41). The sugar content of high energy grasses is highest late in the day when the sun has done its work, so sheep tend to favour the high protein grasses in the morning and the high energy grasses in the afternoon. Sheep that carry a high burden of intestinal worms select high protein grasses to restore nutrients taken up by the parasites. There is some evidence, not too well established, that sheep with a high worm load will select plants with a high content of tannins having antiparasitic properties.

Sheep have an exceptional ability to recognise individual faces and sounds, especially the sound of their own lambs. Key receptors in the brain pick out the sights and sounds that matter from the background noise coming from the continuous input of unnecessary information. These special skills enable ewes to favour their offspring, and thereby their genetic inheritance within the group. The natural behaviour of ewes is to ensure that their milk goes to their own lambs. They will forcibly reject other lambs that approach them and attempt to feed. Shepherds have developed several methods to get ewes that have lost their lamb to foster lambs that are not their own. A traditional practice was to skin the ewe’s own dead lamb and use it to cover the lamb to be fostered. Smothering the foster lamb with placental fluids from the dead lamb may also work just as well. Fostering has become a bigger problem in recent years as a result of selection for fecundity. More ewes are having triplets, which is a problem as they only have two teats. Science, however, has come to the rescue. The hormone oxytocin which facilitates uterine contractions during parturition and milk ejection during suckling is also critical to development of the close emotional bond between mother and child. One can greatly improve the odds of successful fostering in sheep by administration of oxytocin as a nasal spray to the ewe at the same time as you introduce her to a lamb not her own (35). Interpreting this in terms of the simple model of the sentient mind, the oxytocin spray has given positive reinforcement to the arrival of the new lamb by associating it with a strong feeling of pleasure.

The ability of sheep to distinguish and react to sounds that matter is not restricted to potentially hard‐wired signals like the call of their own lambs. Christine Nicol filmed a flock of sheep at pasture but accustomed to getting a daily ration of corn. All day, cars, lorries and Land Rovers passed by on the road without attracting a flicker of attention. However, when the specific sound of the farmer’s Land Rover was heard in the distance the sheep set off at once in the direction of the feed troughs to welcome his arrival.

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