It is almost impossible to herd cats, thanks to evolution
How hard can it really be to herd cats?
Ask Daniel Mills, professor of veterinary behavioural medicine at the University of Lincoln, UK. In a recent study, Mills and his colleague Alice Potter demonstrated that cats are more autonomous and solitary than dogs. Carrying out the research for the project was as difficult as the cat's reputation might suggest.
不妨请教英国林肯大学（University of Lincoln）行为兽医学教授丹尼尔・米尔斯（Daniel Mills）。丹尼斯和他的同事爱丽丝・波特（Alice Potter）在最近的一项研究中证明猫比狗更喜欢自主和独自的状态。猫的这种名声预示这个研究项目会很难进行，事实也正是如此。
"They are challenging if you want them to do certain things in a certain way," says Mills. "They tend to do their own thing."
Cat owners everywhere will sympathise. But why exactly are cats so reluctant to cooperate, either with each other or with a human? Or to flip the question around, why are so many other animals C wild and domestic C willing team players?
Group living is very common in nature. Birds flock, wildebeest herd, fish school. Predators often hunt together too, of course. Even the domestic cat's relative, the lion, lives in a pride.
For prey species there is an obvious "safety in numbers" element to the strategy. "It's called the dilution effect," says biologist Craig Packer of the University of Minnesota in St Paul. "A predator can only take one, and if there's a hundred of you that reduces your chances down to 1%. Whereas if you're by yourself, you'll be chosen 100% of the time."
对于被捕猎的物种来说，其生存战略带有明显的"数量安全"的元素。"这被称为稀释效应，"位于圣保罗（St Paul）的美国明尼苏达大学的生物学家克雷格・帕克（Craig Packer）说，"如果肉食动物只能抓到一只，如果一百只在一起，那么对每个单体来说概率就减少到1%。而如果单独生存，被抓到的概率就是100%。"
Animals in herds also benefit from the "many eyes" effect: the larger the prey group, the more likely they are to detect an approaching predator. "And the earlier you can detect the predator, the more time you have to initiate avoidance behaviour," says Jens Krause of Humboldt University in Berlin, Germany.
群居动物还得益于"多眼"效应：被捕猎动物的群体越大，它们就越有可能发现靠近它们的天敌。"越早发现天敌，就有越多的时间开始躲避，"德国柏林洪堡大学（Humboldt University）的简斯・克劳斯（Jens Krause）说。
This collective vigilance brings other advantages. Individuals can afford to spend more time and energy looking for food.
It is not all about avoiding predators, though. Animals that socialise in groups do not have to roam around for a suitable mate, which is a problem for solitary species that cover large territories. It is clearly much easier just to look to the herd for a date.
And once they have produced their offspring, many group-living animals live by the "it takes a village" maxim: adults may work together to protect or feed the young.
In many bird species, such as the Arabian babblers of Israel, young birds remain in family groups until they are ready to mate. They dance in groups, bathe in groups, and even present each other with gifts.
There are also energy savings to be made from group living. Birds that flock together or fish that school move more efficiently than solitary fliers and swimmers.
It is the same principle that Tour de France cyclists use when they form a peloton. "The ones that are further back, they don't have to invest quite as much energy for the same speed of locomotion," says Krause.
Finally, as both bats and emperor penguins can testify, it can be just plain warmer when you huddle up to friends.
With so many benefits, it might seem surprising that any animal would shun its peers. But, as domestic cats show, group living is not for everyone. For some animals, sharing food just is not worth the benefits of being in a group.
"When you're feeding together, there's a point at which feeding with other individuals in close proximity reduces your intake," says John Fryxell, an integrative biologist at the University of Guelph in Canada.
"当它们一起进食时，达到一定程度后，和其他同类一起进食就会减少个体的食物数量，"加拿大圭尔夫大学（University of Guelph）的整合生物学家约翰・弗里克塞尔（John Fryxel）说。
A key factor then becomes whether each animal has sufficient food, which in turn depends on how much food each animal needs. And cats have expensive tastes. For instance, a leopard will chew its way through 50lb (23kg) of meat every few days. Typically, for wild cats, the competition for food is fierce, so leopards live and hunt alone.
There is one exception to this solitary cat rule: lions. For lions it is a territorial deal, says Packer, who has spent nearly five decades studying African lions. Certain locales in the savannah grasslands offer perfect ambush spots for prey, so controlling that prime real estate offers a significant survival advantage. "It imposes sociality because you have to have teams to dominate your local neighbourhood, exclude competing teams, and the biggest team wins," Packer says.
What makes this happy hamlet possible is that a single lion kill C a wildebeest or zebra C is large enough to feed several females at once. "So the size of the prey allows them to live in groups, but it's the geography that really drives them toward living in groups," Packer says.
This is not a situation domestic cats find themselves in, because they hunt small animals. "You don't want to be around somebody else when they've just caught a mouse, because they're going to eat it whole," Packer says. "It's gone. There is not enough food to share."
This sort of economic reasoning is so deeply engrained in cat behaviour, it seems unlikely that even domestication could have altered this fundamental preference for solitude.
This is doubly true when you consider that humans did not domesticate cats. Instead, in true cat style, cats domesticated themselves.
All domesticated cats are descended from Middle Eastern wildcats (Felis silvestris), the "cat of the woods". Humans did not coax those early cats out of the woods; the cats invited themselves into our grain storehouses, where an abundance of mice fed unchecked. Gate-crashing this mouse party marked the start of a truly symbiotic relationship. The cats loved the well-stocked storehouses, and the people appreciated the pest control.
Domestic cats are not entirely antisocial. But their sociability C to one another or to their human owners C is handled entirely on their terms.
"They retain a large degree of independence and approach, or stay close to us, only when they want to," says Dennis Turner, a cat expert and animal behaviourist at the Institute for Applied Ethology and Animal Psychology in Horgen, Switzerland.
"Cats have evolved lots of mechanisms to keep themselves apart, which aren't exactly conducive to herding," says Mills. Cats spray their territory to help avoid awkward meetings with each other. If they do accidentally come face to face, the hackles rise and the claws come out.
If cats will not stop fighting, they are unlikely to start herding.
In some circumstances it can appear that domestic cats have embraced group living; for instance, a colony living in a barn. But do not be fooled, says Fryxell.
"They're very loose aggregations and they don't have any real group identity," he says. "They just have a common place they come to keep their kittens."
In fact, even in the face of extreme danger, which often brings animals together to form a defensive unit, it is unlikely cats would cooperate. "It's just not something that they typically do when they're threatened," says Monique Udell, a biologist at Oregon State University. Cats just do not believe in strength in numbers.
All of this helps explain why cats have a reputation for being impossible to herd. Even so, there is some evidence that the domestic cat's disdain for group living could be weakening.
A study published in 2014 in the Journal of Comparative Psychology saw scientists probe the personality traits of domestic cats. In keeping with their solitary, uncooperative reputation, cats turned out to be neurotic, impulsive and resistant to being ordered around.
2014年《比较心理学》期刊（Journal of Comparative Psychology）上发表了一项研究。其中，科学家探究了家猫的个性特点。猫具有神经质、冲动、抗拒接受命令的个性，这符合它们独来独往、不合作的名声。
Interestingly, though, domestic cats might be a little less uncooperative than their wild relatives. When the researchers compared the domestic cat to four wild cats C Scottish wildcats, clouded leopards, snow leopards and African lions C the domestic cats proved to be most like those group-living lions in terms of their overarching personalities.
It is also fair to say that domestic cats have come a long way from their ancestors in terms of tolerating each other's company. Although groups of cats living in barns form loose aggregations at best, they still show a remarkable level of acceptance for each other's presence in such confined spaces.
In Rome, nearly 200 cats live side-by-side in the Colosseum, while on Aoshima Island in Japan cats outnumber people six to one. These colonies may not be cooperatives, but they are a far step from the domestic cat's solitary past.
Researchers, meanwhile, might find it easier to control the cats in their experiments by meeting them halfway.
When Udell performed her early experiments on cats, she encountered a lot of difficulties trying to motivate her subjects to engage in the task at hand. She had previously worked with dogs, which would willingly perform any task repeatedly for a food reward. But cats were not so easily pleased. Eventually, Udell started having success when she began giving cats the option of choosing what their reward was.
"I think that part of the challenge is just how much we understand about cats," she says. If scientists start to gain insights into the black box of the feline mind, herding by force could give way to convening cats using cunning coercion.
Much of animal behaviour C including an affinity or resistance to herding C lies deep in a creature's neural circuitry. It is difficult to ever imagine circumventing years of natural selection, Fryxell says.
"But who knows? Obviously, lions managed the feat, so it must be possible for the proper set of mutations to occur," he says. "And if they managed to pull off the trick, maybe [herding cats] is not that crazy an idea, after all."