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Are meerkats naturally generous?

Immanuel Kant didn't think there was such a thing as a truly altruistic act. Could meerkats prove this 18th-century philosopher wrong?
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For centuries, there's been a debate over whether true altruism exists among humans. In philosophical terms, an altruistic act is one that a person performs for the benefit of others, but to his or her own detriment. Eighteenth-century Prussian philosopher Immanuel Kant suggested that there's no such thing as altruism -- in every instance, the giver gets something in return for his or her generosity. This benefit can be as small as a sense of well-being for having helped someone else.

Helping others at our detriment is risky behavior, evolutionarily speaking. Think about it: Say you're overcome with an urge to give your last piece of bread to someone else. The other person eats, but you don't. Ultimately, after enough of these selfless acts, you'll starve and die, and your dangerous habit of helping others should die along with you.

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But the trait hasn't died. People still perform altruistic acts today, and generosity continues to baffle thinkers. In the animal kingdom, altruism poses an equally prickly problem to explain. Why some animals exhibit generosity is a real mystery to biologists. It's not like they're thinking about the tax write-off they can get by donating money or the accolades they'll receive for community service. Their behavior seems automatic -- and inexplicable.

Meerkats have one of the most cooperative societies in the animal kingdom. These African desert dwellers are perfect subjects for an investigation into altruism. For one, they live in a harsh habitat, quite a long way from easy street. Danger lurks around every corner because they sit at the bottom of the food chain. The foods they eat -- insects and lizards -- require long days of hunting and lots of expended energy scrabbling in the hard-baked sand to get to. Water is scarce, and unpredictable dry seasons can wipe out entire meerkat groups, or gangs. What makes their communal nature even more perplexing is that meerkats evolved from mongooses, which generally live alone.

But rather than adopting the habit of looking out for numero uno like their ancestors, meerkats have developed tight-knit societies that consistently display random acts of kindness.

So why do meerkats seem to exhibit a natural generosity toward others in their gang? Find out on the next page.

A meerkat stands sentinel, on guard for threats to the rest of the gang.
A meerkat stands sentinel, on guard for threats to the rest of the gang.

When meerkats are still weeks-old pups, they learn to take care of themselves. First, pups are shown how to find food. Meerkats are largely insectivores -- 82 percent of their diet is composed of insects [source: University of Michigan]. An older meerkat might show them that rocks hide fat millipedes underneath or that thorny brushes contain birds' nests filled with tasty eggs.

At just a few weeks of age, meerkat pups aren't fully able to feed themselves, even when they're lucky enough to find food. They know how to beg, however. Pups emit a high squeal directed toward foraging adults. And adults always feed them, even when the pups aren't their own offspring.

So meerkats feed the young in their gang. Perhaps it doesn't seem like such a big deal, but consider this: Meerkats don't store food. They're foragers and eat what they find on a daily basis. This makes sharing food with youngsters take on an even more generous aspect. What's more, there's a high likelihood that the adult offering food to the pup is not that pup's parent. More than 80 percent of all meerkat pups that survive to emerge from their litter in any given gang are produced by one dominant female [source: Roberts].

The hierarchy of dominance explains much of the altruism displayed within meerkat gangs. The dominant male and female unquestionably rule the gang, and the remaining subservient meerkats adopt an it-takes-a-village-to-raise-a-child mentality. But while this social stratification sets the stage for an expectation of altruism on the part of the subservient masses, it doesn't fully explain this generosity. After all, if times get really tough, they can always just escape: Meerkats often leave their gang with other subservient members, forming dispersal groups to found new gangs. Even within these new gangs, the generous nature of meerkats emerges once again (along with a new dominant male and female).

These acts risk the life of the meerkat undertaking them and provide few recognizable benefits for him or her. For example, whenever meerkats gangs are active, a lookout is posted. There's always at least one of these guards -- called sentinels -- determinedly watching the surrounding area for imminent danger. These threats come in the form of other gangs, martial eagles (which love to eat meerkats), or, on occasion, a bat-eared fox who has woken up a little early for a night of hunting. When danger presents itself, the sentinel calls out to the rest of the gang, which heads for bolt-holes -- hiding places meerkats create -- scattered throughout their territory to provide quick cover.

What's odd is that different subservient meerkats take over for guard duty without any discernable schedule. They appear to simply recognize that the position needs to be filled and stand guard. What makes the act so altogether altruistic is that the sentinel is giving up valuable time to forage for food. However, this altruistic act was explained by a report in 1999 that showed the sentinel was in the best position to escape danger. After 2,000 hours of study, researchers found that no sentinel was killed by a predator, and each one was the first to make it to safety [source: BBC].

But standing sentinel and offering food aren't the only seemingly altruistic acts meerkats perform. Read the next page to find out more.

Two young meerkat pups nestle with an adult caregiver in the Kalahari Desert.
Two young meerkat pups nestle with an adult caregiver in the Kalahari Desert.
Mattias Klum/National Geographic/Getty Images

Young meerkats are often very eager to help the grown-ups care for pups. At just a few months of age, meerkats begin helping around the burrow when new litters are born. This includes a lot more than grabbing a baby wipe while the new mother has her hands full with the pups. In fact, the new mother is very often nowhere around the burrow. Usually, she's off foraging just a short while after giving birth. She leaves her pups to be cared for by the subservient meerkats in her gang.

Dominant meerkat females are believed to engage in this behavior to ensure the survival of their genetic line. If they can remain healthy and fat through uninterrupted foraging, there's a greater likelihood that they'll produce equally healthy meerkat pups in abundance for years to come. While the mother is off finding food for herself, her subservient helpers pitch in to raise her offspring.

Much like standing sentinel, serving as a caregiver for newborns has all the trappings of altruism. Caregiving among meerkats is a little more baffling than guarding as lookout, however. It, too, is undertaken within no understandable schedule. And with both sentinel duty and caregiving, studies have shown that some meerkats are more likely than others to pitch in -- in other words, some meerkats are lazier than others when it comes to generous acts [source: Roberts].

Like sentinel duty, caregiving also results in less time to forage for food. But taking care of pups requires much more time. So a subservient female who opts to look over pups that aren't her own stands to lose a lot more weight than she would standing sentinel. And caregiving is also more dangerous. With the rest of the gang out foraging, only a couple of female meerkats may be left behind to care for the pups. This leaves both young and old exposed to attack from predators and members of rival gangs.

Perhaps most puzzling about this altruistic behavior is that a subservient female who baby-sits meerkat pups may already be lactating (producing milk). In this state, she serves as nursemaid, feeding the pups from her own body. Instances of spontaneous lactation among females that haven't recently been pregnant have been observed in meerkat gangs [source: Roberts]. But more often than not, the lactating female has recently been pregnant. In these cases, the female has time to care for another meerkat's pups because her own have been recently killed -- usually by the same dominant female for whose pups the nursemaid is caring.

While the dominant/subservient social structure of meerkat society explains some of this generous behavior, when it comes to serving as nursemaid, there doesn't appear to be any sort of reward -- only risk in return. Perhaps meerkats have proven Immanuel Kant wrong after all. Of course, meerkats aren't investigating altruism with the same zeal that our philosophers are; it's entirely possible that humans are merely projecting our own values onto these tiny critters.

For more information on meerkats, altruism and other related topics, visit the next page.

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Sources

  • Fuehrer, T. "Suricata suricatta: Meerkat." University of Michigan Museum of Zoology. 2003. http://animaldiversity.ummz.umich.edu/site/accounts/information/Suricata_suricatta.html
  • Roberts, Miles. "Warriors of the Kalahari." Smithsonian Zoogoer. January/February 2007. http://nationalzoo.si.edu/Publications/ZooGoer/2007/1/meerkats.cfm
  • Sharpe, Lynda L. "Meerkats at play." Natural History Magazine. April 2007. http://www.naturalhistorymag.com/master.html?http://www.naturalhistorymag.com/0407/0407_feature.html
  • "Animal altruism myth exposed." BBC. June 4, 1999. http://news.bbc.co.uk/2/hi/science/nature/360255.stm

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