Are meerkats immune to poison?


Scorpions have crawled largely unmolested across the Earth for millions of years, but they've met their match in at least one certain species who loves to dine on them. See more meerkat pictures.
Oxford Scientific Films

Behold the mighty scorpion: ancient, poisonous monster of the Earth. Scorpions were among the earliest species to leave the oceans and emerge onto land. They left the sea in pursuit of their fishy prey, which had recently begun to grow limbs to become the first amphibians.

For 430 million years, the scorpion has crawled over rock and soil -- even high mountains -- changing little except to adapt by growing smaller over the eons [source: University of Arizona]. The species has sustained its existence for such a protracted length of time in large part because of the deadly venom it deals to prey and predator from its vicious, stinging tail. In some scorpion species, the right dose of venom can even fell a human.

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­The scorpion's venom is a mixture of neurotoxins. Once introduced into the victim's bloodstream, these toxins attack the central nervous system. Victims may convulse and froth at the mouth. They may lose control of their extremities; their eyes may dart about involuntarily, and their hearts and respiratory systems may become paralyzed, leading to death.

If a scorpion can kill a human, what kind of match would, say, a meerkat be for the deadly arachnid? Let's find out. Here comes a meerkat now, traipsing across Africa's Kalahari Desert.

As the meerkat approaches, the scorpion senses its presence through pectines, tiny structures on the underside of its body. These sensors pick up even the slightest vibrations. The scorpion knows the meerkat is near; its tail raises, ready to strike.

The meerkat sees the scorpion. It stands on its hind legs and sizes up the deadly threat. The meerkat hops a little closer, perhaps dangerously close, to the scorpion. It doesn't look like this is going to pan out well for the meerkat. The scorpion fully raises its tail to sting. Here it comes. Wait!

Without warning, the meerkat suddenly grabs the scorpion with its forepaws, bites off the stinger, drags it through the sand and chomps into the body. After a few nibbles, the scorpion stops squirming. The meerkat finishes its food and hops off.

What just happened? The meerkat should be dead as a doornail. Why isn't it? Find out on the next page.

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Meerkats' Poison Immunity

The meerkats shown here may be gearing up to mob a dangerous predator.
The meerkats shown here may be gearing up to mob a dangerous predator.
Mattias Klum/National Geographic/Getty Images

Shouldn't the meerkat that just ate the venomous scorpion be dead? It's perfectly fine. In fact, it looks a little lethargic after such a big snack. How can this be? Meerkats have developed a technique to deal with scorpion venom. What's more, meerkats may be able to handle a bite from some types of venomous snakes.

Biologists have substantiated that meerkats are immune to some snakes' venom because they share ancestry with the mongoose family. In some parts of the world, such as India, people prize mongooses as house guards because they can wage battle with deadly snakes, like cobras. This trait may have been passed along on the African plains after mongooses evolved into meerkats. Meerkat immunity to snake venom remains an uncertainty, however. When a snake threatens a meerkat group they gang up on it -- a method called mobbing [source: Animal Planet]. When meerkats mob, they form a circle around the predator, raise their tails and move about in a formation that looks like a single, large animal [source: Roberts].

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Usually, mobbing is enough to scare off even a deadly snake. But not always. Meerkats have been observed being bitten by venomous snakes. While some have survived the attacks, others have died. So biologists aren't entirely certain if meerkats are completely immune to snake venom.

You may have heard that meerkats are immune to scorpion venom. This is a bit misleading. If stung by a particularly deadly species of scorpion -- like a cape scorpion or granulated scorpion -- a meerkat may still die [source: Kalahari Meerkat Project]. However, meerkats have developed a technique for handling the venom found in scorpions they commonly eat.

When a meerkat spies a scorpion, it moves in quickly for the kill. The scorpion may be aware the meerkat is close by, but the meerkat seizes it so fast that the arachnid can't respond. First, the meerkat zeroes in on the tail, biting off the scorpion's stinger and discarding it. Without its tail, the scorpion is unable to introduce venom into a meerkat's bloodstream. Although the clawlike pincers at the end of each of a scorpion's arm may look deadly, they're actually for grabbing and holding -- no venom is distributed through them.

With its stinger removed, the scorpion's fate is pretty much sealed. But there's still venom on its exoskeleton. To combat this, meerkats have learned to brush off any remaining traces in the sand after removing the stinger [source: Meerkat Info]. With the scorpion quickly prepared, it's mealtime.

Observation of meerkats has shown that adults teach pups how to properly eat a scorpion. This lesson is taught in stages. At first, pups are simply given dead scorpions; later on, they get ones with stingers broken off. Eventually, the pups will be handed a disabled scorpion, stinger and all. Finally, as they approach the age at which they're able to go out on their own, an adult may toss a young meerkat a live scorpion [source: BBC]. It's kind of sink or swim by this time.

Since meerkats ingest scorpions in such a specific way and can die if stung by a scorpion or bitten by a venomous snake, it's not entirely fair to say they're immune to the venom. Still, they've adapted pretty well, considering the circumstances.

For more information on meerkats and related topics, mob the links on the next page.

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Sources

  • Gouge, Dawn H., et al. "Scorpions." University of Arizona. http://ag.arizona.edu/pubs/insects/az1223/
  • Roberts, Miles. "Warriors of the Kalahari." Smithsonian Zoogoer. January/February 2007. http://nationalzoo.si.edu/Publications/ZooGoer/2007/1/meerkats.cfm
  • Zimmer, Carl. "Unsafe for any species." New York Times. May 27, 2001. http://www.nytimes.com/books/01/05/27/reviews/010527.27zimmert.html
  • "Meerkat pups go to eating school." BBC. July 13, 2006. http://news.bbc.co.uk/2/hi/science/nature/5177594.stm
  • "Meerkats." Meerkats.net. March 2005. http://www.meerkats.net/info.htm
  • "Meerkats unmasked live chat transcript." Animal Planet. 2003. http://animal.discovery.com/fansites/wildkingdom/meerkats/expert/expert_2.html
  • "Safety issues and other concerns." Kalahari Meerkat Project. April 13, 2007. http://www.kalahari-meerkats.com/fileadmin/files/Research/SafetyProtocol_13April07.pdf
  • "Scorpion stings." Merck. February 2003. http://www.merck.com/mmhe/sec24/ch298/ch298k.html