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Those Little Birds On The Backs Of Rhinos Actually Drink Blood

You think that’s ticks they’re eating?

Oxpeckers hang out with large ungulates–animals with hoofs like rhinos, giraffes and water buffalo. (Derek Keats/Flickr)
smithsonian.com

You’ve seen it: a peaceful image of interspecies togetherness. The adorable oxpecker, perched on the back of a rhinoceros or zebra, happily having lunch while ridding its ride of pesky ticks, flies and other bugs. Not so fast–those oxpeckers are washing the bugs down with a healthy helping of blood. As if the endangered species of sub-Saharan Africa didn't have enough to worry about.

The oxpecker (there are actually two species, one that has a red bill and one that has a yellow bill) does more than just clean bugs for big game animals, writes Encyclopedia Britannica: the birds also hiss loudly when they spot danger, providing a sort of secondary warning system to their larger hosts. However, the relationship isn’t one of total simplicity: though they rid animals of pests, “oxpeckers also take blood from the sores, which may be slow to heal,” writes the encyclopedia.

That’s right. While it is true that oxpeckers do eat bugs, they also eat rhinos, and zebras and giraffes, and whatever other large animals they can hang out with. That means, wrote a group of researchers in a 2011 study published in the journal Evolution, that the oxpecker can also be viewed as a parasite to their larger hosts as well as a helper.  

To figure out more about their relationship, they studied the preferences oxpeckers seem to have for their host animals. They found that both red- and yellow-billed oxpeckers pick hosts with the largest number of ticks, but don’t pick based on how thick their host’s hide is. They interpreted this to mean that oxpickers are primarily looking for animals with the greatest number of yummy ticks, rather than the most potential for bloody sores. “These results support the hypothesis that the relationship between oxpickers and ungulates is primarily mutualistic,” they concluded.

But there’s no denying that oxpickers do damage to their hosts. Until relatively recently, those who studied the two species believed they were a perfect example of mutualistic behavior, where two species help each other, writes Jason Bittel for Slate. However,  “oxpeckers are notorious for pick-, pick-, picking their way into their hosts,” he writes. “Do a quick Youtube search for oxpeckers, and you’ll find videos of these birds digging into hippo flesh, fighting over buffalo blood and straddling the head of an antelope just to get at a face wound.”

The birds also use their four-legged friends/meals for nesting material. Red-billed oxpickers have been found to use wool pulled from the backs of sheep. In captivity, the birds used hairs they pulled from the ears of rhinos they shared an enclosure with.

And oxpeckers aren’t the only birds out there who have this type of relationship with other animals: A researcher at the University of Campinas found that black vultures have a similar relationship to capybaras in southeastern Brazil and other “cleaner bird” species have been found to have similar relationships, writes biologist Ivan Sazima. Just another magical (if gross) corner of the natural world.

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