Crocodiles Hunt Birds With Sticks, The First Reptile Observed Using Tools
Crocodiles are usually thought of as big dummies, but a new study from the University of Tennessee finds that crocs are smart enough to use sticks to lure prey. Two crocodilian species, India's mugger crocodile and the American alligator, have been observed balancing sticks across their nose, drawing in nest-building birds. Birds swoop down to grab the stick, and you can guess the rest.
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"This study changes the way crocodiles have historically been viewed," said study author Vladimir Dinets, a research assistant professor at the University of Tennessee. "They are typically seen as lethargic, stupid and boring but now they are known to exhibit flexible multimodal signaling, advanced parental care and highly coordinated group hunting tactics."
Over the course of a year, Dinets's team observed crocodiles at four Louisiana sites. The researchers found that in areas near bird nests, sticks on crocodiles' noses showed up more frequently. They dismissed the idea that floating sticks just happened to find their way onto croc's noses, as floating sticks were rare in those waters. What's more, the crocodiles appeared to be aware of birds' nest-building seasons; during March through May, there was a "significant increase" in the number of sticks on croc's noses. Dinets told The Telegraph that it was "the first known case of a predator not just using objects as lures, but also taking into account the seasonality of prey behavior."
While other animals are known to use tools in various ways--otters use rocks to crack open clams, bonobos use sticks to fish for termites, elephants use branches to swat flies--this is the first example of tool use by a reptile. Dinets says that the discovery may also shed shed light on the behavior of everyone's favorite crocodilian relatives: dinosaurs.
"Our research provides a surprising insight into previously unrecognized complexity of extinct reptile behavior," said Dinets. "These discoveries are interesting not just because they show how easy it is to underestimate the intelligence of even relatively familiar animals, but also because crocodilians are a sister taxon of dinosaurs and flying reptiles."
Dinets's study was published last week in the journal Ethology Ecology & Evolution.
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