The critically endangered Hawaiian crow can use sticks to deftly fish for food that is out of reach, according to a new study. The discovery means there are now two known tool-using species of crows.
“The Hawaiian crows are incredibly good at using tools,” said lead study author Christian Rutz, a biologist at the University of St Andrews in the United Kingdom. “What we see is similar to the really skilled tool handling in New Caledonian crows.”
Until now, New Caledonian crows had been the only corvid (a group that includes crows, ravens and rooks) species known to use tools. These birds have become famous for their expert ability to fashion hooks from sticks to snag larvae and insects from crevices in logs or branches. [Creative Creatures: 10 Animals That Use Tools]
Rutz had studied the New Caledonian crow for more than a decade. In one paper, published in the journal Nature in 2012, he and his colleagues showed how the birds have physical characteristics that enable their tool control: straight bills and very large eyes with a large field of binocular vision.
Rutz told Live Science he wanted to look for other birds that shared these features, thinking those traits could be preadaptations for tool use. That led him to the Hawaiian crow, also called the ‘alalā (pronounced AH-la-la).
The one problem was that the birds had been declared extinct in the wild by 2004. (Just 131 are alive today.) So Rutz got in touch with San Diego Zoo Global, a nonprofit organization that operates the San Diego Zoo and was breeding the ‘alalā in captivity in Hawaii. People at the captive breeding facility told him they had sometimes seen the birds use sticks but didn’t think much of it.
“I immediately booked my flight to Hawaii,” Rutz said.
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