An international team of scientists and conservation experts has discovered that the critically endangered Hawaiian crow, or ‘Alalā, is a highly proficient tool user, according to a paper published today in the scientific journal Nature. There are more than 40 species of crows and ravens in the world, and many of them—especially those living in remote tropical locations—have not been adequately studied.
“This raises the intriguing possibility that there are some undiscovered tool users out there,” explained the study’s lead scientist, Christian Rutz, Ph.D., from the University of St. Andrews, in the U.K. “We had previously noticed that New Caledonian crows have unusually straight bills, and wondered whether this may be an adaptation for holding tools, similar to humans’ opposable thumb,” Rutz elaborates. By searching for this tell-tale sign amongst some of the lesser-known corvid species, he quickly homed in on a particularly promising candidate for further investigation – the ‘Alalā.
Following a population crash in the late 20th century, the ‘Alalā is now extinct in the wild. In a last-ditch effort to preserve the species, the remaining wild birds were brought into captivity, to launch a breeding program.
“Later this year, in collaboration with our partners, we will be releasing captive-reared ‘Alalā on Hawai‘i (island), to re-establish a wild population,” said Bryce Masuda, co-leader of the study and conservation program manager of San Diego Zoo Global’s Hawai‘i Endangered Bird Conservation Program.
A total of 104 of the 109 ‘Alalā individuals living at the time of the study were observed by scientists, who determined that the vast majority of them spontaneously used tools.
“Current evidence strongly suggests that tool use is part of the species’ natural behavioral repertoire, rather than being a quirk that arose in captivity.” said Rutz. “Using tools comes naturally to ‘Alalā. These birds had no specific training prior to our study, yet most of them were incredibly skilled at handling stick tools and even swiftly extracted bait from demanding tasks.”
The fact that the entire existing population of the species is being maintained in San Diego Zoo Global’s Hawaiian bird center allowed researchers to test almost all members of the species.
The paper—“Discovery of Species-wide Tool Use in the Hawaiian Crow”— is the cover story in the Sept. 15, 2016 issue of Nature.