Saturday, October 22, 2016

The Extinction of a Tool User

There are many reasons to prevent the extinction of species, and one of them is that we have a lot still to learn about plants and animals. My last blog covered three species that have been brought back from the brink of extinction thanks to concerted human effort. Cross your fingers with me that the same can be done for this fascinating one.

U.S. Fish & Wildlife Service
The Hawaiian crow (Corvus hawaiiensis) - known in Hawaiian as the ʻalalā - is a tool user. It can clutch a stick in its bill and use it to dig food out of a crevice. That already puts it in a unique group of bird species that have been found to use tools in this way. But the Hawaiian crow is a bit exceptional even within this group: it not only uses tools, it manufactures them. The crow can pry off a twig and shape it into just the tool it needs. Watch the process in this video: the crow realizes it needs a tool, makes the tool, and then figures out the best place to use it!

Unfortunately, Hawaiian crows became extinct from the wild in 2002 as a result of disease, predation, habitat encroachment, and shooting by farmers who saw them as a threat to their crops. They have been bred in captivity since then in hopes of reintroducing them to the wild. The success of reintroduction is not assured, especially since rising temperatures have allowed mosquitoes that carry bird malaria to thrive in the higher altitudes of Hawaii where the crows once lived. Nevertheless, six fledglings will be released into the wild this November, and you can read about and follow the process here.

There are many reasons to care about the Hawaiian crow and its survival, and one of them is that the species can help us understand something very interesting about the relationship between humans and nature. One of the many early assumptions about the differences between humans and animals was that only humans use tools. Over the last few decades, scientists have discovered tool use among a diverse set of animals: from sea otters that use stones to open abalone shells to bonobos that use leaves as umbrellas to elephants that use branches to swat flies. There is much to learn about the parts of the brain that allow such complex abilities as tool use and when, where, and how tool use is taught rather than instinctive.

And for those of us who aren’t scientists, there is the simple sense of awe that comes from learning what animals can do and how much like us they can be. I hope someday to watch a video of wild Hawaiian crows using tools and showing us their genius, adaptability, and determination.