Using tools in the animal kingdom is a rare ability, something that only a few species have been able to demonstrate. It now seems that another bird is set to join this select few, as the Hawaiian crow (Corvus hawaiiensis) has been elevated to the exclusive class of tool users. Yet with only 130 of the corvids surviving, the birds are perilously close to being lost forever.
The Hawaiian crow, known locally as the 'alalā, now joins the New Caledonian crow in a crack group of expert tool users. Before the discovery of the Hawaiian birds’ prowess with twigs, however, it had long puzzled researchers as to why – despite there being over 40 species of crows and ravens worldwide – the birds confined to the remote island of New Caledonia were the only ones known to be able to manipulate and make tools to get at hard-to-reach food. One researcher started to suspect that they might not be alone.
“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,” explains Dr Christian Rutz, who co-authored the study published in Nature. After looking through all other species of corvids, the researchers quickly turned their attention to the New Caledonian’s Hawaiian brethren, which also have a curiously straight bill. Yet there was a catch: the birds are extinct in the wild.