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Inventive New Caledonian crows appear to be surprisingly technologically advanced: the birds actually make their own tools, researchers found.
To catch a glimpse of the birds’ foraging behaviours, two biologists in the United Kingdom developed small cameras which they attached to the tail feathers of New Caledonian crows.
In the paper – published December 23 in the Royal Society’s journal Biology Letters – the researchers noted that the crows made hook-shaped tools which they used to catch larvae, insects, grubs, and other things from beneath leaf litters or from crevices in logs.
Dr Jolyon Troscianko, co-author of the study and a postdoctoral research associate at Exeter University, said that when he and his colleague looked at the footage frame-by-frame, they saw some of the crows building hooked tools out of a wooden stick.
According to Dr. Troscianko, it takes about one minute for a crow to make a tool using a V-shaped twig, by removing the leaves, pealing the bark off and snapping the stick above the joint where it branches out. To sharpen the stick, the crows also nibble at the end of it, he added.
Most animals do not make their own tools, but use already existing ones. Dr. Troscianko says that few creatures in the animal kingdom use tools, an even fewer manufacture them. Apart from humans, animals able to build complex tools are exceedingly rare.
Chimpanzees are one of those animals, Dr. Troscianko noted. However, in terms of complexity, the New Caledonian crows’ tools are not far behind – which just goes to show that even animals with smaller brains can be good at making tools.
Another bird that is known to manufacture tools for foraging is the Galápagos woodpecker finch. To get insects out of crevices, the Galápagos woodpecker finch uses cactus spines.
A recent study also found that parrots used date pits and pebbles to create calcium powder by grinding up shells. Although they did not manufacture the tools themselves, the parrots were still clever enough to use them.
It might help us better understand the evolution of tool use and tool manufacturing, by studying other animals that also use or make tools, according to Dr. Troscianko. He also said that it is fascinating how humans have evolved to develop such complex tools and to reshape the world around them.
Image Source: cdn
