Crows can make complex hooked tools, like humans

Well... they are smarter than you thought

Published Date
29 - Dec - 2015
| Last Updated
29 - Dec - 2015
Crows can make complex hooked tools, like humans

Apes are generally regarded as the one of the smartest animals in the world due to their penchant for making and using tools. However, new research indicates that our feathered friends may be a step ahead. UK researchers, Jolyon Troscianko and Christian Metz have found evidence of crows making and using tools in the wild by using a ‘crow tailcam’ that they invented. Not just any tools, but hooked tools, which only humans were thought to have mastered due to their complexity.

Crows, especially New Caledonian crows, have been observed making tools in the wild, but no one had ever caught them doing so on camera. Metz had even co-authored a paper about crows making hooked tools by fashioning them out of branches to reach grubs within pieces of wood. However, the crows that made these tools had done so in captivity. Animals in captivity generally develop a proclivity towards making tools, which they wouldn’t have got if they were in the wild. In order to catch crows making tools in the wild, the research duo attached a small camera to the two strongest tail feathers on New Caledonian crows using biodegradable rubber. This gave researchers a below-the-belly view of the crows activities as the birds usually lower their heads when feeding or when making tools. 19 wild New Caledonian crows were equipped with cameras out of which footage from 10 were retrieved.

In order to preserve batteries, the camera only took footage for a few minutes at a time over the course of a week or so. After that, the rubber would degrade enough for the camera to fall onto the forest floor and would then be retrieved by the researchers. The videos show crows engaged in a number of activities such as socialising, feeding chicks, and using tools, specifically hooked tools. Hooked tools are complex tools in the sense that they need to be prepared before then can be used. Hence human beings were thought to be the only species on earth to make them. It is also extremely surprising when one considers that crows lack opposable thumbs. In order to make the tool, crows would have to find the right branch with the right dimensions, trim the leaves and bark, and then shape the hook itself. Then the bird can insert it into wood in order to snare larvae and insects. Troscianko and Metz estimate that the birds observed used tools for foraging about 19% of the time while tool-related behaviour occurred for 3% of the total observation time. 

Just like humans, the crows also seem to hate losing their tools as one was observed recovering its implement after dropping it on the forest floor. This seems to suggest that they value their tools and don’t discard them after use. 

Source: The Royal Society Publishing

Shrey PachecoShrey Pacheco

Writer, gamer, and hater of public transport.