© James St ClairA New Caledonian crow with a freshly fashioned hook.
The manufacture and use of tools has long been touted as a line of demarcation between humans and non-human animals: our technological prowess is what makes us human, it was thought.
But research over the last few decades has blurred that line, as tool manufacture and use, and even the use of tools to make other tools (known as meta-tool use), has been reported in an increasing number of species.Meta-tool use has been seen in numerous primate species, but among nature's most prolific tool-makers and users are the corvids: members of the Corvidae family, such as ravens, magpies and, importantly, crows.
Crows in Japan and California, for example, have been observed to use cars lined up at traffic lights to crack open difficult nuts.
In 1996 Gavin Hunt at the University of Auckland
reported in Nature the remarkable discovery that New Caledonian crows (
Corvus moneduloides) manufactured and used tools while trying to catch prey. The tools had features previously seen only in early human cultures after the Lower Palaeolithic period, which ended 200,000 years ago. They were remarkably standardised, came in distinct types with distinct shapes, and, importantly, used hooks.
Comment: Next time your kids tell you they don't need to study math, cook them up a batch of mathematically perfect potatoes! Argument settled!