Bird’s nifty tool is worth crowing about
A CLEVER species of crow knows how to create a hooked tool to get at its food in a hurry, scientists revealed yesterday.
New Caledonian crows are known for using sticks to lever out food hidden in nooks and crannies.
But some even go to the trouble of working the sticks to give them hooked ends.
Biologists from the universities of St Andrews and Edinburgh estimate that the hooked stick allows the crows to seek out bugs and seeds 10 times quicker than a straight stick.
Their study in Nature Ecology & Evolution found that even though the birds go to enormous lengths to make the hooks, the effort does pay off.
Lead author Dr James St Clair from St Andrews said: “It’s a painstaking sequence of behaviours. Crows seek out particular plant species, harvest a forked twig, and then – firmly holding it underfoot – carve, nibble and peel its tip, until it has a neat little hook.”
He said crows can make a hooked tool in just two minutes. They then carry it around, store it and reuse it. Project leader Professor Christian Rutz from St Andrews, added: “Our results highlight that even relatively small changes to tool designs can significantly boost foraging performance.”
Extensive tests have shown that crows are among the cleverest of birds.
Professor Nick Colegrave of Edinburgh University said: “In nature, getting food quickly means that birds have more time and energy for reproduction and also for steering clear of predators. It’s really exciting that we were able to measure the benefits of these nifty crow tools.” Researchers do not know whether crows inherit the tool-making ability from parents or watch other birds.
But because the skill is likely to make birds live longer it is expected to spread.
Professor Rutz said: “We’ve all heard that the early bird gets the worm. In the case of the New Caledonian crow, it’s the skilled hook maker that gets the worm.
“Or at least it gets many more worms than its less crafty neighbours.”