Wednesday, November 01, 2006

Crows are the MacGyvers of the Avian World


I'm a huge fan of crows, ravens, and other corvids. These birds, especially ravens, rival most higher primates in intelligence. Of all the birds, only corvids have outgrown their evolutionary niche to the point that they have copious free time to play games. And they invent their own games much the same way that human children do.

Live Science posted a story yesterday about crows and how young crows learn to use tools in part from watching their elders and in part as an innate skill. This is from the article:
Compared to other crows, those from the Pacific island of New Caledonia, located east of Australia, are master tool makers and users, second only to humans and on level with chimps when it comes to finding novel uses for everyday objects. In their natural forest environment, the midnight-black birds fashion twigs [video], leaves and even their own feathers [image] into tools for rooting out insects in dead wood.

The crows craft tools to specific needs [image]. They examine a problem and then pick or design an appropriate tool [video]. For example, faced with a snack lodged in a small tree hole, a crow will prune and adjust a leafy oak branch to just the right width to poke into the hole.

Scientists have found that crows living on different parts of the island display variations in tool shapes, a discovery that suggests young crows learn to fashion tools in a particular way from relatives and other crows living nearby. If so, it would mean the birds possess a culture of tool technology on par with that of humans.

To test this idea, researchers at the University of Oxford in the U.K. hand-raised [image] four Caledonian crows— two received lessons [video] in tool use from human foster parents, while the other two did not. Despite their different upbringings, all four juvenile birds used sticks to retrieve food from crevices, proving that crows have an innate ability for tool use.

However, Uek and Nalik, the two birds schooled in tool-making, carried and inserted twigs into crevices faster and more often than Oiseau and Corbeau, the two naïve crows. Also consistent with the idea that tool use among crows is partly inherited and partly learned, the researchers found that tools made by the four captive crows were crude compared with those made by adult crows living in the wild.

The researchers suggest that insights gained from studying crows could be applied to humans to help reveal how tool use evolved in our own species. Experiments can be performed with crows that are not practical with human children, and birds develop faster than chimps.

The study, conducted by Ben Kenward, Christian Rutz, Alex Weir and Alex Kacelnik, will be detailed in an upcoming issue of the journal Animal Behavior.

Anyone who has spent any time watching crows will know how smart crows really are. They, along with some parrots and higher primates, are unique in their ability to solve problems in their head before attempting to perform the solution.

Crows are also extremely social. In Seattle, which hosts the densest population of crows on the planet, tens of thousands of crows gather at sunset in the trees along Lake Washington to share events of the day -- literally. They will share info on food sources, socialize, and the young adults will pair off to form life-long unions.

Crows are much smarter than most people give them credit for. You can read more on this story at USA Today.


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