MSNBC Crows share tricks of the trade

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Crows share tricks of the trade

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.

http://www.msnbc.msn.com/id/15503722/

By Ker Than

Staff Writer

Updated: 4:15 p.m. AKT Oct 31, 2006

 

Bird brained they might be, but crows are the

MacGyvers of the avian world, able to turn twigs

and even their own feathers into tools for

getting at hard-to-reach food.

 

But while young crows are born with a propensity

for crafting tools, it's only after watching

their elders make and use tools that they become

truly proficient, a new study suggests.

 

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, leaves and

even their own feathers into tools for rooting

out insects in dead wood.

 

The crows craft tools to specific needs. They

examine a problem and then pick or design an

appropriate tool. 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 four Caledonian

crows - two received lessons 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.

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