Transcript:

RAVENS - CachingHere's a program from our archives.Ambience: Ravens at a mealAs the weather grows colder, ravens-- like other birds who stay north through the winter-- are finding food harder to come by. It's a season which calls for strategy and some occasional bickering, the sounds of which we're listening to right now.I'm Jim Metzner, and this is the Pulse of the Planet.In winter, ravens compete with each other for animal carcasses left behind by larger predators, such as wolves. "When there are many ravens at a carcass they try to take as much food away as possible and hide it away from the others for later use. And so there's a big rush to get as much food as possible and they fly off with it and they dig a little hole someplace and they stick the food in there and then they cover it up."Bernd Heinrich is the author of the soon-to-be-released book The Mind of a Raven: Adventures and Investigations with the Wolf-Birds. "Now, that's what's called caching although many animals do not remember where the caches have been made, but ravens do. And furthermore, ravens are apparently very unusual in that they watch each other make caches and can remember at least for many days, I have found out, the caches made by others. So they don't only remember their own caches but those they see others make. Now you see strategy involved because if they see another one watching them they won't make the cache. They will try to fly away from the others and hide it in private and but if a bird comes near their cache they presume that it's going to that cache and they chase it away. So you get strategies and counter strategies that might have mental involvement here."Please visit our web site at www.pulseplanet.com.We've been listening to a program from our archives. Check out our website, pulseplanet.com for a link to my latest project - a novel. I'm Jim Metzner and this is the Pulse of the Planet.