RRP mentions "Louis Lefebvre's documentation of eagle intelligence." Here's a quick taste of his work:
"So for the record, the smartest bird in the world isn't your expensive parrot that has learned how to repeat your private comments at the most inopportune time. It's just the common crow.
That won't surprise bird lovers who have long marveled at the cleverness of this member of the corvidae family. There are many celebrated cases of innovativeness among crows, which are known to manufacture tools to accomplish varied tasks.
Perhaps the most famous is the Japanese carrion crow that is clearly over the top when it comes to bird IQ. These crows routinely perch at traffic intersections near a university campus in Japan and wait for a red light.
When the traffic comes to a halt, the crows fly down and place walnuts in front of the tires. The light changes, the cars move out, crushing the nuts. The crows then dine, happy to parcel out that part of the task to someone else.
Bald eagles in northern Arizona, eager to get at minnows trapped in ice-covered lakes during the lean days of winter, have learned how to crack the ice with their beaks. Then they jump up and down on the ice to force the minnows up through the cracks.
The gila woodpecker in the American Southwest and Mexico makes a wooden scoop out of tree bark to carry honey home to its young.
In Britain, there's the now-famous case of the European blue tit, which has learned how to peal off the tinfoil on milk bottles left on doorsteps and pig out on the cream. New Zealand house sparrows dine on cafeteria food by triggering a motion sensor that opens the door."
