Another case of eerily intelligent birds. This is [a] case of some clever experimental design. The authors managed to get newly hatched chicks to imprint on plastic spheres, which has an interesting consequence: apparently, when faced with collections of identical spheres, they'll head for the larger group. With the chicks properly trained, the authors then determined they could count by moving two sets of the spheres behind opaque screens as the chick watched. Once released, the chicks consistently headed for the screen that obscured the larger number of items. To test for math skills, the authors then started moving items between the screens as the chickens watched, and found that they still went to the location with more of the items.I'm sure this has something to do with seeking (and finding) protection from predators by playing the numbers game in a bigger flock: if there are more of us, the chances of me getting eaten by a predator are smaller.
No wonder they outlasted the dinosaurs.
Come to think of it, I use the same kind of thinking during our open water swims in the ocean: the more swimmers in the group, the better odds I have against a shark attack. No need to imprint on plastic spheres for me!