Pigeons are even better at learning than we thought

In a new study from the University of Iowa, researchers found that pigeons can categorize and name both natural and humanmade objects--and not just a few objects. These birds categorized 128 photographs into 16 categories, and they did so simultaneously. 

...the UI researchers used a computerized version of the "name game" in which three pigeons were shown 128 black-and-white photos of objects from 16 basic categories: baby, bottle, cake, car, cracker, dog, duck, fish, flower, hat, key, pen, phone, plan, shoe, tree. They then had to peck on one of two different symbols: the correct one for that photo and an incorrect one that was randomly chosen from one of the remaining 15 categories. The pigeons not only succeeded in learning the task, but they reliably transferred the learning to four new photos from each of the 16 categories.

Also, an interesting quote from the lead researcher:

"It is certainly no simple task to investigate animal cognition; But, as our methods have improved, so too have our understanding and appreciation of animal intelligence... Differences between humans and animals must indeed exist: many are already known. But, they may be outnumbered by similarities."

The full press-release can be read here.