Crows can 'count' similarly to toddlers, according to new study

Before toddlers learn to master symbolic counting–where “one” stands for a single object and “two” indicates double that–they pass through a developmental stage of verbal tallying. In this phase, asked how many apples are in a group of three, a young child might say “one, one, one” or “one, two, three” or “apple, apple, apple,” in a form of proto-counting. They understand there are three apples, but they don’t quite yet have the ability to express that number in the abstract form of “three,” alone.
The study adds to the growing laundry list of cognitive abilities that corvids (the bird family including crows, ravens, magpies, and jays) possess. The new work also aids in the quest to uncover the evolutionary origins of humans’ mathematical ability. By studying other animals’ capacities and limitations, scientists can get a better idea of where and how our own numeracy comes from.