On a visit to SeaWorld (the one in Aurora, Ohio before it merged with Six Flags Ohio in 2000), I remember a concession which sold fish to feed dolphins. For a reasonable fee (I think $5), you purchased three small, sorry-looking fish in a cone-shaped paper cup at a stand next to a large pool containing otherwise untrained dolphins. I took my cup to the edge of the pool, held out a fish, and a dolphin quickly materialized. I dropped the fish into his open mouth — one, two, three — and then he immediately swam away. He knew there were three fish per cup, and hanging around would only waste time. In other words, he could count.

This raises the question, how many animals can do simple math? Near as we can tell, quite a few. As Michael Beran, a professor of psychology at Georgia State University, explained in an email to Live Science, “Many species, including insects, mollusks, lizards, birds and many types of mammals (land living and sea living) can discriminate between quantities of things.” Practically every studied species can make approximate distinctions between different numbers of objects in a set or sounds in a sequence.

Being able to count provides a number of evolutionary advantages. For example, finding food: honeybees count landmarks when navigating toward sources of nectar. For safety: lionesses count the number of roars they hear from intruders before deciding whether to attack or retreat. For mating: one species of frog bases its mating ritual on adding to their basic call.

In addition, there is some evidence that some species can grasp the concept of zero. This is certainly true of crows as explained in a paper published in the Journal of Neuroscience on June 2, 2021.

So we aren’t the only species who can work with numbers.

For more information, see “Animals Count and Use Zero. How Far Does Their Number Sense Go?” by Jordana Cepelewicz (https://www.quantamagazine.org/animals-can-count-and-use-zero-how-far-does-their-number-sense-go-20210809/)