Chicago ? Monkeys perform mental math, pigeons can select the picture that doesn’t belong. Humans may not be the only animals that plan for the future, say researchers reporting on the latest studies of animal mental ability.

“I suggest we humans should keep our egos in check,” Edward A. Wasserman of the University of Iowa said Thursday at the annual meeting of the American Association for the Advancement of Science.

Wasserman, a professor of experimental psychology, said that, like people, pigeons and baboons were able to tell which pictures showed similar items, like triangles or dots, and which showed different items.

This is the definition of a concept, he said, “and the animals passed it with flying colors.”

He spoke at a symposium on “Animal Smarts,” where researchers discussed the latest findings in the mental abilities of animals.

In the last 20 years there has been a major revolution in the understanding of animals, added Nicola S. Clayton, a professor of comparative cognition at the University of Cambridge in England.

Animals not only use tools, there is evidence that some of them save tools for future use, she said.

“Planning ahead was once thought to be unique to humans,” Clayton said. “We now know that’s not true.”

For example, she said, crows have been seen stashing food away for the next day and even finding ways to protect it from being stolen.

Some people may be uneasy as new studies find increasing similarities between animal and human mental abilities, Wasserman said.

The aim is to learn how much thinking ability is general throughout the animal kingdom, he said, and “the evidence that we collect constantly surprises us.”