Giraffes may not just be tall—they may also be able to tally. In an experiment with four zoo giraffes, University of Barcelona researchers found the animals could do math, mentally adding carrot chunks they couldn’t see, per the BBC. The team first showed giraffes two containers holding different numbers of carrots, then closed them. They then showed the giraffes a third container with extra carrots, which were added to just one of the closed boxes. When it was time to choose, the giraffes consistently picked the container that should have held the larger total, suggesting they were adding the quantities in their heads, according to the study published Friday in Scientific Reports.
The giraffes chose the boxes with more carrot pieces 68% of the time, which researchers say is too high to be random chance, UPI reports. However, when scientists tried subtraction—taking carrots away instead of adding—the giraffes struggled, choosing the container with more carrots only at a rate consistent with random chance. Researcher Iker Loidi notes that “subtraction is more difficult than addition,” for humans as well as animals. Still, the research adds to evidence that giraffes could use math to find the “bigger payoff” in the wild. As Sci News reports, a previous study by some of the same researchers found they’re capable of statistical reasoning akin to that of primates, which have much larger brains in relation to body size.