Oct. 22 (UPI) -- Asian elephants can't do trigonometry, but they can comprehend and use numbers, new research confirmed.
Previous studies have shown other mammals posses a basic understanding of numbers. But such arithmetic relies on imprecise estimates of quantity, not the use of absolute numbers.
"Their performance on numerical tasks is affected by the distance, magnitude, and the ratio of comparisons," researchers wrote in their new paper, published Monday in the Journal of Ethology.
Asian elephants, however, boast unprecedented numerical competence.
Scientists in Japan attempted to replicate the results of previous numerical competence experiments, this time using a 14-year old Asian elephant named Authai as the test subject. Researchers first trained Authai to use a touch screen. Once Authai was trained, researchers presented her with a relative numerosity judgment task.
For the task, cards with varying numbers of bananas, watermelons and apples were juxtaposed on the screen. Authai was trained to touch the tip of her trunk to the card on the screen with the greater number of items.
To determine whether Authai confused greater numbers with greater surface area coverage, researchers varied the size of some items. For example, a card featuring three large bananas might be placed alongside a card with 10 small bananas.
Authai correctly picked the card with the larger number of items 66.8 percent of the time. For each correct selection, Authai was rewarded with food.
"We found that her performance was unaffected by distance, magnitude, or the ratios of the presented numerosities, but consistent with observations of human counting, she required a longer time to respond to comparisons with smaller distances," researcher Naoko Irie said in a news release. "This study provides the first experimental evidence that nonhuman animals have cognitive characteristics partially identical to human counting."