Orangutans also know how to spend money

In addition to the ability to recognize the value of coins, orangutans also know how to use them to buy food and carry out "reciprocal" exchanges with each other.

Photo: britannica.com.

The team at the University of St Andrews watched two orangutans named Bim and Dok at Leipzig zoo (Germany). They gave them many kinds of coins. A kind of coin that helps orangutans exchange for bananas for themselves, the second type allows for the exchange of bananas for other children and the third one has no exchange value.

Dok, the orangutans, showed enthusiasm in exchanging coins for bananas for the Bim male. Occasionally Bim points his fingers at the first-class coins to encourage Dok to buy bananas for herself, but the orangutans are not excited. After so many times, Bim uses his second type of coins to 'buy' bananas for Dok. The male orangutan only stopped doing so until the bananas of two children were approximately equal.

Both Bim and Dok never use the third type of coin. This proves that they understand that those coins are not worth exchanging. Dr. Valerie Dufour, the leader of the study, confirmed that the scientific community had never recorded evidence of 'reciprocity' behavior in animals before.

'Calculated exchange is not a monopoly of human behavior. We are not the only species expecting material response when working well for our fellow humans , 'Valerie remarked.

The team also experimented with gorillas and chimpanzees, but they showed no interest in using coins like orangutans.