Kabadayi and Osvath test ravens' abilities to plan for future tool use and trading, rather than for food caching (a behavior that might be considered as an adaptive specialization to gather food in order to eat it at a future date)...The authors presented five ravens with a choice of objects. Only one of these objects was a functional tool, which could be used to retrieve food from a puzzle box. The ravens chose correctly not only when they were offered the box but also when they had to store the tool and plan for the next day. In another experiment, the ravens were trained to exchange tokens for food. When the ravens knew that trading would only happen on the next day, they chose and stored these tokens as soon as they were offered to them. By manipulating tool choice, time, and trading opportunities, the authors controlled the value of the items at choice in relation to current as well as future interactions.
The results from the two experiments show that ravens take temporal distance between item choice and reward into account, exercise self-control, and make decisions for predicted futures rather than arbitrary ones. Thus, the birds opt for a more distant but higher gratification rather than an immediate but lower gratification and do so flexibly across behaviors.