Crows can wait for bigger rewards
The marshmallow task is a classic psychological paradigm (often tested on children) - would you rather have one marshmallow now - or wait and receive two marshmallows later?
Researchers examined whether crows and ravens, known for their intelligence and patience, would rather eat a treat now, or wait a period of time and exchange the treat for a more preferred food item. Their patience depended on the value of the treat, but the clever corvids showed that they exhibit a good amount of self-control. The results have just been published in the journal Animal Behaviour and you can read a summary here.