Decision-making, Inhibition and Planning in New Caledonian crows (Corvus moneduloides)

Abstract

Over the last 25 years, New Caledonian crows have impressed scientists with their tool and problem solving behaviours. From manufacturing their own stick and hook tools in the wild, to solving metatool, water displacement, and a myriad other problems, this species has greatly contributed to the change in our perception of birds from ‘bird-brains’ to ‘feathered apes’. This thesis contributes to our knowledge of the cognition of this species, the New Caledonian crow (Corvus moneduloides), with three experiments that investigated their decision making, inhibition, and planning. The first experiment presented NC crows with a serial reversal learning task, and then compared their performance to pigeons, in order to compare and contrast speed of learning and flexibility when adapting to stimuli that change their contingency. Experiment 2 examined the NC crows’ decision-making abilities, as they had to show flexible behaviour across a number of tasks: picking the correct tool for the presented apparatus and inhibit an immediate response to go for either an available tool or a reward. This study compared New Caledonian crows’ performance to that of human children, human adults, Goffin’s cockatoos, and Orangutans presented with the same tasks. The third experiment tested the NC crows' use of mental representation and pre-planning to solve a metatool task. In this experiment, the apparatuses were out-of-sight of each other, meaning crows had to remember the location of the sub-goal and the goal. The success of crows at these problems provided strong evidence that they use pre-planning to mentally solve metatool tasks before they interact with them. The findings of this thesis provides valuable data on the cognition NC crows use when problem solving, and how they compare to other species when inhibiting behaviour and making decisions.