Planning for future needs has traditionally been considered to be restricted to human cognition. Although recent studies on great ape and corvid cognition challenge this belief, the phylogenesis of human planning remains largely unknown. The complex skill for future planning has not yet been satisfactorily established in any other extant primate species than our own. In humans, planning for future needs rely heavily on two overarching capacities, both of which lie at the heart of our cognition: self-control, often deWned as the suppression of immediate drives in favor of delayed rewards, and mental time travel, which could be described as a detached mental experience of a past or future event. Future planning is linked to additional high complexity cognition such as metacognition and a consciousness usually not attributed to animals. In a series of four experiments based on tool use, we demonstrate that chimpanzees (Pan troglodytes) and orangutans (Pongo abelii) override immediate drives in favor of future needs, and they do not merely rely on associative learning or semantic prospection when confronted with a planning task. These results suggest that great apes engage in planning for the future by out competing current drives and mentally pre-experiencing an upcoming event. This suggests that the advanced mental capacities utilized in human future planning are shared by phylogenetically more ancient species than previously believed.

No abstract

-Play is widespread among vertebrates. Some animal groups stand out in their play behaviors in levels of complexity, innovativeness, sociality, and volume. Despite the vast phylogenetic distance between corvids, parrots, great apes, and dolphins, all are usually identified as among the most playful. These groups also have several complex cognitive skills in common. There is growing agreement that play has evolved multiple times under different selective pressures in different lineages. As these groups appear similar in their complex play but are separated by considerable evolutionary distance, the similarity is unlikely to result from homology. Far more probable is that the similarity has arisen from convergent or parallel evolution. It is important to conduct comparative ontogenetic play studies on these groups to learn more about what basic processes underlie complex play and whether such play is, indeed, related to complex cognition. Toward that end, we explored the play behavior of raven nestlings over the last ten days before they fledged. We found high levels of play both in terms of instances initiated and duration. The play behaviors were at level with -or above -maintenance behaviors and flight training. Most of the play was object play, but social object play and apparent play contagion was also recorded. The importance of play in developing young ravens is clear. The reasons might be less clear, however play could underlie both object-related and social development.