Like any biological trait, cognitive characteristics may vary widely across species. A fundamental task for comparative psychologists and cognitive ethologists (see Griffin, 1981) is to describe these characteristics for any species of interest. The goals of the description are to understand the general and specific structures and processes of cognition, the dimensions of cognition, its continuities and discontinuities across species, how the described cognitive characteristics for given species may relate to the ecological and social pressures of that species’ natural world, and what pressures may select for the evolution of particular cognitive traits.