Résumé
Cognitive processes such as perception, learning, memory, and decision making all have an important influence on behaviour and survival in free-living animals. Animals learn through experience and retain sensory information about their surroundings to make decisions about where to forage, where to find shelter or who to select as a mate. The environment in which a species lives plays a significant role in shaping their cognitive abilities, with some environmental factors having cascading effects upon cognition, and, ultimately, survival. Changes in cognition can occur through environmental pressures, such as predation or social competition, and have been considered as important factors in the evolution of cognition. However, the complexity inherent in the number of factors acting simultaneously in natural ecosystems, makes investigating the impact of any particular aspect or subset of the environment challenging. Additionally, factors can act at different levels of biological organization and across various time scales, from short-term physiological responses that affect cognitive processes to long-term evolutionary changes shaping cognitive development. In this review, we have attempted to summarise and integrate the knowledge we have gained in understanding the influence of environmental factors on cognitive processes in vertebrates across decades of animal behaviour research. We also address the challenges that researchers face when investigating environmental drivers of animal cognition. The information has been organised into broad categories relating to different abiotic environmental factors, as well as biotic factors, and complexity. We end with a discussion on the ways in which multiple stressors may influence cognition and the need to more deeply study this in a changing world.