Domestic chickens solving mirror-mediated spatial location tasks uncovering their cognitive abilities.

The increasing demand on adapting modern livestock farming to higher animal welfare standards requires a thorough understanding of a species' cognitive abilities to determine their adaptability. With the chicken being the world's most numerous birds in animal production, it is mandatory to identify its cognitive abilities and limitations in order to meet its needs. We investigated if chickens are able to use and understand the reflective properties of a mirror that is the correlation of reflections of food rewards and their real location. In total, 18 female chickens of two different breeds were tested in a mirror-mediated spatial location task. Eleven out of eighteen hens solved the task successfully and thus, possibly exploited the correlation between the reflection in the mirror and the real food reward. We found differences on a breed and on the individual level, with different amounts of time needed learning the association of reward and mirror image. The results imply sophisticated cognitive abilities in chickens, assuming they may be able to understand how mirror images represent objects in the real environment, and to make use of it during foraging. The chicken's cognitive ability might lead to a new understanding and provision of animal welfare-compliant production environments.