Domestication and stress effects on contrafreeloading and spatial learning performance in red jungle fowl (Gallus gallus) and White Leghorn layers.

White Leghorn layers (WL) show modified foraging strategies, compared to their ancestor, the red jungle fowl (RJF). Birds selected for high production may invest more resources into production traits and less in other biological processes. This may affect the capacity to adapt to new or variable environments. Thirty birds of each of RJF and WL were raised in a stressful environment (unpredictable light:dark schedule) and 30 control animals of each breed in similar pens, but on a 12:12h light:dark schedule. We studied the differences between breed and treatment with respect to contrafreeloading (CFL), spatial learning ability and the birds' behaviour in a T-maze. WL showed less CFL, were less cautious in the test arena and showed an impaired spatial learning ability compared with RJF in both test situations. Stress impaired spatial learning in both breeds, but stressed RJF showed a more active response to the test situation than non-stressed RJF, by starting to eat faster, while stressed WL prolonged their time to start eating compared to non-stressed WL.Our results may reflect different adaptive strategies, where RJF appear better adapted to an unpredictable environment.