Effects of monochromatic rearing on spectral discrimination learning and the peak shift in chicks.

Chicks were hatched and raised in white or monochromatic sodium (589 nm) light. They were trained on a 590 (+) vs. 580 (-) nm successive discrimination. The combined results of two experiments indicated that rearing illumination did not affect discrimination acquisition. All subjects given generalization tests after discrimination training exhibited peak shifts that were equivalent for the two rearing conditions. The peak shifts exhibited by the monochromatically reared subjects represent maximum responding to stimuli they had not previously seen. This result further confirms the notion that behavioral control by the spectral dimension in birds is organized independently of differential early experience on that dimension.