Fischer G J, Morris G L, Ruhsam J P
J Comp Physiol Psychol. 1975 Jan;88(1):402-6. doi: 10.1037/h0076227.
Studies of color pecking preferences in newly hatched chicks (Gallus domesticus) have shown unimodal preference in the orange region of the spectrum or bimodal preferences at blue and orange. In the present study, dark-harched White Leghorn chicks were tested in darkness with targets illuminated at 1 or 3 radiant intensity levels. Results showed the least amount of pecking at green (541 nm.) and peak preferences in blue-violet and orange-red regions. Findings were similar when other dark-hatched chicks were tested in the light (Experiment 2). Overall, findings suggest unlearned pecking preferences for short and long wavelengths, with minimums at green. Possible evolutionary and photochemical bases for such a bimodal wavelength preference function were discussed. Since bimodality was unaffected by target intensity and background, these variables probably do not account for the unimodal function reported by others.
对新孵化出的小鸡（家鸡）的颜色啄食偏好研究表明，它们对光谱中的橙色区域有单峰偏好，或者对蓝色和橙色有双峰偏好。在本研究中，将深色孵化的白来航鸡雏鸡置于黑暗中，用1或3个辐射强度水平照亮目标进行测试。结果显示，绿色（541纳米）处的啄食量最少，在蓝紫色和橙红色区域有峰值偏好。当其他深色孵化的雏鸡在光照下进行测试时（实验2），结果相似。总体而言，研究结果表明，雏鸡对短波长和长波长有先天的啄食偏好，绿色处最少。讨论了这种双峰波长偏好函数可能的进化和光化学基础。由于双峰性不受目标强度和背景的影响，这些变量可能无法解释其他人报告的单峰函数。
