Role of differential food treatment on hypothalamic NPY expression and migratory phenology of redheaded bunting (Emberiza bruniceps)

The present study explores the effect of differential food treatment on the migratory phenology of redheaded bunting (Emberiza bruniceps). Birds were divided into four groups (N = 10 each) on the basis of the food provided. Group I was fed with seeds of Setaria italica (kakuni), while group II was provided with protein-rich diet (combination of; 3 parts egg white and 1 part kakuni seeds). Likewise, group III birds received fat-rich food (i.e. 3 parts sesame seeds and 1 part kakuni seeds). Birds in group IV were provided with all three food items mentioned above separately. The experiment continued until the appearance of 7 cycles of zugunruhe. The results reveal a significant impact of food on locomotor activity and food intake behavior of birds, although the physiological response as demonstrated by a gain in body mass, fat score, and gonadal recrudescence was mainly influenced by the LHS. Besides the behavioral and physiological responses, the hypothalamic expression of neuropeptide Y (NPY) in infundibular complex (INc) was significantly high for group IV, highlighting the importance of "variety" in food intake. Thus, the present study suggests a significant role of food in influencing seasonal responses via hypothalamic NPY stimulation.