Linking plumage dimorphism and environmental stress

Besides the importance of pigmentation in species recognition, pigments protect body against different biotic and abiotic features. Melanin, dark coloration skin, hairs, feathers, is necessary for protecting from UV radiation. On other hand, lighter a surface is, more solar radiation reflected. Based on these arguments, it possible that pigment distribution would not be same among all regions unicolored individual due to amount exposure. Therefore, three Egretta genus (E. dimorpha, E. gularis, garzetta) which individuals are unicolored, two dichromatic (dark grey/black white), were selected as model studies. We hypothesized within white Egrets, foraging standing postures, exposed sun (like back breast) darker or whiter compared (vent tail), respectively. Visual wavelength reflections five (breast, back, belly, vent, tail) 186 museum specimens measured indicate concentration each region. Reflectance was using Kruschke’s ‘BEST’ (Bayesian Estimation Supersedes t test) framework create Bayesian analogues paired t-test. The results show, regardless species, (back followed by comparison regions. our hypothesis similar supported.