 Despite having dark plumage in a tropical climate, frigatebirds have found ways not to overheat — particularly as they are exposed to full sunlight when on the nest. They ruffle feathers to lift them away from the skin and improve air circulation, and can extend and upturn their wings to expose the hot undersurface to the air and lose heat by evaporation and convection. Frigatebirds also place their heads in the shade of their wings, and males frequently flutter their gular pouches.
