A male sooty grouse displaying apteria (featherless patches of colored skin) to attract a mate. (842c612f-b4ac-40b8-9efb-fa3036eb5e3f).jpegApteria aphylla000004.jpgApteria aphylla kz01.jpgApteria aphylla kz02.jpgFlora Brasiliensis Volume Argumentum.djvuThe animals and man; an elementary textbook of zoology and human physiology (1911) (14598148040).jpg
