Читать книгу A Manual of Philippine Birds - Richard C. McGregor - Страница 231

 a1. Culmen, 115 mm. or more; crown uniform in color with the back.b1. Lower back and rump white or with streaks and spots of black; axillars pure white or with traces of dusky lines. arquatus (p. 115)b2. Lower back and rump brown; axillars white, broadly barred with blackish. cyanopus (p. 116)

 a2. Culmen, 90 mm. or less; crown blackish with a pale or whitish central vertical band. variegatus (p. 117)