Christophe Courteau / Black and white Casqued hornbill (Bycanistes subcylindricus) up in tree, Kibale NP, Uganda.

Anup Shah / Black-and-white casqued hornbill (Ceratogymna subcylindricus subquadratus) male sitting in a Bottle Brush tree. Kakamega Forest South, Western Province, Kenya.

Chien Lee / Grey-cheeked Hornbill (Bycanistes subcylindricus) female, Kibale National Reserve, Uganda

Winfried Wisniewski / Grey-cheeked Hornbill (Bycanistes subcylindricus) calling, Masai Mara, Kenya

Joel Sartore / Photo Ark / Black-and-white-casqued hornbill (Bycanistes subcylindricus subquadratus) female looking around with its beak open, Vogelpark Turnersee, St. Primus. Captive.