Tony Heald / Martial eagle (Polemaetus bellicosus) perched on branch, looking back, Kruger National Park, South Africa. Endangered.

Joel Sartore / Photo Ark / African hawk-eagle (Aquila spilogaster) close up of head, Zoopark Zajezd. Captive.

Joel Sartore / Photo Ark / Philippine hawk eagle (Nisaetus philippensis) close up of head looking around, Eltoro Zoo, Philippines. Captive.

Joel Sartore / Photo Ark / Ornate hawk eagle (Spizaetus ornatus vicarious) close up moving head around to look at camera. Captive.

Ben Cranke / Blyth's hawk-eagle (Nisaetus alboniger) Sabah, Malaysian Borneo