Serengeti National Park, Tanzania - The Secretary Bird, Sagittarius serpentarius, is a large, mostly terrestrial bird of prey. Endemic to Africa, it is usually found in the open grasslands and savannas of the sub-Sahara. Although a member of the order Falconiformes, which also includes many other diurnal raptors such as kites, buzzards, vultures, and harriers, it is so distinctive that it was given its own family, Sagittariidae.
The Secretary Bird is largely terrestrial, hunting its prey on foot, and other than the caracara (such as Polyborus plancus), is the only bird of prey to do so habitually. Adults hunt in pairs and sometimes as loose familial flocks, stalking through the habitat with long strides. Prey consists of insects, small mammals, lizards, snakes, young birds, bird eggs, and sometimes dead animals killed in brush fires. Larger herbivores are not hunted, although there are some reports of Secretary Birds killing young gazelles.
Secretary Birds have two distinct feeding strategies that are both executed on land. They can either catch prey by chasing it and striking with the bill, or stamping on prey until it is rendered stunned or unconscious enough to swallow. Studies of this latter strategy have helped construct the possible feeding mechanisms employed by dinosaur-like 'terror birds' that once walked the earth five million years ago.