Secretary Bird (Sagittarius serpentarius): Facts and Diet

Appearance

Nothing else looks quite like a secretary bird. The body is pale blue-gray above and lighter gray below, with black flight feathers and black “trousers” of feathers on the upper legs. The lower legs are bare, long and pinkish gray, covered in tough scales.

The face is bare skin, bright orange-red in adults, around a hooked raptor’s bill and pale brown eyes with long lashes. At the back of the head grows a loose crest of long, dark feathers. When the bird is excited or hunting, the crest rises and fans out, which is the feature most often linked to its unusual name; see why it is called a secretary bird.

The tail is long and wedge-shaped, with two greatly lengthened central feathers that extend well beyond the feet in flight. Males and females look alike, although males tend to have longer tails and more head plumes. Young birds have a yellow face, browner plumage and a shorter tail.

Size: how big is a secretary bird?

The secretary bird is the tallest raptor on Earth, but most of that height is leg. Its lower leg bone (tarsus) averages about 31 cm (12 in), and its legs are nearly twice as long as those of other ground birds of the same weight.

For comparison, a female golden eagle can weigh more than a secretary bird while standing less than 1 m (3.3 ft) tall. The toes, by contrast, are short and stout, only about a fifth as long as an eagle’s. A secretary bird cannot grip prey or branches the way an eagle does; its feet are built for striking, not grasping.

Habitat and range

Secretary birds live only in Africa south of the Sahara, from Senegal and Gambia in the west to Sudan, Ethiopia and Somalia in the east, and south to the Western Cape of South Africa. They are generally not migratory, but they can be nomadic, following rain and the boom in insects and rodents that follows it.

Their ideal habitat is open country with short grass: savanna, grassland and the dry shrubland of South Africa’s Karoo. They prefer grass shorter than about 0.5 m (1 ft 8 in) and avoid areas where grass grows over 1 m (3 ft 3 in), because tall vegetation hides prey and slows them down. They also avoid forests, thick bush and true deserts. They occur from coastal plains to highlands, wherever scattered trees provide places to roost and nest. You can meet them alongside other grassland wildlife in our guide to African savanna animals.

Diet: what do secretary birds eat?

Secretary birds are carnivores with a broad menu. Insects such as grasshoppers, locusts and beetles are taken in large numbers, but small vertebrates usually make up most of the food by weight. Typical prey includes:

• Rodents such as mice, rats and gerbils, and young or adult hares
• Lizards, small tortoises and snakes, including adders and cobras
• Frogs, eggs and small birds such as larks and doves
• Scorpions, spiders, millipedes and freshwater crabs
• Occasionally larger animals such as mongooses or hedgehogs

The bird’s reputation as a snake specialist is exaggerated. Snakes can matter locally, but in most studies rodents, lizards and insects are eaten more often. Secretary birds do not normally eat carrion, although they will pick up animals killed by grass fires. Most prey is swallowed whole, and indigestible parts such as fur and insect shells are coughed up later as pellets.

How secretary birds hunt

Unlike almost every other bird of prey, the secretary bird hunts on foot. Pairs stride through the grass at about 2.5–3 km/h (1.6–1.9 mph), taking around 120 steps per minute, and they may walk long distances in a day. They often stamp on clumps of grass to flush hidden animals, and they gather at grass fires to catch insects and rodents fleeing the flames.

When prey appears, the bird runs after it with its wings half open and kills it with rapid, accurate kicks. A 2016 study of a trained captive male striking a rubber snake on a force plate measured kicks equal to about five times the bird’s own body weight, with each foot in contact with the target for only about 10–15 milliseconds. That speed means the bird must aim with its eyes rather than feel its way, and it is the reason the long legs, which keep the head and body well away from a biting snake, are so important. The full story is in how secretary birds hunt snakes.

Small items such as wasps are simply picked up with the bill. Larger prey may be held down with the feet and torn apart, as other raptors do.

Behavior and flight

Secretary birds live in pairs on large territories of around 50 km² (19 sq mi). Partners roost together in a tree at night, set out an hour or two after dawn, and often forage separately during the day while staying in sight of each other. Single birds are often young or unpaired males. Larger groups of up to 50 birds sometimes gather where food is plentiful, such as at a waterhole or during a locust outbreak.

Although they spend most of the day walking, they are capable fliers. Their flapping flight is slow and heavy, but they soar easily, using rising warm air (thermals) to climb as high as 3,800 m (12,500 ft). In flight they hold the neck stretched out like a stork, with the legs and long tail streaming behind.

Adults are mostly silent. They make a deep, croaking call during courtship, when greeting a partner and when threatening rivals, and pairs at the nest use softer clucks and whistles.

Reproduction and life cycle

Secretary birds are monogamous and can breed in any month, although nesting is most common late in the dry season. In courtship, pairs soar high in undulating display flights while calling, or chase each other on the ground with wings raised.

Both partners build the nest: a flat platform of sticks 1–1.5 m (3–5 ft) across, placed on top of a dense, thorny tree, often an acacia, between about 2.5 and 13 m (8–40 ft) above the ground. Pairs may reuse the same nest for years. The female lays one to three bluish-green or white eggs at intervals of two or three days.

Parents bring food in the crop and regurgitate it onto the nest floor before passing items to the chicks. In good years all three chicks can survive; when food is scarce, the youngest usually starve. Young birds often leave the nest by jumping or gliding down to the ground before they fly strongly. Chicks and eggs may be taken by crows, ravens, hornbills and large owls.

Lifespan

Secretary birds are thought to live about 10–15 years in the wild, and captive birds have reached about 19 years. Wild lifespans are poorly known, because few birds have been ringed and later found again. Adults have few natural enemies, although tawny eagles sometimes attack them to steal their prey.

Threats and conservation status

The secretary bird is listed as Endangered on the IUCN Red List, a status it has held since 2020 after earlier being classed as Vulnerable. Although its range is huge, the birds are thinly spread, and a 2016 estimate put the total population somewhere between about 6,700 and 67,000 individuals. Long-term monitoring in South Africa has shown declines across the country, even inside protected areas such as Kruger National Park.

The main threats are:

• Loss of open grassland to farming, roads, housing and plantations
• Overgrazing by livestock, which degrades grassland
• Bush encroachment, as woody plants and tall grass spread into once-open areas
• Collisions with power lines and fences, and drowning in steep-sided farm reservoirs
• Disturbance and, in some places, capture for trade or traditional medicine

Read more in is the secretary bird endangered? and in our list of endangered animals.

Myths and facts

Myth: secretary birds are immune to snake venom. There is no good evidence for this. The bird’s protection comes from its long, scaly legs, its speed and its accurate kicks, which keep it out of a snake’s reach.

Myth: secretary birds carry snakes high into the air and drop them. This story appears in older books, but it is based on unverified reports. Stamping on the ground is the hunting method that has actually been studied.

Fact: it has a family of its own. For a long time scientists were unsure where the secretary bird belonged. Genetic studies show it is an early branch related to hawks, eagles and ospreys, but distinct enough to be the only living member of the family Sagittariidae.

Relationship with people

Across Africa the secretary bird has long been admired for its looks and its usefulness in killing snakes and rodents, and in many areas it was traditionally left in peace. Farmers in South Africa once even kept tame birds around homesteads to control pests.

The bird is a national symbol in two countries. It stands at the center of the coat of arms of South Africa, adopted in 2000, with wings outstretched to represent growth and protection of the nation. It has also been the national emblem of Sudan since 1969. More than a hundred postage stamps from dozens of issuers have featured it, and a secretary bird plays a key role in the Oscar-winning animated film Flow (2024). Ancient Egyptian carvings from around 3200 BC suggest the species once lived farther north along the Nile than it does today.