The secretarybird or secretary bird (Sagittarius serpentarius) is a
very large, mostly terrestrial bird of prey. Endemic to Africa, it is
usually found in the open grasslands and savannah of the sub-Saharan
region. Although a member of the order Accipitriformes, which also
includes many other diurnal raptors such as kites, hawks, vultures,
and harriers, it is given its own family, Sagittariidae.
It appears on the coats of arms of
Sudan and South Africa.
4 Distribution and habitat
5 Behaviour and ecology
5.4 In captivity
6 Relationship with humans
6.1 Cultural significance
7 See also
9 External links
In 1769 Vosmaer was the first European to describe the
in one of the pamphlets later collected as his Regnum Animale, naming
it Sagittarius for its gait which was thought to resemble an archer's.
He also mentioned that it was known as the Secretarius by farmers at
Cape of Good Hope
Cape of Good Hope who had domesticated it to combat pests around
homesteads. In 1779 English illustrator
John Frederick Miller
John Frederick Miller also
described it as secretarybird, and it was soon after assigned to
its own genus Sagittarius by French naturalist
Johann Hermann in his
Tabula Affinitatum Animalium. It was not until 1935 that the
species was moved to its own family, distinct from all other birds of
prey—a classification confirmed by molecular systematics. Recent
cladistic analysis has shown Sagittariidae to be an older branch of
the diurnal birds of prey than
Accipitridae and Falconidae, but a
younger divergence than Cathartidae. Sometimes, the enigmatic bird
Eremopezus is classified as an early relative of the secretarybird,
though this is uncertain as the bird is only known from a few
fragmentary body parts such as the legs. The earliest fossils
associated with the family are two species from the genus
Pelargopappus. The two species, from the
Oligocene and Miocene
respectively, were not discovered in
Africa but France. The feet in
these fossils are more like those of the Accipitridae; it is suggested
that these characteristics are primitive features within the family.
In spite of their age, it is not thought that the two species are
ancestral to the secretary bird.
Though strongly convergent with the modern secretarybird, the extinct
Apatosagittarius is thought to be an accipitrid.
Its common name is popularly thought to derive from the crest of long
quill-like feathers, lending the bird the appearance of a secretary
with quill pens tucked behind their ear, as was once common practice.
A more recent hypothesis is that "secretary" is borrowed from a French
corruption of the Arabic saqr-et-tair or "hunter-bird".
The generic name Sagittarius is Latin for "archer", perhaps likening
the secretary bird's "quills" to a quiver of arrows, and the specific
epithet serpentarius recalls the bird's skill as a hunter of
The secretarybird has distinct black feathers protruding from behind
The skull of secretarybird at Museum of Natural History at University
The secretary bird is instantly recognizable as a very large bird with
an eagle-like body on crane-like legs which increases the bird’s
height to as much as 1.3 m (4.3 ft) tall. This bird has an
eagle-like head with a hooked bill, but has rounded wings. Height
can range from 90 to 137 cm (35 to 54 in). Total length from
112 to 152 cm (44 to 60 in) and the wingspan is
191–220 cm (75–87 in). Body mass can range
from 2.3 to 5 kg (5.1 to 11.0 lb) with 20 birds from
Africa found to weigh an average of 4.02 kg
(8.9 lb). Other attempts to estimate the mean weight range
for secretary birds correspondingly lie between 3.5 and 4.2 kg
(7.7 and 9.3 lb). The tarsus of the secretary bird
averages 31 cm (12 in) and the tail is 57–85 cm
(22–33 in), both factor into making them both taller and longer
than any other species of raptor since these features are not as long
in any other living raptor. The neck is not especially long, and
can only be lowered down to the inter-tarsal joint, so birds reaching
down to the ground or drinking must stoop to do so.
From a distance or in flight it resembles a crane more than a bird of
prey. The tail has two elongated central feathers that extend beyond
the feet during flight, as well as long flat plumage creating a
Secretary bird flight feathers and thighs are
black, while most of the coverts are grey with some being white.
Sexes look similar to one another as the species exhibits very little
sexual dimorphism, although the male has longer head plumes and tail
feathers. Adults have a featherless red face as opposed to the yellow
facial skin of the young.
Distribution and habitat
Secretary birds are endemic to Sub-Saharan
Africa and are
non-migratory, though they may follow food sources. Their range
Somalia and south to the Cape of Good
Hope. These birds are also found at a variety of elevations, from
the coastal plains to the highlands.
Secretary birds prefer open
grasslands and savannas rather than forests and dense shrubbery which
may impede their cursorial existence. While the birds roost on the
Acacia trees at night, they spend much of the day on the ground,
returning to roosting sites just before dark.
Behaviour and ecology
Unlike most birds of prey, the secretary bird is largely terrestrial,
hunting its prey on foot. Adults hunt in pairs and sometimes as loose
familial flocks, stalking through the habitat with long strides.
Prey may consist of insects, mammals ranging in size from mice to
hares and mongoose, crabs, lizards, snakes, tortoises, small birds,
bird eggs, and sometimes dead animals killed in grass or bush fires.
Larger herbivores are not generally hunted, although there are some
reports of secretary birds killing young gazelles and cheetah
cubs. The importance of snakes in the diet has been exaggerated in
the past, although they can be locally important and venomous species
such as adders and cobras are regularly among the types of snake
preyed upon. Secretarybirds are kept as pest controllers by
farmers to rid of snakes.
In Namib-Naukluft National Park, Namibia
Prey is often flushed out of tall grass by the birds stomping on the
surrounding vegetation. It also waits near fires, eating anything it
can that is trying to escape. They can either catch prey by chasing it
and striking with the bill and swallowing (usually with small prey),
or stamping on prey until it is rendered stunned or unconscious enough
to swallow. Larger or dangerous prey, such as venomous snakes, are
instead stunned or killed by the bird jumping onto their backs, at
which point they will try to snap their necks or backs. There are some
reports that, when capturing snakes, the secretary birds will take
flight with their prey and then drop them to their death, although
this has not been verified. Even with larger prey, food is generally
swallowed whole through the birds' considerable gape. Occasionally,
like other raptors, they will tear apart prey with their feet before
Young are fed liquefied and regurgitated insects directly by the male
or female parent and are eventually weaned to small mammals and
reptile fragments regurgitated onto the nest itself. The above
foodstuffs are originally stored in the crop of the adults.
The secretarybird has a relatively short digestive tract in comparison
to other large African birds such as the kori bustard. As the
foregut is specialized for digesting large amounts of meat in a short
amount of time, there is little need for the physical breakdown of
food within the digestive tract over extended time spans. The crop
of the secretarybird is dilated and the gizzard is nonmuscular in
comparison to other birds. The large intestine lacks a cecum as
there is little need for fermentative digestion of plant material.
In hunting and feeding on small animals and arthropods on the ground
and in tall grass or scrub, secretarybirds occupy an ecological niche
similar to that occupied by peafowl in South and Southeast Asia,
roadrunners in North and
Central America and seriemas in South
Captive secretarybird with two eggs in its nest.
Secretarybirds associate in monogamous pairs. During courtship, they
exhibit a nuptial display by soaring high with undulating flight
patterns and calling with guttural croaking. Males and females can
also perform a grounded display by chasing each other with their wings
up and back, much like the way they chase prey. They usually mate on
the ground, although some do so in
Acacia trees. Secretarybirds will
stay close to their mate even if their chick has already left.
Nests are built at a height of 5–7 m (16–23 ft) on
Acacia trees. Both the male and female visit the nest site for almost
half a year before egg laying takes place. The nest is around 2.5 m
(eight feet) wide and 30 cm (one foot) deep, and is constructed
as a relatively flat basin of sticks.
Secretary birds lay two to three oval, pale-green eggs over the course
of two to three days, although the third egg is most often
unfertilised. These eggs are incubated primarily by
the female for 45 days until they hatch. The secretarybirds are
facultatively fratricidal. There are conflicting opinions on this
phenomenon also called cainism—"No evidence [exists] of sibling
aggression, but youngest in brood of 3 almost always dies of
The downy young can feed autonomously after 40 days, although the
parents still feed the young after that time. Both the parents feed
the young. At 60 days, the young start to flap their wings, and by day
65–80 are able to fledge. Fledging is accomplished by jumping out of
the nest or using a semi-controlled fall via fervent wing flapping to
the ground. After this time, the young are quickly taught how to hunt
through expeditions with their parents and are considered independent
Secretarybirds specialize in stomping their prey until the prey is
killed or immobilized. This method of hunting is commonly applied
to lizards or snakes. An adult male trained to strike at a rubber
snake on a force plate was found to hit with a force equal to 5 times
its own body weight, with a contact period of only 10–15 ms. This
short time of contact suggests that the secretarybird relies on
superior visual targeting to determine the precise location of the
prey's head. Although little is known about its visual field, it is
assumed that it is large, frontal and binocular.
As secretarybirds are anatomically similar (but apparently not closely
related) to the extinct Phorusrhacidae, it has been hypothesized that
these birds may have employed a similar hunting technique.
Secretarybirds have unusually long legs (nearly twice as long as other
ground birds of the same body mass), which is thought to be an
adaptation for the bird’s unique stomping/striking hunting method.
However, these long limbs appear to also lower its running
The first successful rearing of a secretarybird in captivity occurred
in 1986 at the Oklahoma City Zoo. Although secretarybirds build their
nests in the trees in the wild, the captive birds at the Oklahoma City
Zoo built theirs on the ground, which left their eggs open to
depredation by local wild mammals. Therefore, zoo staff removed the
eggs from the nest each time they were laid to be incubated and
hatched at a safer location. The species now successfully breeds
in captivity around the world, including in the San Diego Zoo and
the Toronto Zoo.
Relationship with humans
The secretary bird has traditionally been admired in
Africa for its
striking appearance and ability to deal with pests and snakes.
Africans sometimes call it the Devil's Horse. As such it has often not
been disturbed, although this is changing as traditional observances
The secretary bird is the emblem of
Sudan as well as a prominent
feature on the coat of arms of South Africa.
In Sudan, it is featured in the middle white strip of the Presidential
Flag; it is the main object on the Presidential Seal, and features
heavily in Sudanese military insignia. The secretarybird on the
Presidential Flag and Seal has its head turned to the right, with its
distinctive crest clearly visible and its wings spread out with a
white banner between its outstretched wings reading "Victory Is Ours".
The secretary bird has been a common motif for African countries on
postage stamps: over a hundred stamps from 36 issuers are known,
including some from stamp-issuing entities such as Ajman, Manama, the
Maldives and the
United Nations where the bird does not exist.
The young are preyed upon by crows, ravens, hornbills, large owls and
kites as they are vulnerable in
Acacia tree tops, with no known
incidents of predation on adults. As a population, the
secretary bird is mainly threatened by loss of habitat and
deforestation. In 1968 the species became protected under the
Africa Convention on the Conservation of Nature and Natural
Resources. Loss of grassland to bush encroachment driven by rising
CO2 levels has also been implicated, as has a susceptibility to power
line collisions. Nevertheless, the species is still widespread
across Africa, and has adapted well to arable land where prey animals
such as rodents are more common than in traditional habitat. The
species is well represented in protected areas as well. They are
assessed as vulnerable by the IUCN due to a recent rapid decline
across their entire range.
Snake venom immunity
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for Conservation of Nature. Retrieved 26 November 2013.
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Secretarybird on ARKive
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Species text in The Atlas of Southern African Birds
Accipitridae (Buzzards, eagles, harriers, hawks, kites, and Old World