The SECRETARYBIRD or SECRETARY BIRD (Sagittarius serpentarius) is a
very large, mostly terrestrial bird of prey . Endemic to
* 1 Taxonomy * 2 Etymology * 3 Description * 4 Distribution and habitat
* 5 Behaviour and ecology
* 5.1 Diet * 5.2 Breeding * 5.3 Stomping * 5.4 In captivity
* 6 Relationship with humans
* 6.1 Cultural significance * 6.2 Threats
* 7 See also * 8 References * 9 External links
In 1779 English illustrator
John Frederick Miller was the first
European to describe the 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
Though strongly convergent with the modern secretarybird, the extinct raptor 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 reptiles .
The secretarybird has distinct black feathers protruding from behind its head. The skull of secretarybird at Museum of Natural History at University of Wrocław
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 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
DISTRIBUTION AND HABITAT
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 consuming it.
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
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
Nests are built at a height of 5–7 m (16–23 ft) on
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 soon after.
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 efficiency.
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
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 65 stamps from about 30 countries are known,
including some from stamp-issuing entities such as
The young are preyed upon by crows , ravens , hornbills , large owls
and kites as they are vulnerable in
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