Secretarybird (Sagittarius serpentarius)

Also known as: secretary bird
  
French: Serpentaire
KingdomAnimalia
PhylumChordata
ClassAves
OrderFalconiformes
FamilySagittariidae
GenusSagittarius (1)
SizeHeight: c. 1.2 m (2)
Top facts

The secretarybird is classified as Vulnerable (VU) on the IUCN Red List (1), and listed on Appendix II of CITES (3).

A large and distinctive bird of prey, the secretarybird (Sagittarius serpentarius) is said to take its unusual name from the strange and distinguishing arrangement of feathers on the back of its neck. This long, raised crest of black, spatula-shaped feathers (2) (4) (5) is said to give the secretarybird the appearance of an old-fashioned secretary who would carry quill-pens tucked behind the ears. More recently, the case has been put forward that the name may actually be derived from the Arabic saqr-et-tair. Saqr means ‘hunter’ or ‘hawk’ and tair means ‘flight’ or ‘bird’, and the translation to French may have resulted in the common name that is used today (2) (5).

Unique not only for its name, the secretarybird stands out because of its distinct profile, quite unlike that of any other bird. The feathers on the body are generally grey across the back and paler towards the rump and breast, while the belly, thighs and flight feathers are all black. The underwings are white. The eyes are brown and are surrounded by bare facial skin that is a deep orange-red, and the bill is blue-grey.

The secretarybird also has long, bare legs, which resemble those of a crane but are much more powerful, and end in small, stubby pink toes. Juvenile secretarybirds are very similar to the adult, but are grey-eyed, with more brown in the plumage, a shorter tail and a yellow face, until the first moult (2) (4) (5) (6).

The secretarybird has a widespread distribution throughout much of sub-Saharan Africa, from Senegal and The Gambia in the west across to Ethiopia in the east, and extending southwards through the eastern African countries into South Africa. A fairly nomadic species, the secretarybird will often travel widely in search of food, or in response to rainfall, fires and other changes in environmental conditions (2) (4) (5) (7).

Although usually found in grassland and open savanna scattered with small thorny trees, the secretarybird also inhabits farmland, particularly where cereals are grown, as well as semi-desert habitats and grassy, open clearings in forests and woodlands (2) (4) (5).

Sometimes described as Africa’s ‘marching eagle’, the secretarybird prefers to move around on foot, easily covering between 20 and 30 kilometres a day when hunting for food (2). It spends much of its time stalking across the open ground, periodically stopping and stamping the floor to strike prey, which it will usually crush underfoot or repeatedly kick, before swallowing whole (2) (4) (5). The secretarybird’s diet primarily consists of large insects and small mammals, mainly rodents. However, it will feed opportunistically on any animal it comes across on its wandering travels, including hares, mongooses, squirrels, snakes, lizards, amphibians, freshwater crabs, and birds up to the size of guineafowl, as well as their eggs. Secretarybirds have also been known to take domestic chickens when foraging in areas close to human habitation (2) (5).

The secretarybird breeds year-round, but with a distinct peak during the spring and summer months further south. Two to three broods are often reared in productive years after good rainfall (7). The secretarybird makes a nest out of sticks, creating a large platform on a flat-topped acacia tree or other thorny bush, and lining it with dry grass and other materials. It may also nest in non-thorny or exotic tree species if preferred nesting sites are not available.

Following a courtship that is performed in flight and includes pendulum displays and calling (5), the female secretarybird will lay a clutch of one to three eggs, which are incubated for around 42 to 46 days. The nestling period typically lasts between 65 to 106 days, with a post fledging-dependence period of 62 to 105 days. After this time the juvenile secretarybirds will leave the parental territory and range over long distances, displaying characteristic nomadic behaviour as immature birds (7).

Although its population is distributed over a vast area covering more than 15 million square kilometres, the secretarybird is generally in decline, and is thought to have completely disappeared from West Africa in the last 30 years (2) (5) (8). This species is increasingly threatened by the expansion of human populations, and the associated spread of cultivation and urbanisation (2) (8). On a smaller scale, some populations of the secretarybird are at risk from hunting and persecution, with several individuals found poisoned or injured in South Africa in recent years (5).

The secretarybird occurs within some protected areas (8), and in some places it has benefited from bush clearance and deforestation of woodlands to make way for agriculture (5) (8). The secretarybird is protected under the African Convention on the Conservation of Nature and Natural Resources, in the hope that the species will be protected by participating states from hunting, killing, capture or collection (9). It is also listed on Appendix II of the Convention on International Trade in Endangered Species (CITES), meaning that international trade in the species should be carefully monitored (3). These actions will hopefully act to safeguard populations of this unusual and charismatic bird of prey, although much will depend on the rate at which vital habitat across its range is lost to human development.

For more information on the secretarybird and other bird species:

Find out more about the secretarybird and other raptors:

Authenticated (25/10/10) by Dr Alan Kemp, retired Curator, Ditsong National Museum of Natural History (previously Transvaal Museum), and Research Associate, Percy FitzPatrick Institute of African Ornithology, University of Cape Town.
http://www.fitzpatrick.uct.ac.za/docs/alan.html

  1. IUCN Red List (June, 2011)
    http://www.iucnredlist.org/
  2. Ferguson-Lees, J., and Christie, D.A.(2001) Raptors of the World. Helm Identification Guides, A & C Black Publishers, London.
  3. CITES (July, 2010)
    http://www.cites.org
  4. Kemp, A., and Kemp, M. (1998) SASOL Birds of Prey of Africa and its Islands. New Holland, London.
  5. Steyn, P. (1982) Birds of Prey of Southern Africa. David Philip, Cape Town.
  6. Global Raptor Information Network. Species account: Secretarybird Sagittarius serpentarius (July, 2010)
    http://www.globalraptors.org
  7. Kemp, A. C. 1995. Aspects of the breeding and behaviour of the Secretarybird Sagittarius serpentarius near Pretoria, South Africa. Ostrich, 66: 61-68.
  8. BirdLife International (July, 2010)
    http://www.birdlife.org/datazone/speciesfactsheet.php?id=3562
  9. African Convention on the Conservation of Nature and Natural Resources (July, 2010)
    http://www.africa-union.org/root/au/Documents/Treaties/Text/Convention_Nature%20&%20Natural_Resources.pdf