Secretarybird (Sagittarius serpentarius)

Cover image of Secretarybird by Johan and Estelle van Rooyen – Kgalagadi Transfrontier Park, Northern Cape – BirdPix No. 230151

The Secretarybird belongs to its own family: Sagittariidae, but are closely related to diurnal raptors. The name ‘Secretarybird’ is derived from ‘Saqr-et-tair’, the arabic name for this species which means ‘hunter bird’.

Identification

The Secretarybird is a large, striking and unmistakeable species.

It is noticeably long-legged with bare pinkish-grey lower legs. The upper legs and lower belly are black. The rest of the underparts and the head are pale grey. The upper parts are mostly plain bluish grey with black flight feathers. There is a characteristic, dark-tipped, long erectile crest on the head. The bare facial skin is orange and the bill is horn-grey. The tail is elongated and grey with broad black bands and a white tip.

The sexes are very similar but males are larger with a longer crest and tail. Juveniles have duller, browner plumage, shorter tails and the bare facial skin is yellowish.

The Secretarybird is unlike any other species but superficially resembles Blue Crane from a distance. That species lacks any black colouration and has un-feathered upper legs.

Status and Distribution

The Secretarybird is an Afrotropical species occurring throughout the savanna regions of Africa. It avoids the Sahara desert of north Africa, the central and west African rain forest belt and the most arid parts of north-east Africa. It is widely distributed across Southern Africa.

The Secretarybird is considered locally fairly common to uncommon in southern Africa and is listed as Near-threatened due to decreases in some local populations. Overall, the current distribution of the Secretarybird is believed to reflect closely the historical range, and any changes are likely to be in abundance and not distributional.

Habitat

The Secretarybird is an inhabitant of open country, mainly savanna, open woodland, grassland, dry floodplains and Karoo shrublands. It prefers habitats with relatively short grass. Some man-made habitats are also used, such as airfields, grazing paddocks and fallow fields. The Secretarybird avoids mountain fynbos, forest, dense woodland and very rocky, hilly or mountainous areas.

Behaviour

Secretarybirds usually occur singly or in pairs, and occasionally in family groups of 3 to 4 birds. Groups of up to 50have been recorded at waterholes in arid areas. The Secretarybird is not known to undertake any regular seasonal movements, but is nomadic with increased local movements outside the breeding season. It is highly nomadic in low-rainfall areas.

Secretarybirds roost singly or in pairs, usually in the crown of a flat-topped thorn tree, and often roosts on the nest. Flies to roost 1-2 hr before dark and often only leaves the roost a couple hours after sunrise. They frequently enjoy a dustbath and drinks water regularly in arid areas. The Secretarybird is often active during the heat of the day, but sometimes rests in shade when it gets too hot.

They are well adapted to soaring which enables them to disperse widely and efficiently. Secretarybirds have to run to take off from the ground, usually by running into the prevailing wind with the wings open for balance and to increase lift.

Spends hours at a time striding across open veld in search of prey, occasionally stamping repeatedly in a small area to disturb or dislodge prey. Raises its wings in excitement and for balance when prey is sighted. All prey is captured on the ground, usually with the bill. Any prey that gets disturbed during stamping bouts is quickly dispatched with hard downward blows from the feet, which are equipped with short, strong toes and robust claws. Small prey items, such as insects or small tortoises, are swallowed whole. Larger prey items are secured with the feet and torn up with bill.

Consumes a wide variety of animal prey. Most prey items are small, favouring grasshoppers, locusts and lizards which usually form the bulk of the diet. Other commonly consumed, smallish prey items include amphibians, rodents and birds, including their young and eggs. Larger prey items include birds up to the size of francolins, mammals up to the size of hares and large snakes, including highly venomous species like puffadder and cobras.

Secretary birds are well equipped to deal with snakes, the long, bare legs are covered with tough armour-like scales to prevent injury or bites from its prey, and the upper legs are densely feathered to provide further protection. However, contrary to popular belief, snakes are not a staple and make up only a small percentage of the Secretarybird’s diet.

Some interesting prey items that have been recorded include Striped Polecat (Ictonyx striatus), Slender Mongoose (Herpestes sanguinea), and Southern African Hedgehog (Atelerix frontalis). Secretarybirds are often attracted to recently burnt areas to feed on animals displaced by the fire, but they do not eat carrion.

The Secretarybird breeds throughout southern Africa and in all months except during mid-winter in the winter-rainfall regions. They are territorial and maintain territories of 20-230 km² around nest, depending on habitat.

The nest is is a large, flat platform of sticks up to, 2.5m in diameter and about 50cm thick. Nests are usually sunk into the top of a dense, thorny tree or large bush making the nest difficult to see. The central bowl of the nest is lined with grass and sometimes with pieces of dried dung.

1 to 3 (usually 2) eggs are laid per clutch. As with most raptors, incubation starts before clutch completion, resulting in asynchronous hatching and chicks of different ages. The eggs are chalky white or pale greenish-blue. Incubation lasts for around 45 days and most incubation is performed by the female. The male provides for the female at this time by bring her food on the nest. The young are altricial and the nestling period lasts for up to 106 days during which time they are fed by both parents. Young chicks are fed by regurgitation but are presented with whole prey items as they get older. If 3 chicks hatch the youngest usually starves to death as it gets out-competed by its older siblings.

Young birds that have left the nest start hunting for themselves, but remain partly dependent on their parents for food for a further 3 months or so.

Further Resources

This species text is adapted from the first Southern African Bird Atlas Project (SABAP1), 1997.

The use of photographs by Anne Todd, Carel van der Merwe, Helen Badenhorst, Johan and Estelle van Rooyen, Josu Meléndez, Lance Robinson, Len de Beer, Stuart Shearer, Vaughan Jessnitz and Zenobia van Dyk is acknowledged.

Virtual Museum (BirdPix > Search VM > By Scientific or Common Name).

Other common names: Sekretarisvoël (Afrikaans); iNtungunono (Zulu); Ingxangxosi (Xhosa); Secretarisvogel (Dutch); Messager serpentaire, Messager sagittaire (French); Sekretär (German); Secretário (Portuguese).

Recommended citation format: Tippett RM 2023. Secretarybird Sagittarius serpentarius. Biodiversity and Development Institute. Available Online at https://thebdi.org/2024/01/13/secretarybird-sagittarius-serpentarius/

Bird identification, birding