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Circaetus pectoralis (Black-chested snake-eagle, Black-breasted snake eagle)

Swartborsslangarend [Afrikaans]; uKhozi (generic term for eagle) [Zulu]; Xithaklongwa [Tsonga]; Circačte ą poitrine noire [French]; Schwarzbrust-schlangenadler [German]; Įguia-cobreira-de-peito-preto [Portuguese]

Life > Eukaryotes > Opisthokonta > Metazoa (animals) > Bilateria > Deuterostomia > Chordata > Craniata > Vertebrata (vertebrates)  > Gnathostomata (jawed vertebrates) > Teleostomi (teleost fish) > Osteichthyes (bony fish) > Class: Sarcopterygii (lobe-finned fish) > Stegocephalia (terrestrial vertebrates) > Tetrapoda (four-legged vertebrates) > Reptiliomorpha > Amniota > Reptilia (reptiles) > Romeriida > Diapsida > Archosauromorpha > Archosauria > Dinosauria (dinosaurs) > Saurischia > Theropoda (bipedal predatory dinosaurs) > Coelurosauria > Maniraptora > Aves (birds) > Order: Falconiformes > Family: Accipitridae > Genus: Circaetus

Circaetus pectoralis (Black-chested snake-eagle, Black-breasted snake eagle) Circaetus pectoralis (Black-chested snake-eagle, Black-breasted snake eagle)

Black-chested snake-eagle. [photo Johan van Rensburg ©]

Black-chested snake-eagle. [photo Johann du Preez ©]

Distribution and habitat

Occurs from Ethiopia and southern DRC to South Africa. In southern Africa it is uncommon to locally common across much of the region, largely excluding southern and central South Africa. It occupies a variety of habitats, ranging from semi desert and open grassland to Karoo scrub and closed deciduous woodland.

Distribution of Black-chested snake-eagle in southern Africa, based on statistical smoothing of the records from first SA Bird Atlas Project (© Animal Demography unit, University of Cape Town; smoothing by Birgit Erni and Francesca Little). Colours range from dark blue (most common) through to yellow (least common). See here for the latest distribution from the SABAP2.  

Movements and migrations

Mainly nomadic, although it may make regular movements to Namibia and the Northern Cape in summer.

Food 

It mainly eats snakes, soaring or hovering while scanning the ground for prey. It then descends in stages, until it finally plunges feet first onto the prey, to crush its skull. A snake may fight back if the snake-eagle misses, entwining itself with the bird, which occasionally results in the death of both snake and raptor. The following food items have been recorded in its diet:

Breeding

  • Probably a monogamous, territorial solitary nester.
  • The nest (see image below) is built by both sexes, consisting of a saucer-shaped structure of sticks, lined with green leaves and placed in the canopy of a flat-topped Acacia or large Euphorbia; it is often well-concealed by foliage or mistletoe. It may also utilise a pylon or utility pole, rarely using the same nest in multiple breeding seasons.
Circaetus pectoralis (Black-chested snake-eagle, Black-breasted snake eagle)  

Black-chested snake-eagle nest with chick, Nylsvley area, South Africa. [photo Warwick Tarboton ©]

 
  • Egg-laying season in South Africa is from June-August, while elsewhere in southern Africa it is from March-October, peaking from June-October.
  • It almost invariably lays a single egg, which is mainly incubated by the female for about 51-52 days.
  • The chick is brooded and fed by the female, with food provided by the male. Parental care is most intense in the first 25 days of the chick's life, after which the adults visit the nest more intermittently. It eventually leaves the nest at about 90-113 days old, usually becoming fully independent six months later, although in rare cases it can stay with its parents for roughly 18 months after fledging.

Threats

Not threatened.

References

  • Hockey PAR, Dean WRJ and Ryan PG 2005. Roberts - Birds of southern Africa, VIIth ed. The Trustees of the John Voelcker Bird Book Fund, Cape Town.