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Polyboroides typus (African
harrier-hawk, Gymnogene)
Kaalwangvalk [Afrikaans]; Seitlhoaeleli (also applied to
Pallid harrier) [South Sotho]; Kaalkopkiekendief [Dutch]; Gymnogène
d'Afrique [French]; Schlangensperber, Höhlenweihe [German];
Secretário-pequeno [Portuguese]
Life
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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: Polyboroides
Distribution and habitat
Occurs across much of sub-Saharan Africa; in southern
Africa it is locally common in Zimbabwe,
Mozambique, northern and eastern Botswana, northern Namibia (including the Caprivi Strip) and eastern and southern South Africa. It generally prefers
savanna woodland, such as Acacia, miombo (Brachystegia) and
mixed-species woodland, as well as forest edges, wooded cliffs, ravines and
other rocky habitats, tall trees along drainage lines, Eucalyptus
plantations and tall trees in gardens.
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Distribution of African harrier hawk 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
Nomadic in the arid parts of it distribution
but largely resident in the moist woodland of the east. It is most
common in the west in the period from March-April, suggesting that
it might make a west to east migration.
Food
It mainly eats birds and their eggs, reptiles and small
mammals, using a wide variety of foraging techniques. It specialises in using
its long legs to extract food from crevices and cavities, such as in the tree
canopy or the ground, often stealing eggs and chicks from weaver nests, or
the more easily accessible nests of other birds (without entrance tunnels). It
also hunts by soaring high in the sky and rapidly descending once it has spotted
prey, sometimes scavenging for roadkills and raiding nests in suburban gardens. The following food items have been recorded
in its diet:
- Animals
- birds
- eggs and nestlings
- adults
- mammals
- reptiles
- frogs
- stranded fish
- carrion
- Plants
- pulps of Elaeis guineensis (Oil palm) fruit
Breeding
- Usually a monogamous, highly territorial solitary nester, although three
adults were once recorded at one nest.
- The nest is built by both sexes in about 30 days, consisting of a
platform about 75 cm wide and 20 cm deep, made of sticks and thickly lined
with green leaves. It is typically placed in the upper branches of a tree,
in a cave or between the base of a bush and a cliff; it also uses the nests
of other birds, such as Black
Sparrowhawk and Martial Eagle.
- Egg-laying season is from August-December, peaking from
September-November.
- It lays 1-3 eggs which are mainly incubated by the female for about
35-36 days, while the male provides food to her at the nest.
- The chicks are fed by the male and brooded constantly by the female for
the first week of their lives, after which she remains near the nest to
protect them. The older chick sometimes kills its younger sibling, even if
it is fully fed and supervised by an adult. The young leave the nest at
about 45-55 days old, remaining partially dependent on their parents for at
least another 10 days.
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.
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