African Harrier-Hawk

About

The African Harrier-Hawk, also known as the Gymnogene, is a medium-sized raptor characterized by its distinctive grey plumage, black flight feathers, and a bare yellow or red facial patch. It is renowned for its unique foraging technique, which involves probing into crevices and cavities with its double-jointed tarsi to extract prey.

Size & lifespan

Length

60-66 cm

Wingspan

118-150 cm

Weight

600-950 g (males), 750-1000 g (females)

Lifespan

Up to 15-20 years in the wild

Diet

Carnivore (omnivorous tendencies)

Physical characteristics

Plumage

Adults have a grey head, neck, and breast, contrasting with black flight feathers and a black-barred white belly and undertail coverts. The tail is black with a single broad white band. The underwing coverts are grey, and the flight feathers are black with fine white barring on the primaries. Juveniles are brown overall, with a streaked breast and belly, and a brown-barred tail. Their bare facial skin is duller, often greyish-yellow.

Beak shape

Strong, hooked beak, dark grey to black with a yellow cere.

Eye color

Dark brown.

Leg color

Bright yellow, with unique double-jointed tarsi that allow for extreme flexibility.

Distinguishing features

The most distinctive feature is the bare facial skin, which is yellow in non-breeding adults and turns bright red during the breeding season. The double-jointed tarsi are also unique among raptors, allowing it to bend its legs forward and backward at the 'knee' (intertarsal joint) to reach into tight spaces.

Juvenile appearance

Juveniles are entirely brown, with a streaked breast and belly, and a brown-barred tail. The bare facial skin is duller, often greyish-yellow, and gradually changes to adult coloration over 2-3 years.

Seasonal changes

The bare facial skin changes color seasonally, from yellow in non-breeding adults to bright red during the breeding season, indicating reproductive readiness.

Sexual dimorphism

Females are generally larger and heavier than males, but plumage is identical.

How to identify

1. 1

   Plumage

   Look for the distinctive grey head, neck, and breast, contrasting with black flight feathers and a black-barred white belly. The black tail with a single broad white band is also a key feature.

2. 2

   Facial Patch

   The bare facial skin, yellow in non-breeding adults and bright red in breeding individuals, is a unique and highly visible identification mark.

3. 3

   Legs and Feet

   Observe its foraging behavior. If you see a raptor probing into crevices or hanging upside down with highly flexible yellow legs, it's almost certainly an African Harrier-Hawk.

4. 4

   Flight Style

   Note its slow, deliberate flight with deep wing beats, often soaring with wings in a slight dihedral. It can also be seen performing agile maneuvers around trees.

5. 5

   Vocalization

   Listen for its characteristic mournful 'wheee-oh' call, especially during the breeding season.

Habitat & range

Biomes

Forests, woodlands, savannas, riparian zones, cultivated areas, and even urban environments with suitable trees.

Geographic range

Widespread across sub-Saharan Africa, from Senegal and Gambia east to Ethiopia and south to South Africa.

Elevation range

Sea level up to 3,000 meters, though most common below 2,000 meters.

Preferred environments

Prefers areas with a mix of tall trees for nesting and roosting, and open areas or rocky outcrops for foraging. Often found near human habitation, especially where exotic trees like Eucalyptus or pines are present.

Behavior

Activity time

Diurnal, active during daylight hours.

Feeding habits

Highly opportunistic and versatile. Its unique double-jointed legs allow it to probe into tree holes, rock crevices, and even bird nests to extract prey. Diet includes small mammals (rodents, bats), birds (especially nestlings and eggs), reptiles (lizards, snakes), amphibians, large insects, and occasionally fruit (especially oil palm nuts). It is known to hang upside down or cling to tree trunks while foraging.

Social behavior

Generally solitary or found in pairs. Pairs maintain territories year-round. Not typically seen in large flocks.

Flight pattern

Often soars on thermals with wings held in a slight dihedral. Flight is typically slow and deliberate, with deep, powerful wing beats. It can also perform agile, acrobatic flights when hunting or displaying.

Migration pattern

Mostly resident throughout its range, with some local movements in response to food availability or breeding cycles. No significant long-distance migration.

Territoriality

Pairs are territorial, especially around nesting sites, and will defend their area from other raptors.

Breeding & reproduction

Breeding season

Varies geographically, typically coinciding with the dry season or early wet season. For example, August-November in southern Africa, and October-January in West Africa.

Nesting habits

Builds a large stick nest, often lined with green leaves, in the fork of a tall tree (often exotic species like Eucalyptus or pines) or on a cliff ledge. Both sexes contribute to nest building.

Clutch size

1-3 eggs (most commonly 2).

Egg description

Typically 1-3 eggs, usually 2. Eggs are dull white or pale bluish-white, sometimes faintly marked with reddish-brown spots.

Incubation period

Approximately 35-36 days, primarily by the female, with the male providing food.

Fledging period

Chicks fledge at around 45-55 days, but remain dependent on parents for several weeks to months after leaving the nest.

Parental care

Both parents care for the young. The female incubates and broods, while the male provides most of the food during this period. After hatching, both parents hunt and feed the chicks.

Where to find

Field tips

1. Look for unique foraging behavior. Watch for raptors actively probing into tree holes, under bark, or into bird nests. This behavior is highly characteristic of the African Harrier-Hawk.
2. Scan tall trees and cliffs. They often perch conspicuously on tall trees or cliff edges, providing good viewing opportunities.
3. Listen for calls. Their distinctive calls can often lead you to their location, especially during the breeding season.
4. Check urban parks and gardens. In some areas, they are quite habituated to human presence and can be found in urban green spaces with mature trees.

Similar species

Quick facts

Unique Feature:

Double-jointed tarsi for probing into crevices.

Facial Skin Color:

Yellow (non-breeding) to bright red (breeding).

Diet Versatility:

Eats small vertebrates, insects, eggs, and even fruit.

Conservation Status:

Least Concern, indicating a stable and widespread population.

Fun facts

• The African Harrier-Hawk is one of the few raptors capable of bending its legs backward at the 'knee' (intertarsal joint), allowing it to reach deep into cavities for prey.
• Its scientific name 'Polyboroides' means 'like a Polyborus', referring to its resemblance to the caracaras (genus Polyborus), which also have bare facial skin.
• It is sometimes called the 'Gymnogene', derived from the Greek words 'gymnos' (naked) and 'genos' (cheek), referring to its bare facial patch.
• African Harrier-Hawks have been observed raiding weaver bird nests, tearing them open to extract eggs and chicks.

Scientific classification

Kingdom

Animalia

Phylum

Chordata

Class

Aves

Order

Accipitriformes

Family

Accipitridae

Genus

Polyboroides

Species

Polyboroides typus

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