Hamerkop

Hamerkop

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Description

The Hamerkop has a long heavy bill, balanced by a backwards-facing crest. Hamerkop is the Africaans word for “hammerhead.” The feathers are a uniform brown color with a slightly purplish gloss on the back. The bill is black and appears thin and flattened from the front. The hamerkop stands about 56 cm (about 22 inches) tall and weighs about 470 g (about a pound). The wings are broad and rounded, similar to an owl’s.

It is not possible to talk about the Hamerkop without describing the nest. The Hamerkop is a compulsive nest builder; a nest is built during breeding season, but new nests or additions to old nests occur all year round. The nests are massive, often 2 meters (6 feet) high by 2 meters wide and up to 100 times the bird’s weight. It can have up to 8000 pieces and takes 3 to 6 weeks to complete. It starts as a stick platform, then sticks are woven together with mud to form a rim. Finally, a dome roof is added to the top. The birds enter from a small hole in the bottom of the structure, and this tunnel and nesting cavity are plastered with mud.

Other birds such as the African pygmy goose and animals such as genets, mongoose, snakes, and monitor lizards, will use the hamerkops’ nest after they are finished with it. Scientists have studied the hamerkop nest building  behavior extensively, and are still not sure why they build such large or so many nests.

Classification

Class
Aves
Order
Pelecaniformes
Family
Scopidae
Genus
Scopus
Species
S. umbretta
Conservation Status
Least Concern

Key Facts

Height
~56 cm (22 inches)
Weight
~470 g (about a pound)

The IUCN Red List classifies Scopus umbretta as a species of Least Concern. The species is widespread and common throughout its range with a largely stable population.

Social Life
Hamerkops pair bond, but pairs can be part of a larger groups containing up to 50 birds. They do not migrate. While in groups they can be very vocal, making a variety of loud, nasal cackles. Hamerkops are diurnal, but are not active during the heat of the day.

Habitat and Range
Found throughout sub-Saharan Africa, Madagascar, and parts of the Arabian peninsula. Inhabits many wetland types including rivers, lakes, estuaries, marshes, and irrigated farmland. In Tanzania it is known to feed on rocky shores. They prefer trees for nesting, but will nest on cliffs.

Diet
Amphibians, small fish, crustaceans, insects, worms, and small mammals. They usually wade in shallow water to find prey.

Lifespan
About 20 years.

Predators
Monitor lizards and snakes often prey on the eggs and chicks.

Reproduction
Both males and females build the nest and incubate the eggs.
Sexual Maturity: Unknown.
Mating Season: They breed year round in East Africa; elsewhere mostly late rains or dry season.
Incubation: 28-32 days; chicks fledge at 44-50 days.
No. of Young: The number of chicks is variable. The female lays 3-7 eggs. Both parents raise the young. Chicks will return to the nest for about two weeks after their first flight.

Information

Description

The Hamerkop has a long heavy bill, balanced by a backwards-facing crest. Hamerkop is the Africaans word for “hammerhead.” The feathers are a uniform brown color with a slightly purplish gloss on the back. The bill is black and appears thin and flattened from the front. The hamerkop stands about 56 cm (about 22 inches) tall and weighs about 470 g (about a pound). The wings are broad and rounded, similar to an owl’s.

It is not possible to talk about the Hamerkop without describing the nest. The Hamerkop is a compulsive nest builder; a nest is built during breeding season, but new nests or additions to old nests occur all year round. The nests are massive, often 2 meters (6 feet) high by 2 meters wide and up to 100 times the bird’s weight. It can have up to 8000 pieces and takes 3 to 6 weeks to complete. It starts as a stick platform, then sticks are woven together with mud to form a rim. Finally, a dome roof is added to the top. The birds enter from a small hole in the bottom of the structure, and this tunnel and nesting cavity are plastered with mud.

Other birds such as the African pygmy goose and animals such as genets, mongoose, snakes, and monitor lizards, will use the hamerkops’ nest after they are finished with it. Scientists have studied the hamerkop nest building  behavior extensively, and are still not sure why they build such large or so many nests.

Classification

Class
Aves
Order
Pelecaniformes
Family
Scopidae
Genus
Scopus
Species
S. umbretta
Conservation Status
Least Concern

Key Facts

Height
~56 cm (22 inches)
Weight
~470 g (about a pound)

The IUCN Red List classifies Scopus umbretta as a species of Least Concern. The species is widespread and common throughout its range with a largely stable population.

Social Life
Hamerkops pair bond, but pairs can be part of a larger groups containing up to 50 birds. They do not migrate. While in groups they can be very vocal, making a variety of loud, nasal cackles. Hamerkops are diurnal, but are not active during the heat of the day.

Habitat and Range
Found throughout sub-Saharan Africa, Madagascar, and parts of the Arabian peninsula. Inhabits many wetland types including rivers, lakes, estuaries, marshes, and irrigated farmland. In Tanzania it is known to feed on rocky shores. They prefer trees for nesting, but will nest on cliffs.

Diet
Amphibians, small fish, crustaceans, insects, worms, and small mammals. They usually wade in shallow water to find prey.

Lifespan
About 20 years.

Predators
Monitor lizards and snakes often prey on the eggs and chicks.

Reproduction
Both males and females build the nest and incubate the eggs.
Sexual Maturity: Unknown.
Mating Season: They breed year round in East Africa; elsewhere mostly late rains or dry season.
Incubation: 28-32 days; chicks fledge at 44-50 days.
No. of Young: The number of chicks is variable. The female lays 3-7 eggs. Both parents raise the young. Chicks will return to the nest for about two weeks after their first flight.