PHYSICAL CHARACTERISTICS:

The Old world Comb Ducks have a black bill with a comb on two-thirds of it. The comb is so prominent that it can be seen even while the duck is in flight. The male comb duck has a wingspan that varies from 347 to 384mm and the females wingspan varies from 273 to 300mm. Males are about double the size of the female. During breeding season the males comb will become larger than normal. Females have a black bill but do not have a comb. Both sexes are generally black and white; the males back feathers are glossy green and white and the females tend to have more spotted heads. Both sexes have white underbellies.

Baby comb ducks have brown feathers on their heads and their upper bodies and their under-bellies are white. The area under their eyes is white and their wings are green.

DISTRIBUTION AND HABITAT:

Old World Comb Ducks enjoy grass savanna woodlands with lagoons or open water that are not close to humans. They range widely throughout sub-Saharan Africa; from Abu Simbal in Southern Egypt to Cape Town, South Africa and Madagascar.  It prefers lowland areas, but has been found at elevations as high as 3,505meters.

BEHAVIOR:

Old World Comb Ducks are able to cling to trees branches with their powerful nails. When migrating, they fly in irregular formations or in a V-formation and they make a loud swishing sound as their wings flap. They are often found alone or in small groups, but during the dry season they will sometimes gather in flocks of a hundred non-breeding birds; sometimes in sexually segregated groups.  They have also been known to associate with other water birds. Their call sounds like a short raspy whistle or a croak.  Different sounds may be made by different sexes. These ducks are mostly polygamous. Although they are generally polygamous, they will become monogamous when the population is small enough.

A drake might mate with two hens at the same time, which is called harem polygamy. Or the drake can mate with up to five different females in succession called successive polygamy. The drake will breed on the nesting grounds of the hens. Although the drake will protect its hens, it will not protect the hens nesting sights. Hens that have not mated during breeding season may try to join a group of ducks if the queen females accept them. Male Comb Ducks that do not have a mate will perch in trees watching the different groups swooping  down to mate with a hen. When this occurs the attending drake will attack the intruder, who usually flees. The fleeing male will continue to stay nearby waiting for another opportunity to mate another female. Comb Ducks are generally docile creatures, although the male can become aggressive when its young are threatened.  

DIET:

Comb Ducks will wade in shallow waters and graze on grass or aquatic vegetation. They will also eat seeds, invertebrates and small fish. They can also be pests to rice farmers.

female comb duck

REPRODUCTION AND GROWTH:

Old World Comb Ducks will only breed in the southern Africa during and after the rainy summer season between December and March. During years of little rain the ducks will not breed at all. The Old World Comb Duck roosts in hollow trees or stumps or on the ground in long grass. Their nests are lined with reeds or grass, with feathers or other fine material; however they do not use down to line their nest.

The female will lay four to eight eggs that are shiny yellow-white and are about 60 to 44mm in diameter. Females can work in-groups to create a "dump-nest", which can have up to 50 eggs. The hens will incubate their eggs for about 30 days and . After the eggs hatch the family is usually found in small flocks.

CONSERVATION STATUS:

The Old World Comb Duck is not often found in zoos or private collections because they are tropical birds that need warmth during winter months. They are generally peaceful birds and do well with other species. At the Honolulu Zoo, our male and female ducks live in the walk-in Manyara Bird Sanctuary with about 20 other species of birds.  The comb duck is not an endangered specie; however, populations in Neotropical areas has declined because of rice pesticides, deforestation, and hunting. Outside of Africa, the estimated popoulation of comb ducks is 40,000 in Venezuela and more than 20,000 ducks in Brazil.

SUGGESTED READING:

Gill, Leonard E. A First Guide to South African Birds. Cape Town, South Africa.; Maskew Miller Ltd, 1968.

Mackworth-praed, C.W. Birds of the Southern Third of Africa. Great Britain, London.; Longmans, 1962.

INTERESTING WEB SITES:

Comb Duck. Frank S. Todd. 1996. www.virtualbirder.com/vbirder/ibis/CODU/CODU185.html 

Comb Duck. Dan Cowell. www.hartman.nl/omnibus/anseriformes/ducks/comb.html 

(Mahalo to Leeward Community College's Zoology 101 Class for their contribution)