Tadorna cana (South African shelduck)

Kopereend [Afrikaans]; Lefaloa (also applied to Egyptian goose) [South Sotho]; Grijskopcascara, Kaapse casarca [Dutch]; Tadorne à tête grise [French]; Graukopf-rostgans [German]; Tadorna-africana [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: Anseriformes > Family: Anatidae

South African shelduck male, West Coast National Park, South Africa. [photo Trevor Hardaker ©]	South African shelduck male, Vrolijkheid Nature Reserve, South Africa. [photo Trevor Hardaker ©]
South African shelduck female (left) and male (right), Kopereend, near Potchefstroom, South Africa. [photo Peet van Schalkwyk ©, see also scienceanimations.com]

Predominantly light chestnut coloured with a grey head in the male and a grey head with variable amounts of white in the female. Endemic to southern Africa, found mainly on waterbodies in semi-arid and grassland regions. Feeds in the water on aquatic invertebrates and algae, and on land on grain in crop fields. 

Records 

Distribution and habitat

Endemic to southern Africa where it is found mainly in Western Cape, Northern Cape, Free State, North West Province, Gauteng, Namibia, south-eastern Botswana and southern KwaZulu-Natal. Prefers waterbodies with shallow waters and exposed muddy shorelines, with low grassy or scrubby vegetation round the perimeter. Distribution is also partly influenced by its highly specialised nest site preference in vacated holes of aardvark and other mammals that make large holes. As a result of these habitat requirements it is mainly found on water bodies in semi-arid and grassland regions. Its distribution is almost the direct opposite of the Comb duck, which prefers tree-lined pans, lakes and rivers. 

Call

Recorded by June Stannard, 1966, [© Transvaal Museum]

Predators and parasites

• Predators (of chicks)
  • Pelomedusa subrufa (Marsh terrapin)
• Pathogens
  • Clostridium botulinum (Type C) causing botulism

Food

Feeds both on land (mainly crop fields) and in the water. Omnivorous with either animal or plant matter predominating in the diet. The following food items have been recorded in its diet:

• Aquatic invertebrates:
  • Crustacea 
    • Branchiopoda > Phyllopoda
    • Notostraca > Apus numidicus
    • Conchostraca > Caenestheriella
  • Tendipedidae larvae and pupae
• Algae:
  • Spirogyra
  • Lagarosiphon
• Grain in crop fields:
  • maize
  • sorghum
  • wheat

Breeding

• Forms breeding pairs, which are territorial in the breeding season. Pair bonds are thought to persist over more than one season.
• The nest is made by the female in a pre-existing cavity in the ground, most typically in an Aardvark (Orycteropus afer) burrow (one nest was at the end of a 9 m long tunnel), but can also be in holes of Springhares (Pedetes capensis) and porcupines (Hystrix africaeaustralis). They have also been known to nest among rocks and in a haystack. Other than helping to hide away the nest (especially useful because the the sparse vegetation surrounding the water bodies they like inhabiting), nesting in burrows also helps to avoid the high temperatures encountered in the semi-arid conditions above. 
• Breeding season is from March to December, peaking from June to September. 
• The female lays 6-15 eggs (usually 7-11) and the incubation period (probably starting after clutch completion) is probably for about 30 days (it has not been measured). Only the female incubates the eggs while the male protects the territory by hissing loudly to inform the female of potential predators.
• Both parents care for the young and drive off any animals that vaguely look threatening - even herons and cormorants. Young are able to fly by 70 days old and they leave the adults from 90-120 days old. 

Threats

Distribution has expanded (e.g. into Namibia and south-eastern Botswana) as a result of the construction of articificial waterbodies such as farm dams. 

References

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