Black-headed Duck (Heteronetta atricapilla)

Black-headed Duck

[order] ANSERIFORMES | [family] Anatidae | [latin] Heteronetta atricapilla | [authority] Merrem, 1841 | [UK] Black-headed Duck | [FR] Heteronette a tete noire | [DE] Kuckucksente | [ES] Pato Cabeza Negra (Arg, Bo, Uy), Pato Rinconero | [NL] Koekoekseend

Subspecies

Monotypic species

Genus

The Black-headed Duck (Heteronetta atricapilla) is a South American duck allied to the stiff-tailed ducks in the subfamily Oxyurinae of the family Anatidae. It is the only member of the genus Heteronetta. This is the most basal living member of its subfamily, and it lacks the stiff tail and swollen bill of its relatives. Overall much resembling a fairly typical diving duck, its plumage and other peculiarities give away that it is not a very close relative of these, but rather the product of convergent evolution in the ancestors of the stiff-tailed ducks

Physical charateristics

The Black-headed Duck has a distinctive shape: the wings are relatively short, contributing a long-bodied appearance, which is accentuated by the relatively long bill and flat crown. This duck is relatively unpatterned. The male is mostly dark brown with a black head; the bill is bluish, and has a red spot at the base during breeding. The female is dusky brown above; the underparts and sides to the face are paler brown, spotted or vermiculated with dusky.


wingspan min.: 0 cm wingspan max.: 0 cm
size min.: 35 cm size max.: 40 cm
incubation min.: 24 days incubation max.: 25 days
fledging min.: 0 days fledging max.: 0 days
broods: 1   eggs min.: 2  
      eggs max.: 6  

Range

South America : Southcentral. Found in central Chile (from Region Metropolitana de Santiago to Valdivia Province) and from central Paraguay south to central Argentina (northern portions of Buenos Aires and La Pampa provinces), including coastal portions of Uruguay and southernmost Brazil.

Habitat

Found in semi-permanent, freshwater marshes dominated by extensive stands of Scirpus californicus; outside the breeding season may be seen in lakes, roadside ditches and sometimes flooded fields.

Reproduction

Brood parasitic. The Black-headed Duck is the only precocial, brood parasitic species. Host species of the Black-headed Duck provide parental care for incubation only. Incubation period about 24-25 days; ducklings brooded by host at most 1 or 2 days before leaving the nest on their own. Captive female laid egg in nest of Rosy-billed Pochard (Netta peposaca) during 8m visit; early behavior of two nestlings seemingly quite different, one young ? hatched before host?s eggs ? was initially quite active climbing over host female and then left the female the next morning; second young ? hatched along with host?s young ? accompanied the host brood, but at increasing distance until it left on its own 4 days later. Three species are known to have reared this brood parasite: Rosy-billed Pochard Netta peposaca, Red-fronted Coot Fulica rufifrons, and Red-gartered Coot Fulica armillata.

Feeding habits

Little information. In an examination of 27 gizzards, seeds of Scirpus californicus were a major item in 20 gizzards, as were snails in 5 gizzards. Dives for food; dives for 3-14s with 2-12s for the rest at the surface between dive.

Video Black-headed Duck

httpv://www.youtube.com/watch?v=pwdn9K8JO6Q

copyright: Josep del Hoyo


Conservation

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
This species is unique among ducks in that it is an obligate brood parasite. In its interactions with its host species, Black-headed Ducks procure the services of incubation from the host; as a precocial species, parental care provided newly-hatched ducklings is minimal since Black-headed Duck young soon leave host broods.
Black-headed Duck status Least Concern

Migration

Partially migratory, although movements not well documented.

Distribution map

Black-headed Duck distribution range map

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