Harteman Wildfowl, presented by Jan Harteman
The yellow-billed teal, Anas flavirostris, is a South American species of duck. Like other teals, it belongs to the diverse genus Anas; more precisely it is one of the "true" teals of subgenus Nettion. It occurs in Argentina, the Falkland Islands, Chile, Peru, Bolivia, Uruguay, and Brazil. It has also established itself in South Georgia, where it was first recorded breeding in 1971. It inhabits freshwater wetlands, preferring palustrine habitat to rivers.
Mitochondrial DNA sequence data is most similar to that of the very different-looking green-winged teal. Apart from the mystifying relationship with the red-and-green-headed teals, it altogether most resembles the Indian Ocean radiation of teals. However, the yellow-billed teal's unicolored underside and namesake bill are unique, as is to be expected from a species that evolved half a world apart from Bernier's or the grey teal.
This species is also unique among its relatives in some aspects of its post-copulation behavior: After dismounting, the drakes stretch themselves up high and swim around and alongside the females.
Traditionally, there are 2 subspecies:
Previously, this species and the Andean teal formed the superspecies speckled teal, but increasingly taxonomists consider the two species distinct. Anas flavirostris (Sibley and Monroe 1990, 1993; Stotz et al. 1996) has been split into Anas flavirostris and Anas andium (Andean teal) by SACC (2008).
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). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to 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 (IUCN, 2013).
The population size has not been quantified, but it is not believed to 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).
Above: female Chilean teal, Anas flavirostris flavirostris
Above: a pair of Chilean teal, Anas flavirostris flavirostris (male left)
Above: male Chilean teal, Anas flavirostris flavirostris
Above: male Sharp-winged teal, Anas flavirostris oxyptera
Above: Chilean teal, Anas flavirostris flavirostris, in aviculture