Yellow-billed pintail

The yellow-billed pintail (Anas georgica) is a South American dabbling duck of the genus Anas with three described subspecies.

Yellow-billed pintail
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Anseriformes
Family: Anatidae
Genus: Anas
Species:
A. georgica
Binomial name
Anas georgica
Gmelin, 1789
Subspecies
Synonyms
  • Dafila georgica

Description

The yellow-billed pintail has a brown head and neck. The bill is yellow with a black tip and a black stripe down the middle. [2] The tail is brownish and pointed. The upper wing is grayish-brown, and the secondaries are blackish-green. The rest of the body is buffish brown with varying size black spots. The species is sometimes confused with yellow-billed teal, but can be differentiated by the yellow stripes on its bill, its larger size and its tendency not to form large groups. [3]

Distribution and habitat

The range includes much of South America, the Falkland Islands and South Georgia. The nominate and smallest subspecies, the South Georgia pintail A. g. georgica, is thought to number between 1000 and 1500 pairs, and is found only in South Georgia. The Chilean, or brown, pintail A. g. spinicauda is widespread on the South American mainland from extreme southern Colombia southwards, as well as in the Falkland Islands, and numbers well over 110,000. Niceforo's pintail A. g. niceforoi, formerly found in central Colombia, is believed to be extinct, having been last recorded in 1952 (and described only in 1946). Their habitat ranges from high elevation lakes and marshes to low elevation lakes and rivers and coasts in open country.[4]

Breeding

Nests are formed on the ground and lined with grass and down. They hide their nests in vegetation close to water. They lay 4 to 10 eggs in a clutch.

Physiology

In high altitude populations of yellow-billed pintail, hemoglobin has a higher affinity for oxygen than in lower altitude populations, which can be attributable to substitutions in their beta-globin gene.[5] These substitutions are shared by speckled teal because of introgressive hybridization between the two species.[6] Gene flow between populations also suggests that yellow-billed pintails that are heterozygous for the βA hemoglobin subunit may be able to acclimate to high altitudes more efficiently than those that are homozygous for the βA hemoglobin subunit.[7]

References
  1. BirdLife International (2012). "Anas georgica". IUCN Red List of Threatened Species. 2012. Retrieved 26 November 2013.CS1 maint: ref=harv (link)
  2. "Yellow-billed Teal (Anas flavirostris)". Peru Aves.
  3. "Speckled Teal Anas flavirostris flavirostris". Birds of the Falkland Islands.
  4. "Anas georgica - Yellow-billed Pintail". Debra Bourne. Wildlife Information. Retrieved 2010-07-14.
  5. Natarajan, Chandrasekhar; Projecto-Garcia, Joana; Moriyama, Hideaki; Weber, Roy E.; Muñoz-Fuentes, Violeta; Green, Andy J.; Kopuchian, Cecilia; Tubaro, Pablo L.; Alza, Luis; Bulgarella, Mariana; Smith, Matthew M. (2015-12-04). "Convergent Evolution of Hemoglobin Function in High-Altitude Andean Waterfowl Involves Limited Parallelism at the Molecular Sequence Level". PLOS Genetics. 11 (12): e1005681. doi:10.1371/journal.pgen.1005681. ISSN 1553-7404. PMC 4670201. PMID 26637114.
  6. Natarajan, Chandrasekhar; Projecto-Garcia, Joana; Moriyama, Hideaki; Weber, Roy E.; Muñoz-Fuentes, Violeta; Green, Andy J.; Kopuchian, Cecilia; Tubaro, Pablo L.; Alza, Luis; Bulgarella, Mariana; Smith, Matthew M. (2015-12-04). "Convergent Evolution of Hemoglobin Function in High-Altitude Andean Waterfowl Involves Limited Parallelism at the Molecular Sequence Level". PLOS Genetics. 11 (12): e1005681. doi:10.1371/journal.pgen.1005681. ISSN 1553-7404. PMC 4670201. PMID 26637114.
  7. McCracken, Kevin G.; Bulgarella, Mariana; Johnson, Kevin P.; Kuhner, Mary K.; Trucco, Jorge; Valqui, Thomas H.; Wilson, Robert E.; Peters, Jeffrey L. (April 2009). "Gene flow in the face of countervailing selection: Adaptation to high-altitude hypoxia in the βA hemoglobin subunit of yellow-billed pintails in the Andes". Molecular Biology and Evolution. 26 (4): 815–827. doi:10.1093/molbev/msp007. ISSN 0737-4038. PMID 19151158.
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