Northern pintail

Northern pintail
Male and female (left-right)
 Call 
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Anseriformes
Family: Anatidae
Genus: Anas
Species: A. acuta
Binomial name
Anas acuta
Linnaeus, 1758
     Breeding range     Year-round range     Wintering range     X Vagrant
Synonyms

Dafila acuta

The pintail or northern pintail (Anas acuta) is a duck with wide geographic distribution that breeds in the northern areas of Europe, Asia and North America. It is migratory and winters south of its breeding range to the equator. Unusually for a bird with such a large range, it has no geographical subspecies if the possibly conspecific duck Eaton's pintail is considered to be a separate species.

This is a large duck, and the male's long central tail feathers give rise to the species' English and scientific names. Both sexes have blue-grey bills and grey legs and feet. The drake is more striking, having a thin white stripe running from the back of its chocolate-coloured head down its neck to its mostly white undercarriage. The drake also has attractive grey, brown, and black patterning on its back and sides. The hen's plumage is more subtle and subdued, with drab brown feathers similar to those of other female dabbling ducks. Hens make a coarse quack and the drakes a flute-like whistle.

The northern pintail is a bird of open wetlands which nests on the ground, often some distance from water. It feeds by dabbling for plant food and adds small invertebrates to its diet during the nesting season. It is highly gregarious when not breeding, forming large mixed flocks with other species of duck. This duck's population is affected by predators, parasites and avian diseases. Human activities, such as agriculture, hunting and fishing, have also had a significant impact on numbers. Nevertheless, owed to the huge range and large population of this species, it is not threatened globally.

Taxonomy

This species was first described by Linnaeus in his Systema naturae in 1758 as Anas acuta.[2] The scientific name comes from two Latin words: anas, meaning "duck", and acuta, which comes from the verb acuere, "to sharpen"; the species term, like the English name, refers to the pointed tail of the male in breeding plumage.[3] Within the large dabbling duck genus Anas,[2] the northern pintail's closest relatives are other pintails, such as the yellow-billed pintail (A. georgica) and Eaton's pintail (A. eatoni). The pintails are sometimes separated in the genus Dafila (described by Stephens, 1824), an arrangement supported by morphological, molecular and behavioural data.[4][5][6] The famous British ornithologist Sir Peter Scott gave this name to his daughter, the artist Dafila Scott.[7]

Eaton's pintail has two subspecies, A. e. eatoni (the Kerguelen pintail) of Kerguelen Islands, and A. e. drygalskyi (the Crozet pintail) of Crozet Islands, and was formerly considered conspecific with the northern hemisphere's northern pintail. Sexual dimorphism is much less marked in the southern pintails, with the male's breeding appearance being similar to the female plumage. Unusually for a species with such a large range, northern pintail has no geographical subspecies if Eaton's pintail is treated as a separate species.[8] A claimed extinct subspecies from Manra Island, Tristram's pintail, A. a. modesta, appears to be indistinguishable from the nominate form.[9]

Northern pintail female wingspan
Northern pintail male in flight
Northern pintail female

Description

Male in river Ljubljanica, Slovenia

The northern pintail is a fairly large duck with a wing chord of 23.6–28.2 cm (9.3–11.1 in) and wingspan of 80–95 cm (31–37 in).[10] The male is 59–76 cm (23–30 in) in length and weighs 450–1,360 g (0.99–3.00 lb), and therefore is considerably larger than the female, which is 51–64 cm (20–25 in) long and weighs 454–1,135 g (1.001–2.502 lb).[11] The northern pintail broadly overlaps in size with the similarly-widespread mallard, but is more slender, elongated and gracile, with a relatively longer neck and (in males) a longer tail. The unmistakable breeding plumaged male has a chocolate-brown head and white breast with a white stripe extending up the side of the neck. Its upperparts and sides are grey, but elongated grey feathers with black central stripes are draped across the back from the shoulder area. The vent area is yellow, contrasting with the black underside of the tail,[8] which has the central feathers elongated to as much as 10 cm (3.9 in). The bill is bluish and the legs are blue-grey.[12]

The adult female is mainly scalloped and mottled in light brown with a more uniformly grey-brown head, and its pointed tail is shorter than the male's; it is still easily identified by its shape, long neck, and long grey bill.[8] In non-breeding (eclipse) plumage, the drake pintail looks similar to the female, but retains the male upperwing pattern and long grey shoulder feathers. Juvenile birds resemble the female, but are less neatly scalloped and have a duller brown speculum with a narrower trailing edge.[13]

The pintail walks well on land, and swims well.[8] It has a very fast flight, with its wings slightly swept-back, rather than straight out from the body like other ducks. In flight, the male shows a black speculum bordered white at the rear and pale rufous at the front, whereas the female's speculum is dark brown bordered with white, narrowly at the front edge but very prominently at the rear, being visible at a distance of 1,600 m (0.99 mi).[13]

The male's call is a soft proop-proop whistle, similar to that of the common teal, whereas the female has a mallard-like descending quack, and a low croak when flushed.[8]

Distribution and habitat

Non-breeding males wintering in India

This dabbling duck breeds across northern areas of Eurasia south to about Poland and Mongolia,[11] and in Canada, Alaska and the Midwestern United States. Mainly in winters south of its breeding range, reaches almost to the equator in Panama, northern sub-Saharan Africa and tropical South Asia. Small numbers migrate to Pacific islands, particularly Hawaii, where a few hundred birds winter on the main islands in shallow wetlands and flooded agricultural habitats.[8] Transoceanic journeys also occur: a bird that was caught and ringed in Labrador, Canada, was shot by a hunter in England nine days later,[11] and Japanese-ringed birds have been recovered from six US states east to Utah and Mississippi.[14] In parts of the range, such as Great Britain and the northwestern United States, the pintail may be present all year.[13][15]

The northern pintail's breeding habitat is open unwooded wetlands, such as wet grassland, lakesides or tundra. In winter, it will utilise a wider range of open habitats, such as sheltered estuaries, brackish marshes and coastal lagoons. It is highly gregarious outside the breeding season and forms very large mixed flocks with other ducks.[8]

Behaviour

Breeding

Breeding pair
Egg, Collection Museum Wiesbaden

Both sexes reach sexual maturity at one year of age. The male mates with the female by swimming close to her with his head lowered and tail raised, continually whistling. If there is a group of males, they will chase the female in flight until only one drake is left. The female prepares for copulation, which takes place in the water, by lowering her body; the male then bobs his head up and down and mounts the female, taking the feathers on the back of her head in his mouth. After mating, he raises his head and back and whistles.[11]

Breeding takes place between April and June, with the nest being constructed on the ground and hidden amongst vegetation in a dry location, often some distance from water. It is a shallow scrape on the ground lined with plant material and down.[8] The female lays seven to nine cream-coloured eggs at the rate of one per day;[11] the eggs are 55 mm × 38 mm (2.2 in × 1.5 in) in size and weigh 45 g (1.6 oz), of which 7% is shell.[16] If predators destroy the first clutch, the female can produce a replacement clutch as late as the end of July.[11] The hen alone incubates the eggs for 22 to 24 days before they hatch. The precocial downy chicks are then led by the female to the nearest body of water, where they feed on dead insects on the water surface. The chicks fledge in 46 to 47 days after hatching, but stay with the female until she has completed moulting.[11]

Around three-quarters of chicks live long enough to fledge, but not more than half of those survive long enough to reproduce.[11] The maximum recorded age is 27 years and 5 months for a Dutch bird.[16]

Feeding

Up-ending to feed (male on right)

The pintail feeds by dabbling and upending in shallow water for plant food mainly in the evening or at night, and therefore spends much of the day resting.[8] Its long neck enables it to take food items from the bottom of water bodies up to 30 cm (12 in) deep, which are beyond the reach of other dabbling ducks like the Mallard.[12]

The winter diet is mainly plant material including seeds and rhizomes of aquatic plants, but the pintail sometimes feeds on roots, grain and other seeds in fields, though less frequently than other Anas ducks.[12] During the nesting season, this bird eats mainly invertebrate animals, including aquatic insects, molluscs and crustaceans.[11]

Health

Male preening

Pintail nests and chicks are vulnerable to predation by mammals, such as foxes and badgers, and birds like gulls, crows and magpies. The adults can take flight to escape terrestrial predators, but nesting females in particular may be surprised by large carnivores such as bobcats.[11] Large birds of prey, such as northern goshawks, will take ducks from the ground, and some falcons, including the gyrfalcon, have the speed and power to catch flying birds.[17]

It is susceptible to a range of parasites including Cryptosporidium, Giardia, tapeworms, blood parasites and external feather lice,[18][19][20][21] and is also affected by other avian diseases. It is often the dominant species in major mortality events from avian botulism and avian cholera,[22] and can also contract avian influenza, the H5N1 strain of which is highly pathogenic and occasionally infects humans.[23]

The northern pintail is a popular species for game shooting because of its speed, agility, and excellent eating qualities, and is hunted across its range.[24][25] Although one of the world's most numerous ducks,[16] the combination of hunting with other factors has led to population declines, and local restrictions on hunting have been introduced at times to help conserve numbers.[26]

This species' preferred habitat of shallow water is naturally susceptible to problems such as drought or the encroachment of vegetation, but this duck's habitat might be increasingly threatened by climate change.[16] Populations are also affected by the conversion of wetlands and grassland to arable crops, depriving the duck of feeding and nesting areas. Spring planting means that many nests of this early breeding duck are destroyed by farming activities,[27] and a Canadian study showed that more than half of the surveyed nests were destroyed by agricultural work such as ploughing and harrowing.[28]

Male flying above Seedskadee National Wildlife Refuge in Wyoming
Female

Hunting with lead shot, along with the use of lead sinkers in angling, has been identified as a major cause of lead poisoning in waterfowl, which often feed off the bottom of lakes and wetlands where the shot collects.[29] A Spanish study showed that northern pintail and common pochard were the species with the highest levels of lead shot ingestion, higher than in northern countries of the western Palearctic flyway, where lead shot has been banned.[30] In the United States, Canada, and many western European countries, all shot used for waterfowl must now be non-toxic, and therefore may not contain any lead.[31][32][33]

Status

The northern pintail has a large range, estimated at 28,400,000 km2 (11,000,000 sq mi), and a population estimated at 5.3–5.4 million individuals.[34] It is therefore not believed to meet the IUCN Red List threshold criterion of a population decline of more than 30% in ten years or three generations, and is evaluated as Least Concern.

In the Palaearctic, breeding populations are declining in much of the range, including its stronghold in Russia. In other regions, populations are stable or fluctuating.[35]

Pintails in North America at least have been badly affected by avian diseases, with the breeding population falling from more than 10 million in 1957 to 3.5 million by 1964. Although the species has recovered from that low point, the breeding population in 1999 was 30% below the long-term average, despite years of major efforts focused on restoring the species. In 1997, an estimated 1.5 million water birds, the majority being northern pintails, died from avian botulism during two outbreaks in Canada and Utah.[22]

The northern pintail is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies,[36] but it has no special status under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which regulates international trade in specimens of wild animals and plants.[11]

References

  1. ↑ BirdLife International (2013). "Anas acuta". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
  2. 1 2 Linnaeus, Carolus (1758). Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata. (in Latin). Holmiae [Stockholm]: Laurentii Salvii. p. 126. A. cauda acuminata elongata subtus nigra, occipite utrinque linea alba
  3. ↑ Jobling, James A (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. pp. 31, 46. ISBN 978-1-4081-2501-4.
  4. ↑ Johnson, Kevin P.; Sorenson, Michael D. (1999). "Phylogeny and biogeography of dabbling ducks (genus Anas): a comparison of molecular and morphological evidence" (PDF). The Auk. 116 (3): 792–805. doi:10.2307/4089339.
  5. ↑ Johnson, Kevin P.; McKinney, Frank; Wilson, Robert; Sorenson, Michael D. (2000). "The evolution of postcopulatory displays in dabbling ducks (Anatini): a phylogenetic perspective" (PDF). Animal Behaviour. 59 (5): 953–963. PMID 10860522. doi:10.1006/anbe.1999.1399. Archived from the original (PDF) on 5 January 2006.
  6. ↑ Livezey, B.C. (1991). "A phylogenetic analysis and classification of recent dabbling ducks (Tribe Anatini) based on comparative morphology" (PDF). The Auk. 108 (3): 471–507. JSTOR 4088089. doi:10.2307/4088089.
  7. ↑ "Dafila Scott". Society of Wildlife Artists. Archived from the original on 16 July 2011. Retrieved 16 January 2008.
  8. 1 2 3 4 5 6 7 8 9 Madge, Steve; Burn, Hilary (1988). Wildfowl: An Identification Guide to the Ducks, Geese and Swans of the World (Helm Identification Guides). Christopher Helm. pp. 222–224. ISBN 0-7470-2201-1.
  9. ↑ Hume, Julian P.; Walters, Michael (2012). Extinct Birds. London: Poyser. p. 50. ISBN 1-4081-5725-X.
  10. ↑ del Hoyo, J.; Elliott, A.; Sargatal, J., eds. (1992). Handbook of the Birds of the World. Volume 1: Ostrich to Ducks. Barcelona: Lynx Edicions.
  11. 1 2 3 4 5 6 7 8 9 10 11 Robinson, Jerry (2002). Johansson, Carl, ed. "Anas acuta". Animal Diversity Web. University of Michigan Museum of Zoology. Retrieved 13 January 2008.
  12. 1 2 3 Gooders, John; Boyer, Trevor (1997). Ducks of Britain and the Northern Hemisphere. Collins & Brown. pp. 58–61. ISBN 1-85585-570-4.
  13. 1 2 3 Mullarney, Killian; Svensson, Lars; Zetterstrom, Dan; Grant, Peter (2001). Birds of Europe. Princeton University Press. pp. 48–49. ISBN 0-691-05054-6.
  14. ↑ Towell, Larry (23 January 2008). "From Tokyo to Tupelo". ESPN Outdoors News. ESPN Outdoors. Archived from the original on 1 September 2009. Retrieved 23 January 2008.
  15. ↑ "Northern Pintail". All About Birds. Cornell Lab of Ornithology. Retrieved 14 January 2008.
  16. 1 2 3 4 Robinson, R.A. (2005). "Pintail Anas acuta [Linnaeus, 1758]". BirdFacts: profiles of birds occurring in Britain & Ireland (BTO Research Report 407). British Trust for Ornithology. Retrieved 13 January 2008.
  17. ↑ Forsman, Dick (2008). The Raptors of Europe & the Middle East: A Handbook of Field Identification. Princeton University Press. pp. 21–25. ISBN 0-85661-098-4.
  18. ↑ Kuhn, Ryan C.; Rock, Channah M.; Oshima, Kevin H. (January 2002). "Occurrence of Cryptosporidium and Giardia in Wild Ducks along the Rio Grande River Valley in Southern New Mexico". Applied and Environmental Microbiology. 68 (1): 161–165. PMC 126547 Freely accessible. PMID 11772622. doi:10.1128/AEM.68.1.161-165.2002.
  19. ↑ "Cotugnia fastigata". Parasite species summary page. Retrieved 14 January 2008.
  20. ↑ Williams, N.A.; Calverley, B.K.; Mahrt, J.L. (1977). "Blood parasites of mallard and pintail ducks from central Alberta and the Mackenzie Delta, Northwest Territories" (PDF). Journal of Wildlife Diseases. 13 (3): 226–229. PMID 410954. doi:10.7589/0090-3558-13.3.226.
  21. ↑ "Feather Lice Infection in Waterfowl". Wildpro - the electronic encyclopaedia and library for wildlife. Retrieved 14 January 2008.
  22. 1 2 Friend, Milton; McLean, Robert G.; Dein, F. Joshua (April 2001). "Disease emergence in birds: Challenges for the twenty-first century". The Auk. 118 (2): 290–303. doi:10.1642/0004-8038(2001)118[0290:DEIBCF]2.0.CO;2.
  23. ↑ "Avian influenza tests complete on wild northern pintail ducks in Montana". News release No. 0402.06. U.S. Department of Agriculture. Retrieved 14 January 2008.
  24. ↑ Marrone, Teresa (2000). Dressing & Cooking Wild Game (Complete Hunter). Creative Publishing International. p. 123. ISBN 0-86573-108-X.
  25. ↑ Cocker, Mark; Mabey, Richard (2005). Birds Britannica. London: Chatto & Windus. p. 97. ISBN 0-7011-6907-9.
  26. ↑ "U.S. Fish and Wildlife Service Proposes Duck Hunting Regulations, Limited Canvasback Season Re-Opened". News Release 1 August 2003. U.S. Fish and Wildlife Service. Archived from the original on 20 August 2007. Retrieved 15 January 2008.
  27. ↑ "Losing ground: The top 10 common birds in decline" (PDF). Common birds in decline; a state of the birds report, summer 2007. Audubon. Retrieved 15 January 2008.
  28. ↑ "Index of Species Information". Wildlife species: Anas acuta. USDA Forest Service. Retrieved 15 January 2008.
  29. ↑ Scheuhammer, A.M.; Norris, S.L. (1996). "The ecotoxicology of lead shot and lead fishing weights". Ecotoxicology. 5 (5): 279–295. PMID 24193869. doi:10.1007/BF00119051.
  30. ↑ Mateo, Rafael; Martínez-Vilalta, Albert; Guitart, Raimon (1997). "Lead shot pellets in the Ebro delta, Spain: Densities in sediments and prevalence of exposure in waterfowl". Environmental Pollution. 96 (3): 335–341. PMID 15093399. doi:10.1016/S0269-7491(97)00046-8.
  31. ↑ "Service continues to expand non-toxic shot options". U.S. Fish and Wildlife Service. 25 October 2000. Retrieved 15 January 2008.
  32. ↑ "Crunch time for lead shot ban". New Scientist. 5 April 1997. Retrieved 15 January 2008.
  33. ↑ "Lead & Non-Lead Shot". British Association for Shooting and Conservation. Archived from the original on 25 May 2006. Retrieved 15 January 2008.
  34. ↑ "Northern Pintail Anas acuta". BirdLife International. Retrieved 16 April 2011.
  35. ↑ Snow, David; Perrins, Christopher M., eds. (1998). The Birds of the Western Palearctic concise edition (2 volumes). Oxford: Oxford University Press. pp. 222–225. ISBN 0-19-854099-X.
  36. ↑ "Anas acuta". Agreement on the conservation of African-Eurasian migratory Waterbirds (AEWA). AEWA. Retrieved 12 February 2015.
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