Bar-tailed godwit (Limosa lapponica)
|Size||Length: 37 - 41 cm (2)|
Wingspan: 70 - 80 cm (2)
Male weight: 190 - 400g (2) (3)
Female weight: 260 - 630g (2) (3)
The bar-tailed godwit is classified as Least Concern (LC) on the IUCN Red List (1).
The bar-tailed godwit (Limosa lapponica) is a distinctive wading bird with conspicuous blue-grey legs and a long, dark, slightly upturned bill with a pink base (2) (3) (4). The breeding and non-breeding plumages of the male bar-tailed godwit are noticeably different, changing from dull grey-brown in the winter to rich chestnut across the back and breast during the summer breeding season (2) (5). The neck, breast and sides of the body are finely streaked with black and there is a dark brown and grey streaking on the back and wings (2). The breast returns to an off-white colour once the breeding season is over (3), while the rest of the plumage becomes duller, with pale fringes to the back and wing feathers (2).
The female and juvenile bar-tailed godwit have a similar grey-brown plumage, with the juvenile showing slightly more buff colouration (4) (6). The female is generally larger than the male, with a noticeably longer bill, and has little red-brown colouration during the breeding season (2). Both the male and female bar-tailed godwit have a distinctive black-and-white barred tail, from which this species gets its common name. However, this barred pattern is hidden when the bird is at rest (6). The colouration on the head of both sexes is broken up by an off-white line above the eyes (4).
Although this species is mostly silent outside of the breeding season, during the breeding season it is often heard making fast, high-pitched calls. The alarm call of the bar-tailed godwit is a piercing ‘krick’, the call during flight a harsh ‘kirrik’ (4), and other calls include a loud ‘ke-ke-ke’ or‘kek-kek’. A ‘k-tek k-tek k-tek’is often given before its northward migration (2).
Three subspecies of the bar-tailed godwit are recognised: Limosa lapponica lapponica, Limosa lapponica menzbieri and Limosa lapponica baueri. The three subspecies differ slightly in their breeding and wintering grounds, as well as in their body size and the extent of the barring of the tail. The eastern subspecies L. l. menzbieri and L. l. lapponica are slightly larger, with short legs and stocky bodies (2).
The bar-tailed godwit can be distinguished from the similar-looking black-tailed godwit (Limosa limosa) by its barred rather than black tail and by a lack of white bars on the wings (3) (4).
The large range of the bar-tailed godwit extends across Europe, Asia, Africa and North America (5), as well as Australia and New Zealand (3).
The wintering and breeding grounds are different in each subspecies. L. l. lapponica breeds between Scandinavia and the Taymyr Peninsula in the north of Russia, and winters along the coastlines of western Europe, the Arabian Gulf and south as far as South Africa. L. l. menzbieri breeds in northeast Asia, from the Taymyr Peninsular to far east Siberia, and winters in Australia and southeast Asia. L. l. baueri breeds from north-eastern Asia to western Alaska and winters in Australia and New Zealand (3).
The Arctic breeding grounds of the bar-tailed godwit are generally situated in open, marshy tundra around swamps, river valleys and bogs near the Arctic treeline (7). The temperate or tropical winter habitats are usually located around intertidal areas along muddy coastlines, estuaries and lagoons (7).
The extreme endurance of the bar-tailed godwit is illustrated in its seasonal migration, where it is known to perform the longest non-stop migration of any land bird. L. l. baueri has been known to fly 10,400 kilometres from its breeding grounds in Alaska and eastern Siberia to its wintering grounds in New Zealand in around 175 hours, with an average speed of 63 kilometres per hour (8). This non-stop flight requires large fat reserves and the ability to shrink the internal organs to reduce weight while in flight. When post-breeding migration begins, each bar-tailed godwit is around twice its normal body weight (8).
The bar-tailed godwit breeds between late May and August. The breeding pairs are normally solitary, although sometimes small colonies can form (7). The nest is a depression in the ground at a dry, elevated site (7), and is lined with grass (9). The female bar-tailed godwit lays one clutch of around four eggs per year, which are olive-green in colour, spotted with dark brown. The eggs are incubated for around 20 to 21 days (9). After the breeding season, the birds move to moulting sites, usually situated along a coastline, before migrating to the wintering grounds between October and November (7).
During the breeding season, the bar-tailed godwit feeds mainly on insects, worms, molluscs and occasionally seeds and berries (7). The non-breeding diet consists of worms, bivalves and crustaceans, although it occasionally takes the larvae of craneflies, as well as tadpoles and small fish (7). Large flocks of bar-tailed godwits can often be seen at the edge of the water (4), probing the soft mud for prey (2) (3).
The bar-tailed godwit is an abundant and widespread species, and is not currently considered to be at risk of extinction (7). However, this species may face a number of threats including degradation of its habitat due to pollution, land use changes and other human disturbances. Outbreaks of infectious diseases such as avian influenza also pose a threat to the bar-tailed godwit (7).
The bar-tailed godwit is listed under the African-Eurasian Waterbird Agreement (AEWA), which calls on parties to undertake conservation actions for birds which are dependent on wetland habitats (10). In the wintering grounds of the bar-tailed godwit in the United Kingdom, the removal of the invasive grassSpartina anglica has proved to be beneficial to the species (7). There are not known to be any other specific conservation measures currently in place for this widespread wading bird.
Find out more about the bar-tailed godwit and its conservation:
RSPB - Bar-tailed godwit:
BirdLife - Bar-tailed godwit:
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- Avian influenza: also known as “bird flu”, a contagious disease caused by any strain of influenza virus that is carried by and primarily affects birds.
- Bivalve: a group of aquatic molluscs in which the soft parts are encased in a shell consisting of two parts, known as valves.
- Crustaceans: diverse group of animals with jointed limbs and a hard external skeleton, characterised by the possession of two pairs of antennae, one pair of mandibles (mouthparts used for handling and processing food) and two pairs of maxillae (appendages used in eating, which are located behind the mandibles). Includes crabs, lobsters, shrimps, woodlice and barnacles.
- Incubate: to keep eggs warm so that development is possible.
- Larva: immature stage in an animal’s lifecycle, after it hatches from an egg and before it changes into the adult form. Larvae are typically very different in appearance to adults; they are able to feed and move around but are usually unable to reproduce.
- Molluscs: a diverse group of invertebrates, mainly marine, that have one or all of the following: a horny, toothed ribbon in the mouth (the radula), a shell covering the upper surface of the body, and a mantle or mantle cavity with a type of gill. Includes snails, slugs, shellfish, octopuses and squid.
- Moult: periodic shedding of (usually) the outermost body covering (such as feathers, fur or skin) during growth and development, or at specific times of the year.
- Subspecies: a population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.
- Tundra: treeless, grassy plains characteristic of Arctic and sub-Arctic regions. They are very cold and have little rainfall.
IUCN Red List (January, 2012)
- Brazil, M. (2009) Birds of East Asia. A&C Black Publishers, London.
- MobileReference (2008) The Illustrated Encyclopedia of North American Birds: An Essential Guide to Common Birds of North America. MobileReference, Boston.
- Peterson, R.T., Mountfort, G. and Hollom, P.A.D. (1993) A Field Guide to the Birds of Britain and Europe. Houghton Mifflin Company, New York.
RSPB - Bar-tailed godwit (January, 2012)
- Dunn, J.L. and Alderfer, J. (2006) Field Guide to the Birds of North America. Fifth Edition. National Geographic Books, Washington.
BirdLife International (January, 2012)
- Newton, I. (2008) The Migration Ecology of Birds. Academic Press, London.
- Perrins, C. (1987) Birds of Britain and Europe. University of Texas Press, Texas.
African-Eurasian Waterbird Agreement (March, 2012)