Limosa lapponica

Limosa lapponica

The Bar-tailed godwit (Limosa lapponica, Linnaeus 1758) is a bird belonging to the Scolopacidae family.

Systematics –
From a systematic point of view it belongs to:
Eukaryota domain,
Kingdom Animalia,
Phylum Chordata,
Subphylum Vertebrata,
Aves class,
Order Charadriiformes,
Suborder Piarist,
family Scolopacidae,
Genus Limosa,
L. lapponica species.
The terms are synonyms:
– Limosa lapponica subsp. anadyrensis Engelmoer & Roselaar, 1998;
– Limosa rufa Temminck;
– Scolopax lapponica Linnaeus, 1758.
Within this species the following subspecies are recognised:
– Limosa lapponica subsp. baueri J.F.Naumann, 1836;
– Limosa lapponica subsp. lapponica;
– Limosa lapponica subsp. menzbieri Portenko, 1936;
– Limosa lapponica subsp. taymyrensis Engelmoer & Roselaar, 1998.

Geographic Distribution and Habitat –
The Limosa lapponica is a bird that occupies a very vast range: it lives throughout northern Europe, throughout Asia, in most of Oceania and Africa, in Alaska, in northern and western Canada, in the United States of Western America, Mexico and Brazil. It is accidental in some interior states of Africa such as Mali, Zimbabwe and the Democratic Republic of Congo, in the Balkan states, on Malta, Mauritius, Réunion, the US Virgin Islands and on many islands in the Atlantic Ocean.
All specimens spend the summer in the northern hemisphere in the Arctic, where they breed, and in the winter they make a long-distance migration south to more temperate areas. The subspecies L. l. Lapland make the shortest migration, some only as far as the North Sea, while others travel as far as India. Alaskan-nesting specimens (L. l. baueri) travel as far as Australia and New Zealand. They undertake the longest non-stop migrations of any bird, and for food they carry the largest loads of blubber of any migratory bird so far studied, reducing the size of their digestive organs to do so.
The L.l. baueri breeds in Alaska and spends the non-breeding season in eastern Australia and New Zealand. The L.l. menzbieri breeds in Siberia and migrates to northern and western Australia. Birds that breed in Siberia follow the coast of Asia north and south, but those that breed in Alaska migrate directly across the Pacific to Australasia 11,000 km away.
Both Australian subspecies make their way north to their breeding grounds along the coast of Asia to the Yalu Jiang coastal wetland in the northern Yellow Sea, the most important stopping places for Limosa lapponica and Calidris tenuirostris on their northern migration.
The Limosa lapponica also nests in Europe and northern Asia. In Italy it is a species that irregularly performs the double step.

Description –
The Limosa lapponica is a wading bird with a length of 33-38 cm and a wingspan of 63-70 cm.
The adult males in summer dress can be recognized by having a brown back with heavy dark speckles and the upper part of the wings as well, which do not have any evident strikethrough. The rump is white and fades towards the tail which is white with many brown bars. The top is brown with fine dark streaks. The rest of the head, neck, chest, abdomen and belly are tawny red with lighter cheeks and the area above the eye. A brown streak starts from the base of the beak, crosses the eye and fades towards the ears.
The legs and beak are black.
The adult female in summer dress differs from the male in summer dress in having a light orange chest that fades to whitish on the abdomen and belly and with slight bars on the sides and towards the paler head; the other upper parts are also lighter.
The adults in winter dress and the juveniles look a lot alike and differ from the females in summer dress in having even paler chest and neck and only tinged with fawn, and the beak with a pink base.

Biology –
The Limosa lapponica is a migratory bird that nests in the northern regions of the boreal hemisphere.
During the winter, it moves to southern regions including Africa, South Asia and Australia.
The reproduction takes place during the summer season in the northern regions where it nests.
In early spring these birds migrate to the northern regions to nest. Usually, they reach their nesting areas between April and May.
Once they arrive in the nesting area they try to establish a nesting territory. Males compete with each other for females and for access to the best breeding areas.
Thus they build their nest on the ground, usually near fresh water, such as marshes or wetlands. The nest is a small, shallow depression lined with plant material.
After establishing a pair, the male and female mate. Subsequently, the female lays 3 to 4 olive-brown eggs in the nest, at intervals of one to two days.
The incubation of the eggs lasts about 22-24 days and is mainly carried out by the female, although the male may occasionally participate (the female during the day and the male during the night). During this period, the parents take turns incubating and foraging.
After hatching, the chicks are precocious and able to move and look for food from the first days of life. The parents feed and protect them until they are developed enough to fly.
After breeding they leave their nesting areas and move to southern regions to spend the winter. Post-breeding migration generally occurs between July and September.

Ecological Role –
The Limosa lapponica, as mentioned, is considered the migratory bird that makes the longest journey without stopping: up to 11,680 km from Alaska to New Zealand (and vice versa). This distance is also the furthest covered by any animal without feeding along the way.
Birds first depart for their breeding sites in the Northern Hemisphere at the age of 2-4 years.
The diet is based on aquatic insects, molluscs, crustaceans, annelids and small fry.
The main food source of birds in wetlands is represented by bristleworms (up to 70%), supplemented by small bivalves and crustaceans. In wet pastures they feed on invertebrates. At an important stopover site in the northern Yellow Sea, they continue to hunt polychaetes, but most of their food is the bivalve mollusk Potamocorbula laevis, which they generally swallow whole.[
Regarding the ecological status of this species it is classified as near threatened and the population is decreasing. Fewer birds have used East African estuaries since 1979, and there has been a steady decline in numbers around Siberia’s Kola Peninsula since 1930. The world population is estimated to number between 1,099,000 and 1,149 ,000 individuals.
The construction of dams and the clearing of mudflats have led to a critical reduction in food supplies for migratory birds, particularly subspecies such as L. l. menzbieri who rely on the Yalu Jiang estuary for both their northward and southward migrations. The populations of L. l. baueri have declined in New Zealand from over 100,000 in the late 1980s to 67,500 in 2018.
The Limosa lapponica is one of the species covered by the Agreement on the Conservation of Migratory Waterbirds of Eurasian Africa (AEWA). In New Zealand the species is protected by the Wildlife Act of 1953.

Guido Bissanti

Sources
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– C.Battisti, D. Taffon, F. Giucca, 2008. Atlas of nesting birds, Gangemi Editore, Rome.
– L. Svensson, K.Mullarney, D. Zetterstrom, 1999. Guide to Birds of Europe, North Africa and the Near East, Harper Collins Publisher, UK.

Photo source:
– https://inaturalist-open-data.s3.amazonaws.com/photos/251494469/original.jpg