Haematopus ostralegus Linnaeus, 1758

The Oystercatcher rather than building a nest,they lay their eggs in a scrape in the ground and both the male and female take turns incubating them, the breeding season starts after mid-April,between two and four (but usually three) cream eggs, spotted with brown are laid. Incubation of eggs takes 24 to 27 days. The young are very well camouflaged. Both the male and the female care for the young until they become independent at between 34 and 37 days. Oystercatcher pairs usually produce just one brood a year, although if the brood is lost for some reason, a replacement brood may be produced (Gooder, J. (1982) Collins British Birds. William Collins Sons and Co Ltd, London). The breeding sites are located on coastal salt marshes, shores of inland lakes, reservoirs and rivers and also agricultural fields. These Eurasian oystercatcher species are mostly monogamous. They pair up with the old mate after wintering. Sometimes the old mate is deserted for pairing up with a new partner. In some cases the male is evicted by a new dominant male from the breeding territory. The Eurasian oystercatchers defend their breeding territory and guard the mate.

The Eurasian oystercatcher species are generally migrant birds. The breeding Eurasian oystercatcher populations in the north migrate southwards for wintering. The inland breeding populations move to coastal areas for wintering. Post breeding, the juveniles may disperse and establish in new locations within the range. They may make local movements for feeding and breeding within their range.

The oystercatcher (Haematopus ostralegus) is 39 to 44 cm in length, the wingspan is 72 to 83 cm long (Mullarney, K., Svensson, L., Zetterstrom, D., & Grant, P.J. (1999) Collins Bird Guide. HarperCollins Publishers Ltd, London) and the bill accounting for 8 to 9 cm.

The diet of these Eurasian oystercatcher species is mostly bivalves. Mussels, limpets, whelks, marine polychaetes, crabs, earthworms and insect larvae are their primary food. The bill shape varies due to wearing. The oystercatchers with broad bill feed on the molluscs by prising them apart or hammering through the shell. The birds with worn pointed bill dig up worms.

The natural ecosystems of the oystercatcher species include coastal lagoons, tidal pools, estuaries, intertidal mudflats, rocky, sandy and shingle shoreline, salt marshes, freshwater lakes, rivers, streams and creeks.

Current Population Trend of the Eurasian Oystercatcher is decreasing.

IUCN Redlist Status: Least Concern

Red List Category & Criteria: Near Threatened ver 3.1

The main threat to the species is the over-fishing of benthic shellfish and the resulting disappearance of intertidal mussel and cockle beds (Atkinson et al. 2003, Verhulst et al. 2004, Ens 2006, van de Pol et al. 2014). Bait digging has also been identified as a threat through loss of prey species and disturbance to the benthic fauna (van de Pol et al. 2014). The species is also threatened by habitat degradation on its wintering grounds due to land reclamation (for example in the Yellow Sea [Melville et al. 2014]), pollution, human disturbance (Kelin and Qiang 2006) (e.g. from construction work or recreational activities [Burton et al. 2002, van de Pol et al. 2014]), coastal barrage construction (Burton 2006), industrial development including development of ports and oil extraction, oil spills, wind farms (Melville et al. 2014) and reduced river flows (Kelin and Qiang 2006). Rapid and extensive land reclamation is reported from staging and wintering grounds for the osculans population in South Korea and China and large-scale planting of Spartina alterniflora on the coast of eastern China may cause loss of foraging and nesting habitats (Melville et al. 2014) Intensive agriculture including frequent mowing of grasslands and high densities of grazing livestock threatens chicks, eggs and nests and high levels of fertilizers and pesticides can reduce soil invertebrate biomass (van de Pol et al. 2014). A reduction in eutrophication is likely to have contributed to declines in some areas, owing to a loss of food resources (van de Pol et al. 2014, H. Meltofte in litt. 2015). Sea level rise leading to increased coastal erosion and flooding is contributing to habitat loss in some areas (Melville et al. 2014, van de Pol et al. 2014). Climate change has advanced the average egg-laying date of the species and is likely to reduce recruitment of bivalves, however warmer winters are expected to benefit the species leading to lower winter mortality (van de Pol et al. 2014). Droughts in some inland areas are likely to lead to a loss of suitable habitat (Melville et al. 2014, Sarychev and Mischenko 2014). The species is hunted in France but the effects of hunting at the population level are not known (van de Pol et al. 2014). It may be subject to subsistence egg collection in China (Melville et al, 2014) and illegal hunting elsewhere (Sarychev and Mischenko 2014). Eggs and chicks are known to be predated by Corvidae, gulls, American Mink Neovison vison, dogs and foxes Vulpes vulpes (Sarychev and Mischenko 2014). The invasive Pacific Oyster Crassostrea gigas has become abundant in the Oosterschelde (Netherlands) and is increasing in the Dutch Wadden Sea (van de Pol et al. 2014). Eurasian Oystercatcher generally does not eat this species of oyster which is reported to be invading mussel beds and may compete with cockles and mussels thus reducing food availability. However Pacific Oyster beds could also provide an area for mussel beds to re-establish. The species is susceptible to avian influenza so may be threatened by future outbreaks of the virus (Melville and Shortridge 2006). Intensive grazing in some areas may pose a threat to this population. Pollution from sewage, heavy metals and organochlorine pesticides have been identified as potential threats (Melville et al. 2014).