Eurasian Oystercatcher

Haematopus ostralegus (Linnaeus, 1758)

Order Charadriiformes

Family Haematopididae

Conservation status: in Bulgaria: Critically endangered CR=[B1a+2 a + c (iii) + C2 a], BDA-III; International: BeC-III.

General distribution. A cosmopolitan species. It mainly breeds along the seashores of Europe and Eastern Asia and along the internal continental water basins of Eastern Europe and Western Asia. A migratory bird for Europe and the northern parts of the Asian area. In the more southern regions it is found all the year round. The European population consists of over 300 thousand breeding pairs [1].

Distribution and abundance in Bulgaria. A breeding summer visitor, passage migrant and rarely wintering species. From the end of the 19th to the middle of the 20th century, it was registered as a passing, wandering or summering species along the Black Sea coast [2, 3, 4] and the valleys of the rivers Maritsa and Danube [5, 6, 7, 8]. The first certain breeding was reported on an island in the Maritsa River near the village of Orizare, Plovdiv region, in 1973 [9], and several years later it was found breeding in Atanasovsko Ezero lake [10]. In 1991 it was found breeding also on Tsibar Island [11]. Until the beginning of the 1990s, the population was estimated at 40 70 pairs [11, 12]. For the period from 1995 to 2005, the data from field studies show some reduction of the numbers: the Maritsa River, 28 pairs (T. Petrov, M. Marinov, D. Todorov, personal communication); Atanasovsko Ezero lake, 1-3 pairs, the Poda locality, 1 pair [13]; the Danube, on an unnamed island on the Danube, 2-3 pairs [14]. During the recent studies of the population along the Maritsa River from the village of Ognyanovo, Pazardzhik region, to the state border in June 2006, a total of 9 pairs and 9 singular individuals were registered (T. Petrov, M. Velev, M. Petrov, personal communication). In the second half of July, along the Black Sea coast, migrating individuals or small groups fly in. Singular Eurasian Oystercatchers very rarely stay to winter in Bulgaria [13]. The total numbers of the population are 30-50 breeding pairs.

Habitats. It breeds on sandy and gravelly river islands amongst flowing waters, dikes of salt pits and rice fields, meadows near fish farms, etc.

Biology. Formed pairs and protection of breeding territories are observed at the end of March. It does not form colonies but along the Black Sea coast it breeds close to other Charadriiformes and probably also in their colonies [13]. Laying eggs takes place from the beginning of April to the middle of May. Because of a flooding of the first clutch, the pair may resort to a second breeding [9]. Food: small crustaceans, mussels, larvae of insects, rarely small fish.

Similar species. None.

Negative factors. Flooding the islands with nests along the Maritsa River and the Danube by high waters; disturbance during incubation, killing the young by stray dogs and cats, predators, etc.

Conservation measures taken. A protected species since 1962, included in the Red Data Book of Bulgaria (1985) as endangered. The breeding habitats in the lakes Atanasovsko and Poda fall within protected natural territories.

Conservation measures needed. Yearly monitoring of the population. Declaration of several islands with breeding pairs of Eurasian Oystercatchers along the river Maritsa Protected Natural Sites.

References. 1. BirdLife International, 2004; 2. Patev, 1950; 3. Prostov, 1964; 4. Peshev, 1967; 5. Reiser, 1894; 6. Boev, 1962; 7. Boev et al., 1964; 8. Nankinov, 1979; 9. Petrov, 1975; 10. Roberts, 1980; 11. Boev, 1991; 12. Darakchiev, 1984; 13. Dalakchieva, 2004; 14. Tinchev, 1997; 15. Petrov, 1985

Authors: Tseno Petrov, Zlatozar Boev, Svetla Dalakchieva

Eurasian Oystercatcher (distribution map)

Eurasian Oystercatcher (drawing)