Slender-billed Curlew
Numenius tenuirostris (Vieillot, 1817)
Order Chardriiformes
Family Scolopacidae
Conservation status: in Bulgaria: Critically endangered CR A[2(a+c) + 3(c) + 4(c)] + B[1a + (b(i+ii+iv+v) + 2(a+b(i+ii+iv+v)]+C[1 + 2(a(i)] + D, BDA-II, III (I); International: IUCN-CR, CITES-I, BeC-II, BoC-I, II, ECS-Spec 1, BD-I.
General distribution. A species with a Siberian type of distribution and on the threshold of full extinction. In the past it inhabited the zone of the forest steppes from Ural to the valley of the river Ob. In the 70s, a drastic decrease of the population was registered. For the period 1990-1999, the data on Europe did not exceed 100 birds. Probably it still winters along the Mediterranean coast of Africa and some countries of Southern Europe, Asia Minor and the Near East.
Distribution and abundance in Bulgaria. A passage migrant and winter visitor that at the end of the 19th century and the beginning of the 20th was found along the Black Sea coast in numbers up to 80 [1], and up to 40 individuals around Sofia [2]. Observed along the shore lakes, along the Dobrudzha shore, in the Sofia region, the Thracian lowland, near the city of Pleven [2,3,4,5,6,7] and along the valleys of the rivers Maritsa and Iskar [8]. In the 1930s it was rare, but a regular migrant mostly for the region of Burgas [9, 10]. After 1946 it was very rare during migrations and wintering (with maximum numbers between 4-7 individuals), mainly along the Black Sea coast: the wetlands around Burgas [11,12], the lakes Shabla and Durankulak [13]. A bird from Atanasovsko Ezero lake was ringed in 1981 [14]. The 48 individuals reported for Atanasovsko Ezero lake in April 1986 [15] remain dubious. Since 1985 it has been observed around Burgas [15,16,19,20,21]: in Atanasovsko Ezero lake – 1 individual on 18 October 1993 [16], between 4 – 9 individuals (2 young) in the period 11-19 April 1996, 1 individual on 18-19 May 1996 [17, 18]*; 1 individual on 06 June 1996 [19]; in Pomoriysko Ezero lake – 1 individual on 03 September 1996 (N. Todorov, in writing), 6 individuals observed by K. Bedev (personal communication) on 12 April 1999*; in the Chengene-Skele Bay – 1 individual on 16-17 November 1993 [16] and near the village of Lyahovo, in the area of the town of Balchik in 1993 [21]. During the mid-winter counts the speices was reported twice: 2 individuals in Chengene-Skele Bay and 1 individual in Atanasovsko Ezero lake in 1993 [22]. The systemic studies undertaken from 1993 onwards [16,20,22] established the presence of a small number of birds, hence the reports of 178 birds in the lakes Atanasovsko and Pomoriysko for the period 1993-2002, and between 33-72 individuals for 1993, 1996 and 1999 [23], are treated with reservations. At present, the key sites are Atanasovsko Ezero lake, the Poda locality and Chengene-Skele Bay. Since 1999 there have been no confirmed observations in Bulgaria. It is possible for singular birds or small groups consisting of 2-3 individuals to pass through the country every year [26].
Habitats. Dry and wet meadows and pastures in the vicinities of lakes, marshes, bogs, sea shallows, lagoons, etc.
Biology. It feeds in shallow basins on benthic invertebrates, probably sea worms, small crustaceans and mollusks, and in dry pastures in Dobrudzha on small snails [3, 26].
Similar species. The Curlew(Numenius arquata), the Whimbrel (Numenius phaeopus).
Negative factors. Drying up of wetlands, changes in the mode of management of agricultural areas, infrastructure development, illegal shooting, pollution of the waters.
Conservation measures taken. Protected according to the Biological Diversity Act. Signed by Bulgaria is a Memorandum of Consent for the Conservation of the Slender-billed Curlew. A National Action Plan has been developed for its conservation for the period 2002-2006 [26].
Conservation measures needed. The sites with more than one observation of the species must be placed under maximum protection as Protected Areas according to the Biological Diversity Act. Development of Management Plans for the Pomoriysko Lake and Chengene-Skele Bay protected localities; monitoring of the territory and the vicinities of the places critical for the species.
References. 1. Reiser, 1894; 2. Hristovich, 1890; 3. Elwes, Buckley, 1879; 4. Alleon, 1886; 5. Andersen, 1905; 6. Collections du Musee Sophia, 1907; 7. Vurbanov, 1912; 8. Yurkevich, 1904; 9. Molineux, 1930; 10. Harrisson, 1933; 11. Prostov, 1964; 12. Prostov, Smilova, 1983; 13. Donchev, 1984; 14. Nankinov et al., 1997; 15. Nankinov, 1991; 16. Ignatov, A. 1994; 17. Nankinov et al., 1998; 18. Nankinov et al., 1999; 19. Michev et al., 2004; 20. Dimitrov et al., 2005; 21. Nankinov,1994; 22. Michev, Profirov, 2003; 23. Nankinov et al., 2003; 24. Tucker, Heath, 1994; 25. BirdLife International, 2004; 26. Iankov, 2002; 27. Heredia et al., 1996.
Authors: Milko Dimitrov, Petar Iankov
* These observations are not approved from the National committee for the rear birds in Bulgaria, so they remain uncertain.
