Slender-billed Curlew (Numenius tenuirostris)
Justification This species has an extremely small population and the number of birds recorded annually continues to fall. This is likely to represent a continuing population decline. For these reasons the species qualifies as Critical.
Identification 36-41 cm. Medium-sized, mottled brown-grey curlew. White underparts marked with black heart-shaped spots on flanks. Decurved bill tapers to distinctly fine tip. Pale, barred inner primaries and secondaries contrast markedly with brown-black outer primaries. Whitish underwings. Rump virtually unmarked and tail has few dark bars on white background. Similar spp. Eurasian Curlew N. arquata is larger and darker. Less contrast between dark feather centres and darker upperparts. Longer, more decurved bill, lacking fine tip. Lacks heart-shaped spots but often has scattered flank spots. Generally less patterned underwings. N. a. orientalis is paler with whiter underwing. Whimbrel N. phaeopus darker with thicker bill and prominent, pale median crown-stripe. Paler N. p. alboaxillaris is difficult to separate. Voice Quiet cour-lee in flight. Like soft, accelerated N. arquata
Range & Population Numenius tenuirostris has only been confirmed breeding near Tara, north of Omsk in Siberia, Russia, between 1914-1924. It migrates west-south-west from its presumed breeding grounds in Siberia through central and eastern Europe, predominantly Russia, Kazakhstan, Ukraine, Bulgaria, Hungary, Romania and Yugoslavia to southern Europe , Greece, Italy, and Turkey, and north Africa, Algeria, Morocco and Tunisia. Reports of birds wintering in Iran persist but require confirmation. Regarded as very common in the 19th century, it declined dramatically during the 20th century. Flocks of over 100 birds were recorded from Morocco as late as the 1960s and 1970s. However, between 1980-1990, there were only 103 records involving 316-326 birds, and from 1990-1999, this dropped to 74 records involving 148-152 birds. Most recent records are of 1-3 birds with the exception of a flock of 19 birds in Italy in 1995. In 1994, the population was estimated at only 50-270 birds, but records suggest it may now be lower.
Ecology The only known nests were recorded on the northern limit of the forest-steppe zone in habitat more typical of taiga marsh. On migration and in winter, a wide variety of habitats are used, including saltmarsh, steppe grassland, fishponds, saltpans, brackish lagoons, tidal mudflats, semi-desert, brackish wetlands and sandy farmland next to lagoons.
Threats Threats on the breeding grounds are unknown. Within its potential breeding range, the taiga has been little modified, the forest-steppe partially cultivated and much of the steppe modified by agriculture. Habitat loss in the wintering grounds is of unknown importance. There has been extensive drainage of wetlands in the Mediterranean and North Africa and potentially important areas in Iraq. Hunting was historically high and may have been the key factor in its historical decline.
Action CITES Appendix I. CMS Appendix I and II. There have been several international initiatives for the species to research key sites in Greece, survey passage sites and potential breeding areas, collate records, raise public awareness and educate hunters. An international working group has been established and a European action plan was published in 1996.
