Corncrake

Crex crex (L., 1776)

Porzana minutta Bp.: Hristovich, 1890: 216.

Order Gruiformes

Family Rallidae

Conservation status: in Bulgaria: Vulnerable VU B1ciii+C2b, BDA-II, III; International: BeC-II, BoC-II, BD-I.

General distribution. Probably a European species. Its natural area in the north reaches Great Britain, the Scandinavian peninsula, Arhangelsk, Siberia, in the south the Pyrenees, France, Italy, Yugoslavia, Bulgaria, the Northern Black Sea coast with the Crimean peninsula, Armenia, the Caspian Sea; the eastern border is Lake Baikal.

Distribution and abundance in Bulgaria. A breeding summer visitor and passage migrant. At the end of the 19th century it was comparatively rare (the areas of the cities of Pazardzhik and Sofia) [1, 2]. In the middle of the previous century, it was common on wet meadows around the marshes [3], but later it was again specified as endangered [4]. Historically, there are 3 fluctuations of the numbers in connection with deforestation leading to the emergence of appropriate habitats. The following intensification of agriculture caused a drastic decrease of the numbers [6]. At present, there is a mosaic distribution mainly in Western Bulgaria [7, 8, 9]. The more significant habitats are in the Sofia region: about 850 courting males, the Western and the Central Balkan range, 1500, Ponor Planina mountain, 120, along the Tran-Breznik line to the border, 250. It has comparatively low numbers along the Danube banks and the Black Sea coast, in Dobrudzha and the Eastern Rhodopes. The total numbers in the country are between 4 000 and 6 000 pairs [6].

Habitats. Wet and mesophytic herbaceous associations with a domination of Poa pratensis, Alopecurus pratensis, Gallium aparine, etc. [10], between 500 and 1 800 m, but it has also been registered at an altitude of 2 500 m [11].

Biology. Understudied. The males are strongly territorial. The area of the individual sectors is 8,9 ha, at the average. It feeds on insects: mainly grass-hoppers, also worms and slugs [13, 14].

Similar species. The species of the genus Porzana and the genus Rallus.

Negative factors. Destruction of the habitats, mowing, burning stubble-fields. Intensification of agriculture, insecticides, destruction of habitats ploughing the meadows, early mowing (in June and July); infrastructure development; hunting.

Conservation measures taken. Protected according to the Biological Diversity Act. Included in the Red Data Book of Bulgaria (1985). A plan has been prepared for the preservation of the species. The more significant habitats are declared Important Bird Areas and included in Natura 2000. The marshes Dolni Bogrov and Dragoman have been declared Protected Localities.

Conservation measures needed. Protection of the more significant habitats in the separate regions of the country; monitoring of the populations every 5 years; yearly monitoring of the more significant habitats; a special mowing regime in the habitats from the centre to the periphery of the field.

References. 1. Hristovich, 1890; 2. Reiser, 1894; 3. Patev, 1950; 4. Boev, 1985; 5. Simeonov et al. 6. Delov, 1999; 7. Delov et al., 1995; 8. Delov, 1998; 9. Delov, Jankov, 1997; 10. Delov, 1995; 11. Delov, 2004; 12. Delov, 2002; 13. Delov, 2002; 14. Delov, 2000.

Author: Ventseslav Delov


Corncrake (distribution map)

Corncrake (drawing)