Crane
Common Crane
Grus grus (Linnaeus, 1758)
Grus cinere: Hristovich, 1890: 216, Klain, 1909: 120.
Order Gruiformes
Family Gruidae
Conservation status: in Bulgaria: Extinct EX, BDA-III; International: CITES-II, BeC-II, BoC-II, ECS-Spec 1, BD-I.
General distribution. A Palearctic species. It breeds in Sweden, Finland, Poland, Northern Ukraine, Russia, Mongolia; It winters in Spain, France, Turkey, Egypt, the countries from Northern Africa, Sudan, Somalia, Northern India, Eastern China.
Distribution and abundance in Bulgaria. At present a passage migrant and rarely winter visitor that at the end of the 19th century bred along the Danubian river bank and in marshes inside the country [1]. Until the first half of the 20th century, in the breeding season it was observed throughout the country – in the districts of Pleven, Dobrich, Varna, the Burgas region, the Sofia region, in the Rhodopes, near Plovdiv, etc. [2]. Its last breeding habitats are the former Batak Marsh and Shabla Lake, where it bred until 1950. During the spring migration it was registered in the regions of Sofia, Dobrich, Pernik [2], Silistra, Haskovo, Kardzhali, Burgas, Varna [1], Pleven [3, 4], Durankulak Lake [5]. During the autumn migration in 1979-1983 between 10 August and 30 October in the region of Burgas Bay, 1 800 birds passed at the average (a maximum number of 4 181 individuals in 1979) [1]. An autumn migration of a flock of 20 individuals was registered in 1993 near Pleven [4]. In the recent years it has been almost extinct as an autumn migrant (T. Michev, personal communication). It wintered regularly in the Pazardzhik region and partly in the Plovdiv region [1]. Its numbers are unknown. In 1887, flocks of 150 individuals were observed, in 1956 – 35-200 individuals. At the beginning of the 20th century, about 30 pairs [2] used to breed. Probably up to 15 individuals irregularly winter [6].
Habitats. Large valleys, in the vicinity of standing water basins, marshes in foothills and mountains, meadows, bogs. During migration on meadows, fallow land, fields, rice-fields, riverside flooded areas, forest meadows etc. Conservative with respect to the places for stationing during migration.
Biology. Ground-nesting, monogamous, migration species. The young ones are nidifugous. In the spring they gather to court with a complex premarital dance. The female lays 2 (1-3) eggs which she incubates for 28-31 days in shifts with the male. The young birds reach their sexual maturity in their 4th – 6th year. Both parents take care of the young. Almost omnivorous.
Similar species. The Demoiselle Crane (Anthropoides virgo).
Negative factors. Destruction and change of habitats, drying up of wetlands, disturbance during breeding and the migration period, illegal hunting, environmental pollution with pesticides.
Conservation measures taken. Some localities used for rest during migration are in protected natural territories. Possibilities are discussed for developing a long-term programme for attracting migrating birds and birds that stop during migration, for the supply of wild individuals from the Ukraine or Russia, breeding them in captivity in closed park-like conditions and for their release initially in flat steppe reserves with the presence of standing water basins.
References. 1. Simeonov et al., 1990; 2. Boev, 1985; 3. Dimitrov, 1981; 4. Shurulinkov et al., 2005; 5. Collections of Natural History Museum, BAS; 6. Kostadinova, 1995.
Author: Zlatozar Boev
