Tadorna ferruginea Pallas, 1764
Tadorna casarca L., 1768: Hristovich, 1890, Reiser, 1894: 183, Klain, 1909: 145; Casarca ferruginea Pall.: Patev, 1950: 230, Peshev, Boev, 1962: 336; Vulpanser rutila Key et Blas, 1844: Klain, 1909: 145; Casarca rutila Bonap., 1838: Hristovich, 1890: 222.
Conservation status: in Bulgaria: Critically endangered CR=A[1a] + B[2(a+b(iv)]+D+E, BDA-II, III; International: BeC-II, BoC-II, ECS-Spec 3, BD-I.
General distribution. A paleoxeric species. Its basic area is from Southeastern Europe (the Balkans, the Black Sea coast), the Ukraine, Turkey to the east through Central and Eastern Asia to China and Mongolia; in the North it reaches the region of lake Baikal, and to the South Iran, Iraq, Tibet. There is a small population in Northwestern Africa (Algeria, Morocco) and the mountainous parts of Ethiopia.
Distribution and abundance in Bulgaria. A breeding summer visitor and passage migrant, as an exception wintering. In the past it was more widely distributed . Today it is extinct as a breeding bird in most places. It is observed mainly in small water basins within Dobrudzha and along the Black Sea coast. About half of the breeding pairs inhabit the open terrains of Northeastern Bulgaria and the largest densities of breeding habitats are around the town of Glavinitsa, Silistra region. It also breeds in the region around Burgas and in the microreservoirs near Karnobat and Aytos. Today's abundance of the species is up to 15-20 breeding pairs.
Habitats. Lakes, fish farms and reservoirs with an open water area in open steppe and agrictultural areas. It often feeds in the fields, far from the water.
Biology. Well studied . Courting and occupation of territories begins at the end of February and continues through March. The beginning of laying has been registered around 10 March at the earliest, but usually it is between 1 and 15 April. In rare cases (during the first breeding), laying begins considerably later, around 15 May. The incubation of the eggs continues for 28 – 30 days. Their numbers vary between 6 and 13. It feeds on insects, carrion, seeds.
Similar species. The Shelduck (Tadorna tadorna).
Negative factors. Loss and degradation of habitats. Illegal shooting and collecting.
Conservation measures taken. Protected since 1962. Included in the Red Data Book of Bulgaria (1985) as endangered. A 10-year programme for the reintroduction of the species in nature has been implemented. Yearly, between 20 and 30 young of the species hatched in Kalimok Biological Experimental Field Station (Institute of Zoology, BAS) are being restored in the Bulgarian nature.
Conservation measures needed. Studying the numbers and the area of the populations and the threats. Carrying out monitoring; designation of new protected territories; reintroduction of artificially bred young birds.
References. 1. Nankinov, 1985; 2. Bogdanova, Zehtindjiev, 2000a.
Authors: Pavel Zehtindjiev, Maria Bogdanova, Kiril Bedev