Danube once appears as the mother of Vrtra, "a dragon blocking the course of the rivers." The Finnish word for Danube is Tonava, which is most likely derived from the word for the river in Swedish and German, "Donau". Its Sámi name "Deatnu" means "Great River". It is possible that "dānu" in Scythian as in Avestan was a generic word for "river": "Dnieper" and "Dniestr", from "Danapris" and "Danastius", are presumed to continue Scythian "*dānu apara" "far river" and "*dānu nazdya-" "near river", respectively. The river was known to the ancient Greeks as the "Istros" (Ἴστρος) a borrowing from a Daco-Thracian
Birds of the Danube Delta and mixed form of colonial nesting. Such an observation and interpretation of the colonial nesting origin in the Danube Delta may constitute an argument for properly explaining the colonial nesting phenomenon in different regions or the globe. Birds of the Danube Delta Following an almost two-decade (1951–1970) research of the Danube Delta territory, 274 bird species were identified of which 176 were brooding (sedentary and migratory) and 98 non-brooding ones (winter, passage, erratic, and accidental birds). The species of brooding birds occurring in the Danube Delta were classified into 12 main biotopes, the classification criterion being represented by the nesting