Siegfried Eck was born in Dresden on 25 May 1942, and died there unexpectedly at home on 11 September 2005. From 1967 until his death, he worked as curator of the ornithological collection at the State Museum for Zoology in Dresden, Germany. His loss has deprived the ornithological community of one of its highest-profile systematists and taxonomists, certainly one of the most important in Europe. He was an expert on the birds of the Palearctic; no problem was unfamiliar to him, no taxon a stranger. Chief among his many interests was individual and geographic variability in songbirds, and the current interpretations of species concepts. Historically, he was particularly influenced by authors such as Christian Ludwig Brehm, Otto Kleinschmidt, and Ernst Hartert, who had contested aspects of species subdivisions and the species concept, and who tended to think in terms of populations. He regularly published papers on all these subjects (listed in Mitteilungen des Vereins Sächsischer Ornithologen 9:119–125  and 9:677–681 , and in longer obituaries in Vogelwarte 43:279–280 , Anzeiger des Vereins Thüringer Ornithologen 5:250–251 , and Zoologische Abhandlungen Dresden 55:3–6 ).
Eck's greatest achievement was to consider species as groups of populations and treat them accordingly, thus gaining a profound understanding of population structure. He was accustomed to noting the most delicate differences in coloration, dimensions, and proportions. One example is his monograph on the genus Poecile (1980). In a large project on the Asiatic Golden-spectacled Warbler complex (Seicercus), a group of cryptic Asian species, his acuity turned a joint project in the right direction (1999). Eck pointed out that many songbird groups exhibit a still unresolved morphological relationship, in which relatively short-winged and long-tailed taxa prove to be closely related to long-winged and short-tailed ones. He spoke of geographic and morphological vicariance. His analyses often encompassed both individual taxa as well as entire faunas. His awareness that morphometric-based population studies required comprehensive material resulted in an enlargement of the Dresden collection. Its contents nearly doubled in the 40 years of his work, which made it one of the most important collections in central Europe.
Eck was an autodidact, never having had the benefit of a university education. Nevertheless, he was highly regarded in his field. He became a Corresponding Fellow of the AOU in 1988. In 2002, the University of Mainz awarded him an Honorary Doctorate in appreciation of his remarkable contributions toward resolving taxonomic and zoogeographic problems of Palearctic and Asian birds. Three subspecies are named after him: the Great Tit of Sardinia (Parus major ecki von Jordans, 1970), the Coal Tit of western China (Parus ater eckodedicatus Martens, Tietze and Sun, 2006), and a sharp- tailed starling (Lamprotornis acuticaudus ecki Clancey, 1980) from South Africa.
Eck was always modest and reserved. He was open to all questions, especially those from students and young colleagues. His humor was delicate and his criticism supportive and restrained. As a scientist and human being, he set and held high standards. He is survived by his wife, Regine, a systematic entomologist; a daughter, Sonja; a son, Rolf; and one grandson.