Parus

Eck, Siegfried, 2006, The Palaearctic Titmouse Species (Aves: Paridae: Parus sensu lato) — A current survey *, Zootaxa 1325, pp. 7-54 : 17

Subgenus Parus , type­species P. m a j o r L., 1758

(Great Tits s.l.)

Detailed descriptions of the effects of contact between different taxa of Great Tits have been published by Kuzjmina in Dolguschin et al. (1972, IV), Eck and Piechocki (1977), Mistschenko (1982), Kerimov and Formozov (1985, 1986), Formozov et al. (1993) and Ivankina et al. (1997). At the Amur the encounter between Great Tits with quite different song forms (the major and minor groups) were closely examined and the taxonomic results discussed ( Martens 1996: 223–227). Very recently the methodical studies by Nazarenko and Valchuk have corroborated the old finding of Stegmann (1928) that major and minor are different species ( Päckert et al., 2005). The relationships among the Great Tits thus provide particularly impressive support of the significance of the superspecies as a category encompassing very closely related species, since these forms are still capable of interbreeding even though not in the sense of a population­level mixing region. This may also explain the decisions made by Hartert in 1923 (p. 38, footnote) or 1933 (in Hartert & Steinbacher, p. 179) regarding the subspecies of Great Tits. As far as I know, he no longer acknowledged the existence of an “Artenkreis” (superspecies). — Recently intrapopular differentiations of Great Tits have been very highly ranked in an evolutionary context ( Garant et al., 2004, 2005). — P. monticolus constitutes a separate series of especially intensely pigmented geographical forms, and is an isospecies next to the superspecies P. [ major ].