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 ].