Gill, F.B., D.H. Funk, and B. Silverin. 1989. The Wilson Bulletin 101(2):182–197.
Stable URL: http://www.jstor.org/stable/4162724
As a first step toward understanding the evolutionary and biogeographical relationships among species of Parus, we compared allozymes at 34 loci of nine North American and six Eurasian species representing six subgenera. The results of this electrophoretic survey provide the first broad summary of genetic relationships between species of the genus Parus. Distance Wagner and UPGMA analyses suggest that: (1) the crested North American titmice (subgenus Baeolophus) are only distantly related to the other parids examined; (2) the Bridled Titmouse (P. wollweberi) is closest to Baeolophus titmice and convergent in appearance to the Crested Tit (P. cristatus); (3) the Marsh Tit (P. palustris) and Willow Tit (P. montanus) probably are sister taxa, but the Carolina Chickadee (P. carolinensis) and Black-Capped Chickadee (P. atricapillus) may not be; (4) the Black-Capped Chickadee is genetically closer to the Mountain Chickadee (P. gambeli) and Mexican Chickadee (P. sclateri) than to the Carolina Chickadee and (5) the Boreal Chickadee (P. hudsonicus) and Chestnut-Backed Chickadee (P. rufescens) are sister taxa related in turn to the atricapillus species group.