4.2. Taxonomy and diversity at the species level

The phylogenies constructed from the cytochrome b sequences by different methods were quite similar in overall topology. The Poecile group was distinguished from the others, and the great tit and blue tit grouped together. The coal tit and the crested tit were placed somewhere in between the former two groups (I). However, if more species could have been included, the topology of the phylogenetic tree could change also with respect to some of the currently included species.

The shortest distance, corrected by the Kimura’s two-parameter method, among species was found between the great tit and the blue tit (2.32%). This result was surprising because the two species are traditionally placed into different species groups (Major and Cyanistes, respectively). The distance between even the closest relatives within the Poecile group (the black-capped chickadee and the Carolina chickadee) was larger (3.28%).

For comparison, we reconstructed small phylogenies using the control region sequences and cytochrome b sequences of the great, blue, willow and Siberian tits (Figure 5). The distance estimated from the control region between the great tit and the blue tit was 10.57%, five times larger than when estimated from the cytochrome b sequences. On the contrary, the distance between the Siberian and the willow tit was lower (5.34%) when estimated from the control region compared to the estimate from the cytochrome b (8.1%).

The largest distance found by comparing the cytochrome b sequences was 12.3% between the willow tit and the crested tit. The mean distance between the different species groups was 9.29% (2.32%-11.15%).