Hybridizing White Wagtail subspecies are separated by head plumage.
The White Wagtail (Motacilla alba) is one of my favorite bird species to observe. They frantically hop around the lawn occasionally wagging their long tail up and down. This small black-and-white passerine has a wide distribution across Eurasia and is divided into several subspecies. Some subspecies interbreed in narrow contact zones. A recent study in Molecular Ecology focused on a hybrid zone between two subspecies: alba and personata.
Distribution of White Wagtail (Motacilla alba) subspecies (from http://www.wikiwand.com/en/White_wagtail)
Sampling across Siberia
Georgy Semenov and colleagues collected samples across a 3000 kilometer long transect which ran from the Altai Mountains in Western Siberia (home of the alba) to Kazakhstan and Uzbekistan (where personata resides). They compared the distribution of several morphological and genetic traits along this transect. Genetically, the center of the hybrid zone was located in…
View original post 202 more words