The International Ornithological Congress however recognized 28 species as of 2012 , based on the elevation of four taxa from subspecies to full species status , including Przevalski 's nuthatch and three species from the europaea group .
It treated S. przewalskii as a subspecies of S. leucopsis .
The International Ornithological Congress recognized 28 species as of 2012 , based on the elevation of four taxa from subspecies to full species status , including Przevalski 's nuthatch and three species from the europaea group .
It treated S. przewalskii as a subspecies of S. leucopsis .