DNA Reveals New Bird Species
Examining the differences in the genetic barcode among birds leads scientists to suspect that 15 unidentified species of birds breed on the North American continent.
At the same time, analysis of 643 bird species finds that 42 of these should actually be lumped as 17 species.
The mitrochondrial DNA of birds presents a genetic fingerprint that varies little within each species, yet differs noticeably from any other. It provides a straightforward means of distinguishing the various bird species. The DNA barcode confirms classification for 93 percent of bird species breeding in the US and Canada.
The proposed new species arise from splitting common raven, warbling vireo, mountain chickadee and winter wren each into two species, distinctions previously suspected by other researchers. Newly suggested divisions from this research include western screech owl, Bewick's wren and hermit thrush. For each of these species, birds from different regions fall into one of two distinct barcode clusters.
Can't tell apart all those large, white-headed gulls lingering along the west coast seashore? Well apparently neither does the mitrochondiral DNA for eight species such as glaucous and herring gulls. Other birds that mitrochondrial DNA cannot distinguish are American from northwestern crows and red-naped from red-breasted sapsuckers. Most of these species with overlapping DNA are known to hybridize.
Kevin C.R. Kerr, Mark Y. Stoeckle, Carla J. Dove, Lee A. Weigt, Charles M. Francis, Paul D.N. Hebert. 2007. Comprehensive DNA barcode coverage of North American birds. Molecular Ecology Notes.