Return of Bird of the Week: Pacific Slope Flycatcher

Once upon a time there was a bird species called a Western Flycatcher. Another member of the Empidonaxgenus. But ornithologists decided in 1989 that what had been called Western Flycatchers were actually two different species, distinguished by song and geography. Not by appearance. Birds of North America, the on-line databases of North American birds, says (paywall): In the hand, Pacific slope and Cordilleran flycatchers may be identified with extreme caution; many individuals must be left unidentified. Sex and age differences exist within each species. That’s right, a difficult to identify bird species was split into two almost impossible to distinguish species. To…