Black Phoebe x Eastern Phoebe hybrid,
Until recently the ranges of Black Phoebe and Eastern Phoebe were well separated but as Eastern Phoebe has taken advantage of habitat changes to extend its range westwards, Black Phoebe too has been extending its range north and eastwards. When they came into contact in Colorado hybrids began to appear and this is well documented in an article "An Apparent Hybrid Black x Eastern Phoebe" by Nathan D Pieplow, Tony Leukering and Elaine Coley (Western Birds 39:209–219, 2008).
Steve informs us that his bird shown here was apparently paired to a normal-looking Eastern Phoebe. His bird is clearly intermediate in appearance between the two species and he tells us that neither species bred in the area until about the mid 1990s.
Black Phoebe x Eastern Phoebe hybrid (same bird as in photo ID 1297 above),
Black Phoebe Sayornis nigricans
Eastern Phoebe Sayornis phoebe