Tuesday, 17 June 2014

Western Kingbird x Eastern Kingbird

Western Kingbird x Eastern Kingbird hybrid, Kinny SWA, Lincoln County (Colorado, USA), 10th June 2012 - copyright Steve Mlodinow
(photo ID: 1279)


Steve tells us that this bird was apparently paired with a Western Kingbird, the two perching close together and defending a small group of trees against other kingbirds. On first impressions in the view shown in the first photo below, the yellow wash on the vent and lower belly seemed rather obvious as did the somewhat masked look, which gave the initial impression of a young Thick-billed Kingbird. Obviously it wasn't a Thick-billed Kingbird and Steve explains:
"The white on the outer portion of the outer rectrices is very similar to that of a Western Kingbird, but is also present on Eastern Kingbirds - though usually it is not quite so obvious.  The yellow wash beneath seems paler than one would expect from a hybrid, but perhaps this is due to the birds obvious wear.  A somewhat masked appearance is something one might expect in a Western Kingbird x Eastern Kingbird cross, and this feature was apparent in the field. Additionally, it looks as if the outer three primaries may have been replaced eccentric - a Western or Cassin's Kingbird (but not Eastern Kingbird) feature that would indicate second year now that lost it's tail. If so the blunt tips would indicate female."
Steve extends his thanks to Peter Pyle, Marshall Iliff, Michael O'Brien, Tony Leukering and Chris Wood for their input on this bird. For a discussion of a mixed Eastern/Western Kingbird nesting pair in Maryland, see North American Birds 57:477.





Western Kingbird x Eastern Kingbird hybrid (same bird as in photo ID 1279 above), Kinny SWA, Lincoln County (Colorado, USA), 10th June 2012 - copyright Steve Mlodinow
(photo IDs: 1275-1278)


Western Kingbird Tyrannus verticalis
Eastern Kingbird Tyrannus tyrannus

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