[CT Birds] Mystery Kingbird Revealed (Brian Kleinman)

snaketat at cox.net snaketat at cox.net
Sat Jan 12 07:18:40 EST 2008


Cograt's to Jim and Clay for attempting to ID this kingbird.  Jim you were right in calling it a hybrid and Clay you were 1/2 right.  Here is the actual report from the CT Rare Records Committee.

CASSIN'S KINGBIRD (Tyrannus vociferans). A single bird thought to be of this species was seen and photographed at Hammonasset Beach State Park on 19 Aug 1998 (99-12). This report initiated one of the most interesting ornithological investigations in ARCC history. The bird was fairly well studied. The photographs were suggestive at best but actually provided some key evidence for this investigation. The write-ups and photos describe a kingbird shaped bird with fairly yellow under parts; a distinct and fairly broad white terminal band to the tail, a dark breast set off from the yellowish under parts by a narrow white area, a "medium" sized bill for a kingbird, and moderately dark upper parts. Lacking, or unable to be determined were the white malar area typical of Cassin's Kingbird, a clear determination of the number of tail feathers evident, the certain age of the individual, or the true extent of the yellowish coloration to the under parts.

Many committee members felt that this bird showed real possibilities to be vociferans but a few were initially troubled by the tail pattern. The white tip seemed to be a bit extreme for Cassin's Kingbird which has white or pale fringing to the tip of the tail and not really a defined white tip as this bird showed. The tails suggested that of an Eastern Kingbird (T. tyrannus), but the yellowish coloration to the under parts seemed to be beyond what reviewers have experienced with the species. Copies of the slides were sent digitally to experts from around the country and what ensued was extremely interesting. Most of these people felt that the bird was not Cassin's Kingbird for the same reasons as stated above. A few felt that the images did not conclusively identify it as Cassin's, nor did they conclusively eliminate Cassin's. The most important bits of information came when the ARCC asked reviewers if they had any experience with hybrid Eastern X Western Kingbird (T. verticalis). Surprisingly, a few people had some experience with this pairing and more importantly, numerous extremely experienced ornithologists felt that these photos suggest what a hybrid of this pairing could, in fact, resemble (V. Remsen, K. Garrett, T. Leukering, pers. comm.)! While identification to this hybrid combination is far from provable, the committee agreed that the bird was not Cassin's Kingbird and that identification of this bird as an Eastern X Western Kingbird hybrid could not be ruled out.

The breeding range of Western Kingbird is spreading eastward at an impressive rate and recent nestings in Tennessee and in the upper Midwest, east of the Mississippi, seem to indicate that hybrid pairings like the one suggested above may become more frequent (Winging It, Aug 99). Observers are asked to carefully note all details of yellow-bellied kingbird observations.

This committee would like to extend special thanks to Louis Bevier, Kimball Garrett, Greg Lasley, Tony Leukering, Van Remsen, and Don Roberson for their careful analysis and comment on this confusing issue.

Thanks for playing!

Brian




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