It is either an Eastern Kingbird with an unusual amount of yellow on the underparts, or it is a hybrid between Eastern Kingbird x Western Kingbird. The size, shape, etc. all match Eastern Kingbird. Dr. Ginest sent me a few other images of this bird, including one showing the back. I include it here below right. This shows that the wing coverts and some tertials as well as scapulars are brown contrasting with gray back. The outermost tail-feather looks tapered, so I think this bird is in its first calendar year. The tail tip also looks quite worn. We should be able to age this bird based on this, but I am confused by the account in Pyle. The chart on page 264 of Identification Guide to North American Birds shows Juv-HY from June through December, while the text says August on.
Discussion on ID-Frontiers brought to light another somewhat similar bird seen this spring at Anahuac NWR in Texas. A photo by Jo Heindel is here. Opinion was divided between whether that bird was a hybrid, or possibly an Eastern Kingbird with yellow underparts. The voice was said to be indistinguishable from Eastern Kingbird. I don't think a consensus was reached on that bird.
Hybrid kingbirds are apparently quite rare. We learned of a mixed pair of Eastern x Western Kingbirds which nested in Maryland. However the young were indistinguishable from Eastern Kingbirds. Tony Leukering reported a mixed pair of Eastern x Western Kingbirds in Michigan. The young resembled Western Kingbirds, but had a white band on the tail tip. It was also brought out that the young in a kingbird nest, may not necessarily have been the offspring of the attending birds. There is a great deal of extra-pair copulation in these species. See: Rowe, D. L., M. T. Murphy, R. C. Fleishcer, and P. G. Wolf. 2001. High frequency of extra-pair paternity in Eastern Kingbirds. Condor 103:845-851.
Our mystery bird certainly has Eastern Kingbird parentage, but whether it is a "pure" Eastern Kingbird remains a mystery. However, I think it does show a white edge to the outer web of r6 suggesting hybrid parentage. Thanks again to all contributors.
|Photo © 2003 Dr. Mel Ginest. All rights reserved.|
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