Probable Black x Say's Phoebe hybrid in Humboldt Co.
- Hi all,
During the Centerville CBC on 4 January 2009, Owen Head, Jim Tietz and Adam Brown found an interesting phoebe in the Ferndale Bottoms of NW California. A Black x Eastern Phoebe hybrid was considered, but the bird was dismissed as a leucistic Black Phoebe because current field guides do not show the ranges of these two species overlapping. Not until 8 January, was the bird reconsidered to be a hybrid when Jim saw the current Black x Eastern Phoebe note in the recent Western Birds (39:209-219). Jim's original email to NWCALBIRD on 8 Jan can be seen here: http://www.sialia.com/s/calists.pl?rm=message;id=241413
On 11 Jan, a number of local Humboldt birders, visited the location and easily refound the bird and were able to study it for a good length of time. Kerry Ross got video of the bird vocalizing, along with some good flight shots, and Rob Fowler got numerous photos of the bird perched. Kerry and Rob's videos and photos can be seen here: http://picasaweb.google.com/migratoriusfwlr/HybridPhoebeFerndaleBottomsHUM11Jan2009?feat=directlink
Currently, we feel fairly confident that this phoebe is a Black x Say’s hybrid despite recent molecular work showing that Say’s is a phylogenetic outlier in the Sayornis genus (Cicero and Johnson 2002). Although this hybrid pair has never been documented, this bird shows a couple features that support this tentative identification. First, the undertail coverts have a warm, buffy color that is more reminiscent of Say’s than of Eastern. In the above mentioned Western Birds article, the Black x Eastern hybrid had white undertail coverts and the authors state that if it were a Black x Say’s, it should have shown warmer tones on the belly. Secondly, the song of this bird sounds more similar to Say’s than Eastern. The “fee-bew” phrases sound a little mournful like the descending whistle of Say’s and many times the bird gives the up-slurred “drreeet” call that is typical of Say’s.
Moreover, this species pair may make more sense geographically than a Black x Eastern, which has only been documented in Colorado and New Mexico where their breeding ranges have just recently come into contact. Black Phoebes, on the other hand, have also recently expanded their breeding range into northeastern California where Say’s Phoebes breed; in Central California and locations further south and southeast, the breeding ranges of these two species broadly overlap. In winter, the occurrence of Say’s Phoebes in Humboldt Co is rare but annual. These individuals may actually come from NE California which is the nearest migratory population.
Late yesterday we posted our sighting to ID Frontiers. After viewing the on-line photos, Steve Gerow provided some interesting insight on other features in support of a Black x Say's hybrid that we overlooked such as the appearance of a relatively smaller head, and longer tail, bill, and wings. He also noted the paler inner webs to the primaries as a Say's feature, and that the contrast of the primaries against the darker secondaries is a feature that none of the three phoebe species show.
Additional comments and insights are appreciated!
James R. Tietz
Shaver Lake, CA