Re: Cassin's or Blue- headed Vireo, Concord, Contra Costa Co.
Great find! Looks like a Cassin's Vireo to me. In fresh plumage,
Blue-headed Vireos usually have more dark contrasting in the malar region
instead of the gradual gray shading of Cassin's. Also Cassin's usually has
the crown darker than the face. In Blue-headed it's the reverse.
Nevertheless, the two can be very difficult, if not impossible to separate
in some cases and they probably hybridize.
On 28 Nov 2014 01:04:22 -0800, "firstname.lastname@example.org [EBB_Sightings]"
Yesterday at the John F. Baldwin Park in Concord, Contra Costa County I found, and today, November 27th, 2014 I had the chance to observe again a Solitary Vireo. To this point I'm not quite sure if this is rather a late lingering migrant Cassin's (Vireo cassinii) or rather a vagrant Blue-headed (Vireo solitarius) , the bird did not vocalize (I will try again to get more data, if possible), and photographs are of poor quality (bad light ). I can only definitely exclude Plumbeous Vireo base on o the presence of yellow pigment.--
Joseph Morlan, Pacifica, CA
"It turns out we're very good at not seeing things" - Jack Hitt