Note that this message was approved by the Ontbirds coordinator. OntBirders,
Back in early January when we posted about the Sedgewick warblers we asked for a Nashville Warbler feather if anyone found one. As you may recall, we suggested that the Nashville that we saw on January 2nd may have been a member of the western subspecies, ridgwayi (Calaveras Warbler). Field identification of Nashville subspecies is not trivial. The western birds typically show more gray on the back than typical eastern birds, brighter yellow underparts and possibly a more extensive white vent - but these characters are variable and overlap between the subspecies seems possible from what we have read. Tail bobbing is typically more phrenetic than the nominate eastern subspecies and the video that Luc Fazio posted shows considerable tail bobbing consistent with our observations in the field. On January 7th, Brad Bloemendal found a small cluster of breast feathers consistent with Nashville Warbler and sent them to me. Scott Kelso and I were able to extract DNA from the bit of tissue on the feather bases and sequence two mitochondrial genes (cytB and COI). Based on this, we can now state that the Sedgewick Nashville Warbler was undoubtedly from the nominate eastern subspecies (ruficapilla). Since we used only mitochondrial DNA there is an outside chance the bird was a hybrid, but we view this as unlikely. Just to muddy the waters a bit: We heard rumblings that there might have been two Nashville Warblers seen at the site. Note that the cluster of feathers sent to us had some tissue attached to them and appeared to be consistent with a predator attack and the likely demise of the Nashville Warbler. We are aware of people reporting a Nashville after this date though. So if anyone photographed a Nashville Warbler after the 7th we would be very interested in seeing the photos to eliminate any possibility of a 2-bird scenario. If only one bird was present and it was seen after the 7th it should have looked pretty bedraggled. Thanks very much to everyone who sent us photos of this bird, to Luc for posting the video and to Brad for taking the time to collect the feathers and send them to us. We are happy to share raw sequence data or details on our identification methods if anyone contacts us privately. Jeff Skevington, James Holdsworth and Richard Skevington -- Jeff Skevington, Research Scientist Canadian National Collection of Insects, Arachnids and Nematodes Agriculture and Agri-Food Canada 960 Carling Avenue, K.W. Neatby Building Ottawa, ON, K1A 0C6, Canada Phone: 613-759-1647 FAX: 613-759-1927 E-mail: [email protected] _______________________________________________ ONTBIRDS is presented by the Ontario Field Ornithologists - the provincial birding organization. Send bird reports to [email protected] For information about ONTBIRDS visit http://www.ofo.ca/
