I promised to send an update on my warbler post to summarize people’s comments and photos sent to me so here goes…
First the Baypoll Warbler: Once photos were circulated most people agreed that the Sedgewick Park bird is a Bay-breasted Warbler (BBWA). There are still a couple of top birders that feel this bird is a Blackpoll but I personally feel that the evidence is now clear that it is a BBWA. I have seen at least 37 different photos from different angles and dates. Here are the BBWA characters: 1. gray feet (every Blackpoll (BKWA) I have seen has at least yellow soles to the feet and often yellow running up the back of the legs), 2. weak eye stripe (BKPW presents a strong eye stripe), 3. wide wing bars (BKWA has narrower wing bars – note that this character is relative and not everyone agrees that the wing bars on this bird are wide), 4. faintly streaked flanks (streaking is only visible in good light and is much heavier on BKWA), 5. flank colour to me is subtlety different – not as yellow as in BKWA and under some lighting conditions photos show bay overtones to the flanks and throat, 6. back colour is less bright than on BKWA, 7. Base of bill is flesh coloured, typical of BBWA. BKWA is usually yellow at the bill base. Here are the misleading characters: 1. back is heavily streaked – BBWA can have a streaked back but it doesn’t usually look this streaked. My opinion is that because this bird is being viewed at our feet and often in bright sunlight the streaking appears to be more pronounced than we would normally see. In the hand, BBWA’s can often look very streaky. 2. Bright white undertail coverts. This is unusual for BBWA in my experience but the character is variable and they can be pure white in BBWA. They are always white in BKWA. There is a nice piece on ID of Baypoll Warblers at http://ebird.org/content/wi/news/id-tip-blackpoll-vs.-bay-breasted-warbler-in-fall. I cannot address the two-bird theory other than to say that we have seen photos of the BBWA going back to December 23rd and no photos of a different bird. If anyone has photos from earlier (the bird was discovered on Dec. 15th), please send them to me or post them online and send a link to OntBirds. Next for the Western Orange-crowned Warbler (OCWA) At least one of the OCWA’s present is a typical celata bird that we would expect anytime in migration through S and C Ontario. One is a very bright yellow bird that is not at all like celata. Here is a link to a great photo of the bird taken by Joanne Redwood: https://groups.google.com/forum/?fromgroups=#!topic/hamiltonbirds/B9wQn5TfZEQ. The yellow on the putative western bird is much brighter than on any celata birds. The yellow is vibrant from the throat to the undertail coverts. On a celata bird the throat is pale yellow to gray and the yellow breast, belly and undertail coverts are dull yellowish green. The eye ring of celata is a broken white ring (broken at front and back – forming white crescents over and under the eye). The western bird seen has yellow crescents rather than white. The head, nape and cheeks of celata are very gray whereas the western bird has a tinge of gray but is overwhelmingly yellow. The back of celata is olive whereas the western bird is a bright yellowish green. There are three western subspecies of OCWA, Pacific coastal lutescens, montaine orestera and the Channel Islands sordida. lutescens is the brightest of the bunch and I personally feel that this bird is lutescens. orestera is intermediate between celata and lutescens in appearance. It would be nice to get some photos of orestera and lutescens to compare to the Sedgewick bird. Additional photos of the Sedgewick bird in different lighting and from different angles would be great. I would appreciate receiving any of these as we may write up this bird for OBRC. And finally for the putative western Nashville Warbler There is a photo of this bird at the link given above under OCWA. The eastern subspecies of Nashville Warbler is ruficapilla. The western subspecies is ridgwayi and has been called Calaveras Warbler. These taxa are no-brainers for elevation to species status so if we have a Calaveras Warbler in Oakville, it would be a good thing to go see! The breeding populations of the two subspecies are allopatric and they are apparently not even sister species. Calaveras Warbler is hypothesized to be the sister species to Virginia’s Warbler (Wier and Schluter 2004). Our Eastern Nashville Warbler is sister to both of these. ruficapilla and ridgwayi are very similar morphologically. The Calaveras differs in being brighter, with a brighter yellow rump and more extensive white feathers on the lower belly. The back of ridgwayi is more extensively gray and the tail is slightly longer than in ruficapilla. Calaveras Warbler also engages in more tail-wagging behavior, something that we noted on the Oakville bird. There is not much information available on differentiating these taxa so any definitive identification will require photos from as many angles as possible, video of the bird to document the tail-wagging, recordings of any contact calls given by the bird (I am not sure if call notes are distinctive but the song is and I would guess the calls are), notes on moult, and perhaps even a bit of DNA. If someone finds a feather from this bird, please put it in an envelope and send it to me. I can attempt to get some sequence data on the bird. My feeling is that the Oakville bird is a strong candidate for Calaveras Warbler based on the characters given above. However, more evidence is needed and more research into the literature is also required before anything conclusive can be stated. Thanks to everyone who sent me comments on these birds! Jeff -- 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/
