Hi all:
Since I only check this venue every so often and I didn't see much in the way of responses to either of the queries in this digest about the identies of photographed birds, I thought that I'd respond now, despite the time lag.? The easier of the two is regarding the query about blackbirds - the two birds with the Eur. Staring are both molting immature male Red-winged Blackbirds (birds hatched this summer). The more difficult?are the two vireos from Boulder Co., as the 'Solitary' Vireos are MUCH more difficult than they're presented to be in the guides, even though most guides present them as tricky.? I think that the easier of the two is in the set of pix labeled something like "Plumbeous or Cassin's" -- that one, I believe, is a Cassin's.? It's throat is dull, the upperparts have a strong green cast to them, and there is too much (at least, I think it's too much) green on the underparts for the bird to be a Plumbeous.? Oddly, that bird might be a bit tricky to separate from the dull end of Blue-headed Vireo, though I think the throat color rules that ID out. The other, grayer, bird is, in my opinion, a Plumbeous Vireo.? I don't have any problem with the amount of color on the underparts of this bird for the species and suspect that it's probably an immature.? The throat is just too white and too crisply separated from the malar/auricular region, as nicely illustrated by "IMG_2676."? Of course, I do hold out the possibility of a hybrid for the beast, but think that it's within the range of variation for Plumbeous.? Obviously, Christian disagrees, but more features of the bird are right for Plumbeous than they are for Cassin's and I've never seen a Cassin's -- in CO or in CA -- with a throat that clean and crisp. Sincerely, Tony Leukering Villas, NJ -----Original Message----- From: cobirds group <nore...@googlegroups.com> To: cobirds digest subscribers <cobirds@googlegroups.com> Sent: Tue, Sep 8, 2009 4:53 am Subject: cobirds - 18 new messages in 16 topics - digest == 1 of 2 == Date: Mon, Sep 7 2009 2:05?am From: Thomas Heinrich I have photos of two vireos, one from a few days ago taken in Boulder, the other from May, 2008 taken at Sale Lake also in Boulder. I would appreciate any observations and opinions as to ID of these birds. Some characteristics seem to fit Plumbeous, others make me wonder if one or both could be Cassin's. www.pbase.com/birdercellist/shrikesvireos The photos are at the end of the gallery. Thanks for any help, -- Thomas Heinrich Boulder, CO teheinr...@gmail.com www.pbase.com/birdercellist == 2 of 2 == Date: Mon, Sep 7 2009 3:17?pm From: Christian Nunes Several birders saw the bird at Sale Lake. My opinion at the time was that it was a Cassin's, and I still feel comfortable with that conclusion. It is certainly on the tricky end of things. But I have yet to find a Plumbeous on the local breeding grounds that approaches that bird in the yellowish-green wash on the vent/flanks. Who knows, though, it could be a hybrid. I don't think it's a bright male Plumbeous, rather a drab female Cassin's. Bright male Plumbeous are notable for their contrasting gray flanks. This kind of bird is exactly why there were formerly considered a super-species. Here's my photo of that one: http://www.flickr.com/photos/christian_nunes/2493369157/in/set-72157603385936136/ I would call the recent Boulder individual a Cassin's as well, if I am analyzing the amount of greenish-yellow in the plumage correctly. The bill is big, though. It would be interesting to hear what other CO (Plumbeous) birders have to say on this issue. Is there a local congruence of opinion on the subject? Is it similar to, say, the local agreement among birders in Blue-headed or Cassin's core ranges? Or are we biased by our general exposure to Plumbeous? Would a WA birder be tempted to call the Sale Lake bird a Plumbeous just because it's on the drabber end of their search image spectrum? The comment on the photograph linked above is from a WA birder. I've tried to use other features like wing-bar prominence and size, and bill size, as determining characteristics on confusing birds, but they just don't work very well with the amount of variation that is involved. Good luck! Christian Nunes pajaro...@hotmail.com http://www.flickr.com/photos/christian_nunes/ <I have photos of two vireos, one from a few days ago taken in Boulder, the other from May, 2008 taken at Sale Lake also in Boulder. I would appreciate any observations and opinions as to ID of these birds. Some characteristics seem to fit Plumbeous, others make me wonder if one or both could be Cassin's. www.pbase.com/birdercellist/shrikesvireos The photos are at the end of the gallery. Thanks for any help, -- Thomas Heinrich Boulder, CO teheinr...@gmail.com www.pbase.com/birdercellist ============================================================================== TOPIC: Bobolinks? http://groups.google.com/group/cobirds/t/596d24a5a1871082?hl=en ============================================================================== == 1 of 1 == Date: Mon, Sep 7 2009 2:44?pm From: Chris Petrizzo I was near Stearns Lake?today, and I saw two birds that I really could not definitively identify. They both seem to be in the process of molting. I think they're Bobolinks, but it's hard for me to tell. You can see pix here:? http://www.facebook.com/album.php?aid=32225&id=1043048586&l=91354a68c3 ? Thanks for your insights! -- Chris Petrizzo cpetri...@yahoo.com --~--~---------~--~----~------------~-------~--~----~ Colorado Field Ornithologists: http://www.cfo-link.org/ Colorado County Birding: http://www.coloradocountybirding.com/ You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To post to this group, send email to cobirds@googlegroups.com To unsubscribe from this group, send email to cobirds+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.as/group/cobirds?hl=en -~----------~----~----~----~------~----~------~--~---
