Jeff, Your junco is pretty clearly a White-winged. There are a few misconceptions about White-winged Juncos that are exacerbated by modern field guides. One is that they should have dark lores. The other is the color of the head. White-winged Juncos can have contrasting dark lores, or they can lack it. White-winged Juncos can have a head that is as dark as a Slate-colored, or as light as a Pink-sided. These details are misinterpreted by field guides. The monograph on the species (Miller 1941) describes White-winged Junco as lacking dark lores. But the Sibley guide points this out as a useful field mark. They are both right, to some extent, since this feature is simply variable. The head color varies from very pale (Pink-sided gray) to very dark (equal to or darker than Slate-colored). This is a detail that Miller noted, but modern field guides fail to encompass. A Junco with thick white wing-bars, a large, horn-colored bill, and that is gray overall can confidently be called a White-winged here in CO where they are common. The small size is interesting, and in one photo it is quite apparent with the bird standing next to a Gray-headed. Two of the tertials are edged with brown, and the third with gray. It's probably a hatch-year bird. They molt a variable number of tertials in the fall (often 0, often 1, less often 2-3). A bird with retained juvenile tertials at this time of year can confidently be aged, while those with completely replaced gray tertials cannot. I've recently uploaded a bunch of junco photos with a couple confusing hatch-year White-wingeds which can be seen at the end of this set: http://www.flickr.com/photos/christian_nunes/sets/72157609842959747/with/5537208275/
Christian Nunes [email protected] From: [email protected] To: [email protected] Subject: [cobirds] Slate-colored Junco with broad white wing bars - Teller Co Date: Mon, 21 Mar 2011 10:48:48 -0600 Many juncos moving through Teller County today; slate-colored, Oregon, pink-sided, gray-headed. And several singing. But one caught my eye – a small slate-colored with broad white wing bars on primary and secondary coverts. Bird is smallish – like other slate-coloreds there; definitely smaller than gray-headed and pink-sided – white-winged should be noticeably larger. Lacking contrasting lores that aikenii (white-winged) would have; and throat is not paler as you would expect in aikenii. Didn’t get a good read on amount of white in tail feathers. Overall, the bird was darker (slate-colored) that you would expect for white-winged; but I don’t think the photos capture the true tone correctly and show it a bit lighter than it looked with naked eyes and binos. Got fair enough pics through the dirty window with sun on it. http://www.sendpix.com/albums/11032116/16411000000000754107cec347bed66d00c670cb7366/ Certainly welcome any comments if others feel that this might be an aikenii. Jeff J Jones ([email protected]) Teller County - 8500' - Montane Woodlands -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/cobirds?hl=en. -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/cobirds?hl=en.
