Slate-colored Junco with broad white wing bars - Teller Co
Jeff J Jones
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
Teller County - 8500' - Montane Woodlands
Christian Nunes
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
paja...@hotmail.com
From: JJo...@JonesTC.com
To: cob...@googlegroups.com
Subject: [cobirds] Slate-colored Junco with broad white wing bars - Teller Co
Date: Mon, 21 Mar 2011 10:48:48 -0600
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Jeff J Jones
NOTE: I appreciate Christian responding to the group on this and I hope that if you find this too long you just delete it. If all the experts in their own areas have private conversations about this offline, we all cannot learn from them. And I hope/believe that this is one of the goals of this list. I realize there are also several blogs/forums for discussing such difficult identification, but hope that we can continue to discuss particulars here that are germane to Colorado birders. For example, Limpkin ID issues may not belong here but junco subspecies differentiation seems particularly useful for Coloradans.
Christian,
Thanks much for the analysis. And, as I continue to learn the intricacies of Junco race differentiation, allow me to ask a few exploratory questions.
First, you mention brown in the tertials. I don’t see that. In fact, I went back to the dozens of photos I took in my photo software (where I can blow each photo up as needed; camera has an 11Mpixel resolution) I don’t see anything that makes me think brown in its tertials. A couple pictures maybe hint at it, but I think that is just backlighting. I don’t remember seeing any brown when looking through binos at 20 feet.
Now, this often confounds me as when, in the CFO quiz answer, Tony says something about a photo that I don’t remember noticing. I download the photo, import it into my bitmap/photo software; blow it up; look at it from every angle; and I will be darned if I see what he sees. I start thinking, perhaps he has a better resolution picture than the photo quiz that he is using for description, or since he has other angles of the same bird, he knows what should be there – but lots of times I simply cannot find what is being described – such as ‘brown tertials’. In either case, I cannot find an indication of brown in this bird’s tertials. I say this just to let you know that there is evidence that this is all my color perception problem. J
In addition, we discussed this on CoBirds a couple months ago; but brown tertials, even if present, as I understand it, are not an indication of age. Adult females of all races (according to Pyle) can have brown terts after hatching year. Shape, however, should be and age indicator. But I didn’t get a good photo or look at that.
Thanks for pointing out the bit on the presence/absence of lores on aikenii. I will try to get that field mark out of my mind now.
And since I didn’t get the amount of white in the tail, we are left with size. I didn’t think many years ago that one could differentiate the small size differences between the Junco races. But when dozens show up at your feeder for months each winter, it becomes quite easy (once you know to start looking) to spot at a glance the difference between the large and bulky pink-sided and white-winged, for example, and the small Oregon or medium gray-headed/slate-colored. This bird was small; Oregon and slate-colored size. I thought I was getting pics with other juncos in it, but the only one that came close was the one I posted. This bird was also near several dinstinctly slate-colored individuals and appeared to me to be the same size as those.
So, interested in knowing if you still feel confident about the white-winged diagnosis?
If so, perhaps I can get you to take a different approach and tell me why it can’t be a slate-colored? Some percentage of slates have white wing bars of varying degrees as we all know.
You also mention the bill color. Is this a reliable field mark for separating hyemalis from aikenii? Pyle says “pale pinkish to whitish” for slate; with no mention for white-winged.
On another note, Sibley also states a “pale throat” on white-winged individuals. But I don’t find that backed up anywhere else. Is this a generalization also that can’t be trusted? The bird I photographed does not seem to have a pale throat or a throat area otherwise differentiated (pic 146a) from the rest.
Thanks
Bruce Webb
Wow.� Could you provide a photo of a White-winged Junco as dark as or darker than a Slate-colored Junco?
I guess it depends on if said Slate-colored is a pale one, but I have never seen anything approaching slate as you described.
When I was banding juncos in Bluebell Canyon decades ago, I photographed more than one Slate-colored Junco (in every respect) showing thin, but distinct wingbars. Such "white-winged juncos" are well represented in the literature on online photos.� These birds never have the 3-4� white rectrices, nor, if I recall from my photos, the pinkish or bicolored bill typical of a Slate-colored.�� I only remember White-winged Junco males being unicolor lighter gray.� A photo would be really nice to see.
For a look back here is an article I wrote about two hybrid juncos I banded in Boulder.� One hybrid that I called 'Rusty" is in color on the pdf.
http://elibrary.unm.edu/sora/wb/v11n04/p0205-p0206.pdf
Bruce Webb (former Boulder birder visiting Colorado Springs this week and enjoying lots of Juncos.)
Granite Bay, CA
On 3/21/2011 11:22 AM, Christian Nunes wrote:
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
paja...@hotmail.com
�
From: JJo...@JonesTC.com
To: cob...@googlegroups.com
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.
Certainly welcome any comments if others feel that this might be an aikenii.
�
�
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-- Bruce Webb Granite Bay, CA 'Have scope - Will travel'
Bruce Webb
Christian's Junco photos with frost or snow covered vegetation reminded me that White-winged Juncos would show up in Bluebell Canyon after a light dusting of snow.� I assumed they were at higher elevation when it was not snowing.
On Monday behind the Red Rocks Trading Post there was a nice mix of 4 types of Juncos, but none with white wings.
I would love to look for any recent White-winged Junco sightings along the Front Range.� Anybody?
Bruce Webb
visiting from Granite Bay, CA
Christian Nunes
1) Intergrade vs. Hybrid- The rigid definition is as Bruce describes, with "hybrid" being ascribed to the interbreeding of two "species", and "intergrade" as a mixing of two subspecies. But this definition has its flaws, especially when applied to superspecies like the Dark-eyed Junco. For instance, there are cases of secondary hybridization between White-winged and Pink-sided Juncos. They do not have a hybrid zone, or an area of introgression, where you find a mixture of parental types. A few individuals may turn up in each other's adjacent ranges and hybridize. In the case of Gray-headed x Pink-sided, there are several regions, entire mountain ranges, where there are intergrade populations, with most individuals showing mixed characters. Most cases of junco hybridization can be described as intergrades. But in some cases, such as with White-winged x Pink-sided, the cases are so rare that describing the event as hybridization is perfectly acceptable, as far as I am concerned. The known rate of hybridization between White-winged and Pink-sided is less than the rate found in areas of Yellow-eyed x Dark-eyed Juncos. Interesting.
2) Recent sightings of White-winged Juncos- I found one yesterday in a burned Ponderosa Pine forest in Jefferson Co. It was associating with a Pink-sided. As others have noted, Pink-sideds and Oregons are moving through. A few scattered Gray-headeds are turning back up on the breeding grounds. White-wings are moving out, I think, with a few still around. The birds I have seen recently have predominantly been hatch-year birds. I haven't seen a spanking adult male White-winged in a few weeks.
3) Intergrade Pink-sided x Gray-headed- Bruce, I've had your article for a while and appreciate that someone took the time to publish on that situation. I used to see a few a winter in AZ, and I see them in CO annually. As I think you mention, Miller (1941) identified several regions of introgression. These include several mountain ranges due north of the CO border in WY, as well as areas of northern UT. Photos:
http://www.flickr.com/photos/christian_nunes/5155736875/
http://www.flickr.com/photos/christian_nunes/5156347106/
4) White-winged Junco Darkness-
Miller made a scale to judge the head darkness of juncos. It ranges from 1-11, from darkest to lightest. One the dark end are the Oregon types (NOT Pink-sided!). On the pale end are Pink-sided, White-winged and Carolina. Here's a little table:
Male Pink-sided: 9-10
Male White-winged: 8-10, typically 9
Male Slate-colored: 6-8, typically 7
Male Montana "Oregon": 4
Male Carolina: 8
Female Pink-sided: 9-11
Female White-winged: 10-11
Female Carolina: 8-10, typically 9
Female Slate-colored: 8-10
From this data, I ascertain that there is a lot of variation in head color between the sexes and between subspecies groups. Some female Slate-coloreds are as pale as male and even female Pink-sideds and White-wingeds. White-winged males can be as dark as a male Slate-colored (both can be an 8). This jives well with my experience with White-wingeds in CO. Some adult males are strikingly dark (http://www.flickr.com/photos/christian_nunes/3055226426/), young birds are not (http://www.flickr.com/photos/christian_nunes/5172728728/). A photo will be published in the upcoming Colorado Birds of an adult male White-winged specimen that is at the dark end of the spectrum. I can't share those here, unfortunately.
Now take a look at the Sibley Guide. I don't have mine in front of me, so can't tell the page numbers, but there should be Pink-sided next to White-winged, next to Slate-colored. I would judge Sibley's colors on Miller's darkness scale as Pink-sided (10), White-winged (9) and Slate-colored (7). He chose to represent the averages.
5) Tertials-
Jeff wrote:
<In addition, we discussed this on CoBirds a couple months ago; but brown tertials, even if present, as I understand it, are not an indication of age. Adult females of all races (according to Pyle) can have brown terts after hatching year. Shape, however, should be and age indicator. But I didn’t get a good photo or look at that.>
Well now, I never got on this train. Brown tertials, when present on particular sub-species, are highly indicative of age. I come to this conclusion from reading Pyle. It might not be possible to age/sex every single bird, but there are some things to look at to get a pretty good clue.
During a juncos' first Pre Basic (PB) molt, they can replace 0-3 of their tertials. This occurs from July-October. Southern subspecies are more likely to replace all three tertials, northern birds (White-wingeds) less so. So a bird like this can be reliably aged as a HY because it has replaced one brown-edged juvenile tertial with an adult gray-edged tertial (http://www.flickr.com/photos/christian_nunes/5172125607/). This bird hasn't replaced any tertials, so they are all edged with brown (http://www.flickr.com/photos/christian_nunes/5172728728/). It is still pretty clearly a HY bird because of the brown wash, and the brown tertials! Who says adult female White-winged Juncos have brown tertials? I don't believe that. White-wingeds are characterized by having less sexual dimorphism than other subspecies, notable less than the sexual variation in Slate-colored. So, if you said that brown tertials on a female Slate-colored weren't a reliable indication of age, I'd agree that that could be a possibility. In Pyle, he describes After Hatch Year female juncos' tertials as being, "dusky with brown (western subspecies) to gray (eastern subspecies) edging." I take that to mean that an adult female Slate-colored, Carolina and White-winged can or should have gray-edged tertials.
A White-winged, Slate-colored or Carolina Junco that has a mixture of retained brown-edged juvenile tertials and replaced gray-edged adult tertials can be reliably aged. I believe I am seeing this effect on Jeff's bird, but it's hard to say for sure. I would also argue, according to my view on my monitor, that his bird is of about type 9 or 10 on the color scale, which is more in the range of White-winged. And also, the white wing-bars on his bird are very thick and pronounced. I have never seen a variant Slate-colored that has this much white on the median and greater wing coverts. Despite the apparent small size (highly relative), I don't see much else to suggest that it's not a White-winged. Bill color is useful, but maybe not definitive for every individual. Slate-colored rarely has the whitish-horn colored bill that White-winged and Carolina Juncos often have. They are much more typically pinkish, with some duskiness around the nostrils or on then ridge of the upper mandible. Bill size is diagnostic. Your photos don't give the detail that is desired to get a good feel for the bill size, but in at least one photo it is suggestive of White-winged (http://www.sendpix.com/albums/11032116/16411000000000754107cec347bed66d00c670cb7366/?a=view&i=506344&d=0).
Ok, on with my life! Sheesh.
Christian Nunes
