Rich Ditch's Photography Blog

April 23, 2009

More Questions than Answers

Filed under: Birds, Boyce Thompson Arboretum, curiosities, favorite places, light — richditch @ 3:20 pm
Mystery Bird at Boyce Thompson Arboretum 090421

Mystery Bird at Boyce Thompson Arboretum 090421

Usually I know what I’m photographing, and if I have some question about identity in the field I can figure out my subject from the photo and my too large collection of books. But I’m having trouble with this bird sen at Boyce Thompson Arboretum, near Superior, AZ, on 04/21/09. (8:42 AM)

It came into the fake waterfall with Yellow-rumped Warblers including the nice male I posted here yesterday. I didn’t think much about it at the time (it stayed in the darkness on the rocks themselves), but I took a few shots just to see what I’d get. At ISO 800 I could only get 1/40th second wide open at f/5.6, and even with the 2x on my 300/2.8 this tight composition required a significant crop. I’ve done that only to show maximum detail on the bird rather than go with my usual small-in-frame compositional style.

My questions:

  1. is this a Yellow-rumped Warbler
  2. is this a molt I don’t normally see here
  3. if not a molt, is it a juvenile
  4. if so, what’s it doing at Boyce Thompson Arboretum (where they shouldn’t breed) at this time of year (the AZ BBA shows they breed in the High Country beginning in May)
  5. if its not a Yellow-rumped, what are the other possible warblers it could be (Lucy’s and Yellow both breed here but it doesn’t look right for either)
  6. is the bill too fat for a warbler anyway
  7. could it be a vireo (bill seems wrong for that as well)

Ok – please tell me what you think it is, and why.

Addendum 04/24/09:

So far I’ve received 17 replies, including the comments here. They break down as follows:

  • Yellow-rumped Warbler: 1 for Audubon’s (the western form), 5 for Myrtle (the eastern form), and 8 undecided or unspecified. Total Yellow-rump: 14
  • Pine Siskin: 2
  • Western Bluebird: 1

My thanks to all who provided input and especially those who gave detailed analysis.



  1. Hey Rich,

    Looks like an “Audubon’s” Yellow-rumped to me. I’m not looking at any books right now, but my guess would be that it is a first winter female that is *extremely* worn. The coverts and tail feathers especially look like the war, so to speak.

    Comment by John Yerger — April 23, 2009 @ 3:55 pm

  2. Have you considered a juvenile Western Bluebird?

    I suspect it’s much too early in the year for that. (I’m only beginning to learn about breeding seasons, and I don’t have any of my guide books with me.)

    Nonetheless, the bill profile and bluish tail and rusty streaking make me wonder.

    To me, it does not look much like a Yellow-rumped

    Comment by John Ulreich — April 23, 2009 @ 5:24 pm

  3. This bird, & many very close in plumage, are Yellow rumped Warblers, most likely a last year female. In my last life, I saw many almost exactly like this ever spring. I could be wrong, but this is my 2 cents worth. Roger Tess, Tucson

    Comment by Roger Tess — April 23, 2009 @ 5:59 pm

  4. I believe this is an adult female yellow-rumped warbler, but cannot say for sure whether it is myrtle or Audubon’s.
    Pale throat (myrtle or Audubon’s female)(but Audubon’s should show a tinge of yellow, this bird doesn’t=favors myrtle)…goes into thin streaking (Audubon’s) but has thick flank streaking (myrtle)
    mostly eye ring, no whitish line through eye=more likely Audubon’s, though the lighting in this photo isn’t best for seeing eyeline.
    the little splotch of yellow on the lateral breast essentially marks it as a yellow-rumped.
    probably a first spring female not full molt from last fall.
    bill looks thick, but much of that could be projection as the bird has a 1/8 turn towards the camera.
    Incidence…THE most common warbler, earliest migrant, in Arizona now…they were all over the place and were the most common, with orange-crowneds second, at Huachuca canyon Saturday the 18th…much less common, but one bird seen seinging beautifully there, was a Sinaloa wren!

    Karl Stecher
    Centennial, Colorado

    Comment by Karl Stecher — April 23, 2009 @ 6:52 pm

  5. Hi, Rich,

    I second most of Karl’s remarks but would lean much more strongly toward second-year female “Myrtle” based on the extremely dull, worn plumage and the shape of the whitish throat patch – extending back along the sides of the neck to a point rather than rounded as in “Audubon’s.”

    Given the distribution of western “Myrtles” to the north of “Audubon’s,” there would be no rush for members of this form to get to their nesting grounds.

    Comment by Sheri — April 24, 2009 @ 9:47 am

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