Wednesday, December 11, 2013

More on Bell's and Sagebrush Sparrow

I checked through my notes and photos and found that I do not have a photo of Bell's Sparrows from Ukiah, California.  I saw and heard Bell's (Sage) Sparrows at Cow Mountain Recreation Area east of Ukiah with distinct white marks in the lores and very gray heads and unstreaked backs.  I heard the tinkling call of Sage Sparrows, which are similar to juncos.  In addition, I also saw Fox Sparrows, which I obviously photographed.  The Fox Sparrows had a very thick call note, "tschup."  I am not sure where the "Salt" came from in the name I previously used, Saltbrush Sparrow instead of Sagebrush Sparrow.  I wrote a lot of that blog post for Arizona very early in the morning at Adak when I got up regularly at about 4:00 am.  Maybe I wasn't really awake as claimed by my Adak colleagues!  :>)  :>) 

With regard to the record of Bell's Sparrow, I believe that I saw and photographed the canescens subspecies of  Bell's Sparrow at the Thrasher Spot in Arizona.  Bell's Sparrow includes belli and canescens.  Belli has a dark grey head, thick malar stripe and no (or sometimes very little indistinct) streaking on the back while canescens has little streaking on the back and a malar strip that is intermediate in width between the very thin malar strip of Sagebrush Sparrow (nevadensis) and the thick malar strip of belli.  In general, canescens is intermediate between belli and Sagebrush Sparrow.  I have used the excellent summary article about field marks, by David Vander Pluym, which points out that the width of the malar strip may be the best field mark to distinguish the two new Sage Sparrow species, Bell's and Sagebush, as well as the canescens subspecies.  See also Neil Hayward's discussion on his Accidental Big Year Blog.  Below I include photos of what I believe are Bell's Sparrows, the canescens subspecies with the rationale included in the captions.
Bells Sparrow (canescens)
very little to no streaking on back, intermediate width malar stripe
Bell's Sparrow (canescens)
same bird as above, slightly different view
Bell's Sparrow (belli or canescens?)
apparent thicker malar stripe may be caused by the angle of viewing, light and shadows, unstreaked back

Bell's Sparrow (belli or canescens?)
same bird as immediately above, note difference in appearance of malar stripe

Bell's Sparrow (canescens?)
Bell's Sparrow (canescens?)
same bird as immediately above
notice how angle of viewing and light affects the appearance of malar strip
It is an adventure in field identification to identify these new species and related subspecies of Sage Sparrow.  I make no claim to expertise in this area, and have learned a lot and will probably learn more in the future on how to identify these new species and subspecies of Sage Sparrow.   There is a lot of variability across individual birds of these two new species and of the existing subspecies.  If time permits this year, I will try to see the belli subspecies of Bell's Sparrow, if my path to other new birds of the year takes me within range of belli.  The reason for wanting to see both canescens and belli is to preserve a possible additional species if canescens is split in the future as a separate species.

There is no change in my total species list reported in my post, Clean Sweep in Arizona.     


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