Re: [SBB] local Savannah Sparrows query

[Bill Bousman <[[email protected]]>]

At 12:46 PM 10/16/05, Tom Grey wrote:
> Where are we with classification of SAVANNAH SPARROWS found locally? Here
> is a 1996 exchange on the subject I found via Google between James Rising
> and Steve Rottenborn back in 1996:
> http://listserv.arizona.edu/cgi-bin/wa?A2=ind9610b&L=birdchat&F=&S=&P=7734
>
> I'm stimulated to ask by a SASP picture I took yesterday at the Shoreline
> Amphitheater overflow parking lot. This is a "typical" or "grassland" SASP,
> right?
> http://www.pbase.com/tgrey/image/50799522
>
> Are the "typical" SASPs found near the Bay winter residents only? Do we
> have year-round (nesting) "typicals" up in the foothills?
>
> By contrast, here's what I understand to be one of our resident saltmarsh
> types:
> http://www.pbase.com/tgrey/image/32810299
>
> I labeled that one a "Belding's," following the Rising sparrow book. But I
> see that other books, and the BNA Savannah article,  say that Belding's
> extends no further north than Morro Bay. If Belding's is a candidate for
> species status, this may be of general interest to local birders.

Folks:

Locally, we have multiple populations of breeding Savannah Sparrows.  Most 
in Santa Clara County are found around the edge of the South Bay, but 
upland birds are found in fog-shrouded grasslands along the Santa Cruz 
Mountain crest, in the southern Santa Cruz Mountains above the Pajaro River 
(often affected by fog as well), and west of the Coyote Narrows, which is 
seemingly unaffected by fog.  Whether all of these breeding birds are 
resident is unclear.  There have been no banding studies that would 
determine whether they are resident or summer visitants.

Tom's questions as to whether there are differences between the salt-marsh 
birds and the upland birds has been asked by many thoughtful observers for 
more than a century.  Many have noticed differences (Squires 1916, 
Mailliard 1917), while others, using a larger series of specimens have 
concluded that there is no great difference (Mailliard and Mailliard 
1920).  Although Rising (1996) ascribed the salt marsh birds to _beldingi_, 
in later work (Rising 2001) the issue was considered to be unresolved.

It is possible that systematic photographs may assist in this effort, but 
it is likely that specimens will be required to obtain a complete resolution.

Steve Rottenborn has spent some time with this issue and most of my 
comments above are from a draft manuscript he has written.  He may wish to 
elaborate on this issue or correct errors on my part.  He agrees with 
Rising (2001) that the issue is not resolved at the present time.

Bill

References (most available on SORA on the web):


Mailliard, J.  1917.  Concerning the two forms of the Bryant marsh sparrow 
in California. Condor 19:69-70.

Mailliard, J. and J. W. Mailliard.  1920.  Bryant marsh sparrow upon the 
hills. Condor 22:63-66.

Rising, J. D.  1996.  A Guide to the Identification and Natural History of 
the Sparrows of the United States and Canada. Academic Press, London, UK. 365.

Rising, J. D.  2001.  Geographic Variation in Size and Shape of Savannah 
Sparrows (Passerculus sandwichensis). Studies in Avian Biology 23.

Squires, W. A.  1916.  Are there two forms of the Bryant Marsh Sparrow in 
San Francisco County? Condor 18:228.



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