<<Chuck said: "An interesting difference between the two recordings. The
Dickcissels I heard last month in Morgan, Washington, and Yuma Counties
while doing BBS routes were all similar to SeEtta's Canon City area
recording. In those counties, I haven't heard birds singing the song type
recorded by Nathan Pieplow in Prowers County. Birds of North America Online
reports there is individual variation in song within populations of
Dickcissels, but no differences between populations. The BNA account also
notes that Dickcissel vocalizations have not been well studied." >>

Chuck's identification of the same song by the northeast Colorado
Dickcissels as the one I recorded in Canon City is interesting especially
in light of the following info from an abstract, "GEOGRAPHIC PATTERNS OF
SONG SIMILARITY IN THE DICKCISSEL" published in AUK in 2008.

   - "Abstract.—Song sharing among neighboring males is a well-known,
   frequent outcome of song learning in oscine passerines
   and some other groups, but only limited investigations of the spatial
   scale of this phenomenon have been pursued. On the basis of recordings of
   1,043 individuals, we investigated song sharing in Dickcissels (Spiza
   americana) at local and regional scales at sites from northern Kansas to
   northern Oklahoma. Classification of song elements revealed decreasing song
   similarity with increasing distances between individual birds at small to
   intermediate scales, to ~10 km. At the largest spatial scales (10-300 km
   between sites), there was very little similarity among sites and no obvious
   tendency for a decrease in similarity with increasing distances among our
   30
   sites.  At our intensively sampled site, analyses of quantitative
   measurements showed that, at least for our most widely shared song
   element,frequency and duration were more similar in closer birds. Thus,
   distance between birds influences both quantitative and qualitativesong
   similarity in Dickcissels. Variability existed among sites in the shape of
   the song-sharing decay curve, which indicates that other factors besides
   distance also govern song-sharing patterns..."

Given that study it would seem more likely that Nathan Pieplows Dickcissel
from Prowers County would be more similar to the Canon City Dickcissel
since it is located much closer than Chuck's Dickcissels in northeast
Colorado.  It would be interesting to know if the Dickcissels being
reported near Boulder and Longmont sing songs similar to either in my
recording or Nathan's <http://birdsandnature.blogspot.com/>.

BTW, I should have noted that the song I recorded from the Dickcissel in
Canon City this year is the same song (with minor variations I hear not
only between birds but between songs by one bird such as an extra 'ciss,
ciss') I have heard from Dickcissels that I have followed in the Canon City
area since the first Dickcissel was found (I was present but not the
identifier).

SeEtta Moss
Canon City
Personal blog @ http://BirdsAndNature.blogspot.com
Blogging for Birds an Blooms Magazine @ http://BirdsAndBloomsBlog.com

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