Update: May 25, 2002: Here
are two recording clips from Alberta; they are copyrighted
by and courtesy of Jim and Barb Beck of the University
Clip One is representative of the BHVIs in Alberta.
Clip Two is representative of the CAVIs in Alberta.
On the mornings of May 13 and 14, 2002, I heard and saw a "Solitary-type" vireo in my yard (located on southwest corner of Lake Worth, west of Fort Worth, Tarrant County, Texas). I did not attepmt photos, as I obtained very good views that confirmed it was either a very dull, poorly-marked Blue-headed Vireo (BHVI) or a bright-ish Cassin's Vireo (CAVI). It sang regularly, yet intermittently, for about an hour each morning, and I concentrated on obtaining audio recordings. I presume that it must be a male, given the persistent singing, thus I feel that the observed plumage would possibly be too dull for a male BHVI, yet well within the brighter end of the range for male CAVI (I wrote a full description).
The most ear-catching note in its repertoire was interspersed
about once every 8 - 15 notes, and is in this file: vireo1b.wav
- to hear it in context, as the 4th note in a phrase of six (it was typically preceded by a pause), listen to this file: vireo1a.wav (2,532Kb)
The most frequent note-phrase was a two-note sequence typified by this file: vireo1c.wav (967Kb) - but with numerous minor variations in modulation; some less burry, some more burry.
Another phrase that was used in unpredictable bursts (fairly long sequences without it, yet some with it being used 2 or 3 times in succession) is in this file: vireo1d.wav (1,031Kb).
Some of the upslurred high notes were so rapidly-ascending that they strongly recalled American Goldfinch's "jeiiII!" note.
I would appreciate getting feedback about these vocalisations (I have lots of audio, but the constraints of my dial-up WWW connection limit me to brief cuts); especially:
- can BHVI be reasonably ruled out, based on these recordings?
- does it sound like CAVI?
- could PLVI be ruled out, based on the recordings (on plumage it is definitely ruled out - this bird has obvious - yet dull - greenish flanks and greensih edges to the remiges)?