I was hoping someone else would give you some feedback on your nice series of
thrush calls. Not only have I been talking too much lately but this topic can
be a special quagmire.
I want to note that I have one monitoring station that is the first landfall
directly southwest of the island of Newfoundland. Therefore, the flight calls
of Gray-cheeked Thrush that I record there are very likely Catharus minimus
minimus. They are consistently less humped and more descending than Catharus
minimus aliciae. Their maximum frequency is 4 KHz or a little greater. I had
another monitoring station that is the first landfall southwest of Cape Breton
Island where Bicknell’s Thrush breed. These thrush calls have a maximum
frequency over 5 kHz. I have attached a photo illustrating these three types of
calls, including one from Louisiana provided by Bill Evans. Perhaps some of
your calls are C.m.minimus. Given this race is believed to winter in South
America, including Columbia, one cannot rule out the possibility of them flying
over Etna, NY.
It would be interesting to get a series of night flight calls from these two
species in areas close to their breeding range.
[mailto:bounce-120825839-28417...@list.cornell.edu] On Behalf Of Christopher T.
Sent: September-26-16 08:15
To: NFC-L <nf...@list.cornell.edu>
Subject: [nfc-l] Bicknell's Thrush - More Classic Example
Albeit soft and slightly distant, this bird was recorded over Etna, NY on 23
September 2016 at 23:25.
I would consider this to be a classic example because its peak frequency is
above the 5kHz “safety” demarkation line.
This bird peaks around 5.25 kHz and has an overall duration of about 250
milliseconds. Similar to the “possible Bicknell’s Thrush” examples posted
yesterday, the sharp onset followed by a variably modulated and notably longer
trailing descent is the call structure which caught my eye while browsing
through my data last night.
Attached are both the recorded call (with some lower cricket and noise bands
gently filtered out) and a screen grab of the call for visual representation.
Good night listening!
Christopher T. Tessaglia-Hymes
Field Applications Engineer
Bioacoustics Research Program, Cornell Lab of Ornithology
159 Sapsucker Woods Road, Ithaca, New York 14850
W: <tel:607-254-2418> 607-254-2418 M: <tel:607-351-5740> 607-351-5740 F:
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