I have been noticing all spring that the number of singing birds in our vic=
inity has been dramatically down this year compared to previous years. I do=
n't know if this is true for the area in general or just around our house, =
but the absence of many of our regular singers (especially veerys and wood =
thrushes) has been conspicuous. I've been waiting for the solstice to docum=
ent it, because I started last year to record the dawn chorus on the mornin=
g of the solstice.
I posted a 1-minute clip on soundcloud with the result.
http://snd.sc/125LGYo
The first 30 seconds is from last year, and the second 30 seconds from this=
morning. I recorded for three hours both years. These clips both come from=
approximately 6:00 am EDT. The chorus usually begins around 4:15 and ends =
by 7:00. I chose these clips in part because they are not masked by one bir=
d vocalizing very close to the microphones. Last year a catbird and this ye=
ar a robin drowned out large segments of the recording.
Both clips were recorded using a home-built boundary array based on EM172 c=
apsules. The 2012 clip was recorded on a Sony MZRH1 minidisc recorder and t=
he 2013 clip on an Olympus LS-11. I usually run the LS-11 on low sensitivit=
y, and the MZRH1 on high sensitivity, so I have raised the level of the sec=
ond recording to make them roughly comparable, probably within a dB or two.=
The location and orientation of the microphones is the same both years. Th=
e hiss is not microphone noise but two streams that run through the propert=
y.
I am really puzzled by this decrease in singing bird activity this year and=
wonder if others are experiencing the same thing.
John
John Crockett
Westminster, Vermont
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