I finally finished a call count and basic evaluation of the notable early
August night flight from Etna, NY. Data were collected from 20:54-05:45 EDT.
All data were hand-browsed. The most difficult aspect of this was the pervasive
early cricket noise in the 2.5-3.0 kHz frequency band.
Correction! "Amplification" is the incorrect term to use in my previous email.
A better explanation would be that the amplitude of the source sound will
decrease less when produced over something reflective, such as the smooth
surface of a calm pond or lake (or harbor channel...), versus
And...sound is amplified when reflected off the smooth surface of water.
Similar to how, from shore, you can hear people vocalizing while they are
boating or swimming out on a lake or pond, even though they may be relatively
far away. It all makes sense now.
Good discussion, though.
Chris -
Unfortunately, that salt marsh is close to relatively dense suburban areas,
with houses as close as 0.5 km (right across the harbor channel) and a golf
course directly adjacent to it. I am not that surprised that a sound like
this drifted across the water, although it is better recorded
Fascinating. The sound is remarkably similar in structure to Red-headed
Woodpecker, when viewed as a spectrogram (I had initially only listened to it
with my iPhone); however, I notice that this example does start off with
intense modulation, followed by a more pure tone. This is different from
Amazing. Bill, I think your first impression may be right. I went back to
the original file (which I *had* gone back to, but hadn't looked more than
several seconds on both sides of the sound in question to see if there was
anything related). Sure enough, starting about 8 seconds earlier I start
Oops, I overlooked that the call was from May 12, which would be in the window
for a spring migrant in NY, though the call sounds doesn’t sound like it is
from a bird in flight.
Bill E
From: Bill Evans
Sent: Tuesday, August 07, 2012 9:38 AM
To: Benjamin Van Doren ; Christopher T.
My first impression was a scream from a girl on a swing set. I then quickly
came around to agreeing with Ben’s first impression and Chris. Pretty early for
migrant RHWO though, as based on my experience their southbound migration in NY
is the latter half of September and early October – perhaps
Dave,
Your prediction was pretty good. There were mixed results Sunday night
depending on whether one was listening to the east or west of the cold front,
and as it turned out, last night was the biggest night flight calling event of
the season across northeastern US.
Bill E
From: david
