Date: 7/9/18 10:52 am
From: Lars Norgren <larspernorgren...>
Subject: [obol] If a bird sings in the forest and no human is there to hear it....
I live in the middle of extensive woods, and sometimes don't make the
commute to Portland until mid day. I've noticed that after the dawn chorus
there are long periods of quiet. Then some bird will start to vocalize, I'm
not sure if it's necessarily singing, and in the course of 90 seconds many
other unrelated species will also vocalize. Eventually every species within
earshot seems to have joined in. I've never taken notes: Is it some
particular species or set of spp that initiates things? It seems like
non-passerines make up part of the mix as well. This is a year round
phenomenon, not just spring.
I don't know if I've had the experience away from home. When in a
birding mode I'll probably move on in the face of two minutes' quiet. The
silent spells preceding said sonatas may last 20-40 minutes. Someone at
this year's Willamette Valley Bird Symposium gave a talk that was at least
tangential to this topic, but when I tried to describe it during a break
his dismissal was thunderous. I assume this brief,semi-spontaneous chorus
is widespread, even universal. I would say it it's characterized by calm
and leisure, never involves alarm calls or anything that could be construed
as mobbing response. The vocalizations come from all quarters, never a
focal point. It's extremely pleasant to experience as I'm texting and
responding to customers. Not a new phenomenon, it's been bonus wallpaper
the whole 2 1/2 decades we've lived here.
Certainly has implications for point counts. Last weeks BBS along
Hwy 6 involved almost continuous traffic noise at 11 stops, yet at one of
those stops I detected a dozen species, more than double the average count
at the others. Lars

 
Join us on Facebook!