Nocturnal migration, Frick
Park
19-20 September 2005
Ted Floyd
The following post from Ted Floyd appeared on PABirds on Friday, September 23. Republished here for those who do not subscribe to PABirds.
Subject: [PABIRDS] Nocturnal migration, Frick Park, Allegheny County,
19-20 September 2005 From: "Ted Floyd" <tedfloyd@ABA.ORG>
Date: Fri, September 23, 2005 9:08 am
To: PABIRDS@LIST.AUDUBON.ORG
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Hello, birders.
I spent the early morning (late night) hours of Monday and Tuesday, 19 and
20 September, listening to nocturnal migrants flying over Pittsburgh's Frick Park.
Monday morning was fabulous. In the coupla minutes that I waited on Beeler
Street for Steve Carbol to pick me up, shortly before 5am, I heard a few
Swainson's going over. And in the coupla minutes that Steve and I searched
for Dave Wilton near the Frick Park Nature Center (needless to say, Dave being Dave, he was there early), right around 5am,
we heard Swainson's going off pretty much continually. At around 5:15
a.m., although we were distracted by three vocal Eastern Screech-Owls, not to mention my imitations thereof, we were still
hearing Swainson's Thrushes. Next, we hoofed it up to the summit of
Riverview Hill, and set up on the north side of the hill, about 15
vertical feet from the summit (maybe 300 horizontal feet from the
summit). And the next hour was amazing. Swainson's Thrushes were audible
pretty much continually, sometimes going off at >1 per second, sometimes
"slowing down" to ~5 per minute. We also heard 25+ Wood Thrushes and 15+
Gray-cheeked Thrushes that I felt pretty good about the identification of,
and we had 5+ vocalizations that I thought were good for Veery and 2 that
sounded like Hermit (but the Hermit/Swainson's distinction is fuzzy, to my
ears, anyhow). And, of course, several hundred thrushes that we weren't
sure of. Our main concentration was on the spot-breasted thrushes, but we
also heard some Chipping Sparrows, some Scarlet Tanagers, some Blackpoll or Blackpoll-like Warblers, maybe a Northern
Waterthrush, and the usual unidentified birds. During the daylight hours,
down on the ground, we heard many more Swainson's Thrushes (giving their daytime 'pip' call) than we had during the daylight hours
the day before.
Tuesday morning was comparatively slow. In 1+ hour of listening from the
same spot, Steve and I and three other members of the Three Rivers Birding
Club had only ~15 Swainson's Thrushes, 2 Wood Thrushes, and 1
Veery. The birds were, on the whole, quite a bit higher up than they had been the
day/night before. During the daytime hours, there were still a lot of
Swainson's and Wood Thrushes on the ground, and, indeed, I saw and heard
several right in town, during the course of various non-birding activities. So I'm thinking there was a big arrival
overnight on Monday, with birds lingering on the ground (at least) through
Tuesday.
THE BIG QUESTION: How do y'all in Pennsylvania count these birds? On the
one hand, if you're simply reporting the numbers of calls, then we had
more than a thousand Swainson's Thrushes on Monday morning. But it's no
doubt the case that a single bird can call repeatedly on its way over. On
the other hand, the "rarer" thrushes that we heard typically called just
once during their period of audible transit past Riverview Hill. On the
other other hand, call frequency presumably varies among species; for
example, maybe individual Swainson's Thrushes call with greater frequency
than do individual Wood Thrushes, or whatever.
In any event, the nocturnal thrush migration over Pennsylvania is
amazing. I used to think that the most special thing about birding in
Pennsylvania, from my western perspective, is the warbler passage
through the state. (Now, don't get me wrong; those warblers *are*
amazing. But, relatively speaking, we get some pretty impressive warbler
flights out West; daily species counts are lower, but tallies of
individuals can be just as good, and the potential for rarities is
considerably greater.) But, for my money, honestly, the most evocative,
the most magical, thing about birding in Pennsylvania is the passage of
nocturnal migrants on chilly autumn nights. I strongly concur with those
on this list who are encouraging the rest of us to get out and observe
nocturnal migration.
Oh, and it was great to see so many of y'all these past few days!
All the best,
Ted
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Ted Floyd
Editor, Birding
American Birding Association
P.O. Box 7974
Boulder, Colorado 80306-7974
303-444-6363
tedfloyd@aba.org
Please visit the website of the
American Birding Association:
http://www.americanbirding.org
