After a stretch during which Mansfield's weather was fit for neither bird
or beast (humans anyway), VCE returned to our long-term study site after a
2-week hiatus. Last week's field trip was scuttled by the polar express
that saw wind chills of 14F on the ridgeline.

Brendan Collins, Steve Faccio, Susan Hindinger and I arrived on the
ridgeline in early evening on Tuesday to mostly clear skies, but a brisk
northwest wind. Other than American Robins, of which 4 were singing
robustly within earshot of the parking lot, we heard few birds. We fanned
out and set 27 nets, mainly on the Amherst, Long and Lakeview trails. Our
first capture was a Yellow-bellied Flycatcher, second a Swainson’s Thush.
Although we were treated to a spectacular sunset, with the Nose positively
glowing, the dusk chorus was subdued. I don’t think I’ve ever heard so few
Bicknell’s Thrush (BITH) singing and calling on Mansfield in mid-June. Even
the White-throats were muted. A few BITH let loose with brief flight songs
as darkness fell, but with far less intensity than 2 weeks ago.



The wind dropped overnight, and we were back on the ridgeline shortly after
4 am to open nets. The dawn chorus continued evening’s uninspired trend,
with robins again providing a notable exception. This weak vocalizing may
have been partly an artifact of timing, as early-nesting robins are likely
tending nestlings, while other species are still incubating, or even
building (we caught one female Swainson’s Thrush with nesting material in
the net).



An early morning surprise was the recapture of a feisty male Sharp-shinned
Hawk, a bird that we banded in 2013 and have now caught in each year since.
It’s interesting that this individual has been prowling the ridgeline for
at least 4 consecutive summers (one wonders how many BITH he’s fed to
nestlings - we recovered a female BITH’s radio transmitter in a Sharpie
nest in Underhill several years ago). Further, of the 7 Sharpies we’ve
netted in mountaintop forests over the years, all have been male. No
wonder, considering the advantage of smaller size when navigating at high
speeds through the krummhloz!



Despite the ridgeline’s seemingly low vocal activity, by morning’s end we
had 53 total captures (including a dozen the previous evening), of which 41
were new bandings or returns from previous years, and 12 recaptures of
birds banded earlier this season:



Sharp-shinned Hawk  1     male banded in 2013, captured every year since
Yellow-bellied Flycatcher  2     neither bird in obvious breeding condition
Bicknell's Thrush  6     2 new, 4 returns (2 females with full incubation
patches)
Swainson's Thrush  4     3 new, one male banded in 2015
Hermit Thrush  1     yearling female with regressing brood patch, probably
a failed breeder
Black-and-white Warbler  1     female w/regressing brood patch, probably
another dispersing failed breeder
Magnolia Warbler  1     male
Blackpoll Warbler  8     7 new; one male return originally banded in 2009,
so at least 8 years old (possibly our oldest bird on record)
Dark-eyed Junco  3     all new bandings
White-throated Sparrow  9     5 new, 4 birds banded in previous years
Purple Finch  4     all new birds (2 yearling m   78u ales, 1 older male, 1
female)
Pine Siskin  1     free-flying juvenile

We couldn’t help wondering if last week’s harsh weather caused some
mortality, either of adult birds or nests, leading to the reduced vocal
chorus. However, we found no direct evidence for this. The female Blackpoll
Warbler that had nearly completed building her nest on June 1 was now
incubating 4 eggs, and the persistently singing male robins almost
certainly had active nests. Most netted females of all species showed
well-developed incubation or brood patches. So, despite several days of
severe weather that must have stressed energy budgets and diminished
feeding opportunities, it seems most everyone survived. Living in
mountaintop forests is not for the avian faint of heart.

________________________

Chris Rimmer
Vermont Center for Ecostudies
PO Box 420 | Norwich, Vermont 05055
802.649.1431 x1
http://vtecostudies.org/

<http://vtecostudies.org/>


To post messages, send e-mail to:  [log in to unmask]
Set your e-mail application to PLAIN TEXT ONLY to post messages.
To contact the list owner:  [log in to unmask]
To unsubscribe:  E-mail this command to [log in to unmask]:  UNSUBSCRIBE UV-Birders
To change your e-mail address:  E-mail this command from your old address to: [log in to unmask]:  CHANGE UV-Birders [new e-mail address]

Web based archives and subscription management are available at:
http://listserv.dartmouth.edu/Archives/uv-birders.html