Date: 8/4/17 10:46 am
From: Chris Rimmer <crimmer...>
Subject: [VTBIRD] Mansfield revisted
Having claimed that last week's field visit to Mansfield would be VCE's
last until a mid-September wrap-up trip, the lure of one more outing (and
great weather) proved irresistible. A small contingent arrived on the
ridgeline Tuesday evening and quickly set 23 mist nets under ideal
conditions of light winds, unusually warm temperatures (~70F) and cloudless
skies. Although there was virtually no dusk chorus to be heard (1 or 2
Bicknell's Thrushes and White-throated Sparrows sounded off briefly), it
was a fine evening. We closed nets at dusk with 11 captures of the usual
suspects.

We all slept outside on decks of the Octagon or ski patrol hut and were
back on the ridgeline by 4:15 to open nets, forgetting how much shorter the
days are now (we could have slept in another 10-15 mins!). All nets were
open well before first light, but a hoped-for N. Saw-whet Owl failed to
appear. The next 6 hours were steady, though never truly busy. We ended up
with a total of 48 captures. The most noteworthy change was the absence of
adults in our sample - only 1 Bicknell's Thrush, no Blackpoll Warblers,
only 1 Yellow-rumped Warbler and White-throated Sparrow. Juveniles again
dominated. Those adults we did capture were generally in early or
mid-stages of flight feather molt, which reduces their inclination to fly.
Most are also likely no longer feeding kids and so moving about less on our
study site.

Our most surprising bird by far was an adult female Bay-breasted Warbler
with a regressing brood patch, indicating that she had nested earlier in
the season. She was almost certainly far from her breeding site, as the
species is not currently known (based in large part on the second VT
Breeding Bird Atlas) to nest anywhere within Vermont. She was molting her
innermost 2 primaries on each wing, and her appearance could indicate a
true "molt migration", but is more likely an extended post-breeding
dispersal. Regardless, it was an unexpected and rewarding encounter for us.

Our banding totals:

Golden-crowned Kinglet 3 2 in full juvenal plumage; one beginning molt
into first basic
Bicknell's Thrush 6 1 recaptured adult male, 5 free-flying juveniles
Swainson's Thrush 5 2 new males, i recaptured female, 2 juveniles (1 a
recapture)
Hermit Thrush 2 free-flying juvenlles
American Robin 3 1 new adult female, 2 recaptured adult males
Cedar Waxwing 1 adult female
Black-and-white Warbler 1 immature female in first basic plumage
Bay-breasted Warbler 1 adult female with regressing brood patch in
early primary molt (photographed)
Blackpoll Warbler 9 all free-flying juveniles in various stages of
first prebasic molt
Black-throated Blue Warbler 4 immatures: 2 males, 2 females in full
first basic plumage
Yellow-rumped Warbler (Myrtle) 2 1 new adult male in primary molt, 1
new free-flying juvenile
Canada Warbler 1 immature, probable female
Dark-eyed Junco (Slate-colored) 8 3 new adult females, 1 recaptured
adult male, 5 juveniles including one bob-tailed bird only a day or two out
of nest
White-throated Sparrow 1 new adult female

View this checklist online at http://ebird.org/ebird/view/
checklist/S38473561

________________________

Chris Rimmer
Vermont Center for Ecostudies
PO Box 420 | Norwich, Vermont 05055
802.649.1431 x202
http://vtecostudies.org/

<http://vtecostudies.org/>
 
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