VCE’s July 10-11 banding session on Mt. Mansfield — our sixth of the 2018 season — featured the first appearance of juveniles of regularly-breeding species, as well as several adults in very early stages of flight feather molt. Weather was ideal for netting, with light winds and comfortable temperatures. Thunderstorms rolled in on Tuesday night soon after we had closed our nets and cleared the skies well before dawn, giving us a perfect day on Wednesday. We had many visitors of all ages and geographies (MD and MA, as well as VT), with 19 people in on the action at one point. The birds didn’t disappoint, with 2 male Black-throated Blue Warblers being the show-stopper.
Bicknell’s Thrush (BITH) again easily outnumbered all other species, a reflection, I believe, not of their greater abundance but of their unique spacing system, in which males occupy large and overlapping home ranges, rather than traditionally defended territories. With such extensive movements, it seems likely that we capture a higher percentage of the individual BITH on and around our study area than of species like Blackpoll Warbler and White-throated Sparrow, which occupy much smaller, discrete territories and have more confined movements. Most newly-banded individuals of BITH and other species were yearlings (SYs), likely reflecting the fact that 2017 was yet another summer with low squirrel populations and solid avian productivity. It is always surprising to capture previously banded BITH for the first time so late in the season (we had 4), but these may be birds whose home ranges only marginally overlap our netting area (vs. male #2341-24303, a 2015-banded bird whom we have caught at least 6 times so far this season).
Our 53 mist net captures included:
Red-breasted Nuthatch — 2 free-flying juveniles
Bicknell’s Thrush — 15: 6 new (3 males, 3 females), 4 returns from previous years (male and female from 2013, female from 2017, male banded as hatching-year in Sept. 2017), 5 within-season retraps
Swainson’s Thrush — 1 new SY male
American Robin — 3 new adult males
Blackpoll Warbler —11: 9 new (5 males, 4 females), 2 within-season retraps
Black-throated Blue Warbler — 2 new SY males
Yellow-rumped (Myrtle) Warbler — 7 (1 free-flying juvenile, 4 new males, 2 within-season retrap males)
Dark-eyed (Slate-colored) Junco — 8 (5 free-flying juveniles, 1 new female, 2 within-season retraps)
White-throated Sparrow — 4 (1 free-flying juvenile, 1 new male, 2 within-season retrap males)
Purple Finch — 1 within-season adult male retrtap
Pine Siskin — 1 free-flying juvenile
Finches, including Purples, siskins and crossbills were much less in evidence this week than earlier in the season. There are very few cones from last summer’s crop left on the firs and spruces, and I have yet to see a single new cone developing this year. We flushed a N. Saw-whet Owl during our net closing on Tuesday, and we’ll hope to capture one (or more) during our final three weekly sessions this month. Still no hide nor hair of red squirrels on the ridgeline…
As always, we enjoyed sharing the Mansfield banding experience with our visitors, and especially involving two eager youth, Sayre Fisher and Eli Grimsley, in our work.