Mansfield Update: Returning Sharpies and Thrushes

Jacqueline Huettenmoser (left) with a banded Swainson’s Thrush and Spencer Hardy (right) with a look-alike Bicknell’s Thrush. © Michael Sargent

Not even a month into calendar summer, mid-July is already bringing changes to the Mt. Mansfield ridgeline. The avian chorus is a shadow of its former self, independent fledglings are out and about, some adults are in early stages of flight feather molt, and non-local breeders are dispersing. VCE’s 14-15 July banding session featured all of these and resulted in a total of only 43 captures. Never lacking a surprise or two, this outing—our sixth of the 2020 field season—yielded two in particular: an adult female Least Flycatcher (one of very few we’ve ever banded on Mansfield in 29 years) and a return male Sharp-shinned Hawk (our third individual of the season, in itself a record) that we had first banded as an adult almost exactly 3 years earlier.

A male Sharp-shinned Hawk first banded by VCE on 6 July 2017 registers his disapproval of another mist net capture on Mansfield 3 years later, 15 July 2020. © Micheal Sargent

A yearling male Blackpoll Warbler in early flight feather molt. Of the 9 primaries, which molt sequentially from inside to out, the first is nearly half-grown, the second barely erupted from its sheath, and the next two missing. The outer 5 orimary feathers are old and will be the next to shed. © Michael Sargent

Our 2-day totals included:

Sharp-shinned Hawk — 1 male, a return capture from 7/6/17
Yellow-bellied Flycatcher — 1 female with full brood patch
Least Flycatcher — 1 female with refeathering brood patch
Ruby-crowned Kinglet — 1 adult female with regressing brood patch
Red-breasted Nuthatch — 2 hatching-year birds
Bicknell’s Thrush — 4 males (1 new, 1 return from 2016, 2 within-season recaptures)
Swainson’s Thrush — 1 new yearling male
American Robin — 2 new males
Purple Finch —1 within-season male recap from 9 June
Dark-eyed Junco (Slate-colored) — 5 (3 new, 2 within-season recaps; female with full incubation patch, possibly a second attempt)
White-throated Sparrow — 8 (4 free-flying juveniles, 2 new, 2 within-season recap adult males)
Blackpoll Warbler — 11 (7 new birds [5 yearling males all in early flight feather molt], 4 within-season recaps
Yellow-rumped Warbler (Myrtle) — 5 (1 new, 3 return males from 2018 and 2019, 1 within-season recap)

A diminutive adult female Ruby-crowned Kinglet ready for release after banding, Mt. Mansfield, 15 July 2020. ©  Michael Sargent

With only 3 weeks to go before our summer field season wraps up, we expect a flurry of juveniles, more molting adults, and inevitable surprises in the form of non-local dispersers. We’ll relish the plaintive songs of White-throated Sparrows and nasal ‘beeer’ calls of Bicknell’s Thrushes while they last.

Jacqueline Huettenmoser releases a banded Swainson’s Thrush on Mt. Mansfield, 15 July 2020. Creative photo stitching © Michael Sargent