Powdermill Nature Reserve
Winter 
(December-February) 
2003-04 
Bird Banding Totals

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• Winter banding took place at Powdermill on 45 days from December 1 through February 29 with a total of 308 birds being banded of 18 species.  Most numerous was American Goldfinch (108 banded), followed closely by Dark-eyed Junco (96).  As usual here in winter, a few mist nest were used very sparingly near feeding stations on milder days, but most birds were caught in Potter-type coated wire traps baited with seed.  Although the winter banding season seemed quite slow from the standpoint of numbers and variety of unbanded birds caught, as is so often the case, when compared to results from previous seasons, this winter was pretty much average across the board.

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Click here to view a complete table of winter totals and averages by species for all years.  The linked table summarizes winter banding data for the past 43 years.  Only two species were 1 S.D. or more above average in winter 2003-04: Sharp-shinned Hawk (one banded) and Red-bellied Woodpecker (three banded), and, given the small numbers involved, neither of these was an especially noteworthy difference.
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The graph below depicts banding totals for the past 43 winter banding seasons along with the number of banding days for each season.  Winterized housing did not become available to the banders at Powdermill until 1974, so winter banding occurred only sporadically and on comparatively very few winter days for the first dozen years of the Powdermill banding program.  Despite the low banding effort during this time, winter banding totals were comparable to many later years with far greater effort.  This is most likely due to the banding program, as a whole, being "young," with a larger percentage of the resident birds at Powdermill as yet unbanded.  In addition, because banding was sporadic, birds may have been less "trap shy," with the result that larger numbers were caught with less effort than in later years when traps were operated almost daily in winter.  Naturally, the added value of banding on more winter days in the later years at Powdermill lies in the opportunity to collect information on overwinter survival, winter site fidelity, and daily and seasonal body mass dynamics through recaptures of previously banded birds.

• Contributing to our sense that the banding this winter was slow was the virtual lack of any of the irruptive, so-called "northern finches."   In fact, although there were scattered reports of Pine Siskins and Common Redpolls at neighboring feeders, and a few even appeared briefly at the banding station, none was caught at Powdermill during the season.  With none banded this winter, it is nearly a decade now since our last Evening Grosbeak was banded in winter at Powdermill.  In fact, not counting goldfinches, our only northern or "winter" finch to band this season was the Purple Finch (27 banded--most of these very early in the season).

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The bird pictured below was an unusually brightly colored hatching year (HY) male banded in December (note the contrastingly very brown and worn retained juvenal alula and primary coverts).  Unlike the congeneric House Finch, males of which usually acquire extensive orange or reddish coloration on their head, chest, and rump in their first fall (i.e., following their first prebasic molt), most Purple Finches cannot be reliably sexed by plumage in their first year, because males do not attain their bright "purple" adult plumage (or, for that matter, usually any "purple" color) until their second prebasic (fall) molt.  Most HY male PUFIs, therefore, cannot be distinguished from females.
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To confuse matters a little more, adult female PUFIs often will acquire bright reddish coloration like the young male pictured below, making it imperative in the case of both brown and slightly colored PUFIs that age be correctly determined before the bird's sex is decided.  In December, a known hatching year PUFI like the one pictured can be confidfently called a male; an adult with similar plumage can be confidently called a female (as can an adult having no bright coloration); but an HY bird that lacks color cannot confidently be sexed, because all immature females and many young males lack color altogether.   Adult male PUFIs, of course, are unmistakably bright "purple" in winter.

• In the table below, our totals for winter banded species for all years are given in descending order, with the corresponding winter 2003-04 total alongside.  A total of 58 species has been banded at Powdermill during winter months, with 14 of these species being represented by just one capture in 43 winter banding seasons.

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• Evening Grosbeak (EVGR), once exclusively a northwestern North American breeding bird, expanded its breeding and wintering ranges eastward across Canada and the U.S. beginning as early as the 1940-50's (perhaps in response to increased plantings of box elder, a favorite winter food, and also due to expanding outbreaks of spruce budworm, which nesting EVGRs feed to their young).  Through the 1970s and 1980s, the species became increasingly common and regular as a winter visitor to feeding stations throughout eastern North America.  Maximum winter banding totals at Powdermill were 812 in 1976-77 and 586 in 1986-87.  Since then, however, the range of EVGRs apparently has begun retracting to the species' historical westerly breeding and wintering areas, and the species occurrence (including observations and bandings) at Powdermil, even in migration, has been minimal in the last decade or so.

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Testifying to the species' former abundance as a wintering bird in the East, Evening Grosbeak, with just 50 banded at Powdermill in the last 10 winter seasons (and none in the last seven winters), still sits very comfortably in first place among winter banded birds at Powdermill!

In concluding our summary of winter 2003-04 banding at Powdermill, we thank our faithful, and decidedly not "fair weather," volunteers who braved the snow, cold, and icy paths to help us with the banding: Amy Cunkleman, Randi Gerrish, Brian Jones, Carroll Labarthe, and Annie Lindsay.  As indicated on our "Home" page, a summary of the fall 2003 banding season is forthcoming, and we will begin posting our spring banding totals at least weekly beginning in April.  We appreciate everybody's patience with the lack of updates to our website in the past few months.  We are embarking on the 2nd Pennsylvania Breeding Bird Atlas, a five-year project beginning this year, and coordinating and making preparations for this very big and complex statewide project has demanded the bulk of our time since last fall.  As the first field season for the Atlas begins getting underway, we expect to be able to return to our usual schedule of banding website updates.

Last Updated on 3/8/04
By Adrienne Leppold