Pictorial Highlights_ 092228

POWDERMILL NATURE RESERVE
BANDING NOTES AND PICTORIAL HIGHLIGHTS
September 22-28, 2003

September 27-28, 2003: Our second bander development workshop finished up on Sunday. We thank those attending--Tom Greg, Danielle Skoncey, Cindy Cartwright, and Sue Finnegan--for their interest in and dedication to working to improve their banding knowledge and skills, and for their enthusiastic participation and assistance with the operation of the Powdermill banding station. Without their help, we would have had to settle for much less banding effort and many fewer birds at a time of year when the extra effort and the additional birds are always welcome! In addition to the workshoppers, we appreciate the help we received from Sue's husband, Bill, from guest ringer, Prof. David Norman, and, over the course of the week, from our regular volunteers, Randi Gerrish, Carroll Labarthe, and Hope Carpenter.

The main point and purpose behind these informal workshops has been to share and compare techniques for determining the age and sex of birds in hand, and also for measuring birds, with the goal being to calibrate determinations and measurments among all the banders present. Working to do this both helps to ensure the accuracy of the data collected by each bander, and also enhances the collaborative use of data collected by several banders. On a much larger scale and in a much more formal way, such training and calibration meetings were integral to the successful European Science Foundation's Migration Monitoring Network (under the leadership of Prof. Franz Bairlein), which involved some 30 ringing or research groups from 18 countries working at more than 50 study sites from 1994-1996.

We hope that these informal workshops at Powdermill, which grew out of roundtable and other discussions at the Eastern Bird Banding Association meeting held in early April at Powdermill, might be a small step in the direction of eventually undertaking similar regional collaborations among the North American banding community. Below is an "album" of the week (thanks to Tom Greg, who provided several of these pictures)

From left to right: Bob Mulvihill, Sue Finnegan, and Cindy Cartwright processing a bird at the Powdermill banding lab

At right--examining the wing plumage of a Magnolia Warbler for possible wing molt limits. MAWAs, like most wood warblers, have a partial first prebasic molt which typically replaces their juvenal body plumage and the juvenal lesser, median, and greater wing coverts, carpal covert, and, more often than not, the small, proximal feather of the alula (the so-called "alula covert"). The exact number of feathers replaced during the partial first prebasic molt, of course, varies among species, and, to a lesser extent, among individuals.

The molt limit, or the discernable boundary between any molted first basic feathers and adjacent retained juvenal feathers, is what banders look for to identify a bird as being a hatching year (before January 1) or second year (after January 1) bird. Importantly, skull condition is very useful and reliable as an ageing criterion in fall and should be used by banders on a regular basis, as a double-check against age determinations made based on other criteria. In the spring, however, when the skulls of most immature (SY) birds are fully pneumatized, molt limits become the principal ageing criterion. Learning to recognize molt limits in the fall, when the correct age of a bird can be confirmed by skull condition, is a very useful exercise for recognizing molt limits in the following spring, when skull condition ordinarily cannot be used to distinguish the age classes.

Comparing different wing molt limits on two hatching year Eastern Phoebes at Powdermill. The upper bird has two retained juvenal outer greater coverts, while the bird below has molted all of its greater coverts, as well as the carpal and alula coverts.

From left to right: Sue Finnegan, Cindy Cartwright, Tom Greg, David Norman, and Mike Lanzone discuss the ageing criteria for Ovenbird, at the same time making a side-by-side comparison of an HY and an AHY bird.

Sue Finnegan measures the wing length of a female Black-throated Blue Warbler. Throughout the workshop, banders compared measurements for many birds and made small adjustments to their techniques, with the result that agreement among the banding crew increased substantially by the end of the week. Such close agreement among banders benefits studies of geographic variation in size (as measured by wing length) across broad geographic areas. Analyzed carefully (i.e., restricting comparisons to samples of same age/sex birds), such well-calibrated measurements among banders working at widespread sites can provide evidence of the migratory routes and wintering areas used by different populations of birds.

Ontario bander, Cindy Cartwright, enjoys the experience of handling a "rare" (up there!) Eastern Tufted Titmouse.

Danielle Skoncey puts a Blue Jay into the weighing cone at Powdermill. Danielle received extensive banding experience under Mr. Jul Wojnowski at Lesser Slave Lake Bird Observatory in Alberta, Canada shortly before attending the Powdermill workshop.
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One of the many good things that can come out of workshop experiences like this is the opportunity to see and learn about the different methods employed by other banders/stations. The workshop participants all shared with us techniques, tools, and ideas that we will benefit by incorporating into the banding program here at Powdermill.
We encourage other banders and banding stations to create and/or take advantage of opportunities to participate in and/or conduct similar workshops, where the positive interchange of ideas, knowledge and experience will surely benefit all concerned.

And, finally, a few belated bird photos from the last couple days of the workshop session! We banded our first Black-billed Cuckoo of the fall season on Saturday, 9/27. The top photo below shows just how long and lean cuckoos really are! The second photo below shows the yellow orbital ring that marks this as a hatching year bird (the eye ring of BBCUs turns red as they age). The bottom photo nicely shows the features of juvenal tail feathers in this species--somewhat narrow and tapered with indistinct pale tips on the outer four rectrices (viewed from underneath).

Magnolia Warblers (with 69 banded) were the second most commonly banded birds (after Swainson's Thrush; 84 banded) during this workshop week. As the migration of MAWA moves into the latter stages at Powdermill, there always is an increase in the proportion of adult birds in the banding sample, due to differential migration timing between the age classes. In this species, HY birds precede AHY birds by more than ten days on average (see Woodrey, M. S. ad C. R. Chandler. 1997. Age-related timing of migration: geographic and interspecific patterns. Wilson Bull. 109-52-67; this is a comparative study of migration timing at three banding sites in eastern North America, including Powdermill).

Below is a picture of one of three AHY male MAWA banded on Sunday, 9/28 (the entirely black upper tail coverts are diagnostic of this age/sex class); the second photo below is the same bird ignoring and being ignored by a large tachinid fly that landed on the photographer's finger!

A total of 28 Hooded Warblers banded during the recent workshop week is the highest weekly total for HOWA thus far this fall. Like the MAWA, most of the AHY HOWAs (like the AHY male photographed by Tom Greg below) have been caught toward the end of this species' migration period. The later migration by adults of many species probably is related, in part, to their undergoing a more lengthy complete prebasic molt following nesting and before initiating migration.

September 22-26, 2003: The second bander development workshop at Powdermill is underway, with banders from Pennsylvania, New Jersey, Massachusetts, and Ontario attending. There was a partial rainout on Thursday, but otherwise the weather and the birds have cooperated very nicely, and visiting banders Tom Greg, Danielle Skoncey, Sue Finnegan, and Cindy Cartwright have had their hands full most of the time. In addition to all of the opportunities for back-and-forth learning that these workshops are providing for everyone, it has been a real help having a team of such skilled and enthusiastic banders on hand to assist us with running the station at this very busy time of year. Because of all the available help from the workshoppers, our regular volunteers, Hope Carpenter, Randi Gerrish, and Carroll Labarthe, and visiting ringer, Dr. David Norman, we have been able to put out a much greater daily banding effort than usual (1,725 net hours through Friday, even with the rain-shortened day on Thursday).

September 22-28 Bander Development Workshop group
(left to right: Puppy, Danielle Skoncey, Bob Mulvihill, Tom Greg, Sue Finnegan,
Mike Lanzone, and Cindy Cartwright; not pictured, Bob Leberman and David Norman)

In the first four banding days of the week, we have banded 456 of 55 species--Winter Wren (see photo below) and American Woodcock were new for our fall banding list, which now stands at 83 species. Top species for the week so far are Swainson's Thrush (74 banded); Magnolia Warbler (51); American Redstart (39); Common Yellowthroat (31); and Hooded Warbler (23; eleven banded on Friday alone!); Gray Catbird (20); and Black-throated Green Warbler (19; twelve of these on Thursday).

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