March - April 2007
Banding effort occurred on eighteen days during the month of March and we netted a total of just 150 new birds. Our highest count was 47 on the last day of the month and we had a maximum of twelve species on 3/18. With 128 banded, Dark-eyed Junco was far and away the most common species during the month.
The junco pictured to your left shows what is an uncommon (but by no means rare) plumage variation in the "Slate-colored" subspecies, distinct white wing bars. Such birds are sometimes mistaken for the "White-winged" Dark-eyed Juncos (Hyemalis aikeni).
Because we had them in hand at the same time on 3/30, we couldn't resist taking this picture of a male House Sparrow (a species that we catch and band only rarely) and a returning banded male Brown-headed Cowbird. We realize that these two "bad boys" of the bird world are on the "Most Wanted" lists (and we don't mean check lists) of many a bird watcher, but we refuse to blame them for their admittedly detrimental impacts on other bird species, when we know where the real blame lies.
April began with two weeks of extensive freeze, and spring arrived in western Pennsylvania much later than usual. As a result, total birds banded for the month (728) was considerably down from April 2006 (1,383). Our first real push of migration occurred on 4/24 when we banded 104 birds of 26 species.
This included 26 Ruby-crowned Kinglets and 18 Chipping Sparrows. Another 116 RCKIs were banded on the succeeding four banding days. Still, the migration came too late to push our April banding total up where it usually belongs.
While waiting for the weather to moderate, we banded this second-year Sharp-Shinned Hawk on 10 April.
This bird presented a good example of the intermediate stage in the transition of eye color from yellow (HY) to red (ASY) in Sharp-shinned Hawks and other accipiters.
We banded 47 White-throated Sparrows during the month of April, including the usual polymorphic mix (i.e., variation not strongly related to age or sex) of bright- and dull-plumaged birds.
Neotropical migrants finally began to arrive on 24 April. One of our first arrivals was this ASY female Blue-gray Gnatcatcher.
The spring "warbler wave" began with this SY male Prairie Warbler, a species that we can easily miss catching in the spring.
24 April also brought our first Black-throated Green Warbler, this ASY male.
On 26 April we banded our first Northern Waterthrush, an ASY bird possibly ascribable to the large-billed northwestern race, Seiurus noveboracensis notabilis, which also has less yellowish underparts compared to the nominate race, S. n. noveboracensis.
Other warblers species banded before the end of April were Yellow, Chestnut-sided, Yellow-rumped, and Black-and-white Warblers, along with Common Yellowthroat and American Redstart.
On 24 April our new "double decker" mist net, at 14-ft. high, proved to be quite productive with the capture of an ASY Warbling Vireo, another easily missed species at Powdermill during any season. In fact, our 46-yr. average banding total for this species is less than one a year.
A second-year Marsh Wren was banded on 25 April, the same date we banded one last spring. The photos to your left show molt limits in the bird's tail (R1 on the left and the outermost rectrix on the right are retained juvenal) and wing (outer primaries 7-10 and inner secondaries 5-9 are molted).
On 4/26 we banded our first Winter Wren (top photo to your left), and also our first White-Crowned Sparrow (bottom photo to your left).
Our first (and only) Rusty Blackbird of the month was not banded until 27 April, a very late first banding date for this species at Powdermill. Adrienne Leppold, our Bander-in-Charge, has been actively participating in the International Rusty Blackbird Technical Working Group and attended their recent conference in Mississippi, where she gave a presentation on the usefulness of migration data for assessing and monitoring long-term population declines in this quintessential boreal breeding bird.
For more information on the meeting, including PDF's of all presentations given, visit the Smithsonian National Zoological Park Migratory Bird Center website for the Rusty Blackbird Workshop Program.
27 April also marked the return of several breeding species to their summer nesting grounds at Powdermill, including this pugnacious SY White-eyed Vireo, and this striking ASY male Hooded Warbler.
A couple visiting banders from Wisconsin were particularly thrilled to see this most handsome and very common breeding warbler, as the HOWA's range is restricted primarily to the eastern half of the U.S.
Highlights on the last banding day of the month, 29 April, included our first Lincoln's Sparrow and our second Sharp-shinned Hawk of the season; best of all, this brilliant ASY male Brewster's Warbler.
Finally, we thank the following volunteers for their help during this banding period: Lauren Schneider, Dean Thompson, Greg and Felicia George, Holly McChesney, Pam Ferkett, Mike Comley, Jessica Scopel, Carol Shanahan, Annie Lindsay, Mary Shidel, Brent Worls, Molly McDermott, Briana Smrekar, Kristin Sesser.
We also welcomed Danilo Mejia and Maria Paulino this month as our Louisiana Waterthrush interns this year. Both are from the Dominican Republic and will continue studies of LOWA's this winter from home. They were hired by Steve Latta, Assistant Director of Conservation and Field Research at the National Aviary, who is now collaborating with us on our long term studies of LOWA's breeding biology and use as a bioindicator of water quality on nearby streams.