Pictorial_Highlights

POWDERMILL NATURE RESERVE
PICTORIAL HIGHLIGHTS
APRIL 29-May 5, 2002

Sunday, May 5, 2002:

Two new species were added to our spring banding list today: Mourning Warbler (an after second year, ASY, male) and Canada Warbler (an ASY female; photo below).

We banded four Least Flycatchers (photo below), our highest daily total so far this spring. Our running spring total for this earlier migrating species stands at 12, but we have yet to catch our first of any of the other four eastern Empidonaxspecies.

Saturday, May 4, 2002:

We banded our second Warbling Vireo and our first Lincoln's Sparrow of the season today. The finer markings on this congener of the Song and Swamp Sparrow (all are in the genus Melospiza) set it apart, as does the combination of a buffy eye ring and moustache streak, white throat and thinly streaked buffy breast band.

Our third Palm warbler for the season was our first of the "Western" form, which is the much commoner of the two races here in the western Appalachians. Compared to the SY male "Yellow" Palm Warbler banded in mid-April (bottom photo), this typical ASY male "Western" Palm Warbler (top photo) has much less extensive yellow in the underparts and head (note the whitish, rather than yellowish eye ring), and much narrower and duller chestnut streaks on its throat, breast and sides.

Today we banded a female Rusty Blackbird (top photo) and a female Common Grackle (bottom photo). Although superficially similar (both are medium-sized grayish-brown blackbirds with white eyes), female RUBLs (ave. 53.0 grams) are about two thirds the size of female COGRs (93.0 g) and have a proportionately much thinner bill and shorter tail. Also, RUBL females in spring have faint rusty feather edges and lack any of the iridescence present even on duller female COGRs like the SY-F pictured below.

Friday, May 3, 2002:
Solitary Sandpiper (two banded today)

Chestnut-sided Warbler (two ASY males banded today)

Warbling Vireo (an SY-U)

Thursday, May 2, 2002:

The Potter traps were quite productive throughout the day, catching, among other things, all of the American Goldfinches (16 banded), Chipping Sparrows (11), Blue Jays (10), and Rose-breasted Grosbeaks (2) banded today. In the short time they were operated, the mist nets caught a variety of birds, including the first Magnolia Warbler (an ASYmale) of the season.

We recaptured a returning ASY male Indigo Bunting (originally banded as an SY-M in June 1999; i.e., now about four years old) that was in particularly outstanding breeding plumage.

Compare the appearance of the wing plumage of this ASY male with the SY male INBU pictured in the notes for April 30 below. Note that there is a discernable molt limit between the darker and less worn inner three secondaries (i.e., the tertials, at the bottom left of the photo), replaced in late winter during the prealternate molt, and the other flight feathers, grown last fall during the definitive prebasic molt. In addition, all of the lesser, median, and greater coverts were replaced during the prealternate molt, but these do not contrast very strongly with the blue-edged primary coverts retained from the basic plumage.

Wednesday, May 1, 2002:

Our resident pair of Canada Geese picked a beautiful day to bring their seven goslings off the nest for the first time.

Three new species to band this spring were Veery (a very large ASY male, with a record--for us--wing chord length of 105.5 millimeters!), Blue-headed Vireo (top photo below) and a female Orchard Oriole (bottom photo below). Female ORORs (the similarly yellow-plumaged, second year males have a black chin) are much smaller than female Baltimore Orioles, have yellow, rather than orangeish plumage, and a slightly more decurved bill. Because of their very small size, female ORORs could even be misidentified as wood warblers. Note that in relation to the hand holding it, the OROR is not much different in size from the BHVI pictured above it. In fact, the BHVI had a wing length of 75.5 millimeters compared to 75.0 mm for the OROR; the BHVI (with large fat deposits) weighed 18.5 grams, compared to 19.0 g for the OROR, which had no fat deposits. In comparison, a lean female BAOR weighs about 31 g and has a wing length of 89.0 mm on average.

Tuesday, April 30, 2002:

The majority of birds continue to be captured in the few nets set near our feeders, and the majority of birds caught there continues to be American Goldfinches (another 26 banded today). The extra nets run in what we call "the outback," natural habitats away from the feeders, helped considerably with species diversity, however, compared to yesterday--twice as many species were banded today, including one new species for the spring, a Worm-eating Warbler.

In spring, we often distinguish second year (SY) from after second year (ASY) birds by the presence of two, rather than one generation of wing feathers (i.e., juvenal and first basic feathers vs. all defnitive basic feathers). In birds in which both SY and ASY birds also replace some wing feathers during their prealternate molt, we look for evidence of three, rather than two feather generation in SY birds.

We recaptured a second year (SY) male Indigo Bunting today that provided a good example of an overall wing "plumage" made up of not just two, but three feather generations. That is, the feathers of its wing today were produced during three different molt cycles: those leading to the juvenal plumage, the first basic plumage, and the first alternate plumage. Yet another plumage in this species, the supplemental plumage, is worn for a comparatively short time in late summer and early fall and is eclipsed by the subsequent first basic plumage (i.e., no feathers from the supplemental plumage remain after the first prebasic molt).

The INBU pictured below shows the following molt limits: between the juvenal (very brown) primaries 1-3 (numbered from left to right; primary 2 lines up with the lower right corner of the picture) and the adjacent, light bluish first basic primaries 4-9; between the juvenal secondaries 1-4 (numbered right to left; secondary 1 has the most frayed outer web) and the first alternate secondaries 5-9 (even darker and bluer than the first basic primaries 4-9; only secondaries 5-7 show in the photo); between the very brown juvenal primary coverts and the light blue-edged first basic carpal covert, first greater covert, and two larger alula feathers; finally, between these first basic coverts and alula feathers and the adjacent, much darker and more brightly blue-edged and less worn first alternate greater coverts 2-10 (numbered from right to left), median coverts (the row above the greater coverts), lesser coverts (the epaulet, above the median coverts), and the small alula covert.

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