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THE WILSON JOURNAL OF ORNITHOLOGY . Vol. 123, No. 3. September 2011 
TABLE 1. Stable 
hydrogen isotope values (8 D f ) from 
feathers of six species 
i of migratory songbirds captured in 
the Albany Pine Bush Preserve 
in autumn 
2007. 2008, 
and 2009. 
Species 
SOf Range 
&D, Mean (/i) 
Ruby-crowned Kinglet 
-113.35 to 
-83.86 - 
109.14 (6) 
Nashville Warbler 
-118.69 to 
-82.93 - 
101.85 (13) 
Magnolia Warbler 
-116.78 to 
-80.15 
-99.35 (8) 
Palm Warbler 
-123.75 to 
-68.10 
-89.74 (19) 
Blackpoll Warbler 
-170.86 to 
-123.85 - 
148.64 (8) 
Lincoln's Sparrow 
-129.52 to 
-77.85 
-97.34 (7) 
northerly birds arrived earlier (leap-frog migration) 
(Fig. 3). 
The generally east-to-west inclination of the 
isotope contours from the growing season model 
for North America precludes precise delineation 
of the longitude of the breeding sites of captured 
migrants. Our data indicate that 32 of 61 
individuals from all six species had 6D ( values 
< — 100%o, corresponding to the -75%<. 8D p 
contour, which is at least 750 km north of the 
APBP (Fig. 4). Only for Palm Warbler (6 of 19 
individuals) and Lincoln’s Sparrow (2 of 7 
individuals) did <50% of individuals originate 
southeast of the -75%o 8D p contour. Blackpoll 
Warblers had 5D f values of -170.86 to -123.85 
(mean of 8 measurements = - 148.64), indicating 
breeding sites that are at least 1,500 km north or 
northwest of APBP (Fig. 4). These patterns are 
noteworthy because all six species selected have 
breeding populations in New York’s Adirondack 
Mountains ~100 km north of the APBP. It is 
possible that some Ruby-crowned Kinglets. Nash¬ 
ville Warblers, and Magnolia Warblers originated 
in the Adirondacks, but most individuals of even 
these species come from much farther north. 
DISCUSSION 
Our data indicate early successional habitat 
maintained by fire on inland pine barrens attracts 
migrating species that do not breed in these 
habitats. A number of the captured species breed 
in early successional shrubland habitats (e.g., 
Tennessee Warbler [Oreothlypis peregrina], Nash¬ 
ville Warbler), but most species captured breed 
exclusively in closcd-canopy deciduous forests and 
spruce-fir (Picea-Abies) dominated boreal forests. 
We did not attempt to quantify the importance of 
pine barrens as stopover sites relative to other 
habitat types, but comparison of our capture data 
(Fig. 2) to those obtained over the same time 
period (Fall 2007-2009) at the well-studied 
Braddock Bay Bird Observatory (BBBO) indicates 
all species captured at APBP were also present at 
BBBO. The Braddock Bay site, on the southern 
shore of Lake Ontario near Rochester, New York. 
-300 km WN W of the APBP. supports a mosaic of 
abandoned fields, early-successional landcover, 
and second-growth forest (Bonter et al. 2007). 
A large staff of scientists and volunteers at BBBO 
operate 20-30 mist nets every day during the fall 
migration, resulting in a much greater effort 
Date 
Bush Preser^nH Z * ydr ° 8en '*° t0pe values measured from feathers (SD f ) of six species captured in the Albany Pine 
crownS SeTi'- ntlTnT ° f rCgrCSSi ° n line * < not shown) « statistically different from zero (Ruby- 
0m07 P = 0 9 n I f = NaShvi " e Warbler ** = 0.0084, P = 0.75, * = 13; Palm Warbler r = 
8; Lincoln's Sp n^T' " = ^ " = * ^ ** = 00096 ’ " = °- 81 ’" = 
