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THE WILSON JOURNAL OF ORNITHOLOGY • Vol. 124. No. 2. June 2012 
remainder of the breeding season, includin 
during construction of a replacement nest alk 
her first nest had been depredated. The femal 
sang a total of 29 songs in a I-hr observation fror 
0715 to 0815 hrs on 31 May 2011, mostly Iron 
the top of a bush. The female's mate also sanj 
from a nearby perch in the top of another bus! 
during the same period. We did not see the femal, 
singing and carrying nest material on the saint 
day and it is unclear if these behaviors over 
lapped. The female successfully built and laic 
eggs in two nests during the breeding season anc 
was apparently physiologically capable of repro¬ 
ducing. We were unable, however, to collect data 
on her nestlings: the first nest was depredated 
during the egg laying stage, and the second was 
depredated after the eggs had hatched, but before 
the nestlings had fledged or been sampled. 
The female s song did not resemble a typical 
Common Yellowthroat male song. Male songs 
consist of a series of clear repeated phrases with 
rapid frequency modulation across a wide band¬ 
width (Fig. 1A). The female’s song also had 
repeated phrases and limited frequency modula- 
lon, but had a raspier quality and noisier syllables 
I' g a! , T i ,IS song was dwsimilar froni |he 
broadband chips and rattles typically given by 
males and females (Fig. IC, D) ^ 
We do not know the age of the singing female, 
but she was a first time breeder at our site. 
Females usually move <400 m between years at 
our study site (CCT, unpubl. data) and, because 
much of the study site is surrounded by 
unsuitable woodland habitat, unhanded birds 
generally are assumed to be first time breeders. 
However, the singing female's territory was near 
one end of the site where unmonitored territories 
are accessible across a road. We estimate 2-3 
additional territories were within 400 m across 
the road and we cannot discount between-season 
dispersal by an older female from the unmoni- 
tored area. 
The singing female was within ±1 SD of the 
mean for wing and tarsus length, and bib size and 
coloration ( Table 1). She had somewhat less mass 
than the average females in the population (1.9 
SD below the mean: Table 1). This difference was 
most likely caused by an earlier than average 
capture date, rather than smaller body size; the 
lemale was captured just after arriving from 
migration whereas many other females were 
captured after they had been in breeding areas 
lor 2 weeks or more and some may have been 
gravid. Her territory was in an area with a typical 
breeding density for our site. The female's 
physiological measures (hematocrit, testosterone. 
