The occurrence of interesting sex-related
plumage variations continued clear through the end of the spring season
with the capture of this very dull appearing SY male Kentucky Warbler.
The confirming and undeniable characteristic that it was a male was the
presence of a cloacal protuberance (a swelling of the cloaca that only
males get during the breeding season - click
here for more about CP's). For comparison, the bottom photo shows
a more typical (actually, an unusually bright example) SY male KEWA banded
last June.
The parade of confusing (with respect
to age and sex) spring warblers continued with the capture of this SY female
Magnolia Warbler that had undergone minimal prealternate molt--her body
plumage was composed mostly of very worn first basic feathers.
The wing below belongs to the same
female. It shows the expected (for an SY bird) carpal covert molt
limit (i.e. her first prebasic molt included but stopped at the carpal
covert; all three alula feathers being retained juvenal). Interestingly,
she skipped over the second greater covert (the longer, browner, and more
faded covert among the row of medium length feathers in the middle of the
photo). Note, too, that her very limited prealternate molt included
only two inner greater coverts (four or five is more usual).
Similarly this SY male MAWA caught
just a round later had an even less extensive prebasic molt, including
lesser and median coverts, but only eight of the greater coverts.
The outer two GCs, as well as the carpal and alula coverts, are retained
juvenal. The prealternate molt, however, was quite extensive, resulting
in the bright white edged median and inner seven greater coverts.
The transition into the summer (i.e.,
breeding) season here at Powdermill was further evidenced by the capture
of a family of Carolina Wrens on 1 June. After banding, these four
recently fledged young (number 4 was a little shy!) were released near
the net where they were caught (as are all dependent young banded at Powdermill),
where they were immediately (and noisily!) reunited with their parents.
Just a few days before the season's
official close, we added our first Blackpoll Warblers, an ASY male (top
photo) and an SY female (bottom photo) to our Spring 2006 banding list.
