Wellfleet Harbor, Cape Cod, MA. December 3rd, 2005.
Allen Bird Club trip to Cape Cod.
| Common Tern Sterna hirundo.
Apparently retaining summer plumage.
| Several
Common Terns were present in Wellfleet Harbor when we arrived, and two
of these were in winter plumage at very close range. Towards the end of
our visit, and after the Franklin's Gull had appeared, a sterna
tern suddenly appeared which immediately struck me
as odd. A couple of
seconds later the penny dropped and I realized that the bird was in
near full summer plumage. It had a full black cap, no white forehead,
an orange-red bill with a black tip, rather uniform upperwing with only
a subtle
dark wedge on the primaries, a gray underbody and white rump and tail.
We
only saw it in flight and it stayed up high for most of the time, so I
only managed to get a few marginal images. However, most of the
relevant
features can be seen in these images.
Reference to Olsen and Larsson (Terns of Europe and North America)
would suggest that any sterna tern showing near full summer plumage in
winter is exceptional. In fact, that reference only cites two records
of summer plumaged Common Terns in winter - one from Madagascar in
January and one from Holland which over wintered. These are apparently
birds that simply didn’t molt in winter plumage.
It would certainly be interesting if anyone visiting the area could
take a few good quality images of this extremely unusual bird.
| | Images taken using Canon Powershot A-95 through 10x42 binoculars, |
|
