[CT Birds] Barnacles-a-commin
dennisvz at optonline.net
Wed Feb 29 10:07:21 EST 2012
Here is the general overview of the Phenomenal phenomenon
When the Phenomenon occurs one will see thousand of gulls sitting on
the water feeding heavily. The birds are pecking at the water. They
are not diving as for fish. Although most of the gulls are Herring
and Ring-billed, all other regular species have been found at one
time or another. Although, Great-Black-backed Gulls don't seem to
participate much. In addition to Gulls one can see Brant, Scaup and
the puddle ducks, including Blue-winged Teal and Northern Shovelers.
The mix of species depends upon the time of the year.
The phenomenon has been observed since the turn of the century. I
don't recall it occurring in the 80's
Due to Geology, rocky coast and narrow Sound, the phenomenon is
confined to wester Connecticut, nowhere else on the east coast (as
far as I can tell from communications). The same species of Barnacle
is found and europe and it is know to have synchronized reproduction
over there. The western most observation I have of them is the
Norwalk Islands, but I suspect that it could be found in Stamford.
The eastern most observation I have is Morningside in Milford, But, I
imagine it could be occurring off New Haven Harbor and perhaps the
I have seen it occur any time from late February to early May over
the years. Full and new moons increase the probability of it
occurring but we have seen it at other times, particularly in heavy
years. Some years it has been spotty with patches here and there.
Other years it has been intense. and thousands of birds could be seen
feeding on them from horizon to horizon.
The weather makes a difference in the availability of the larvae to
the birds. For organisms as small as the larvae water is more like
molasses. Wind and wave action are more important in dispersal that
actual swimming. During days of low wind, the water becomes flat and
traps the larvae at the surface. That is when big flocks of birds are
I tried communicating with people at the marine lab at Avery Pt. At
first they were attempting to be helpful. When I told them about the
part about gulls feeding on them, they did not believe it and thought
I was seeing the birds going after fish feeding on the larvae. They
soon lost interest.
Conclusions: The synchronized reproduction of the Barnacles is an
annual event. The actual mechanism has yet to be determined and needs
a study of the barnacles themselves. But, the combination of time of
year and weather conditions determine how available the larvae are to
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