[Tweeters] Barrow's Goldeneye Communal Roost on Green Lake, Seattle

Wayne Weber contopus at telus.net
Sat Jan 24 19:07:59 PST 2015


Martin and Tweeters,

I enjoyed reading your account of the Barrow's Goldeneye roost on Green
Lake. The same thing happens on Lost Lagoon in Vancouver's Stanley Park. (I
covered this area for many years on Vancouver's Christmas Bird Count,
although I have not done so recently.) Lost Lagoon is a shallow freshwater
lake in Stanley Park. Barrow's Goldeneyes are not seen there during the
daytime; they feed on nearby rocky saltwater shorelines, often in mixed
flocks with Surf Scoters.

Vancouver has much higher numbers of Barrow's Goldeneyes than Seattle; we
average about 2000 of them, and usually have the highest count in the world
on the Christmas Bird Count. Not all of them spend the night on Lost Lagoon;
there are usually several hundred there, although I don't recall the highest
count offhand. Large numbers of Common Goldeneyes roost in Lost Lagoon at
night as well, although unlike the Barrow's, small numbers of them can
usually be found there during the day as well.

It sounds like all your attempts to count Barrow's Goldeneyes at Green Lake
have been in the early morning. My experience is that it is easier to count
them in the late afternoon; they usually come into Lost Lagoon to roost when
it is lighter out than when most of them leave in the morning.

I'd be interested in hearing from people in Olympia, which also usually has
large numbers of wintering Barrow's Goldeneyes. Do the Barrow's Goldeneyes
there spend the day on salt water and roost at night on Capitol Lake? This
may in fact be a widespread pattern, not just something that happens on
Green Lake.

Good luck and good birding,

Wayne C. Weber
Delta, BC
contopus at telus.net



-----Original Message-----
From: tweeters-bounces at mailman1.u.washington.edu
[mailto:tweeters-bounces at mailman1.u.washington.edu] On Behalf Of Martin
Muller
Sent: January-24-15 3:09 PM
To: tweeters at u.washington.edu
Subject: [Tweeters] Barrow's Goldeneye Coomunal Roost on Green Lake, Seattle

Tweeters,

For many years I have known (and occasionally reported on) wintering
Barrow's Goldeneyes forgoing their customary salt water hangout to fly to
freshwater Green Lake to roost. Their numbers vary between 30 and 60 during
the winter months. One has to get to the area they favor on the lake (the
south corner near the Aqua Theater) before sunrise. A scope helps.

I expect to find the birds in this location during the CBC in late-December.
Usually we start the CBC in this area (because of the Barrow's presence
there). Starting at around 07:25 - 07:30 the birds leave the lake in
(initially) small groups of 3 - 10, but the last group, right around 8 AM
may be a single flock of all remaining birds (up to 25). Then the rest of
the day one may find only one or two Common Goldeneyes on the lake.

This past (2014) CBC, to my surprise, I didn't find any Barrow's Goldeneyes
at Green Lake when I arrived at 07:30. Did I miss them or had they changed
their behavior?

Today, January 24 2015, I got my answer. I was supposed to meet with a group
of birders to walk the lake, and decided to go early and check on the
goldeneyes. I arrived at 07:22 (sunrise at 07:45) near the Aqua Theater and
initially had difficulty making out any birds out on the water. Within five
minutes my eyes had acclimated enough (and the sky was "brightening" despite
the cloudy conditions) that I could make out a raft of birds about 200 feet
offshore. Using my scope I could make out 246 Barrow's Goldeneyes & 30
Common Goldeneyes. I was so surprised by the numbers (the highest counts for
either species during many visits to the lake since November 1983) I counted
the Barrow's three times. Just to make sure. I did not attempt to get a sex
ratio, since it would be difficult/impossible to distinguish sub-adult males
from females under the low light conditions.

Soon after I completed the third count (still 246; I like it when the birds
string out in almost a single line.) the first small groups started to
depart. It's always fun to watch the first small groups try and overcome the
flock mentality. They take off, flying east, then circle up out over the
water, then head straight west for salt water. But as they start to head
west they fly over the remainder of the flock still paddling, preening,
jockeying for position, displaying around the lake, and invariably, the
flock pulls one or two of the flying birds back down. As hunters know so
well: a swimming/roosting/feeding flock is practically irresistible to birds
of a feather. Those birds not quite sure whether they should go or stay,
will take the tumble, rapidly descending towards the flock, most of the time
instinctively followed by the others in their early-commuter group. They
usually don't land, but then head back east, only to gain altitude out over
the lake again, before, once again, heading west.

Later departing groups appear to have less and less difficulty overcoming
the remaining floating flock's attraction, and may even depart on their
first attempt.

Shortly before 8 AM, waiting at the meeting place near the Bathhouse
Theater, while investigating a trail of Glaucous-winged feathers strewn
along the lawn (trying to see if I could find a partially eaten carcass that
would shed light on how the gull had met its demise, and possibly who had
contributed/caused said demise) my attention was drawn to the island, where
some 200 crows had gathered on their way from their communal roost to their
respective daytime hangouts. A daily ritual in winter. However, this morning
it was interrupted by an adult peregrine repeatedly stirring up the flock of
crows (all of them taking flight while cawing, dodging the falcon, and then
re-alighting in the tops of the trees on the island). I watched the falcon,
during three different bouts, circle around (and through) the cloud of crows
some twenty times. She made some feigns in their directions, but to me she
didn't appear intent on nailing a crow. It was quite the spectacle, though.
Never did get a good look at the falcon, since she landed on the far side of
the island.

Right around 8 the morning commuter flight of (200+) Mew Gulls arrived,
flying in from the northwest (do they spend the night out on salt water?),
streaming in past the island, dispersing over the lake for their morning
routine of bathing, preening, and looking for breakfast.

All under the watchful eyes of the pair of Bald Eagles perched in a nearby
tree.

Always fun to visit Green Lake.

Cheers,
Martin Muller, Seattle
martinmuller at msn.com

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