Subject: Iona Settling Ponds & Causeway (No LAGU), July 30 1997
Date: Jul 31 01:02:59 1998
From: Michael Price - mprice at mindlink.bc.ca


Hi Tweets,

--No sign of this summer's CMF (acronym for a common Brit term for a
MegaRarity; the full term is too adult for this list) for Vancouver BC, the
1st BC/Western Canada-record Laughing Gull Larus atricapilla seen yesterday
on the Iona tidal flats. Too bad, woulda been a lifer; however, the 200+
flock of RING-BILLED GULLS L. delawarensis contained an Alt 2 MEW GULL L.
canus (race brachyrhynchus)--the first southbound returnee at this location,
7 juv Ring-billeds, 2 juv and 3 Alt CALIFORNIA GULLS; the other Ring-billeds
were in various molt-states, some 'adult' birds evidencing flecking on head
and breast, showing pre-Basic molt underway.

Drat it, I left my notebook there tonight--thereby ensuring rain. If anyone
finds it, would he or she put it in with the Iona sighting book? Thanks!

--in the settling ponds themselves, mostly the SE & SW ponds, about 90% of
the ~200 WESTERN, 95% of the ~25 LEAST and *100%* of the 31 SEMIPALMATED
SANDPIPERS (respectively, Calidris mauri, minutilla and semipalmatus) were
juveniles, whereas both of the visible PECTORAL SANDPIPERS C. melanotos were
Alternate plumaged 'adults'--on size differential, I'd say male and female.
Only 2 LESSER YELLOWLEGS were there, an Alternate bird and a crisply-spotted
juv, though a flock of six longlegs flew in without calling as I was leaving.

--the sighting book had up to 8 PESA there earlier in the day, aged as juvs,
but the juvs are still a couple of weeks away from their average arrival
date of Aug 12, and they usually stick pretty close to it. If they *were*
early, on their form, I'd start looking around Aug 05-06 for the first
arriving juvs. This is one Calidris species where separating adults and juvs
is rather difficult due to the similarity of adult Alt and Basic plumages
and an overall similarity of both to a washed-out juv plumage, except that
at this time of year the juvs will be fresh, not faded. I'd be looking for
richer chestnut fringes and edgings to scap and coverts and obvious white
mantle-V's, where the Alt adults are showing pale buff fringes and edgings
and are overall kinda non-descript.

--speaking of bright mantle-V's: one small-bodied, small-billed juvenile
Calidris with a well-defined split-supercilium, rufous crown and scapular
fringes and conspicuous white mantle- and scapular V's had me reaching for
the alarm button with my heart-rate in the low hundreds. Why was it not a
classic grey-morph juvenile Little Stint C. minuta? It was obviously
differently-marked than the others, and had most of the field marks.
Luckily, the bird was close: small, hard-to-see webs between outer and
central toes. SemiSandpiper.

--some behavior I've been watching this summer to see if it's consistent (it
is) is the actions of SemiSandpipers, Westerns and Leasts in mixed flocks.
Besides showing more overall aggressiveness toward each other and the other
two, the SemiSandpipers also invariably take the lead in moving to a new
area in which to feed. As the flock disperses upon landing, but generally in
the same direction in an almost-ameboid fashion of sending ahead pseudopods,
the birds at the very end of each advancing arm are almost invariably all
SemiSands. Least Sandpipers, on the other hand, hang back and let the two
bigger species take the chances.

--*many* swallows, mostly juv BARN SWALLOWS Hirundo rustica, were sitting
and pounce-feeding on bugs in the sawdust covering the NE pond. One juv bird
had a white chin, neck and forehead and whiter underparts than the others
and I wondered if it couldn't maybe have been a hybrid between Barn and
Cliff Swallow H. pyrrhonota.

Cheers.

Michael Price A brave world, Sir,
Vancouver BC Canada full of religion, knavery, and change;
mprice at mindlink.net we shall shortly see better days.
Aphra Behn (1640-1689)