Hi Tweets,

An Alternate-plumaged CLARK'S GREBE Aechmophorus clarkii was off Acadia and
Tower Beach on the N side of Point Grey in Vancouver BC this afternoon. The
bird associated loosely with three Western Grebes A. occidentalis and one
juvenile Red-necked Grebe Podiceps grisegena. It was last seen swimming N
directly away from Tower Beach and was lost to view at approximately 2 km
out from shore. Direct comparison with its companion Westerns and the
Red-necked Grebe established and confirmed its identity and plumage state.

The bright golden-orange bill with dusky restricted to the basal one-quarter
of the upper mandible, white face, the black crown feathering restricted to
a narrow median crown stripe, pale grey wings and back, and white flanks
were all consistent with an Alternate-plumaged Clark's and differed
perceptibly from the bright greenish-yellow bills of the Westerns which were
outlined with dusky on culmen and keel, more extensive black crown-striping
extending below the eye, darker grey back and wings and dark grey to
grey-mottled flanks.

This continues a pattern of late-September arrivals of Clark's Grebes with
the first arriving Western Grebes in the Point Grey/Spanish Banks littoral.
Averaging the available records results in an average arrival date of Sep 26
for this species in the Greater Vancouver (BC) Checklist Area. It is only
local tradition which maintains that this species is a 'winter' species, as
its 'winter' distribution lasts from average Sep 26 arrival to average May
15 departure.

Incidentally, another species generally (and equally incorrectly) considered
to be a 'winter' species, Yellow-billed Loon (White-billed Diver) Gavia
adamsii, has a similarly early average arrival date for the Vancouver BC
checklist area, Sep 27, and equally late departure, May 05. Almost
invariably, the first southbound birds of this species recorded in the
southbound migration in the area have--oddly--been juveniles. Other than a
few shorebird species such as Sharp-tailed Sandpipers Calidris acuminata and
Buff-breasted Sandpipers Tryngites subruficollis, I can think of no other
species in which southbound juveniles arrive in Vancouver before the adults.
Certainly the other loon species tend to arrive in Vancouver in family
units, typically two adults with a juvenile, joining large concentrations
such as the Common Loon G. immer staging area along the N side of the
Tsawwassen Ferry Terminal Jetty, where those family units can still be seen
holding together for another few weeks after arrival on the coast. Some
thinking might be done about why this species departs from that pattern. For
example, where are the adamsii adults? Do they migrate down the *outer*
coast? Do they move south earlier than the juvs moving along the inner,
protected waters? What is *their* chronology? Etc.

Those few adamsii seen in 'adult'--that is, Alternate-- plumage here are
likely immature birds in their second and third years; like Common Loons in
the same plumage-state, they assume 'adult' plumage in their second year but
don't join the migration to breeding areas until their fourth year: though
in 'adult' (Alternate) plumage, they're actually adolescents.

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)