Hi Tweets,

This is very interesting.

First, the location is on the N side of the Fraser River in New Westminster
BC, about 12-15 km upstream from the outlets to Georgia Strait, and my
office is on the second floor of a building about a block N of the river.
Ostensibly on the phone to clients, I can see what's moving over the river
if not on most of it, and spend as much time as I can on the phone ;-)

In the last week there's been the odd break from the sodden, cold
non-spring of the last several weeks, and from my office window I've
noticed several tight flocks of what look like Mew gulls moving upriver,
close to the river's surface. Presumably, they're keeping close to spawning
schools of oolichan (eulachon). One flock of small white gulls *could* have
been Bonaparte's. Why don't I use my bins? Well, the street below is pretty
seedy and the people desperate (a great line from one of Ferron's songs: "I
have eaten with the hungry, and we eat each other raw."), a lot of dealing
in various merchandise and commodities goes on: someone at a window with
binoculars is likely to be perceived to be a cop. Since I have to walk that
street a couple of times a day, I'd rather not give anyone cause to mistake
my innocuous motives for being at a window looking anywhere but inward.
With a recent influx of warmer air from any other direction than
damn-cold-for-this-time-of-the-year, a really healthy whack of adult and
First Year Ring-billed Gulls, totally absent from the area through autumn
and winter, started moving *down*river and continues to do so. My hunch is
that, in contrast to just about every other northbound migrant species I
can think of here in Greater Vancouver BC, they're interior migrants moving
N and *out* to the coast.

Coincident with this break in what I've come to think of as the
Semi-Permanent Vancouver BC Cold Low (*pace* Jack Bowling ;-) and downriver
movement of RBGU is an obvious upriver movement of other gulls (most medium
to large) *at great height*, something I've not seen since starting here in
August. Again I'm only guessing, but these might be Mew, Ring-billed,
California, Herring, and Thayer's Gulls on their way from wintering on the
coast. None of them breed locally, and most a good ways off to the N and E.
In addition, I'd guess that this is the time when a lot of local sexually
immature Glaucous-winged and Western X Glaucous-winged Gulls get the boot
and start their vagrancy (gets them out of the hair of the adults trying to
raise young: survivors return to breed).

One of the problems here is that, as someone wittily pointed out, the
distribution of birds usually corresponds point-to-point to the
distribution of birders. Obviously the wintering and transient gulls and
shorebirds leave and move through the area, but *how* do they move through?
Where and when is the main movement? Nobody has a clue.

There's an intellectually-enticing sighting someone related to me a few
years ago when I was still the Vancouver BC Bird Alert operator: one day in
late April, an observer (I wish I could remember who, because he really
deserves credit for braving the usual local
'oh-you-couldn't-possibly-have-seen-that' skepticism and telling it anyway)
watched a movement of gulls going N up Harrison Lake at the E end of the
Fraser Valley that he estimated contained over ten thousand gulls in a few
large, tight flocks. Though he didn't feel able to make a definitive ID,
they sounded like Mew Gulls. Supportive of that number, several years ago I
saw a huge, pure flock of 5,000-6,000 Mew Gulls (nearly entirely adults) in
*unison* flight (thought they were Bonaparte's at first) at the E end of
Boundary Bay a few years ago, just about the time of the spring that they
clear the area. Do the other wintering gulls do this, this massed
migrational staging? Or is the small steady eastward trickle at higher
altitude their style? No one here knows.
Locally, among the few who care, there's some guessing that the Fraser
River is a migrational route, but once the birds leave Vancouver BC, where
amateur field ID experts comb through them for vagrants at various regular
sites, they disappear and their invisiblity becomes profound. Then, our
ignorance becomes like an opaque window beyond whose dull face the most
incredible rituals of migration could be performed like a twice-yearly
dance, and we'd never know.


Michael Price The only alien planet is Earth.
Vancouver BC Canada
mprice at mindlink.net - J. G. Ballard