Hi Tweets,

Apologies in advance for any weird terminal/CR stuff: I've been having some
trouble with my terminal recently; also why I'm posting this late.

While walking to catch the 7AM bus Monday morning, I noticed far off the SW
a line of 23 *large* birds headed north that resolved into a fairly acute
'V' in which the birds were covering considerable real estate, but keeping
station. Migrants. Hot stuff, I thought, some of those thousands of
Sandhill Cranes I've been reading about recently have made it to Vancouver.
I could see, though, that the flight-style seemed far too relaxed and
floppy, even at great distance. Not right for geese or swans and too big.
P-P-Pelicans (very rare for Vcr BC)? Still not right. Eagles? Absurd.

That's when I saw, nearly 200 meters directly overhead, a *tight* formless
flock of *58* large birds. My senses said 'Great Blue Herons': my mind
said, forget it. Great Blues don't flock like that (one exception, see
below). Carrying my bins in my pack paid off; I got'em out and confirmed
a.) the species and b.) the number.

When they reached a point directly over the Burrard Inlet shoreline, many
(about 30) began to go into full soar. They looked like a migrant flock of
one of those large vultures which migrate over Gibraltar. Some soared
several complete circuits, while others began to slope down to the beaches.
Still other kept going northward out over Burrard Inlet. I had lost sight
of the other flock when it flew below the horizon line to the west, but it
likewise was headed for the Inlet.

All 81 birds came from the direction of southern Point Grey, where there is
an extensive (20+ pairs) heronry.

Two possibilities. First, they were from the heronry, though it's hard to
believe that it contains that many adults and that they would all leave at
once and in the same direction. I can't imagine any circumstance that would
result in such a *huge* number leaving the heronry so 'en masse' in such a
coherent flock. Normally, and this is based on about fifteen years of
observation in this neighborhood, GBHE traffic is the dreary commute of
adult to feeding area to nest and back. At most there'd be two or three
adults trudging back and forth to pick up vittles for the kiddies at any
one time. This type of massed flight is unprecedented for this
neighborhood, and no-one else has reported such a phenomenon.

Secondly, they were migrants. Now, according to official Vancouver BC
wisdom, there's no such thing as a Great Blue Heron migration (though, as
always, such assumptions are better for proof), or if there is, it's so
masked by local abundance that even if a Vancouver observer *were* looking
for it, it would be difficult (but definitely not impossible) to define.

In the only other instance of this massed flight I've seen or heard of,
about twenty years ago, in September 1976, I watched a similar flight of
about 40 GBHE's kettling over the northern tip of Point Grey, like
vultures. There seems to be nothing anywhere about these massed GBHE flocks
and kettles.

Anyone else ever seen this? And *is* there a Great Blue Heron migration to
more northern areas along the coast of Cascadia?

Cheers,
M


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