Tweets

To follow up on my Tues post, Malcolm Bailey and I went exploring the south
shore of the Fraser R. on the north east corner of Chilliwack Mtn. tonight
to see if the large flock (min.5000) of Barn Swallows he had observed on
Monday was still in evidence. We got to within between 1/3 to 1/2 mile east
and in full view of the sandbar where the birds Malcolm had observed had
descended to roost.

As we pulled up to the river bank and opened the door of the truck, we
immediately heard many Barn Swallows calling overhead. Getting out and
looking up there were singles and groups of birds up to 100 or so heading
from the south-east toward the sand bar which was to our West. The birds
immediately visible were approx 25 to 75 feet above our heads. As our eyes
brought more birds into focus, we realized that these groups extended
vertically up to probably 400 feet or so. We had to use our binos to
resolve the high dots into swallow silouettes. Our swallow watching was
briefly interrupted by a Merlin flying low up-river, skirting the riparian
Cottonwoods.

Looking west to the area of sky above the sandbar, my first impression and
comment was 'they look like a swarm of locusts.' (Just like I saw on TV as
a kid in the '60's). This was great stuff - kinda like a mega-twitch!

As we started to get a sense of where the birds were in the sky, the
problem of trying to estimate their numbers became apparent. It was hard to
concentrate on this, as we were really enjoying the spectacle of these
masses of birds and the groups which would suddenly form into a votex and
spiral downward for a hundred feet or more. Wow!

The light was far from perfect and at our distance from the birds, the best
estimate we could get was when the majority of them 'bunched' up into a
flock about 1/4 mile + long and stretching vertically from between 200 to
500 feet. From our angle we couldn't see the breadth of the flock. A very
conservative estimate was 6000 birds. We had already seen many birds
dropping into the sandbar trees and we have no idea how many we missed in
our estimate. Within a period of 10 mins the sky was empty. We didn't even
see the big flock go in to roost; they just disappeared while we were
momentarily distracted by a second Merlin downriver.

Now if Birds of B.C. is correct, and the southern mainland Barn Swallow
migration peaks in August, maybe there are truly enormous flocks at this
location in August. And maybe Michael Price is correct and we don't know
what's happening there because the area is rarely birded. We intend to
continue to visit the area - certainly next August.

Brian Self, another local birder, has been working out at the Reifel Bird
Sanctuary on the Fraser Delta for the last couple of weeks. He told me
tonight that last week there 200 hundred or more Barn Swallows around the
Sanctuary. This week all but one or two have left. No more long lines of
them are perched on the wires. So if they have more or less disappeared
from, at least some, coastal locations but there are still thousands up the
Fraser Valley, what does that tell us about swallow migration in this part
of the world?

Other birds seen were a few American Robins, 30+ Canada Geese and 2 Great
Blue Herons. There was a group of about 20 gulls on an unvegetated sandbar
about 150 yds in front of us but we were so taken by swallow watching, that
they flushed before we had a look at them. Maybe we missed one of those
Sabines!


* George Clulow *
* Langley School District *
* 4875 222nd Street Tel: (604) 530 2711(work) *
* Langley, B.C. Fax: (604) 530 2906 *
* V3A 3Z7 *