[Tweeters] Swift counts
lpatters at ix.netcom.com
Tue Aug 31 21:33:04 PDT 2010
All of tweeter land will want to check out this YouTube taken a year
ago at the U of Oregon by Garth Hagerman. http://www.youtube.com/watch?v=1TT07lAdNaM
Richard, you might want to send this link back to your East Coast
friends and see if they still consider a 10,000 swift evening unlikely.
At the really large chimneys, like Agate Hall in Eugene or Portland
Chapman, when the birds are really in a hurry they can go in at 300
plus per second. So those sites often end up having their counts
expressed as estimates. The sites with smaller chimneys are a lot
easier, with the swifts going in at close to 10 per second. So our
counters are usually simply counting by tens. Last week Richard Repp
in Yakima averaged his count by tens total with another observer's
total and came up with 830. Someone else had filmed the birds entry,
took it home and played it through in super slow mo. They ticked off
1041 swift entries, one at a time.
On our Vaux's Happening website is a photo taken down the Rio Lindo
Academy chimney by Brad Benson. http://www.vauxhappening.org/Vauxs_Happening/Data.html
He counted nearly 7 thousand swifts going in that night. Does
the chimney has room for triple that? It looks like they are hanging
on each other 4 deep. Must have been a cold night.
> Is the thing on the top a counter or a video cam? A high quality,
> very sharp video camera which we got up and running 6 hours ago
> Does the rope go to a door you can close? The rope will be used to
> pull up and secure a 40 foot extension ladder when service is
> Do the birds nest in hollow trees or smaller chimneys, or both?
> Both. One little chimney will only have one nest. One great big
> chimney will usually not have any.
> Do predators ever raid the flock? We watched 4 VASW get eaten by
> crows this afternoon. We were able to record one.
> In LA Ravens grab swifts near their roost chimney. This April's
> downtown LA huge roost site discovery was one of Audubon Vaux's
> Happening's most rewarding accomplishments. Now to protect it.
On Aug 31, 2010, at 8:50 AM, rccarl at pacbell.net wrote:
> My East Coast friends, astonished at the Monroe Swift numbers, are
> referring to them as "Sarah Palin crowd estimates". So how do you
> count those Swifts? We watched them last night and agree that
> thousands entered that chimney but where do they all fit??? Is the
> thing on the top a counter or a video cam? Does the rope go to a
> door you can close? Do predators ever raid the flock? In LA Ravens
> grab swifts near their roost chimney. We've seen hawks troll
> through bat clouds to catch bats. Do the birds nest in hollow trees
> or smaller chimneys, or both?
> Way cool !
> Richard Carlson
> Full-time Birder, Biker and Rotarian
> Part-time Economist
> Tucson, AZ, Lake Tahoe, CA, & Kirkland, WA
> rccarl at pacbell.net
> Tucson 520-760-4935
> Tahoe 530-581-0624
> Kirkland 425-828-3819
> Cell 650-280-2965
> Tweeters mailing list
> Tweeters at u.washington.edu
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