Subject: Black Swifts
Date: Jul 19 21:55:33 1996
From: "Jack Bowling" - jcbowling at mindlink.bc.ca


On Fri, 19 Jul 1996 11:49:39 -0700, bmg wrote:

> Hi Jack!
> I was watching BLSW near what I believe to be their
>breeding area when I witnessed a new (for me) behavior I hope you can shed
>some light on.
> 2 BLSW flying at about 250 meters above a newly cut forest
>block(unobstructed view). Both birds began a steep 80 0ive. The top bird
>seemed to be touching the back of the bottom bird as they dove; much like an
>eagle would force down a gull. As they dove there was some rocking from
>side to side. I had the impression the bottom bird was trying to escape but
>couldn't.
> I could not tell if they were actually touching but they could not
>have been more than a couple of cm apart as they fell at least 200m in a
>very fast dive.
> Then, about 50m from the ground, the birds separated about 10 cm
>and began a tight (3m diameter) corkscrew in perfect unison (one behind the
>other), which they pulled out about 1m before they hit the ground. They did
>3 revs of the corkscrew and at the bottom produced (what I think is) an
>air-wingfeather noise not unlike the CONI.
> The wing noise had little of the buzzy, rough quality of the CONI
>but clearer, almost flute-like.
>Both birds then flew upwards in loose spirals while feeding.
> What did I see? Mating? Aggression? I've looked through my books
>and can't seem to find anything.
> Unfortunately, my computer is going in for surgery in Vancouver
>today and I won't be able to recieve your message for several days at least.
> Cheers, Max
> B.Max Gotz Box 291 Whistler BC V0N 1B0 0>
> bmg at whistler.net \ phone(604)932-7247 _/_)_
/
Hi, Tweets. I am taking the liberty of forwarding this query Max sent me
to Tweeters for three reasons:

1) Very little is known about Black Swift behaviour so this is an extremely
useful datapoint;
2) The collective wisdom of Tweeters is more extensive than my conjecture would
be;
3) It is an utterly cool observation!!

My feeling is that it may be courtship since Black Swifts have been known to
nest very late, although admittedly, there is very little nesting data to go on.
Perhaps post your own theories and then Max can catch up when his conputer gets
out of the shop.

cheers,
Jack


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| Jack Bowling |
| Prince George, BC |
| jcbowling at mindlink.bc.ca |
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