Bryan Gates wrote:

>The annual fall migration of Turkey Vultures from Vancouver Island
>continues. On Sept. 30, we were at Rocky Point on the s. tip of
>Vancouver Island and were able to get a fairly accurate count of 413 (+
>or -
>15 ) TUVUs as they broke out of a high "kettle" and streamed out, in
>almost
>single file, over Juan de Fuca Strait toward the Olympic Peniunsula.
>The
>time was 1050. I watched them for as long as I could see them in my 20X
>scope and was satisfied that almost exactly 200 may have made it across.
>
>The rest clearly turned back toward Rocky Point and East Sooke Park, at
>the
>s. tip of Vancouver Island. Later in the afternoon, we were able to
>count
>about 200 birds still with us, although they were dispersed and counting
>was
>more difficult.
>
>The birds that kept going were headed into or over a dense fog bank that
>hugged the US side of the Strait (our side was bright, sunny and warm).
>If
>the birds made it across, it is unlikely that Diann MacRae and her
>fellow observers would have been able to see them as they hit the
>Washington shoreline. Perhaps others did see them. Any information on
>where
>they hit land, how many and the time of arrival would be greatly
>appreciated.
>
>Together with the earlier "arrivals" reported by Diann MacRae, it
>appears
>that upwards of 2000 TUVUs may move south from s. Vancouver Island.
>Where
>do they all come from?

I believe Bryan is asking the question of the day. Checking out Campbell et
al. Birds of British Columbia, one finds that virtually all Turkey Vulture
records in BC are from either Vancouver Island on the coast or south of
latitude 52 on the mainland. Its hard to imagine 2,000 vultures on Vancouver
Island. Come to think of it, its hard to imagine that many vultures breeding
in all of BC.

Has logging been so intense that that significant tracts of the island has
become TV habitat? Use to be that the coastal Garry oak/arbutus woodlands
were the favored habitat. But it hardly seemed that habitat type was
extensive enough for so many vultures which are now being tallied at
Vancouver Islands south tip. These numbers stretch my imagination...then
again I haven't been on the ground on the island for some years.

Just an idea... is it possible vultures are coming from the interior and
augmenting the coastal birds?

Another thought...could vultures be undertaking a reverse movement after
they breed, ie, birds from the south moving north, as do Cattle Egrets,
various herons, Tropical Kingbirds, etc? I know this one sounds wild, but I
have a bloody hard time accounting for such a huge number of vultures moving
south from Vancouver Island.

A final thought...could these birds be teasing observers...kind of like
Sooty Shearwaters off the coast. I mean shearwaters sometimes kind of do
loops off the coast, thus our perception of the total numbers may be skewed.
Are we double counting vultures?

Anyways, I think Bryan poses a question that deserves all the attention
Tweeterites can muster!

Andy Stepnniewski
Wapato WA