[Tweeters] Possible Black Swift (long)

[Robert O'Brien]

I live in the Willamette/Clackamas River Valley 20 mi SE of Portland.  A
very rural area and been here 50 years.  Elev. 138'
In this time I've seen exactly one Black Swift, flying NW at about 500'
 This was in the 'olden' days with telephone reports of
rare birds  Interestingly, a single Black Swift was reported a little later
from Sauvie Island, about 40 miles NW of here, the direction
my bird was headed!.  I've always wondered whether this was the same bird.
Reports of Black Swifts in the Portland tri-county
area are exceedingly rare.
Bob OBrien  Carver OR


On Mon, Jul 3, 2023 at 7:35 AM Michael Price <loblollyboy at gmail.com> wrote:


> Hi tweets

>

> Sound like a Black Swift to me: appearance and locality sound just right.

> Their current scarcity is relatively recent, and they might still be found

> when conditions are right.

>

> It's often said that Black Swifts appear only in very small numbers at sea

> level almost only when it's overcast, in advance of an incoming Pacific

> Low. That's usually how I saw them. Except when I started seeing them

> regularly in larger numbers under very different conditions. But that's

> likely a historical construct.

>

> True to script, I saw my first-ever Black Swifts one overcast afternoon in

> the early 80s when Mike Force and I were watching a skirmish line of

> several BLSW just over the water of the outer pond at Iona Island in

> Richmond BC. The birds were about 5 meters above the water, flying parallel

> to each other upwind into a gentle southeasterly breeze (in Vancouver BC, a

> southeasterly is our incoming rain-envelope wind). Whenever they reached

> the eastern edge of the pond, they wore downwind back to the western edge

> and reorganised their line. Rinse and repeat several times.

>

> Then there were the exceptions. These required a different physical

> topology, but they were consistent, and most close to sea level.

>

> 1. On any warm late afternoon or evening between June and August above

> the heritage park behind the Museum of Anthropology out at UBC in the 80s

> and 90s, there'd be large numbers of both swift species, swallows and

> nighthawks. This location is near the western end of Point Grey, nearly 200

> ft/60m above Burrard Inlet, just south and east of the west- and

> northwest-facing cliffs. They still may show up there.

>

> 2.  In the 80s and 90s, I lived in the NW corner of Kitsilano, a

> residential district on the west side of Vancouver BC. Most late summer

> afternoons and early evenings, I could open my south-facing window and

> watch Black Swifts low and close, often so close I could hear their

> vocalisations and even could hear their bills snapping shut as they hawked

> insects. To the south of my house, there was a high southwest--northeast

> ridge.

>

> 3. On hot, humid later-summer afternoons in the 80s and 90s, when there

> were multiple ant/termite hatches on Vancouver's West side, I would

> sometimes see the sky jammed full of hawking swallows, Black and Vaux's

> Swifts and the smaller gull species---Bonaparte's, Ring-billed, California,

> even maybe a couple of juv Franklin's---heck, even some Glaucous-wingeds

> clomping about with all the grace and elegance of WWE wrestlers auditioning

> for Swan Lake), up to the upper limit of the 10x40 bins in my backpack.

> Well, used to. Swifts and swallows and nighthawks are all pretty much gone

> now: I've yet to see one this summer in my neighborhood where twenty years

> ago they were almost absurdly abundant from mid-April on. To the south,

> there was a long east--west ridge.

>

> 4. In the first decade of the 2000s, I would take my mid-afternoon lunch

> to the east-facing back porch of the business where I worked in East

> Vancouver. It was a pretty standard small/specialty-retail district on a

> busy street. Hardly typical Black Swift territory. But any warm sunny day

> from mid-June to early August, I could sit and watch up to 5-10 Black

> Swifts amid the Vaux's and the swallows hawking their prey above the

> alleyway behind the store at distances ranging from 10-150 meters. They

> were there every afternoon from mid-June to their southbound departure in

> August as long as a warm west wind blew. Never got tired of watching them,

> especially when they would deliberately go into their hammerhead stalls,

> something the Vaux's never did. This location was at the western base of a

> long north--south ridge

>

> What did these sites have in common? Ridges and warm westerly to

> northwesterly breezes---winds such as this region typically gets when the

> semi-permanent Pacific High sets up shop offshore from June to September,

> creating up-drafting ridge waves lifting airborne insects for the local

> aerial insectivores to chow down on. These ridge-wave updrafts are swift-

> and swallow magnets.

>

> So, I'd guess that if you're where the topology's flat, you're gonna have

> to wait for an incoming Low to come trundling in off the Pacific and trust

> to luck, but if you can find yourself a nice little ridge with a warm

> westerly, insect-laden wind, you may see them regularly during their summer

> residency. If they're still there to see.

>

> best wishes

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