Hi Tweets,

John Shelton queries:

>Other than size. Is there a reliable/simple way to differentiate a Swift
>from a Swallow when they are flying?

Depends, John, on the species of swift and the types of swallows in the
area. Usually, the ID problem is a swallow in silhouette, at altitude or
distance, whose plumage detail is inaccessible and whose flight-style and
-profile resemble a swift; past a certain point of birding experience, one
will almost always recognise a swift for what it is.

Most swallows don't resemble swifts except momentarily. Usually the swift
never flexes its wing where the swallow does so typically, except in one
instance we'll get to in a minute. A swift wing is typically long and thin
for nearly all its length, a swallow's broad at the wrist, broader at the
base. A swift in glide will typically hold its wings markedly below the
horizontal and will often rock side-to-side while maintaining flight in the
same direction, whereas if a swallow yaws, it does so to begin a turn.

Species by species, Barn Swallow (BNSW) flight-profile is almost always
self-evident and self-identifying; Northern Rough-winged Swallow (NRWS) is
long-winged but usually flies with a graceful swooping style where much of
its flight is with wing tucked closely to body after each flicking
downbeat--more like a thrush--and is a vociferous bird beside, uttering its
farty little call pretty incessantly; typical Tree Swallow (TRSW--don't hit
that '4-Letter Code'-thread button just yet: Trumpeter Swan is TRUS)
flight-style is a usually a little more fluttery than Rough-winged but more
similar to it than a swift; Cliff--and, I'd surmise, Cave--Swallow (CLSW,
CASW) mostly has a stubbier profile, broader wing bases, but can sometimes
go into a sustained glide in swift-like form, but usually has a flight-style
where the bird climbs, picks off the flying insect, and falls away; Bank
Swallow (BKSW) is pretty much a small, stubby, very fluttery swallow that
almost never would have you wondering, 'swift?'.

In Cascadia, nearly all the instances of swallow/swift confusion are caused
by Violet-Green Swallow resembling Vaux's Swift. More than any other
swallow, the VG has the 'swift' look. Its wingbeats have the same rate of
flutter; there's the same long glide, the same non-flexure in the wing. The
VG doesn't help remove the confusion in that it has a territorial/courtship
display--'stiff-winged' display, wouldncha know it?--where it looks *very*
swiftlike in both powered flight and glide for long (+30 sec) stretches of
time. Often the only way to separate them, in the absence of seeing the
plumage pattern, is to wait and see if the bird drops out of display mode
and becomes a swallow again. If it doesn't and you still can't tell, I'd
suggest you just let it go: you'll never know which it was.

Black Swift (BLSW) shouldn't be too much of an ID problem: the apparent
headlessness, long tail and long, narrow, unbending wings give it an
anchor-shape not possessed by any other terrestrial bird outside the swift
family, except momentarily (nighthawk or kestrel). Fairly slow wingbeat and
long glides where the bird sometimes rocks side-to-side. If Black Swift ever
migrated over the ocean, an observer might be forgiven for wondering what
new type of all-black petrel or tiny shearwater he or she was seeing.
Usually silent, but heard 'em once when they were working the bugs low over
the Outer Pond at Iona (actually looking down on them from the
embankment)--sounded like a throaty low 'chuk-chuk-chuk'.

Where there's VG's, Vaux's Swift (VASW) ID is more problematical. The
descriptive 'flying cigar' sobriquet is quite apt. Unlike most swallows, and
unlike BLSW, which have a no-necked look, VASW seems equally long
fore-and-aft the wings.

Chimney Swift (CHSW) is a titch larger and darker--you can see the
difference only if birds of both species are very close or in hand--but so
similar to VASW in appearance, style and profile as to be indistinguishable
visually at any distance. Voice would be the best way to separate them: VASW
song is more organised, its usual main component is a dry
'ticka-ticka-zwee-zwee' which it tacks almost invariably onto the end of any
long run of twittering, or 'tickety-tickety-ticka-zwee-zwee' where CHSW is
typically a more more random, more musical, downward-inflected tinkling
*lacking* the 'ticka-ticka-zwee-zwee' component.

I'm not sufficiently familiar with White-throated Swift (WTSW) to speak on
its flight characteristics, particularly in regard to a comparison to
swallows, but five gets ya ten that there can be WTSW/VGSW ID hassles. If
someone from the Interior could comment on how to get around them?

Hope this helps to answer your query.

Jane Stewart writes:

>A very good bird watcher once told me that swallows beat their wings
>together and swifts alternate.

Wouldn't bet on that horse if I were you, Jane. Conceivably, a swift could
possibly fly that way, but it would do it only once before augering in.

It's odd, though, how it actually *appears*, as Burton points out, to
alternate wingbeats. Maybe it's the side-to-side rocking that throws off our
perception; after all, there's other birds with equally quick or faster
wingbeat frequencies which we have no trouble seeing as symmetrical. A
question, then, for all you eye-brain-perception specialists out there. Why
do we see the small swift flight as alternating?

Michael Price The Sleep of Reason Gives Birth to Monsters
Vancouver BC Canada -Goya
mprice at mindlink.net