Hi Tweets

Chris Hill writes:

>Anyway, back to the point of the story, both species of Cuckoo are present
>in that area, but scarce. An ACTIVE birder might see 5-10 yellow-billeds
>and one or two Black-billeds a year. I felt lucky to find (usually by
>ear) one or two Yellow-billeds a summer. But these urban peregrines were
>feeding more heavily on Yellow-billed Cuckoos than any other species.
>Conservatively they were bringing in several per week, perhaps it was even
>several per day (I can't remember, but do remember it was a staggering
>number).
(snip)
>Cuckoos must have a special vulnerability to hunting falcons. Funny since
>they seem such skulkers. But of all the places a vagrant cuckoo in
>Washington could turn up, a peregrine nest seems quite plausible.

There's a similar story--I think here in Vancouver BC, but it may heve been
Seattle WA--where a downtown Peregrine was being monitored and among the
Bonaparte's Gull wings was an adult Sabine's Gull wing. Jeez, do you know
how *rare* Sabine's are here even at usual places like the end of the Point
Roberts and the end of the Iona South Jetty? One or two per year is normal.
A week later there was a different Sabine's wing.

So something is clearly going on--beside wounded birder pride at Peregrines
being better rarity-finders than hardcore birders--that east or west they're
taking birds that are rare to very rare in the checklist area and doing so
in numbers. Well, mistnetting for the first time in an area often shows
species normally considered rare to accidental may actually pass through in
numbers, often at night, when all good little birders should be fast asleep.

I'd be wondering how they're getting those cuckoos because, brother, I can
tell you from experience gained in an eastern boyhood that cuckoos are such
good skulkers that after seeing Black-billed and Yellow-billed lifers no one
in his or here right mind bothers to get visuals on them from then on, any
more than Western birders bother tracking down every singing Swainson's or
Varied Thrush or booming Blue Grouse. So the 'grine's gotta be popping them
either in migration or at some migration chokepoint where the cuckoos are
crossing water and/or are between covering trees or shrubbery. So why don't
local birders see them there in larger numbers? Because they may be night
migrants.

So here's a two-cent's-worth series of interlocking speculations to account
for this stuff: a) that Sabine's Gull are when migrating overland sometimes
to often nocturnal migrants (apparently they're fairly closely related to
Swallow-tailed Gulls Larus furcatus, which *are* nocturnal); b) both cuckoos
are--no speculation here, we know--also nocturnal migrants as well as being
fairly lousy fliers and c) that when it suits them, Peregrines are
(partially) nocturnal hunters on those passing nocturnal migrants that would
normally overfly otherwise.

Michael Price We aren't flying...we're falling with style!
Vancouver BC Canada -Buzz Lightyear, Toy Story
mprice at mindlink.net