Subject: [Tweeters] Xantus' Murrelet; thinking like a bird
Date: Apr 27 00:20:37 2005
From: Daniel Froehlich - dfroehli at u.washington.edu


Hi all,
On Thursday last week, I took a trip up to Victoria on the Victoria
Clipper to check Grosbeaks at the Royal BC museum.

Weather was decent and I spent all morning on deck scanning the
water. Lots of the typical alcids including 14 Marbled Murrelets all
in full breeding plumage. Out in the middle of the strait one flying
bird made itself noticeable by it's smaller size, more rapid
wingbeats and clean all white underparts (wing and belly to throat),
indicating Xantus' Murrelet.

This is an unusual record, both for being inside, off the open ocean
and for the time of year. The Burke has only two WA specimens, both
from the winter. Pelagic trends suggest a late summer pattern.

That was a fluke observation, just chance, completely unpredictable.
Not all rare sightings happen like that though. The Brown Thrasher
sighting near Westport just two days later, so aptly described in
Matt's Saturday posting, actually represented the culmination of
heavy calculations. Late April is the time period when species that
breed in the southern half of North America undertake their
migration: they're moving. So while it might be the time to look for
earlyish northern migrants, it's actually the best time to watch for
southern migrants that overshoot.

The front that passed through early on Saturday provides the perfect
conditions for such overshoots, offering a jolt of south winds before
it hits, then grounding the new arrivals with high winds and poor
feeding conditions. The birds are forced to stick around until the
weather breaks, the insects crawl out of their shelter and the birds
stock up for their next leg and take off.

So when our pelagic was canceled, I was thinking Blue-gray
Gnatcatcher, White-eyed Vireo, something that MOVES in April, with a
few extra days to make it the extra distance to the wrong coast.
Coastal strips are the place to look, as they provide a natural
concentrating feature. But starting along the coast the winds were
still very strong, making birding difficult and keeping the birds
down. So I thought just inland, where the outer woods break the
winds some, but not yet up on the hillsides, that's where grounded
migrants might still make a stand for food. The extensive cranberry
bogs with little bird habitat made birding seem a dismal prospect,
but in fact we found some warblers and sparrows, even a Chipping
Sparrow among the few hedgerows, generally in their lee. We finally
found the thrasher tucked right up against the steep slope of the
hillside. Even then confirmation only came when the bird responded
to a thrasher tape, apparently concerned by the prospect of having to
face a territorial bird in its presumably fatigued state induced by
the storm and extra-long migration.

Finally, another way to find rarities is to go to where bird numbers
may be high. On Sunday, with the weather breaking, I figured
Leadbetter Point would be a promising spot: again coastal
concentration and a two-day storm system that brought birds in and
grounded them. While the 4-hour visit in the morning produced no
rarities, it was a spectacular fall-out, of the Gulf Coast kind or
that one day each spring in the Northeast, when warblers seem to
emerge from leaf stomata and the sparrows zipping around you suggest
you're an impediment to something more important: migration. It was
my first such experience after 10 years on the West Coast and it only
lasted an hour or two; but it's breathtaking. There were hundreds
and hundreds of Common Yellowthroats, Orange-crowned and Myrtle
Warblers, lots of Pacific-Slope Flycatchers and Audubon's Warblers
and Hermit Thrush, even a pod of Black-throated Gray and Townsend's
Warblers and a single Cassin's Vireo: a stunning spectacle.

The point of this is in fact NOT merely as a guide for finding
rarities, but to suggest that carefully considering aspects like
weather and geography from a bird's perspective can make your birding
both more fun and more productive. Weather that's unpleasant for us
(and even bad for birds) can be good for birding and habitat that
seems unsuitable for birds can accommodate interesting birding by
dint of geography and weather patterns, even if only temporarily.

As always, good birding,
Dan
--
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Daniel Froehlich
Burke Museum
U. of Washington
Box 353010
Seattle, WA 98195-3010
Cell 206-595-2305
W 206-685-9866
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