[Tweeters] Pt Wilson seabirds: massive daily movements in both directions

[Steve Hampton]

I want to share some insights I've recently gained about daily seabird
movements at Pt Wilson, Port Townsend, which I probably should have figured
out a few years ago.

Pt Wilson sits at the intersection of the Strait of Juan de Fuca and Puget
Sound. Each morning, thousands of seabirds pour into the Sound southbound.
Every afternoon, they return to the north. At present, we've seen large
daily movements of Rhinoceros Auklets, Common Murres, Red-br Mergansers,
Marbled Murrelets, and even Red-necked Grebes. Possible Brandt's Cormorants
are involved too. The Pigeon Guillemots and other corms and gulls are more
near-shore local birds that go back and forth at random times.

On Wednesday morning (Mar 13), I estimated in one hour of seawatch (
https://ebird.org/checklist/S164701591 ), all southbound,
4200 Rhinos
2400 Common Murres
1200 Marbled Murrelets
900 Red-br Mergansers

That afternoon, we estimated (https://ebird.org/checklist/S164746528), all
northbound,
3000 Rhinos
2400 murres
240 murrelets
600 mergansers

I suspect the afternoon movement is more drawn out. The morning movement
may start at dawn, but we've seen days where it didn't really pick up until
9am. The Rhinos, of course, are going to their colony on Protection Island,
just around the corner. But the others? John Piatt suspects they spend the
night in open waters, probably west of Smith Island. I think they are
foraging largely in the area of the PT-Coupeville ferry line and toward
Marrowstone. The ferry often goes past thousands of birds on the water.

Of course, these numbers vary seasonally and even daily depending on
species present and presumably food availability. The numbers the last few
days have been really high. I'm not convinced that tide has much to do with
it. I have noticed these large MAMU numbers only in Feb and Mar, and even
then, it varies from week to week.

I should add that, from Pt Wilson, these birds are pretty far out, and
fly-bys (though some are in the water, especially when a changing tide
brings them drifting by). They offer reasonable scope views, but are mostly
too far for good pics. Passersby see nothing. Those with just binoculars
see dots, but identifiable if you're familiar with these in flight. They
each have their own distinctiveness. The Marbled Murrelets, for instance,
are typically in pairs, about 2-6' apart, and flying like bumblebee
torpedoes, slightly rocking, and seemingly twice as fast as any other
species.

good birding!

-- 
Steve Hampton
Port Townsend, WA  (qatáy)
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