Subject: sharp-tail migration Date: Sep 30 16:10:05 1994 From: Dennis Paulson - dpaulson at ups.edu
Since I'm now committed to this exchange, I'll add this in response to Bob O'Brien's posting. I have little doubt that the hordes of Sharp-tailed Sandpipers that move into Alaska do so on their way to the South Pacific or Australia, rather than on their wy to someplace like South America. Probably this is merely because feeding conditions are good in AK (Yukon delta?), and from the standpoint of a far-flying sandpiper, it's not much out of the way. From my own experience this summer, feeding conditions must be much better for shorebirds in AK than on the Chukotka Peninsula in Russia. These birds hit Alaska, stay for a little while, and then move on across the Pacific Ocean at some unknown longitude. Small numbers of them keep going south in the New World, but keep peeling off out into the ocean. Pacific Golden-Plovers surely do the same thing, as do Wandering Tattlers and Ruddy Turnstones from Alaska (and Siberia?). Sharp-tails certainly decrease as you go south on the American Pacific coast, as Bob wrote, and I think this is the reason.
Buff-breasted and Baird's, as Bob implied, and also American Golden-Plovers, Stilt Sandpipers and others, are heading generally on a southeasterly course, as they migrate to South America, and it would be expected that more of them show up in the NW than in California. Look at the record for Semipalmated Sandpiper if you want an even better example of this.
One interesting thing about Siberian stints is that they occur at (1) Iona Island and thereabouts, and (2) on the coasts of OR and northern CA. My guess as to why they aren't recorded from WA also rests on the "sampling-bias" hypothesis. The WA coast is far from our urban centers, and it is extremely undersampled, even at the height of migration. A whole lot of the early OR reports of rare stints are probably not valid, by the way, although there *are* a few definite records of Long-toed, Rufous-necked and Little. I don't know why we can't find these species in WA. There's a lot of habitat in Grays Harbor and Willapa Bay, perhaps more estuarine habitat than at any locality in BC or OR, a lot of places for the Lone Vagrant to hide, and a lot of Western Sandpipers among which to hide. I think the way to find rare stints would be to check large Western Sandpiper roosts (wherever you could get good close looks) at Grays Harbor in the fall, but I've done it a lot of times without finding any.
As for Great Knot, there are sight reports from Boundary Bay in late spring and the WA coast in fall that may be valid. I wish all shorebird seekers could carry cameras....