Hi Tweets,

Regarding Stuart Mackay's bright juv Sharp-tailed Sandpiper (SHSA), another
facet of migration arises--the late hatch juvenile. Stuart's bird's bright
plumage tells us it's a juvenile in fresh plumage instead of the more
seasonally-appropriate Basic 1 or pre-Basic molt. It's clear some birds
hatch very late, the latest arriving SHSA (Nov) clearly not leaving the
nesting territory and beginning their southbound migration until the first
arriving juveniles (early Sep) have already been on wintering territory for
some time.

At Iona Island a few years ago, there were Western Sandpipers (WESA)
arriving in very fresh juvenile plumage (buff wash on breast: they lose the
wash very quickly) even well into October, which means a protracted hatching
period from mid-June to mid-September. Since according to the Birder's
Handbook the fledging period for WESA after hatch is 19-21 days, this would
mean that the Arctic summer and autumn are over and winter underway *before*
these late-hatch birds start south.

A late-hatch SHSA appearing in North America, and presumably travelling with
Pectoral Sandpipers (PESA), would first, after hatching sometime in early to
mid-September, have to cross whatever part of Asia to the Bering Strait,
cross over, then traverse Alaska in late October. That's just to get here. A
few years ago, there was a fairly extensive thread on Tweeters about where
West Coast-migrating SHSA goes when it leaves here, with the consensus that
since there's a marked absence of northbound adults the next year, that
somewhere between here and Central America, they undertake a long over-ocean
flight to the more conventional wintering territories in the South Pacific.

However, Stuart reported no PESA with it--and how often do you hear of a
single SHSA *without* PESA? That started me wondering. There has been a
series of strong Lows in the northern Pacific for the last few weeks, and
it's conceivable that this bird was actually migrating down the Asian coast
before a storm-assist brought it here. The similarly-timed appearance of a
wagtail in California just a week or so after a couple of real whompers hit
the northern BC coast is so tantalising; intuition says this is no
coincidence. It's times like these I wish we had the same kind of coverage
of the BC outer coast and Queen Charlotte Islands to the same degree as the
US Pacific states and that, like American observers, the people were online.
Maybe in another quarter-century. Beside the fact that there must be a ton
of Asian birds moving through there unseen until they hit the States, we
could see the relationship between the October-November storms and the
appearance of species such as SHSA.

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