Hi Tweeters,

On March 08 1997, Michael Patrick posted his bird survey of the Montlake
Fill. Among its comments was his remark:

>and I'm sure I heard the first half of a Swainson's Thrush song....

That caught this suspicious ol' eye. He's asked me to post my private
response to him to the list, as he thinks it might be useful to others. Here
it is, very slightly edited with one addition.

(quote begins)
And, having fallen for this one before myself a number of times until I was
able to see the bird, am pretty sure you likely had a tuning-up Varied
Thrush (VATH). Swainson's Thrush (SWTH) are still well down in S Amer., and
don't migrate until late April/early May. Local average arrival date is May
09. VATH are moving through right now in some numbers in their quiet,
slinking way.

Based on personal experience and experience as one-time operator of the
Vancouver BC Bird Alert, the rule of thumb I've come to adopt regarding
extremely early out-of-season arrivals--particularly our late-migration
Neotropics--is *always* to see the bird; otherwise, not count it. That way I
avoid counting *very* early Orange-crowned Warblers (variant Dark-eyed Junco
trills), Western Tanagers (variant Purple Finch calls), and as probably in
this case, Swainson's Thrush (Varied Thrush throat-clearing; it's even quite
early for Hermit Thrush), Warbling Vireo (Purple Finch song), or
Black-headed Grosbeak (variant Ruby-crowned Kinglet or Fox Sparrow song).

When I ran the Vancouver BC Bird Alert, I noticed that our birders would, in
the competition to find the first arrival sometimes rely on heard-only ID,
and for a couple of years had wildly-early arrivals on some species. This is
why I emplaced a policy of visual confirmation of excessively early
arrivals. Not to say it couldn't happen, but the visual would remove the
necessary element of doubt and give you a firm datum.
(quote ends)

Hope it helps.

M




Michael Price
Vancouver BC Canada When I found out that seven of my years
(604) 668-5073 vx was only one of theirs,
(604) 668-5028 fx I started biting absolutely everything.
mprice at mindlink.net
michael.price at istar.ca -Max Carlson (Ron Carlson's dog)