I found the following description from The Unabashed Guide to Selected
Oregon and Washington Bird Songs and Calls, compiled by Kelly A.
Bettinger with input from many fellow birders, May 1998 version:

Wilson's warbler (WIWA)
"chet chet chet chetchetchetchet" song that speeds up, but not
two-parted at all. OCWA (Orange-crowned) much faster, with WIWA you
hear individual notes. Doesn't have the urgent quality of YEWA.(Yellow
warbler). Described as rubber tires skidding but not slowing. Call a dry
"chat". Someone suggested "Mr. Wilson dons a black cap and does the
cha-cha-cha."


Franny Drobny
Seattle, Washington
fdrobny at cairncross.com

-----Original Message-----
From: mprice at mindlink.bc.ca [SMTP:mprice at mindlink.bc.ca]
Sent: Wednesday, May 13, 1998 10:55 AM
To: tweeters at u.washington.edu
Subject: Re: RFI: Wilson's Warbler Song?

Hi Tweets

Gail Spitler writes:

>I have been boning up on bird songs again. Amazing what you
forget over the
>winter. Does anyone have any suggestions about identifying
Wilson's
>Warbler's song? I am particularly interested in the pileolata
race.

Wilson's Warbler Wilsonia pusilla almost always sings a loud,
dry
'chi-chi-chi-chi-chi-chet-chet-chet', loudest in the middle;
sometimes a
'chi-chi-chi-chi-chi' on one pitch, suggesting Blackpoll Warbler
Dendroica
striata but louder and drier (by comparison, Blackpoll whispers,
almost
hisses, 'zi-zi-zi-zi-zi-zi-zi', loudest in the middle),
sometimes a louder,
drier version of Orange-crowned Warbler Vermivora celata.
Happily, 99.95% of
the WIWA you hear will sing the conventional song, but
occasionally one will
sing a variant song somewhat reminiscent of its own species in
quality but
suggesting another in pattern. Then it's often a merry old
bushwhack to try
to locate the bird uttering the odd hard-to-place song, only to
get that
triumphant 'Only me!' look when you find it.

Michael Price A brave world, Sir,
Vancouver BC Canada full of religion, knavery, and
change;
mprice at mindlink.net we shall shortly see better
days.
Aphra Behn
(1640-1689)