The big one that got away:

Yesterday I went with net and binoculars to Lincoln Park (West Seattle) to
check on plants, butterflies, birds and other organisms. I hoped to see a
second brood Spring Azure, maybe a Brown Elfin (none seen in the park yet
this year) or something unexpected. The expected Western Tiger Swallowtails
and Lorquin's Admrals were flying, but as I walked along the trail in the
woods along the top of he wooded bluff something indeed unexpected showed
up, a dark Swallowtail
flew ahead of me. Though it was fairly worn and beaten the immediate
thought was that it was a Spicebush Swallowtail - Papilio troilus, possibly
the most common butterfly of wooded areas of Long Island where I spent my
elementary school summers catching butterflies, but not naturally occuring
west of the Rockies. I had to double check that it wasn't one of those
tricky dark phase Eastern Tiger Swallowtails, but it didn't look like one.

Though as I indicated before, I'm don't usually collect butterflies anymore,
I decided that this should be collected to document it. As it wasn't a
local species, but alien to the region I decided that the benefits of
collecting it outweighed the negatives of killing it. It soon perched on a
close shrub giving me my chance and I caught it. I then double checked the
rows of spots and checked for phantom stripes to verrify that it was not a
dark phase Eastern Tiger Swallowtail and sure enough it was a Spicebush.
Hesitant to kill it, I brought it home alive, putting it in a bug box in my
refrigerator, but intended to submit it as a specimen to the Burke for the
record.

This morning, when I went to re-examine the butterfly in full sunlight to
check the color of the scaling on the dorsal hind wings to determine the sex
(blue for females, green for males) the butterfly escaped through the
venetial blinds and out the window. The greenish scaling indicated it would
be male.

I still have one tail, but I guess there will be no specimen for the Burke.

It could have escaped from the Woodland Park Zoo's butterfly house (that at
least used to have Spicebush Swallowtails) or the Pacific Science Center
butterfly house or could have been purchased and released at a wedding or
birthday. It could have been brought in as a pupa or adult by some kid like
I was and escaped or been released or it could have come in unintentionally
as pupa or even adult in a container, plane or car. It is improbable that
it got here from east of the Rockies on its own steam.

I don't approve of importing and releasing butterflies from other regions,
but at least this one is unlikely to find a mate and add to our naturalized
alien species list. That said, I'm sure a number of you were rooting for
the butterfly and would be happy that it got away.

Stewart Wechsler
Ecological Consulting
West Seattle
206 932-7225
ecostewart at quidnunc.net

-Advice on the most site-appropriate native plants
and how to enhance habitat for the maximum diversity
of plants and animals
-Educational programs, nature walks and field trips
-Botanical Surveys

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