Kelly Cassidy asked about:

>Opossum:

I've seen roadkill possums along the lower Columbia gorge in Clark and
Skamania counties.

>Fox Squirrel (Sciurus niger):

Fox squirrels used to be common in the UW arboretum, but I haven't seen one
there for years. Are they still there? I have the feeling they may have
disappeared from some of the other localities you listed, too. Not like
eastern gray squirrels, which you can't make go away. In the east, fox
squirrels thrive in dry oak woodland, so I wonder if they might compete
with western gray squirrels here.

>Tree squirrels are not easy
>to distinguish! You will have to get a good look or have the squirrel
>in hand, and you will need to study the squirrel carefully against a
>good field guide. You will need to supply an excellent description, or
>a body, for a reliable record. (Note: please don't shoot at something
>that looks like a Fox Squirrel; they look a lot like the increasingly
>rare native Western Gray).

That's funny, I thought it was *easy* to distinguish eastern fox squirrels
(those of our introduced populations have entirely buffy bellies) from
either species of gray squirrel (both of which have white bellies) in the
NW. In addition, the western gray squirrel is entirely gray and white,
eastern gray has a lot of brown and buff on back and sides, and fox
squirrels (ours--I know some eastern populations are gray, or even black)
are very reddish.

BTW, everyone should know that the black squirrels in Stanley Park in
Vancouver are a black morph of the eastern gray squirrel (more common in
the western part of its native range).

>Black Rats (Rattus rattus) and Norway rats (Rattus norvegicus). Both
>introduced from Europe. The field mark given in most field
>guides as diagnostic is that the tail on the Black Rat is greater than
>the length of the body and the tail on the Norway is less than the body
>length. You will undoubtedly find yourself holding a rat with a tail
>equal to its body length.

You're absolutely right. We keep getting Rattus in the museum the identity
of which is puzzling. Most are immature, perhaps not with full-length
tails.

Dennis Paulson, Director phone: (206) 756-3798
Slater Museum of Natural History fax: (206) 756-3352
University of Puget Sound e-mail: dpaulson at ups.edu
Tacoma, WA 98416