Mike Smith wrote:

>I have seen several bats in Seattle. A really good spot is Seward Park.
>On the north side of the peninsula, there are 2 fishing docks. Both are
>good lookouts for bats at dusk. You can see 2 sizes here, apparently
>some small Myotis, and some larger one.

Average weights of the species of myotis of western WA range from 4.4 g
(California Myotis) to 7.2 g (Long-legged Myotis), so you could certainly
distinguish larger from smaller ones, but there's a whole range of species
inbetween to complicate the issue. Silver-haired Bat at 9.0 g is a bit
bigger but still weighs less than the average warbler. Average weight of
Big Brown Bat is 15.2 g, twice as large as the largest myotis.

The Hoary Bat at 28.4 g is the monster of Cascadian bats, but, alas, one of
the least likely species to be encountered; I've never seen one for sure in
28 years in Washington. Hoary Bats are migratory and thus may turn up in
odd places, as one I found once roosting a foot above the water on a
cattail stalk at a pond in California.

A terrific resource for chiropterophiles is Bats of British Columbia, by
David Nagorsen & Mark Brigham, a Handbook of the Royal British Columbia
Museum.

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