I tuned in to tweeters and noted the bird-pond thread.

I've had a pond in my yard for years now, and it's a wonderful enhancement.
It does attract raccoons, which trash the plants we plant in it to the
point of driving us close to distraction. We've had Great Blue Herons come
in and capture the few freshwater fish we've introduced into it, so we
finally decided that introducing fish that furnish us pleasure by being
visible (i.e., that hang around the surface) probably doesn't work. It
hasn't attracted any other water birds in the 4 years we've had it.

Interestingly, most of our birds seem to prefer to drink from and bathe in
shallow bird baths rather than the pond.

Finally, koi are just carp, as most of you know, and carp feed by rooting
around in the bottom sediment. If your pond develops any such sediment
(it's an inch thick in ours), these fish will only keep the pond muddy.
Goldfish don't do this but are sure to attract raccoons, which try their
hardest to eliminate your population.

We find the pond mostly an aesthetic amenity, which will attract at least
some dragonflies. Insects such as bees and wasps come to drink in good
numbers, so you had better like them. You can also introduce aquatic
insects and other invertebrates into it by dipping them from nearby ponds
and lakes.

Overall, I'd say a pond is wonderful, but its value in attracting local
wildlife is at least somewhat dubious.

The Grinch.

Dennis Paulson, Director phone 253-756-3798
Slater Museum of Natural History fax 253-756-3352
University of Puget Sound e-mail dpaulson at ups.edu
Tacoma, WA 98416
http://www.ups.edu/biology/museum/museum.html