I once was walking along a stream on the Kenai Peninsula that had ice coated
rocks sticking out of the flowing water. A dipper flew up and landed on one
of the rocks and slid about 5" before splashing into the water. I didn't
really think anything of it until I saw it happen a 2nd time on another
rock. Land, slide, splash. I can't say for sure the dipper was ice skating
but it appeared to be doing so.
Incidentally, I've heard dippers singing even when the temperature has
been well below freezing.
Steve Ellis
Coupeville, Wa
sellis at coup.wednet.edu