Bob Ringler noticed my claim of seeing a Northern Waterthrush at Tuckahoe. 
This is how I answered his question:

"I had good, clear looks at the Waterthrush but not long enough to pick up 
any of the fine details.  Not being sure of the ID, I consulted Sibley's, 
Eastern Edition.  He clearly describes the Northern as a tail pumper but 
says nothing about this behaviour characteristic for the Louisiana.  The 
Louisiana was ID'ed by song alone.

Yeah, I did some more reading after I got your email and learned that both 
have similar behaviours, although slightly different ways of bobbing and 
weaving and pumping.
Based on your astute questioning (i.e. a state record for Northern?) and my 
further reading, I humbly withdraw my claim for a Northern and must call the 
bird a Waterthrush (sp)."

Jim Wilson
Queenstown