I was there last Monday morning. Got there at about 7am, in time for opening. Free admission until 8am or something.
U will need a lot a patience in these places, even a slight sound from you turning around will scare the birds away.
Took with me
70-210mm
400mm
2X extender
mono pod
a Pentax MG
Fujicolor 200 Superia. (would recommend 400 if you can, coz some areas are dimm)
Tried to snap with the 400mm, found it to be a hassle as I cannot really turnaround on a monopod and aim up. A few good shots were managed with the 70-210, in fact, I think this is sufficent for me at that moment. For that 1 roll, I took something like 3 hrs to complete.
Point where your ears tells you and then stare hard at that direction. You may be able to see the singer on the branch. Prayed hard that it is still there when you lifted your camera, point and focus. All green background do look alike in the viewfinder.
Will have to wait till next week to D&P the roll.
For more info on the park, try
http://www.sbnp.org/
Hoped this helps.