Thanks everyone. Shark Valley is usually very nice from this time of year until after May, when it gets very hot and the nesting birds leave. You don't necessarily have to use a really long lens there to get good shots. (A 70-200 will do fine as the birds and gators are pretty tame and very used to people.) I'd suggest coming earlier than I did because the sun sets directly behind the roadside waterway going toward the Observation Tower (which is where the birds are). I encountered some brutal lighting conditions which accounts for the difference in my two shots. Probably going to rework the second and see if I can get a better result.
My Gear: 6D, 7D, EOS-M w EF-M 22 f2 STM and EF-M 18-55 f3.5-5.6 IS STM, 17-40L f4, 24-70L f2.8, 100 f2.8 non-IS macro, 70-200L f/4 IS, 400L f5.6,, Canon 1.4x II TC, Canon Speedlite 430 EX II, Better Beamer. Manfrotto carbon fiber tripod, 2 monopods, Manfrotto ballhead and pistol grip tripod heads.