Bald eagles: are most common from the middle of September through the beginning of May. I call them by name and they fly down by the side of the tour boat for some awesome photo opportunities.
Alligators:February through the beginning of November is the best time for alligator tours but, the peak time for feeding large gators is after the mating season, around the beginning of May. I call the alligators by name as well and they are familiar with my boat.
Migratory Birds: such as teal, mallards, coots, geese, etc., are best during the winter months, around October through February.
You will also see many species of birds such as the great blue heron, great white egrets, pelicans, limpkins, snowy egrets, anhingas, red-tail hawks, owls, etc., (too many to mention).