Miami is a two day drive for us. Limited to a week, St Mark’s was as far as we could go. Next Florida visit will likely be in early May when we’re signed up for camping in the Tortugas. Wonderful assortment of species there including migrant songbirds.
I forgot to mention Hontoon Island SP just a few miles north of Blue Springs and also on the St John's River. Much fewer people and probably better birding. No car access; a 5 minute free ferry takes you across the river.
My wife and I just returned from five days in the Big Bend of the Florida Gulf Coast, specifically St. Mark's NWR. Unlike your overly warm weather, we had three mornings of frost and several windy days which dampened the songbird activity as does unusually high temps. Finicky creatures, aren't...