The only population of Snail Kites in North America is in FL. There are 1,000 birds, up from 10 in 1965. They are listed on the federal & state endangered species lists.
Snail Kites are extreme specialists. Armed with a strongly curved bill, purpose built for plucking meat from a shell, their diet is almost exclusively freshwater apple snails of the Everglades & other south FL wetlands. These wetlands have all but disappeared & the water quality of the remaining is a mixed bag. Apple snail numbers plummeted taking Snail Kites down with them.
State & federal programs to protect wetlands in preserves & refuges provided relief & snail kites, and Limpkins, another exclusive apple snail consumer, have stepped back from the brink of extinction.
And in a rare case of benefiting from invasive introduction, populations of non-FL native island apple snails have grown & migrated north to protected wetlands in central FL. Snail Kites have followed them and are increasing in number.
An excellent example is Paynes Prairie Preserve State Park just south of Gainesville. The parks 2018 Christmas Bird Count recorded 29 total individuals in the county. The 2019 count recorded 104 individuals.
These shots were taken along the LaChua Trail.