I agree, there are many isolated populations of things that are very interesting and unique.
From what I have seen, especially in the past decade or two is that many of the south Florida "brooksi" are definitely in major trouble and their numbers are declining at a VERY alarming rate!. The habitat encroachment for development is bad enough, and the fire ants have had to have taken a heavy toll as they emerge from the eggs as well. But many of the wild-caught snakes these days seem to also be extremely thin, or even found dead. I am thinking there is some heavy-duty environmental poisoning that has impacted their numbers down south.
Being that they feed on just about anything that moves, it only makes good sense that when they are constantly feeding on things like tadpoles, frogs, lizards, and other snakes in these areas, especially around canals and other water areas that they would have to be ingesting accumulating quantities of pesticides, fertilizers, etc.. from run-off. And over time has been killing many of them off in a slow agonizing death.
It's really sad situation for them and many other animals.....Seems that man's so-called "success" all too often equals the demize of many animals as he blazes the trail.. 
~Doug
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"a snake in the grass is a GOOD thing" 
my website -Serpentine Specialties