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Fellow herpers:
 

As you all know kingsnakes have long been in decline throughout the  
southeast and have been totally extirpated in many areas of Florida where they  
were once common such as Paynes prairie. Many other species are in equally bad 
 shape. The general consensus has long been that fire ants were the primary 
 cause, along with roads, habitat destruction, and resulting ecosystem 
collapse. 

There are problems with each of these explanations. Kingsnakes and other  
species have disappeared in remote wilderness areas, so it is clearly not 
just  rednecks, roads, or lack of habitat. 
 

Long ago I noticed that kingsnakes persisted in small numbers on the  
islands along the gulf coast. I am told that they persist on dikes in the  
everglades too, particularly in agricultural areas, but I have not seen them  
there. Kingsnakes still exist in upland locations further north and perhaps west 
 but I have no personal experience further west. If fire ants were the 
problem  how could they continue to exist on dikes in the glades? Fire ants can 
fly, and  I have often seen them on the gulf coast islands, so there goes 
that  explanation. 
 

If it is a disease there must be either a vector or some other means of  
transmission. Snakes are not communal animals so direct transmission is  
unlikely. If there was a vector such as mosquitos then the snakes on my back  
porch would long ago have died since they can easily be bitten through the  
screen. Ditto for an aerosol pathogen.
 

More recently natricines, once the most common of snakes, have disappeared  
too. Our creeks and rivers are now effectively devoid of watersnakes where 
there  used to be thousands of them, and Steve Christman has for years 
offered a reward  for anyone who can find a male blue garter snake. Natricines 
are extremely  prolific. It certainly isn't lack of food for there are still 
plenty of small  fish. 
 

Let's review what used to be the basic food chain at Paynes prairie:  
plants>bugs>frogs>watersnakes>kingsnakes. (Yes, I know kingsnakes  eat things 
besides watersnakes, and it is true that there was a catastrophic  decline in 
cotton rats, perhaps caused by fire ants) The point is that  kingsnakes used 
to eat watersnakes and garter snakes both of which eat frogs. 
 

Why do the islands serve as refuges? What is different there from the  
mainland? Lack of standing fresh water! What needs standing fresh water?  Frogs!
 

I recently read that ranaviruses have been shown to infect various  
reptiles, so I cannot help but suspect that frogs infected the natricines that  
infected the kingsnakes. Perhaps the natricines persisted after the kingsnakes  
simply because they are more prolific.
 

The kingsnakes on the gulf islands presumably eat lizards, mice, possibly  
birds, and salt marsh watersnakes. Nerodia clarkii is fairly scarce, lives 
in  brackish water, and thus rarely eats frogs. Likewise kingsnakes living in 
upland  places like Tennessee probably have less contact with frog eating 
natricines  than those living further south in swamps. 
 

There are some holes in my theory such as the presumed persistence of  
kingsnakes on dikes in the glades where surely there must be plenty of frogs. Or 
 are there? Is it possible that agricultural spraying in the cane fields 
has  reduced the number of frogs thus forcing the watersnakes to eat fish and 
the  kingsnakes to eat the abundant rodents? I don't know.
 

Moccasins eat frogs and they are doing fine. They have recently been show  
to carry eastern equine encephalitis without exhibiting any symptoms, but 
that  just proves that they are indestructible. Ditto for bullfrogs.
 

Even rat snakes are in decline, but there are still some around, especially 
 large adults. Young rat snakes specialize in small frogs and lizards 
whereas the  adults do not. I don't know if hylids are susceptible to ranaviruses 
or not. Is  it possible that their arboreal lifestyle limits exposure to 
waterborne disease  and thus not all rat snakes have died out from eating them?
 

I don't know anything about ranaviruses or other herp diseases, but cannot  
help but suppose that the persistence of kingsnakes on small islands may be 
an  important clue. So who does know about these things? 
 

That is why I am writing this, to see if any of you can point me in the  
right direction or have any thoughts on the subject. Feel free to forward  
this.
 

Sleazeweazel
AKA: Bruce J. Morgan
Environmental Designs
POB 1519
Archer, FL  32618 USA
352 495 9748
_www.environmentaldesigns.org_ (http://www.environmentaldesigns.org/)