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David:
 
Thanks for a great overview of the problem. 
 
I noticed that ranavirus sometimes manifests by affecting the feet of  
turtles. About ten years ago I had a large collection of various species of  
turtles that was devastated by disease. Only two animals survived, a Terrepene  
and a Cuora and they are still alive today. I spent thousands of dollars  
trying to discover the causative agent. I got reports from histologists 
saying  that every organ was affected in the diseased animals. One of the most 
startling  symptoms was that the turtles' feet were rotting off.
 
You also mentioned that wildlife rehabilitators can be part of the problem  
or part of the solution. About a month after the epidemic I discovered a 
missing  Rhinoclemmys pulcherrima. To my horror I discovered that all four 
feet had been  reduced to skeletons yet the animal was still alive and walking. 
In retrospect I  should have destroyed it, but instead I took it to a 
wildlife rehabilitation  center in Gainesville FL. I explained that I was leaving 
the country and could  not care for it myself. I provided a child's 
swimming pool as an isolation cage,  a supply of antibiotics that had been 
prescribed by a vet, a stipend for its  care, and a donation to the facility. That 
afternoon I got a call from a friend  who sometimes volunteered at the 
facility. She told me that I had been indicted  for animal cruelty and the police 
were on the way to arrest me. The people who  ran the rehabilitation center 
were animal rights fanatics who would not listen  to reason, but she 
eventually convinced them to drop the charges. I can only  hope that they did not 
release the sick animal into the wild. 
 
Bruce
 
 
 
 
In a message dated 10/24/2012 8:47:34 A.M. Eastern Daylight Time,  
[log in to unmask] writes:

Hi, Bruce,


I've done an overview on Ranavirus _here_ (http://potomacwildlife.
org/disease/ranavirus.pdf) .  I  believe your theory is very plausible.  




David
 
David Stang  
_ZipcodeZoo.com_ (http://zipcodezoo.com/)   




-------- Original Message --------
Subject:  Kingsnake decline, a possible cause
From: Bruce Morgan <[log in to unmask] (mailto:[log in to unmask]) >
Date: Mon,  October 22, 2012 7:15 pm
To: <[log in to unmask] (mailto:[log in to unmask]) >


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/)