Wednesday, November 6, 2013

Readers Write In: Should I Be Concerned About This Giant Snake in my Yard?


I found this snake in my backyard in southwest Florida. I need to know if it's poisonous and do I have to worry about leaving my dog outside to do her business. Any help would be greatly appreciated. Thanks in advance. 

Stephanie M.
Florida

    Oh my. 

    Let's cut to the chase. This animal is prominently displaying a rattle at the end of its tail. The only snakes that have rattles are the snakes collectively known as the rattlesnakes. This group includes animals in the Sistrurus genus (Pygmy and Massassauga Rattlesnakes) and animals in the Crotalus genus (every other snake with a rattle). All rattlesnakes are pit-vipers and all are venomous. They are all potentially dangerous.

    Every snake with a rattle is a rattlesnake. But not every rattlesnake has a rattle. Babies are born with only one rattle segment (they are added on each time a snake sheds). Rattles on adults can break off and Pygmy Rattlesnake rattles can be so small they barely make a noise, if they do at all.

    To make things more complicated, many harmless snakes that are not venomous shake their tails when they are threatened. If the snake is in some dry leaves, you might even hear something that sounds like a rattling noise. But, if you look at the tails of these harmless snakes, you'll see that they end in a point, not a stub or rattle. Just because a snake is shaking its tail does not mean it is a rattlesnake. Go ahead, shake ya tail feather; I promise you that you're not a rattlesnake either. 

    Big rattlesnakes can eat things as large as rabbits. I've never heard of a dog being eaten by a rattlesnake but I guess it's possible, given a big snake and a little dog. In any case, a bite by a venomous snake is something you want to avoid both for your dogs and for yourself.

    I'm not going to reinvent the wheel here, Steve Johnson and colleagues at the University of Florida have created excellent resources regarding how to identify Florida snakes and determine if they are venomous. I refer the reader there for further information.

   Don't worry dear patient readers, I've left a challenge for you. In southwestern Florida, there are only two species of rattlesnakes: Pygmy Rattlesnake, Sistrurus miliarius, and the Eastern Diamondback Rattlesnake, Crotalus adamanteus. Which one did Stephanie find in her yard? How can you tell?

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