In recent days, several people have brought my attention to a story circulating about a large Cottonmouth, Agkistrodon piscivorus, that was killed in Baldwin, Florida. Fair enough-this is easy enough to believe. After all, Cottonmouths are very unpopular among the general public, perhaps in part due to the numerous myths surrounding the swamp creature. They are also very common throughout Florida.
However, this story quickly veers into the nonsensical because of a combination of two all-too-common themes: 1) a photograph using a camera trick called forced perspective to make an object look larger than it really is (something that happens all the time with Rattlesnakes) and 2) journalists/reporters that are just a little too quick to believe something that might make for a sensational story.
The individual that originally sent me the news article said it might be the, "worst snake story (he) had ever seen." I'm inclined to agree. The reporters don't say how they obtained the measurements on this animal (probably because it wasn't with a tape measure or scale).
Despite what is reported in the story, this snake is not seven feet long (1.9 m) and 87 pounds (39.5 kg). For reference, the largest known Cottonmouth (i.e., the World Record) was only a little over six feet long. Based on my experience with big bulky vipers like rattlesnakes and including Cottonmouths, my guess is that this World Record snake would almost certainly weigh less than ten pounds and definitely less than twenty. So, the length/weight ratios of snakes rule out a seven foot and 87 pound animal. It's not possible. So, even if we accept that the snake is seven feet long (remember, this would make it the longest Cottonmouth ever known), then the weight can't be true. And if we know the weight isn't true, then why should we believe this is the world's longest Cottonmouth in the first place?!
Now, the snake in the picture is a large individual but it looks bigger than it really is. I am hoping someone in the construction or farming business can inform me regarding how far apart the teeth on that 'dozer are (I'm not actually sure that is even a bulldozer).
This picture reminds of a python that was doing the rounds a few years ago. That snake was also hoisted up by construction equipment and claimed to be the world's largest boa. It wasn't.
Updated 12/20/12 9:30 PM
I've now heard from a couple readers (in the comments and via e-mail) knowledgeable about the construction equipment in the picture above. It is apparently a root rake mounted on a tractor and they estimate the teeth are between 8-12 inches apart. So, now we can estimate the snake's length; let's assume the largest possible distance and say the teeth are 12 inches apart. The Cottonmouth clearly spans the gap between two teeth, so that's 24 inches. There is a little slack so we'll round up to 26 inches. Let's be generous and say the head would have reached the next tooth if it wasn't draping down. Now we're up to 38 inches. It's also clear the the back portion of the snake could at least reach the next tooth (50 inches). Let's get crazy and say it could have reached the tooth after that (62 inches). Finally, we can add six inches for the total length of all the actual teeth (not the distance between them). Our final (very generous) estimate is 68 inches, in other words: roughly five and a half feet long-a huge Cottonmouth but no world record.