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All posts for the month November, 2013

I want to share this snake ID request so that you can get an idea of the experience of many animal ID requests that I get.  I often receive vague descriptions and sub-par photos of snakes or other animals to try to identify, and while challenging, these experiences are often very enjoyable and require a lot of careful thought.  Hopefully you’ll have fun trying to figure this one out as well.

While I’m always happy to help remove a nuisance animal from within their homes/yards, sometimes I’m not available within a reasonable amount of time to get the animal.  Just recently, a friend of mine called to see if I could help her remove a snake that had gotten in her house in Oviedo, FL.  I was unfortunately out of town, so she called her nephew to come help her. While her nephew is familiar with Central Florida snake identification, my friend asked me to try to confirm over the phone whether the snake in her home was venomous.  She described the snake as dark grayish, patterned (but with no obviously consistent patterning or major shapes), very small and thin, and had a long, thin, pointed tail.  Given the area, the time of year (last week of October), general coloration, and shape of the snake, I felt confident in my assessment of whether the snake was venomous, and had a good guess at what species it was.  For anyone reading this and interested to give it a try, would you suspect that she has a venomous or non-venomous snake in her house?

 

After discussing the situation, she managed to send me the picture below.  I immediately confirmed my suspicion before, and I also managed to correctly identify the snake.  Anyone care to take a guess at what species it is?  Did it agree with your guess based on the description (at least the venomous/nonvenomous part)?  Also, what characters from the description/image led you to your conclusion?

 

Here's the picture that my friend sent of the mystery snake in her house in Oviedo.  It was under an island in her kitchen, so it was hard for her to take a good picture.

Here’s the picture that my friend sent of the mystery snake in her house in Oviedo. It was under an island in her kitchen, so it was hard for her to take a good picture.

I’d like to again thank everyone who responded to the ID request.  Unfortunately, Mom, it is not a young black racer, but I’m glad that you knew that juvenile black racers are not just black (like the adults).  The consensus from the other responses agreed with my assessment: it is a Striped Crayfish Snake, Regina alleni.  One of the key differences between this snake and its close relative, the Glossy Crayfish Snake (Regina rigida) is that the dorsal scales (those lining the back) are not keeled in R. alleni (except above the cloaca), but they are keeled in R. rigida.  There are also color pattern differences (as well as distribution differences – R. rigida is mostly restricted to northern Florida, R. alleni is common throughout the peninsula), although these characteristics are less clear-cut and can sometimes be confusing.

 

For those of you who may not be familiar with the term, “keeled scales” refers to a trait in many snakes where the center of each scale has an elevated ridge (made largely of keratin, the major protein that comprises the rest of the scale – it also is the major component of finger nails, hair, rhinoceros “horns,” and many other structures in the animal world).  The elevated ridge makes the scales feel more rough, and it also provides a rougher looking appearance to the snake.  Biologists adapted the word, “keel,” from boat terminology, as the keel is the (often protrusive) midpoint on the bottom of a boat’s hull.  The similarity in shape to biological traits has encouraged its use in many characteristics other than snake scales: bird breast-bones, sagittal keel (thickened mid-line of some skulls), etc.  It is also used to describe a personality that is relatively calm and constant, even in the face of adversity (an easygoing person may often be referred to as “even-keeled”).  Here are a few images to highlight the disparity between keeled and non-keeled (sometimes referred to as “smooth” scales) scales.

Keeled scales of a Mojave Rattlesnake (Crotalus scutulatus).  Notice the elevated, ridge-like centers of each dorsal scale.

Keeled scales of a Mojave Rattlesnake (Crotalus scutulatus). Notice the elevated, ridge-like centers of each dorsal scale.

Non-keeled (smooth) scales of a Long-nosed Snake (Rhinocheilus lecontei).  Notice the smooth, even surface of each dorsal scale (no central ridge).

Non-keeled (smooth) scales of a Long-nosed Snake (Rhinocheilus lecontei). Notice the smooth, even surface of each dorsal scale (no central ridge).