The Why of a Brown Chin
We were down in the Apalachicola National Forest, hoping to see a Scarlet King or some of the other local herps, but the weather was not cooperating. It was an overcast morning in the low sixties, and while driving down the sand roads it started to sprinkle, and the temperature started to dip a little more. Nothing for it but to press on, and hope for a herp hunkered down under a log or bark.
We were stopped at a likely spot, where a number of trees were down, and getting our trousers thoroughly soaked from the wet vegetation. Rick came up with something from under a log. "I've got a racer!"
"Regular or Brown Chin?"
Well, now. The dreary morning just got a little more interesting. Sure enough, this racer had a brown chin. Everything below the mouth was a dirty brown. There was something missing from the picture, however. No blood! This Racer was so cold it never offered to bite, or even wiggled around much.
The BrownChin Racer, helvigularis, is considered a subspecies of the Black Racer, Coluber constrictor constrictor. It lives in the Chipola and Apalachicola River valleys, from the coast north to just into Georgia. It is surrounded on all sides by the Southern Black Racer, C. c. priapus, which looks pretty much the same, except its chin isn't brown. It's white. It's not just the chin of helvigularis that is different - the whole ventral side is much darker than priapus' pale belly.
The trouble is, down here in the Apalachicola you can find Racers with both kinds of chin colors. Lots of herping folk find the 'regular' kind of Racer, but never see the BrownChin.
Now that we had the Real McCoy right in our hands, the question to ponder was Why A Brown Chin? What's the reason for it? Is there some advantage to a brown chin, here in the piney, ferny environs of the Apalachicola? Or, perhaps, simply a funky roll of the genetic dice?
Perhaps the color helps to hide the snake from predators, or conceal it from prey, or both. Does anyone know? A lot of people don't believe helvigularis should be a separate subspecies - to them it's a priapus with a brown chin.
At any rate, it was our first and last snake in the ANF that day - the heavens opened up and the heavy, cold rains ensued, blown in from the Gulf. I'll mark this one down as a new subspecies for my Life List, until someone proves it otherwise!
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