Reptile & Amphibian Forums

I found this little girl (aprox 3.5 foot) crawling among a pile of rocks near a creek while hiking near Ft. Bragg last November. I thought it was VERY intersting in how much black she already has, because all the other adult black rats' near my house are light/bluish gray. But if you drive about 20 miles north of here, which is where I found her, I found out that they ARE black instead of light gray. That's quite a change in just 20 miles of driving (with almost no elevation change). All this in the same county (Cumberland county)! Just thought I would share, since I am not an expert on these and don't breed them. I am mostly a kingsnake guy, sorry (but I do like ALL American colubrids. . .)

Zee

Is this what I can expect in the near future for my Franklin County, NC (WC) female BRS? Mecklenburg co. has much sandier soil, always seems warmer and has a lot more naturally occuring pine trees. Are these factors? Or does 90 miles just not matter.

Jason

sorry for the extra post, I meant Cumberland CO.

Jason

Well, I figure since you're in a slightly cooler location you would think that the color will be darker as the snake ages, since the extra melanin in the snake will help it thermoregulate better (in cooler areas). But since we're not talking about Huge differences (such as Pennsylvania vs. Georgia) that IS not a neccessarily a guarantee. Where do you live (I live near Fayetteville)?

Zee

Just north of Raleigh, in Franklinton. About 10 min n. of Wake Forest.
I have noticed snakes like the one you presented in Mecklenburg CO. VA, just north of here. They are patternless on their back and completely white or slightly checkered on bottom.

Jason

Some of the blackest black rats I've ever seen have been from the Carolinas, especially from the western parts of the states. I've had adult specimens from New york state that were more brownish or grey and not really that dark. A lot of the ones from the northwestern part of the range tend to look like Texas rats, while from Arkansas they can be as black as coal, and mostly black underneath. Elevation may have a lot to do with it. Happy Herping.
Alan,

Back in the late 60's I would see lots of Black Rats in an area just west of Richmond Va. Most of the adults were black with little pattern showing, but from time to time I did find ones that were a dark brown in color. If you think about it, these variations in a population are a good thing. It allows for natural selection to take place. If conditions change, and being very black became a disadvantage, then those snakes that were slightly lighter in color would have slight advantage and become more common. If there were no variations, populations might disappear entirely.

It is not clear why E. o. obsoleta are black while in the same area, E. g. guttata have all that coloring. Both snakes can be found in the same areas, and they seem to share a common niche. I think that we can conclude that we really don't understand why nature has selected these colors and patterns over others, but we are the lucky ones who can both see and enjoy what nature has done.