Reptile & Amphibian Forums

HI everyone~can anyone tell me that how to differentiate between Thayer's kingsnake & Durango mountain kingsnake?i am confused.can they cross breed?

is it a durango mtn.king?sorry for my poor english~thx a lot~

Thayers kings and Durango Mtn kings are thought by some to be separate subspecies of Lampropeltis mexicana. The third subspecies being the Mexican king or San Luis Potosi king refered to as mexmex. However, you will often see the subspecies designation in quotes and the animals considered as variants, not true subspecies. Some see them more as the same snake with no subspeciation, but only geographical/color variability.

I have kept all three, and they are very similar in shape/size and habits. However, "pure" mexmex, thayeri, and durangos have very distinct and unique patterns and colors to themselves that make them each distinct and desirable. However, I am sure much breeding between the variants has been/is being done, and many are concerned they are no more "pure" thayeri, mexmex, or durangos these days. Only mixed bred animals that look like the original forms did, or enhanced through selective breeding to bring out the best traits of the original form (ie, brighter red blotches in mexmex and durangos, more orange groundcolor in thayeri).

Hope this helps more than confuse.

Form what I can see in the picture the snake you showed is a classic L. m. "greeri". The classic greeri meets this discription:

Dorsal
Simple black mark on the head.
Large black bordered, pale centered red "omega" shaped nuchal blotch;
followed by a few increasingly smaller black bordered red diamonds;
followed by a few narrower black blotches lacking red;
followed by increasingly larger black bordered red diamonds again.
Towards the last 1/3rd of the body the black bordered red diamonds tend to develop light centers.
Greenish-gray backround color.

Ventral
Front 1/4 white with a broken black stripe.
After the first 1/4 the black borders of the red dorsal blotches become continuos so as to from complete or near complete black rings on the underside. Between the black rings there are black blotches and/or broken stripes.

Aside from this classic description there are some variations such as narrow black dorsal blotches lacking red randomly occuring on the body rather than just in the sequence described above. Sometimes the hollow centered red blotches occur in random sequence as well. Occasional specimens may also have red in every dorsal blotch or occasionally almost all of the dorsal blotches will lack red.

-----------------

L. m. "thayeri" are alot harder to describe. They come in three basic phases and are alot more variable than greeri. The basic phases are leonis, milksnake and melanistic.

Leonis essentially has narrow black bordered red bars on a gray, greenish gray, buckskin, yellowish or orangish backround.
The narrow bars can also sometimes lack red, have pale centers, be split longitudinally so as to form two parallel spots or be constricted in the middle so as to form "butterfly" shapes. Sometimes there are black spots on the sides alternating between the narrow bars. The head pattern is extremely variable but often there is red blotching and it's usually more complex than in greeri.

Milksnake phase has wide red, narrow black and narrow pale rings in the same sequence as a L. triangulum (red-black-pale-black-red). The pale rings can be white, gray, buckskin, yellowish or orangish. The head pattern is just as variable as in the leonis phase or sometimes solid black.

Melanistic phase is all black.

In addition there are specimens intermediate in appearance between the leonis and milksnake phases. Often the intermediate specimens have squarish pale-centered, black bordered red blotches rather than narrow bars or wide rings.

Thayeri are so variable it is often impossible to tell if they have been crossed in captivity. Also most captive lines have focused on brightening the red and intensifying the orange.

KevinM and Aaron, thx a lot~
finally, i bought 2 baby snakes from shop~ 1 durango(female) and 1 thayer(male)~ my old durango is female,too~ i still can't get a male durango~ this spp. is rare in HK~

The top pic is of a classic buckskin Leonis phase thayeri and shows very well the classic narrow red dorsal bars.

In my opinion the juvenille snake in the two bottom pics is not a greeri. The head pattern is tri-lobed or what some people call a three leaf clover, plus it has red in it. Greeri rarely have red in the head pattern and a three leaf clover shape is almost unheard of in greeri. I think that snake is a San Luis Potosi King.
San Luis Potosi Kings typically have a three leaf clover head pattern with red in it and they usually have squarish shaped dorsal blotches. What does the belly of your snake look like?
Greeri usually do not have any red on the belly. San Luis Potosi Kings usually have red, black and white mottling and barring on the belly.