Reptile & Amphibian Forums

Lets take the San Bernardino mtns for example. Parviruba exist there. They also exist in the San Jacintos. The 2 ranges are separated by a desert valley for the most part. At the closest point they may have some foothills in common, but those hills are full of Cal kings, so the snakes couldn't/wouldn't cross from one range to another (would they?).

Maybe zonata were once lower elevation kings that found a niche in the higher elevations or in habitat not inhabited by the bigger getula kings? That might explain how they can occur on neighboring mtns but not inbetween.

The Todos Santos Mtn kings occupy thorn scrub habitat just above sea level. They don't have Cal kings or any other getula to contend with. Perhaps being by the ocean helps with getting moisture, but nevertheless it gets very hot down there (I've been) and isn't what comes to mind when one thinks of zonata. Point is, they are zonata and do fine in a non-montane habitat that gets hot but is devoid of Cal kings.

Does anyone have any thoughts/knowledge on this?

You think a lot huh? LOL.

I just saw an excellent presentation by Joe COllins (co-author of Peterson field guide to NA reptiles and amp)

Anyway...DNA work has showed close relations between the scarlet kingsnake and the L.zonata group. Two species separated by thousands of miles, the Appalacians, the Mississippi river...100's of miles of desert...the rocky mtns...more desert...etc.

An educated guess would be that all of the milks, mtn kings, grey bands...have a relatively recent common ancestor and each species adapted to it's particular habitat (mountains, lowlands, desert, forest...etc). For whatever reason, certain habitats ended up non-suitable for survival of these animals long term (like the desert between the CA mountain ranges).

So...you have these species like the San Diego and San Bernadino mtn kings that are a stunning example of parallel evolution.

Their ancestors ended up on 2 separate mountain ranges, evolved to a stunningly similar end point on these mountain ranges because of the similar habitats...and died out in between.

Again...just a hypothesis.

But, take as an example...rat snakes in the US are black and look VERY similar in MO and in NJ. Compare a MO rat snake to an IL rat snake from right across the MS river...and you'll find they are LESS closely related than the same MO rat snake is to a TX rat that looks much less similar. So...the mighty Mississippi, although a natural barrier...did not stop parallel evolution. Snakes on both sides of the river ended up very very similar because of the similar habitat!

Have I digress???

This is a great topic...
we should take it to one of the more popular forums...

Parallell evolution? I wonder if the populations you speak of (parviruba and pulchra?) may have in fact been part of a larger population and they did not evolve similar phenotypes but in fact are becoming increasingly distinct due to separation? Perhaps it was a larger population that was divided by the climate change (desertification?). It is well known that things were more damp in the past (fish bones and net weights are common artifacts in the desert). I think the "sky island" theory in reference to the montane species of Arizona/Sonora may apply. Maybe Rick Staub will read this and comment, he did a lot of DNA work with zonata.

Re: the separation of current ranges of zonata. There are relatively low levels of genetic differentiation among the subspecies of zonata--in fact, there is little genetic support for recognition of current subspecies. Low levels of genetic difference means a relatively recent shared gene pool--perhaps as recent as Pleistocene in some cases. Lots of reptiles and amphibians in the West, whose current ranges consist of montane isolates, were connected during the Pleistocene--cooler, wetter conditions meant that woodland habitats occurred at lower elevations than they presently do and desert environments occurred farther south. Species of herps associated with those woodlands occurred at lower elevations as well, and so populations of zonata in various mountain ranges in southern California were likely in contact. The nice thing about examining DNA is that one can estimate how long ago two populations last shared a common gene pool/ancestor. Because zonata populations have been in genetic contact relatively recently (perhaps a few hundred thousand years ago), their differences have not risen to the level where we could say these are distinct species--with the possible exception of herrerae on Todos Santos, which Grismer considers a distinct species (L. herrerae).

Re: the comment made in a post below concerning possible relationships between zonata and scarlet kings (L. t. elapsoides), there is not any published evidence to suggest such a relationship. Not sure what Joe Collins had to say, but there is work that ought to be published soon that shows that elapsoides should be regarded as a species quite distinct from L. triangulum, and that there is good evidence that the elapsoides pattern is the result of coral snake mimicry. The most recent DNA work (Bryson et al. 2005. Journal of Herpetology), using zonata, pyromelana, and various Mexican Lampropeltis, suggests that zonata is the sister taxon to a group that includes pyromelana, ruthveni, the new species webbi, and mexicana. It is likely that all of these species, including L. triangulum, evolved in the highlands of Mexico, with a subsequent northward radiation into the U.S. There are several groups of workers examining kingsnake relationships using DNA, so it is likely that some/most of these questions can be answered in the next few years.

Lastly, coral snake mimicry has been proposed for zonata by some workers, but soundly rejected by others. Perhaps the biggest problem confronting this proposal is the large geographic distance between the modern range of zonata and any species of coral snake. This is not necessarily a fatal flaw, if the ancestors of zonata occurred in northwestern Mexico in proximity to a species of Micrurus, and the pattern has simply been retained. However, as was suggested, it is also possible that the bright ringed pattern has value apart from its resemblence to coral snakes--cryptic when the snake is immobile, and disruptive when in motion. There is ample support for mimicry of coral snakes by various harmless snakes (kingsnakes and others) in the New World tropics--one simply has to look at co-occurring species of Micrurus and Lampropeltis (or Pliocercus--the false coral snakes) to see the remarkable patterns of similarity, which include similar patterns of geographic variation.

This is all good stuff to ponder, and is the subject of many papers and books. Keep thinking and asking questions!

Cheers,

Bob

It would seem like a natural "test" to try an experiment to see how natural predators reacted when presented with a tri-color
r/y/b or r/w/b/ snake.

It could be conducted within the range of the coral, and outside the range of the coral.

You may be able to use rubber snakes...i.e. try a rubber "garter" snake...see if birds went for it, then the rubber tri-colors.

Has anyone ever tried somthing like this that you know of?

Yes...as a matter of fact, such field experiments have been conducted by E. D. Brodie III and colleagues (see Brodie's web site for discussion and links to relevant papers: http://www.bio.indiana.edu/~brodielab/index.html). It is very cool stuff, and provided supporting evidence to show that predation attempts (as measured by predator bite marks on plasticiine snake models) were lower if the dummy snake resembled a venomous model (coral snake). They also varied the pattern/color combinations to show that a perfect match between mimic and model was not necessary to achieve some measure of protection.

Cheers,

Bob

Hi Bob,

I agree that some subspecies of zonata have low levels of genetic differences, but others seem to be older in their divergence. The southern (parv and pulchra) and northern populations are probably separated by at least 2 million years. Even multifasciata appears to have been separated from z. zonata and multicincta for 2 million years also. Aside from the Todos Santos pop, the others show little divergence. Certainly pulchra and multicincta are not justified.

Nice trip you guys had.

>>Re: the separation of current ranges of zonata. There are relatively low levels of genetic differentiation among the subspecies of zonata--in fact, there is little genetic support for recognition of current subspecies. Low levels of genetic difference means a relatively recent shared gene pool--perhaps as recent as Pleistocene in some cases. Lots of reptiles and amphibians in the West, whose current ranges consist of montane isolates, were connected during the Pleistocene--cooler, wetter conditions meant that woodland habitats occurred at lower elevations than they presently do and desert environments occurred farther south. Species of herps associated with those woodlands occurred at lower elevations as well, and so populations of zonata in various mountain ranges in southern California were likely in contact. The nice thing about examining DNA is that one can estimate how long ago two populations last shared a common gene pool/ancestor. Because zonata populations have been in genetic contact relatively recently (perhaps a few hundred thousand years ago), their differences have not risen to the level where we could say these are distinct species--with the possible exception of herrerae on Todos Santos, which Grismer considers a distinct species (L. herrerae).
>>
>>Re: the comment made in a post below concerning possible relationships between zonata and scarlet kings (L. t. elapsoides), there is not any published evidence to suggest such a relationship. Not sure what Joe Collins had to say, but there is work that ought to be published soon that shows that elapsoides should be regarded as a species quite distinct from L. triangulum, and that there is good evidence that the elapsoides pattern is the result of coral snake mimicry. The most recent DNA work (Bryson et al. 2005. Journal of Herpetology), using zonata, pyromelana, and various Mexican Lampropeltis, suggests that zonata is the sister taxon to a group that includes pyromelana, ruthveni, the new species webbi, and mexicana. It is likely that all of these species, including L. triangulum, evolved in the highlands of Mexico, with a subsequent northward radiation into the U.S. There are several groups of workers examining kingsnake relationships using DNA, so it is likely that some/most of these questions can be answered in the next few years.
>>
>>Lastly, coral snake mimicry has been proposed for zonata by some workers, but soundly rejected by others. Perhaps the biggest problem confronting this proposal is the large geographic distance between the modern range of zonata and any species of coral snake. This is not necessarily a fatal flaw, if the ancestors of zonata occurred in northwestern Mexico in proximity to a species of Micrurus, and the pattern has simply been retained. However, as was suggested, it is also possible that the bright ringed pattern has value apart from its resemblence to coral snakes--cryptic when the snake is immobile, and disruptive when in motion. There is ample support for mimicry of coral snakes by various harmless snakes (kingsnakes and others) in the New World tropics--one simply has to look at co-occurring species of Micrurus and Lampropeltis (or Pliocercus--the false coral snakes) to see the remarkable patterns of similarity, which include similar patterns of geographic variation.
>>
>>This is all good stuff to ponder, and is the subject of many papers and books. Keep thinking and asking questions!
>>
>>Cheers,
>>
>>Bob
-----
Rick Staub
R&R Reptiles

>>Re: the separation of current ranges of zonata. There are relatively low levels of genetic differentiation among the subspecies of zonata--in fact, there is little genetic support for recognition of current subspecies. Low levels of genetic difference means a relatively recent shared gene pool--perhaps as recent as Pleistocene in some cases. Lots of reptiles and amphibians in the West, whose current ranges consist of montane isolates, were connected during the Pleistocene--cooler, wetter conditions meant that woodland habitats occurred at lower elevations than they presently do and desert environments occurred farther south. Species of herps associated with those woodlands occurred at lower elevations as well, and so populations of zonata in various mountain ranges in southern California were likely in contact. The nice thing about examining DNA is that one can estimate how long ago two populations last shared a common gene pool/ancestor. Because zonata populations have been in genetic contact relatively recently (perhaps a few hundred thousand years ago), their differences have not risen to the level where we could say these are distinct species--with the possible exception of herrerae on Todos Santos, which Grismer considers a distinct species (L. herrerae).
>>
>>Re: the comment made in a post below concerning possible relationships between zonata and scarlet kings (L. t. elapsoides), there is not any published evidence to suggest such a relationship. Not sure what Joe Collins had to say, but there is work that ought to be published soon that shows that elapsoides should be regarded as a species quite distinct from L. triangulum, and that there is good evidence that the elapsoides pattern is the result of coral snake mimicry. The most recent DNA work (Bryson et al. 2005. Journal of Herpetology), using zonata, pyromelana, and various Mexican Lampropeltis, suggests that zonata is the sister taxon to a group that includes pyromelana, ruthveni, the new species webbi, and mexicana. It is likely that all of these species, including L. triangulum, evolved in the highlands of Mexico, with a subsequent northward radiation into the U.S. There are several groups of workers examining kingsnake relationships using DNA, so it is likely that some/most of these questions can be answered in the next few years.
>>
>>Lastly, coral snake mimicry has been proposed for zonata by some workers, but soundly rejected by others. Perhaps the biggest problem confronting this proposal is the large geographic distance between the modern range of zonata and any species of coral snake. This is not necessarily a fatal flaw, if the ancestors of zonata occurred in northwestern Mexico in proximity to a species of Micrurus, and the pattern has simply been retained. However, as was suggested, it is also possible that the bright ringed pattern has value apart from its resemblence to coral snakes--cryptic when the snake is immobile, and disruptive when in motion. There is ample support for mimicry of coral snakes by various harmless snakes (kingsnakes and others) in the New World tropics--one simply has to look at co-occurring species of Micrurus and Lampropeltis (or Pliocercus--the false coral snakes) to see the remarkable patterns of similarity, which include similar patterns of geographic variation.
>>
>>This is all good stuff to ponder, and is the subject of many papers and books. Keep thinking and asking questions!
>>
>>Cheers,
>>
>>Bob