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Anyone have any opinions on the differences between these two animals?

I once heard a well known breeder talk about how slowinskii are nothing but emoryi and how the race is invalid. I don't know whether or not slowinskii is a valid race because I'm not a rat snake phylogeographer. However I disagreed with his outright synonomy of the two. Having only found one wild slowinskii, I can't say that I've seen a reliable cross section of the animal...but I do feel comfortable in stating that the habitat of emoryi and slowinskii is very different. It is so different that I have a hard time relegating slowinskii to a variation of emoryi. Any thoughts?

Without getting into "species" or "subspecies", IMHO, animals from the published range in popular field guides are pretty recognizable from morphology.
As you know, the real rub comes from East Texas, and especially from SE OK and SW AR, where morphologists and cladists still have some issues.
As you mentioned, habitat is everything and the word integrade is not used enough.
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Regards, Bill McGighan

Interesting thoughts, and I like what you and Bill both have to say. I have been herping my corner of Texas (south coastal) for 30+ years, and have seen hundreds of emoryi "meahllmorum" in the wild. This is an adaptable animal, and the most common and prolific lampropeltine over much of this region.

I mention meahllmorum because its habitat is different from the typical woodland habitat of slowinskii and from the grassland habitat of emoryi "emoryi". This form is known to intergrade with e. emoryi along a wide zone across their ranges, basically through the middle of Texas. The thornscrub habitat which dominates meahllmorum's range is unique in that it is a combination of habitats. There are thickets of mesquite (woodland scrub) and large areas of grassland with prickly pear (desert scrub), and even riparian habitat at the edges of river floodplains is utilized. A large portion of this region has been converted into cropland where, amazingly, meahllmorum still thrives.

The academics never mention intergrades (or hybrids) of slowinskii and emoryi, but I believe that they probably exist. Slowinskii has been documented as far southwest as Calhoun County, TX, a county where emoryi meahllmorum are also known to exist. If there is intergradation/hybridization this would be a good place to look imho. My personal feeling (opinion) on this group of snakes is that they are so closely related that they should have never been put in separate species, and that the guttatus/emoryi group are all one species with many variants or forms. I believe that the form changes with the habitat, and all have features unique to themselves. Where one habitat type gives way to another, might not intergrade animals also be found? I think it is far too simplistic to say that slowinskii is just emoryi, or just guttatus. Unfortunately, the current trend in taxonomy seems to be to get rid of subspecies altogether. The latest paper from Collins and Taggart has the group split into guttatus, slowinskii, and emoryi, with no subspecies.

-Toby Brock
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Southwestern Center for Herpetological Research

>>My personal feeling (opinion) on this group of snakes is that they are so closely related that they should have never been put in separate species,and that the guttatus/emoryi group are all one species with many variants or forms.>>

I agree with that opinion. There are splitters and there are lumpers. The splitters will always keep splitting on the basis of minute differences, and the lumpers will simply ignore those differences. To me guttata and emoryi are the same species. mtDNA data shows that they are part of the same lineage and that the red rat snake is descended from the great plains ratsnake which migrated eastward from Texas.

>>I believe that the form changes with the habitat,>>

Absolutely. Red coloration evolved in woodland habitats with lots of leaf litter because there is lots of red coloration in those habitats. Gray coloration is more adaptive in more open habitats, where red coloration is not cryptic.

>>and all have features unique to themselves. Where one habitat type gives way to another, might not intergrade animals also be found? I think it is far too simplistic to say that slowinskii is just emoryi, or just guttatus. Unfortunately, the current trend in taxonomy seems to be to get rid of subspecies altogether. The latest paper from Collins and Taggart has the group split into guttatus, slowinskii, and emoryi, with no subspecies.
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>>-Toby Brock

Collins does not like the subspecies category and he published a short note years ago that attempted to do away with dozens of subspecies all at once. He was roundly criticized for that paper. Apparently he is unrepentant. He and the cladists do not realize that the subspecies concept is useful and that it will continue to be used by biologists world wide.

Hello great and powerful Cking. We've chatted before...

I do have a question as a student of evolution...

If slowiskii is more red because of a more wooded and coastal habitat...and emoryi are not due to their habitat selection...would this not be indicative of speciation? If each were to persist in the same habitat that they do now (isolated from one another), wouldn't each of their trajectories make them seperate species eventually? Thanks.

>>Hello great and powerful Cking. We've chatted before...
>>
>>I do have a question as a student of evolution...
>>
>>If slowiskii is more red because of a more wooded and coastal habitat...and emoryi are not due to their habitat selection...would this not be indicative of speciation? If each were to persist in the same habitat that they do now (isolated from one another), wouldn't each of their trajectories make them seperate species eventually? Thanks.>>

Within any one species, there are different ecomorphs. It is true that exploitation of a new ecosystem has led to morphological changes, and in some cases even to the appearance of new species. The job of a scientist is not to identify future evolutionary trajectories or trends, because scientists are not in the business of fortune telling. We have to decide instead whether the ecomorphs that exist today represent a single wide ranging species or two or more different species. That to a large degree will depend on data which show whether two populations that are in contact will or will not interbreed freely. If two populations are allopatric, then the job of determining conspecificity becomes more difficult.

What I was objecting to is the delimitation of mtDNA clades as "species." mtDNA cannot be used to ascertain morphology or the ability to interbreed, since mtDNA does not code for morphology. Besides, the mtDNA data shows that Elaphe guttata is a clade, not a polyphyletic assemblage. So, as far as the available mtDNA data show, E. guttata is but a single wide ranging species. If other sorts of data (e.g. number of chromosomes) shows that there is a good likelihood that the populations currently grouped under E. guttata cannot be conspecific, then we may have to divide it up into separate different species.

From C. King >>What I was objecting to is the delimitation of mtDNA clades as "species." mtDNA cannot be used to ascertain morphology or the ability to interbreed, since mtDNA does not code for morphology. Besides, the mtDNA data shows that Elaphe guttata is a clade, not a polyphyletic assemblage. So, as far as the available mtDNA data show, E. guttata is but a single wide ranging species. If other sorts of data (e.g. number of chromosomes) shows that there is a good likelihood that the populations currently grouped under E. guttata cannot be conspecific, then we may have to divide it up into separate different species.

Nice summary from Toby. We've been sharing similar info for quite awhile.

King, I was in the one species (guttata) camp for a very long time. However, we don't have examples of intergrades to show the continuation of the species bt. Pantherophis (Elaphe) emoryi emoryi and P. guttatus slowinskii that I know of. I've switched to the two species theory based on the fact that emoryi and guttatus seem to have been separated for a very long time and are morphologically distinct. There seems to be gaps bt. ranges of the two species. If we were to find areas where they were intergrading I likely would buy back into the one species theory. But for now it seems like the two species idea works well. I don't like the idea of basing our decisions on mtdna either, but think it should be a combination of things.