Posted by:
nategodin
at Fri Jan 22 19:06:22 2010 [ Email Message ] [ Show All Posts by nategodin ]
Hello,
This post was going to be entitled "Meristic and mensural morphology of much-maligned mostly micropholis milksnake mutts", but I guess that was too many m-words for the subject line input field!
So, a few months ago, I managed to find a reasonably priced copy of the 1988 edition of Ken Williams' Systematics and Natural History of the American Milk Snake, on Amazon. For those of you who don't have this book at home, it's currently the definitive guide to L. triangulum, including information about everything from scale counts and range maps to historical and paleontological data. In a bold move (which may well have been a deliberate attempt to drive taxonomic lumpers and OCD-stricken collectors even crazier than they already were), he divided milksnakes into a total of twenty-five subspecies, based primarily on head and body coloration. At the time, most herpetological taxonomists preferred to use scale counts as the primary basis for subspecies distinction. Unlike Williams, I don't think any of those guys ever tried to examine 2800 different specimens of milksnakes, much less write a book about it (with pictures!), so whether or not you agree with his methods, he has made a significant contribution to the milksnake world, being the first to describe perennial favorites such as hondurensis, sinaloae, and andesiana, in the original 1978 edition.
One of those guys who would rather be counting scales is Bill Lamar. Lamar has his name in the bylines of several books as well, but is probably better known for his extensive field work. After contacting Bill Lamoreaux about some "micropholis" that he had for sale, he was kind enough to share with me some correspondence he received from Lamar regarding the origins of the founding stock of these milksnakes. There have been a few different versions of this story passed around, so I hope this will both set the record straight and start a spirited discussion.
Back in the 1970s I collected tricolored kingsnakes from several locales over
a period of years while I lived and worked in Colombia. The terrain is
unspeakably rugged and the risks then and now of being in that area are also
unspeakable. I also obtained specimens from a colleague in Europe who made
several trips to Colombia and who worked with close colleagues of mine. All
animals had locality data and most of them keyed out to be andesiana. Not all
of them, however, represented that population. Over a period of years I
allowed persons in the private sector to produce and distribute
andesiana...some of these relationships were good and some were not, but such
is herpetoculture.
Late in the game, and working with the highly competent Stan Grumbeck, a
single male micropholis from my collection was bred to an adult female that
was obtained from an entirely serendipitous event. Naysayers will shake their
heads and assume this to be some sort of fabrication but I say to them, if it
were necessary to fabricate a history for a snake, why not simply say it also
was obtained by me or colleagues in Colombia? We received a snake from an
elderly woman from the northwest. It had evidently been suitcased into the
country by her grandson and she had no idea what it was or for that matter
cared. We keyed the snake--the real way--and, to our astonishment, it proved
to be a female micropholis, so we bred it to my male. Her progeny formed the
nucleus of the material presently drawing so much interest.
Like the snakes or not, and personally I find them to be magnificent and
beautiful animals, they key directly and unequivocably to micropholis using Ken Williams' monograph. Sort it out and dicker as you see
fit, but in the case of the snakes in question, there has never been any willful
misrepresentation. Key the shed skins and decide.
So, I decided to do exactly that. For those of you following along at home, please turn to page 159 and refer to Table 24. For everyone else, here's the Cliff's Notes version...
micropholis:
Red body rings (neck to vent): 11-18, average 13.8
Dorsal scale rows: 21-23, average 21.6
Subcaudals: 42-51, average 45.6
andesiana x micropholis:
RBR: 17-25, average 20.9
Dorsal scale rows: 19-21, average 20.7
Subcaudals: 50-53, average 51.3
andesiana:
RBR: 24-37, average 30.7
Dorsal scale rows: 1?-21, average 19.1
Subcaudals: 43-47, average 45.7
As you can see, in terms of number of red body rings and dorsal scale rows, the intergrades are, as you would expect, intermediate between the two "pure" subspecies. The really odd thing is the number of subcaudal scales... intergrades seem to have a significantly higher number. Here's what I found when I keyed a shed skin from the male that I purchased from Don Shores last year:
RBR: 18 - could be micropholis or intergrade, closer to intergrade average
Dorsal scale rows: 21 - could be anything, closer to intergrade average
Subcaudals: 52 - definitely intergrade
So, it would seem that what I have here is a Colombian intergrade. Not that there's anything wrong with that, mind you... I knew what I was signing up for when I bought him, and I have never encountered any willful misrepresentation, either. I know a lot of the regulars here have sold off all of your Colombian milksnakes, but I'd like to hear from people who are still working with them, and wouldn't mind providing scale and band counts for your specimens, as well.
Thanks,
Nate
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 Meristics of Mostly Micropholis Mutts - nategodin, Fri Jan 22 19:06:22 2010 
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