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This post is to report summaries on only a few articles in the scientific literature available on Eastern hognose coloration.

Edgren, R. A. 1957. Melanism in hog-nosed snakes. Herpetologica 13(2):131-135

- Reported that out of 879 specimens, 9.33% were melanistic.

Platt, D.R. 1969. Natural history of the hognose snakes Heterodon platyrhinos and Heterodon nasicus. University of Kansas Publications Museum of Natural History. 18 (4):253-420.

- Melanism is most common in the southeastern part of the range and is rare or absent in the northeastern and northwestern parts.
- Melanism is not correlated with habitat or sex.
- Reported that two other researchers found image were melanistic specimens and also 2 black hatchlings.

Lazell, James. 1993. Heterodon platirhinos (Eastern hognose snake). Melanism heredity. Herpetological Review. 24 (1):35.

-Only the grayest hognose snake hatchlings, those without a red pigments, would make the shift to melanistic adults.
- The author recommended that the first hypothesis to attempt to reject is that Eastern hognoses never hatch black.
- The author reported his observation of a litter of seven hatchlings from a melanistic female. All had some red nape coloration, appeared normally pigmented, and were boldly patterned with body sattles.

* I believe that some of information by Platt related to geographic distribution of melanistic Easterns is incorrect, I encourage others to post their observations.

I have lived in the eastern and western edges of platirhinos and have noticed that melanism appears to work differently in different areas.

In South Carolina, a reasonable percentage of the adult hogs I saw were shiny jet black. It was probably less than half, but they weren't uncommon enough to be noteworthy. I'm sure Whit Gibbons has published the ratio in this area in one of his books. Here's a typical black SC snake -

In eastern and central Texas, I have seen a few dark hogs but they are less common than in SC (certainly less than 10% of the hogs I have seen). These snakes were either dark chocolate brown or dark gray, often with some pattern showing through. They were very different than the glossy black snakes of South Carolina. In Texas, the dark snakes darkened in a similar way that watersnakes do, ending up a dull sooty or brownish black (not at all like the glossy black of the SC snakes).

Here is a mostly dark central Texas hog (they do get darker than this) -

Anyone ever seen a shiny black hog in Texas?

I have never seen a black juvenile hog in either area.
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Chris Harrison
San Antonio, TX

I have seen only 3 black easterns from the wilds of southern MD. One was solid black. One was black with almost black patterns. And the third was solid black with thin dark yellow bands down the back. That last one was a monster too - definitely 3 feet in length, maybe slightly longer. The first two I know were female (laid eggs). The monster I pegged as a male looking at the base of the tail, but there is no guarantee on that. All other hogs I've seen over the years have been normal colored. All babies essentially have the same grayish/tannish/brownish colors and the adults have mainly been muddy yellow to high in yellow with brown/black patterns. I did have a red yearling brought in earlier this year (first time I'd ever seen a red).

My own yearling eastern is captive bred and came from a dark female. I bought her when she was 2 months old (hatched July 2004). She looked like any normal baby hognose I might find in the wild color wise. Until this summer she had been showing signs of being a normal colored snake with some nice dark/mustard yellows developing. Then between one shed and the next, everything went dark and looks to be continuing down that path. Whether she will ultimately be a solid black or a partial dark snake we'll see.

My snake at 7 months (Feb 2005):

.
And at 14 months (Sept 2005):

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PHWyvern

Geographically, I have found melanistic Easterns in New Jersey and Florida with very little distinction.