Richard Hoyer - What can you tell me about this Boa?

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Richard Hoyer - What can you tell me about this Boa?

Post by Porter »

I found this awesome looking Rubber Boa in the Sierras last night/this morning. Anyone can respond, it doesn't have to be Hoyer necessarily, but I did want to direct it towards the expert. I got a cortisone shot recently and decided to put it to the test. Took a drive up to my boa spot that I scouted out myself back in 2011. I was successful in finding one back then (which is why it became my boa spot :lol:). Hadn't been up there except for two times since the 2011 boa find and I actually road cruised a sharp-tailed snake one of those times. No Boas tho.... I ended up road cruising 4 there in my all together, so I was pretty stoked. Even though I've been hoping to see a zonota lifer there since 2011 :lol: ...close, but no cigar 8-) In all honesty, this find over ranks the zonata for me :thumb: Everyone knows, I love those aberrant morphy looking things. I barely saved it from a logging truck as well, so I will have a good story for everyone at the end of the year :beer:




Richard F. Hoyer
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Re: Richard Hoyer - What can you tell me about this Boa?

Post by Richard F. Hoyer »

Porter,
Twice over the years, I have obtained on loan the vouchered Rubber Boas from many of the major institutions. During those times, I noted a number of boas from certain regions that possessed varying amount of black pigmentation on the ventrals and scale rows 1 to about 3 of 4 just above the ventrals.
For example, I recall observing that situation from the boas collected in southeastern Washington.

Locally here in northwestern Oregon, finding some black pigmentation on the ventral is not all that uncommon but such black pigmentation is sparse. Years ago, I did find one mutant which had totally black ventrals and up to the 4th or 5th scale row. Much to my dismay, she died only a few weeks after capture of unknown cause.

Then about 17 – 19 years ago during my study of the Common Sharp-tailed Snake here in Oregon, very frequently I was in the OSU Zoology Dept. Mason Lab. (Dr. Robert Mason), to scale clip those snakes in a coded fashion before being released. On one of those visits, I observed a female Rubber Boa that herpetologist Dr. Steven Arnold had found near Shaver Lake in Fresno County. The ventral of that snake were solid black with perhaps only two or three small spots of yellow. He was going to voucher the female but I talked him out of it and traded him to boas from other regions for that one female.

Then the next year, John Stevenson of the Marysville / Yuba City area had a male Rubber Boa his wife had found in Plumas county in which the about 75 % of the ventrals were black or mostly black. I was given that specimen and gave both to my son in Utah with the idea of making controlled crosses and obtaining litters with some chance of learning the mode of inheritance. It was not long after that the Utah wildlife agency law enforcement confiscated all of the boas Ryan was maintaining in assisting in my research and the ended up killing all but three boas.

At any rate, nice find. It would appear that boas with varying amounts of black pigmentation on the ventral occurs at least from Plumas Co. down into Fresno County. I also believe one of the preserved boas Dr. Glenn Stewart had at Cal. Poly, Pomona had considerable black on the ventrals. And that boa was from near Lee Vining in Mono County.

As as is the case with a very high percentage of adult Rubber Boas, you can note in your video that the female exhibits a grossly scarred tail tip. And thanks for posting your observation. And your observation of having found a Sharp-tailed Snake road cruising is also a very neat observation! Do you happen to have any elevation and locality information on that Contia tenuis?

Richard F. Hoyer
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Re: Richard Hoyer - What can you tell me about this Boa?

Post by Porter »

Cool stuff :thumb: Thanks for the quick response, Richard!

So, is it safe to say this is a melanistic boa? I was originally thinking that it must be, based on a melanistic Valley Gartersnake I found a little while back. It was very colorful. It had similar blue tones and displayed some bright yellow and orange on the neck. I'll add a pic below. Of course the cellphone video and night flash pics don't do it justice, but this guy had a more bluish grey look to him, some orange speckling, and a bright orange tail tip. With the yellow belly, I swear the tail reminded me of a male Gilbert's Skink in breeding colors :lol: Pretty trippy. When I passed it on the road, it looked like a damn sea snake... all black on top and bright yellow sides. The other boas I cruised looked orangish-red under my headlights like the pine debris in the road. It threw my mind such a curve ball at first, that I was even more pleased to see it was a boa! My thought process just didn't go there... first was dark pattern-less rattlesnake...? and then OMG-some crazy zonata...? lol It was also twice the size of the other boas I was seeing out there, so I wasn't expecting to see an adult. Boas are still new to me. I've only seen a few. I think 7 all together now counting my lifer when I was a kid an a couple bay area boas.

That sucks they killed your boas! You'd think there would be a law from preventing that... you have too many boas, so since you're mistreating boas, we are gonna kill all your boas and make things right. F*cking insane (excuse the language).

I just finally got Google Earth to download last night. Haven't had it since 2011. I had to download google chrome and I couldn't figure out how to get the elevation. It's definitely not a range extension... I wanna say about 5,500 maybe? If you want a precise number, let me know and I'll pm you. I remember exactly where it was and on which road. At this certain bend in the road, in a grassy open area. Actually, maybe closer to 6,000 now that I think about it.

Wow... Black-belly Rubber Boas. Can't wait to find one and let it go 8-)


ImageMG for Gary by California Reptile & Amphibian Appreciation, on Flickr



I just started going through my photos and thought I'd post one real quick. It will be awhile before I get a chance to edit them. Here's an unedited raw of the snakes colors from that morning. As you can see, it almost looks purple in the natural dark morning lighting...

ImageDSC_0020 by California Reptile & Amphibian Appreciation, on Flickr
Richard F. Hoyer
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Re: Richard Hoyer - What can you tell me about this Boa?

Post by Richard F. Hoyer »

Porter,
From your photo / video, the rubber boa you found appears to be of normal coloration for the species. That is, its dorsal coloration was some shade of brown and its ventral coloration was yellow with a heavy dose of black pigmentation which as mentioned, is a fairly normal occurrence with some populations of the species. You can note that the black pigmentation extends up 5 – 6 scale rows above the ventrals as well.

In western Idaho, I recorded information on a sizeable series of boas in which 1/2 exhibited solid orange colored ventrals and the other 1/2 had the normal yellow colored ventrals. I observed boas with similar all orange colored ventrals in the population found up near Burney, Calif.

The neonates of all boas I have examined from many populations from Oregon, Washington, Idaho, Utah and Calif. have immaculate ventral coloration at birth - light yellow, cream, flesh or slightly orangish. But in some populations, such as the one here in northwestern Oregon, over time and as the boas age, some of the specimens develop varying degrees of ventral brown mottling that overtakes the yellow. In some cases, the brown mottling occurs continuously over all of the ventrals. I suggest that the same scenario occurs with the black mottling as seen in the specimen you found.

And the shade of brown dorsal coloration varies considerably between populations. The boas found at high elevation, open, arid regions generally exhibit a very light tan dorsal coloration whereas population found more in association with coniferous forest habitats have a much darker dorsal coloration that can be as dark as chocolate brown.

On the data sheet I complete for each boas I survey, I have sections on the form in which record whether or not there occurs brown ventral mottling, and the estimated the degree of such mottling from rare, slight, medium, heavy, to continuous. I also record if specimens exhibit any back and / or orange pigmentation or flecking. Both black and orange pigmentation are frequently associated with healed injuries. And black pigmentation also results at areas on boas that have been burned or badly singed which can occur when under pieces of mental such as roofing tin.

Last, I have found two mutants of the species. In my first reply to your post, I described the one boa , a subadult female, that possessed totally black pigmentation on the ventrals and up to the 4th. of 5th. scale rows above the ventrals.

Then in the early 1970’s, I found two boas that exhibited a uniform grayish coloration dorsally, all white ventrals, and with black eyes. From a litter of 5 produced by a wildtype (normal appearing ) female, 3 more of those mutants were recovered. I was able to get some of those mutants to adult status and then made a series of controlled crosses. I was able to determine that mutation was due to a single, recessive gene which I named ‘lilac’. I never
submitted a full length manuscript of those efforts but did submit an abstract of those results that was publish in the proceedings of abstracts of the joint national Herps. Association meetings held at Knoxville, Tennessee in 1979.

My email address is [email protected] should you wish to contact me and provide locality information on county, elevation, etc. I would be interested in knowing about the same information on your sighting of the Sharp-tailed Snake.

As for size, from all of the information I have gleaned from individuals that cruise roads at night and have found boas, the large majority of such specimens are juveniles and subadults. But some adults also occur on roads at night as was the case with the specimen you found. The boa appears to be an adult female of about 2 feet or perhaps larger. Female boas from the Sierras can reach 30 inches and perhaps longer. And a few years ago, I recorded a female boa from San Mateo County that also measured 30 inches.

One of the two preserved female boas in the Cal. Poly, Pomona collection from near Lee Vining measured 29 inches when I surveyed the boa. Preservation shrinks snakes by a significant degree. So when alive, that female boa undoubtedly measured over 30 inches.

As for the Common Garter Snake, I would classify it as only partly melanistic. I believe total melanistic garter snake are all black with possibly only a faint hint of a pattern due to degrees of shading in the black pigment. I believe the melanistic common garter snakes were discovered by researchers named Blanchard in N. Michigan many years ago. And I believe they worked out the mode of inheritance of the mutant gene that produces the melanistic feature.

There are melanistic members of Thamnophis elegans that I have observed along the Malheur River in eastern Oregon near the community of Juntura.

As for the variety of sea snakes you might encounter in the Sierras’, I hope you take suitable precautions as I understand that the venom of the Sierra Sea Snake subspecies is far more potent than the ones that sometimes wash up on shore in S. Calif. However, let it be known that the Cascade Mts. Seas Snakes here in Oregon are even more dangerous than those up in the Sierra’s. He he.
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Re: Richard Hoyer - What can you tell me about this Boa?

Post by Porter »

Ok, so basically I just found a really old snake that's lived a hellava life... she did have a lot of scarring! I don't know how well that comes out in the video, but when people see the pics at the end of the year they'll be amazed. I've never seen a boa this chewed up (from other peoples photos). Interesting about the orange coloration being the result of healing injuries. The tail looked to have the most damage and the most orange.

I figured out that google earth thing with a little help from Brian Hubbs. The elevations are actually a little lower than I predicted. I'm send you an email. At the time I saw the sharptail, I was pretty disappointed that it wasn't a boa :lol: However, it is pretty cool to see one that high up. Before that, the highest elevation I saw one was around Pollock Pines area. Flipped under a rock.

The only way to find a Sea Snake these days, is by road cruise. Any other way is just too damn easy. The trick is, wait till the weather starts getting miserably hot and dry... that's when they start migrating from Mono Lake and down through the Sierras. Sneaky little devils ;)
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