Reptile & Amphibian Forums

I have talked with many people who breed snakes from beginners to pros and there seems to be a lot of disagreement as to where the blame goes when things go wrong when attempting to breed snakes. Some of these things are discussed matter of factly, yet other people will say nothing could be farther from the truth. I will attempt to begin this discussion by asking everyone who replies to NOT mention a specific snake. This is not important right now.
Example number 1 will be the recommendation which comes with some snakes that we should not breed morph to morph but het to morph, or het to het instead, to assure better chances of producing healthy offspring.
Example number 2 would be advising against breeding offspring back to a parent.
Example number 3 would be breeding sibling to sibling.
Rumors of defects and tragedies coming from these pairings includes
1. One eyed snakes or snakes with no eyes at all.
2. Kinked backs and tails
3. Eggs that go full term only to leave fully formed babies dead in the egg
4. Eggs that come out infertile from day 1, or go bad soon after being deposited
Seems like I hear about these things quite often, but there's many questions that should be asked. Size and age of the breeding pair, cage temps, brumation times and temps and incubation specifics. Most importantly it seems like many people fear failure two years in a row so after a pair doesn't produce they switch the snakes to be bred to a different mate. This makes it even harder to find out what went wrong the first time. There's still not enough people discussing these things for proof of any theories as to why they did not get healthy clutches from any given pairs of snakes. A very experienced breeder friend of mine tried to explain it in the sense that he may have over 20 pairs of one type of snake. And that even accurate gathering of info from his colony would still only be a tiny piece of the puzzle that needs to be put together before anyone can rightfully say something like,"You didn't get any good eggs from that pair because you bred morph to morph". This is just an example but as mentioned in the beginning I don't want to start naming snakes and have anyone be insulted or threatened due to rumors surrounding a snake they may specialise in. I could contradict myself til cows fly on this subject, I have heard of certain types of snakes being inbred over and over with no downside and others that outcrossing was mandatory. One of the first questions that should be adressed is does anyone feel that any of the 3 examples listed above applies to any one certain snake or snakes, or will anyone stand by what they assume to be facts that say the opposite, that in no cases do any of the 3 examples amount to anything? I hope I wrote this correctly as it is hard to summarise. Especially when trying to keep from naming specific snakes to specific rumors. All replies are appreciated, but be prepared to explain how you came to your conclusion on the subject. Tom

It is a fruitless effort in finding the info because you can't prove it one way or the other and here's why.

We have very little data from snakes in the wild as to:

clutch size
fertility rate
hatch rate (deformed snakes/babies that go full term but don't hatch, etc...)
survival rate

But we do know that in some species of snakes that they have a VERY small home range and therefore in-breeding has to occur. Father to daughter; mother to son; sibling to sibling; does occur in the wild, as in most of the animal kingdom. What are the affects in relation to the above mentioned factors? We don't know. Very little data from wild snakes is recorded and the few that are, ARE NOT enough to come to a conclusion (not a good sampling).

Is in-breeding bad? IMO, no it is not. In the wild in-breeding is common, BUT the bad genes that are passed because of in-breeding produces baby snakes that probably don't make it to adults (breeding age); and therefor the passing of bad genes stays in check compared to captive breeding where we have a higher success rate in breeding (no predation on snake eggs) and mortality is lower (getting finicky babies to eat). And could be passing on bad genes more than what nature would. In-breeding IS NOT BAD unless bad genes are being passed.

Also, some of the bad things that people are saying is caused by in-breeding also occurs when 2 unrelated snakes are bred together.

Kerby...

Good points. Everyone knows that inbreeding is an excellent way to isolate recessive genes. This includes isolating bad genes. Once isolated they can be eliminated. The problem is that most of these bad genes are, in my opinion, things like were mentioned, ie. full-term dead eggs, finicky hatchlings, etc. This is why I am a firm believer in letting "nature take it's course" on problems like this. Sure, I'll try everything I can to get a hatchling to eat, but I would never force-feed. Likewise, I would never cut an egg open. With a little work, both of these kinds of babies can grow up to be perfectly healthy adults, but will they produce offspring with the same problems? There's no way of knowing for sure but if I had to guess I would say that they would be more likely to.
-----
Martin Whalin
My Email

Quotes from guys named Carl:

"Science stops at the frontier of logic. Nature does not, she thrives on ground as yet untrodden by theory."
-Carl Jung

"It is foolish to let singleness of purpose deprive one of the joy and delectation of the many wonderful sights and sounds incidental to the quest."
-Carl Kauffeld

We do see an occasional glimpse of results from the wild. I have a Northern Scarlet Snake wild caught this year with orange bands and a Hard "Wavy" spine from 2/3 of the way on down. The animal has full function and is likely about 2 years old, also collected an Eastern Cottonmouth with a single large spinal Kink. That animal is a mature female, again with full body function past the massive kink which would lead me to believe it was a congenital problem. It is likely that the vast majority of malformed wild animals are very short lived and we only see and capture a small percentage of the survivors. The fact that we find any at all may imply it is a far more common problem than we know in the wild. As far as hatching rates it is again difficult to get a good sample. This year I have found two of last years nests one was very likely a Black Racer that had 11 eggs all of which had the telltale double hatching slits. The other, found under a log, was a huge adherent cluster (likely Yellow Rat Snake) of 36 eggs all of which appeared to have been successfully hatched. Of course it is quite possible that the "bad" eggs were "bug food" and no remnants remained.
Whereas it does seem cruel not to go to extreme measures to get a hatchling to feed, it is likely that ol' mother nature doesn't force feed anyone and has stronger animals as a result. What she doesn't get is all the appearance aberrations we love to see.

.

>>it is likely that ol' mother nature doesn't force feed anyone and has stronger animals as a result. What she doesn't get is all the appearance aberrations we love to see.

isn't speciation considered part of evolution which would include aberrations in appearance? Take the Pituophis/Lampropeltis/Elaphe situation, and animals within each of those, for example, where there are situations where offspring shouldn't be fertile but often are, suggesting either they're not different species or the definition of species needs to be changed. Might they all trace back to original north american snakes, which as they evolved produced animals that had appearance differences, as well as differences in epiglottis/sound production, size, scale counts, and other body structure differences? We can debate whether the cross section shape of the 7th vertebrae, or the presence of x or (x 1) supralabials is a bigger evolutionary change than the difference in appearance between, say, a black rat snake and a red rat snake. But those two animals, just as one example, might be nothing more than an illustration/consequence of a color "aberration" at some point in the past. And it's easy to imagine that if we were around when that first aberrant "red" rat appeared, there would have been speculation that it would never succeed in the wild, its bright colors attracting predators that the elusive black rat snake would avoid! All in all, it sorta depends on which way we're peering thru the looking glass at some of these changes, imho.

I'd like to see more from those of you who are more knowledgeable than I am about such things...paul, others? Yes, perhaps the first red and black rats differed only slightly (maybe the red rat was first, and the black was what we might have called a melanistic morph of it?!) and evolved only gradually to their present appearances. But there's also considerable evidence evolutionary advances (no value judgement implied) occur not in tiny changes but in rather dramatic ones. How do we properly position our thoughts re: color morphs into the larger evolutionary story? What insights can we gain into color varieties, from what's happened as our colubrid species evolved?

peace
terry

I have been wondering similar thoughts about White Sides. Recently a W.S. Gopher was supposedly caught in wild. Adult size too. Too keep it simple I wonder if after dozens of generations of breeding if it just happens to be the time when evolution is being seen in action with oddball things appearing in the wild without manipulation by us. Not new subspecies, just color and patterns. Kind of like what came first, the stripe or banded version of any given snake. For all we know in a few hundred years populations of these snakes may equally number what we know as the normal versions. I am not saying it is likely. It shouldn't be wrong to wonder if there's legions of definite het W.S Gophers in that area though. I wouldn't doubt there was others like it in that area which may not have been lucky as far as survival. But it does seem like there's always a big WOW popping up when something new appears, much moreso when it happens without our influence. I have heard of an area where many Albino Gophers, and also another with Albino Garters have been seen and collected. Same goes for rumored areas where certain kings and milks intergrade. Cool stuff to think about. Imagine way back when there was one snake that was one shape and color. Probably tasted like chicken to the cavemen LOL Tom

I agree with Kerby that we simply don't know the frequency of these sorts of aberrations in the wild. We don't have any idea what percentage of wild eggs hatch and produce healthy offspring.

Inbreeding has potentially negative consequences. This really isn't debatable. And it is particularly true in a captive population of snakes where inbreeding is deliberately done to try to maintain particular traits.

Can we predict the outcome of this inbreeding? No. Inbreeding results in increased frequencies for all the alleles in the inbred snakes. This includes the desired as well as the deleterious alleles. But there is no way to know in advance what the phenotypic outcome of this inbreeding depression is going to be.

Interestingly, we as snake breeders also seem to ignore the consequences of pleiotropy, which is the ability of a particular genotype to affect many seemingly unrelated aspects of the phenotype. We shouldn't be surprised if the trait we are selecting for (reduced black, for example) results in snakes that are more likely to die during development.

Rumors of defects and tragedies coming from these pairings includes
>>1. One eyed snakes or snakes with no eyes at all.
>>2. Kinked backs and tails
>>3. Eggs that go full term only to leave fully formed babies dead in the egg
>>4. Eggs that come out infertile from day 1, or go bad soon after being deposited

I have seen all four of these outcomes occur in snakes I have bred, but in wild matings or matings of captive individuals that couldn't have been related. Yes they occur in inbred matings, but do they occur more frequently than they do in outbred matings? We simply do not have the data to make that induction.

Furthermore, consider the fact that most evidence indicates that the first 3 of your examples are known to be, in part, caused by improper incubation conditions. It appears that, at least sometimes, genetics may have very little to do with the appearance of those problems.

The fact that certain pairs of animals have low fecundity could be the result of inbreeding (or even inbreeding avoidance mechanisms), but there are simply too many unaccounted variables to be able to jump to conclusions on this regard.

That said, outcrossing should be encouraged whereever possible. Breeders should consider not selling pairs of siblings to the same individual. Or if you get the spontaneous appearance of a presumptively new heritable phenotype, why not wait an extra generation and outcross the animals, rather than always breeding the daughters back to their fathers? Of course the answer is simple - $$$$$$. When someone sees a new phenotype appear within their clutch, they get blinded by the dollar signs!

-----
Chris Harrison

Just a few posts above this someone states something about infertility in a specific line of snakes. I have heard of this, and think this example was blamed on inbreeding. Linebreeding or inbreeding was indeed a big part of what I wanted to hear about but I also wanted to adress the other end of morph to morph, het to morph, and het to het breedings. Especially because I spoke to 3 different breeders about a specific colubrid, None knew I had talked to the others, and in our conversation they ALL said that they had problems with the snakes until they outcrossed it. Now other people will say this is heplful down the line, which I am all for and agree with. The thing is other people said my effort was futile and it didnt matter. We were talking about a snake which was "new". So right off the bat there was low fertility or defects from a snake that was early into it's reproducing of that morph. I know we can't gather info from the wild populations of snakes. This is why I stated the thread should be about snakes in captivity. I often wonder why it is so critical to maintain as exact a temp as possible when incubating when weather conditions and temps vary so much in nature? I have only talked to a few people who bred a pair of snakes again even after they had failure in previous seasons. This is what I wonder about. The bottom line, are most of us herpers new to breeding using a cookbook format for EVERY colubrid when trying to produce offspring, and what are the most important details. Your input was and is greatly appreciated Tom

>>...but I also wanted to adress the other end of morph to morph, het to morph, and het to het breedings. Especially because I spoke to 3 different breeders about a specific colubrid, None knew I had talked to the others, and in our conversation they ALL said that they had problems with the snakes until they outcrossed it.

that's not a statistically meaningful sample PLUS there are a multitude of other reasons that could account for their initial disappointing results. Understand--there could BE a real problem. I'm just saying that more often than not, these "factual reports" evaporate when subjected to closer examination or subsequent breeding experiences. The example above is representative--somebody thinks there's a problem with a particular snake, and someone else responds with observations that contradict the first conclusion.

>> Now other people will say this is heplful down the line, which I am all for and agree with. The thing is other people said my effort was futile and it didnt matter.

there's nothing wrong with wondering, with questioning, about anything. it's just important not to leap to conclusions (not that YOU were, but I have no doubt some of the people who report such "findings" or conclusions are drawing conclusions from vastly inadequate data, or even simply drawing false conclusions from the data.

>> We were talking about a snake which was "new". So right off the bat there was low fertility or defects from a snake that was early into it's reproducing of that morph.

maybe there was, maybe there wasn't. all you know is that 3 people reported such results, and subsequently someone else has pointed to ads suggesting multiple others are apparently having awfully good results with the same snake. Remember, for example, that when those 3 had good luck the next year outcrossing, their morph animals were a year older. (disclosure: I do NOT work with that type of getula so i have no interest in that debate other than academic).

>>I often wonder why it is so critical to maintain as exact a temp as possible when incubating when weather conditions and temps vary so much in nature?

Is it so critical? who says? what's the foundation for that statement? we see lots of people here who say they incubate at 80, or 82, or 84, for example, and have good resutls. They report incubating using a variety of media, with good results. Some use incubators. Some incubate on the shelf. With good results.

>>I have only talked to a few people who bred a pair of snakes again even after they had failure in previous seasons. This is what I wonder about. The bottom line, are most of us herpers new to breeding using a cookbook format for EVERY colubrid when trying to produce offspring, and what are the most important details. Your input was and is greatly appreciated

It's good you posted this, the opinions & experiences you elicit will be useful to all of us.

terry
btw: there's further discussion of this same issue on the milksnake forum:
click here to go to related discussion on milksnake forum

It seems like herpers, especially those of us breeding herps, could be doing a lot more talking about things like this. I hope these posts stir up some debate and get people thinking about maximising success by fine tuning thier approach. Please note when I spoke of temps in nature fluxuating I meant it in comparison that most of us try to keep our eggs incubating at a constant temp. Some even fear a flux of 1 degree or 2 while others are succesful with a very casual approach. Talking with some of the more experienced herpers who have been doing this for 20 and 30 years I get the impression data and info were eagerly shared to get the basics of breeding down to a science so to speak. When I was into herps as a kid in the late 70s I was told by many pet store people "snakes just wont breed in captivity, or if you even got eggs no one knows how to hatch them". Times have sure changed, Tom

Last year I watched the temperature of the eggs like a hawk, even though I was doing the "shelf" incubation.

This year I have a temp gauge, but glance at it rarely. The thermostat of the house is set at 82, the house itself is often between 80 and 84, occasionally warmer. I'm sure the eggs will hatch if they are destined to do so, and don't worry about temperature changes at all.

Of course I'm a newbie, and I HAVE lost some eggs this year, but I don't think it's due to ignoring the temperatures. My biggest loss was with a snake who got too hot while gravid.

Of course we'll see if the temp spike from early incubation has caused problems with my eggs. Could be they're all full of deformed hatchlings because there was a 12 hour temp spike. But my guess is that the temp spike won't make that big of a difference.
-----
~Sasheena

>>The thermostat of the house is set at 82, the house itself is often between 80 and 84, occasionally warmer. I'm sure the eggs will hatch if they are destined to do so

Hi Sasheena,

I'm one of the incubate-on-the-shelf guys too, i try to keep my snakeroom 80-81 but it sometimes gets close to 84 when the car's just been parked in the adjacent garage and the engine's still pouring off heat, or just on hot days here (florida) if i'm in and out of the snakeroom the open door lets the heat in. Like you, i think any failures of my snakes' eggs will have to do with circumstances other than temp variations within that 80-84 range.

btw, tom, you make a good point that things vary in nature. but as has been pointed out in this thread and others, we don't know a lot about hatch rates in the wild, for example, but as herpetoculturists we're trying to OPTIMIZE results, so controlling things more than they are controlled in nature--temps, brumation duration, incubation temps, humidity, absence of predators, regular provision of food items, etc.--is all a part of that effort.

I WILL bet you this: more eggs have been lost due to incubators that failed (power outages, thermostat failures, what have you) than have been lost to variations of one to four degrees during the incubation period. Here in florida, with eggs "on the shelf", my biggest concern is a/c failure. Other than regularly monitoring the temps, i haven't figured out a way to fully eliminate that risk.

terry

>When I was into herps as a kid in the late 70s I was told by many pet store people "snakes just wont breed in captivity, or if you even got eggs no one knows how to hatch them". Times have sure changed, Tom

ROTFLMAO!

I was hatching bullsnake eggs in the early 1960s, using information from a book named something like A Boy's Book of Snakes. And Bern Tryon had developed the Vermiculite method of incubation by the late 1970s.

Henry Fitch had a paper out around 1970 named Reproductive Cycles in Lizards and Snakes. In the Pituophis part, it mentions that the San Diego Zoo was breeding and hatching Pits back in the 1930s. Interestingly, a number of their babies came out with eyes smaller than normal.

BTW, I came across this thread on the milksnake forum and posted there, too.

Paul Hollander

When I was into herps as a KID in the late 70s, I was not even 10 years old. My parents barely let me keep snakes never mind breed them. We're talking about pet shop employees giving advice on snakes, which in many cases is still as unrelieable as it gets. I don't think it is so hilarious. Tom

Posted this on the milk snake forum but since this in large part is a different crew.....

Good questions but unfortunately no really good answers. I am an advocate of limiting inbreeding. Notice I said limiting not eliminating. Even in the natural state some inbreeding occurs. Evolution would not work without it.

I specialize in a small form of North American milk and can tell you that I’ve had great success with a local line that is inbred to the max while at the same time experiencing difficulty with another inbred local line of the same form. Sometimes all other things being equal you decide out breeding is the appropriate course. Other times you might conclude that some other factor was in play. Given proper day-to-day care and ignoring the out breeding thing, the most common causes of poor fertility IMHO are:

Breeder age – we often associate maturity with size alone. I can only site this anecdotally, but an 18 month old female that is 22” long is more likely to have reduced fecundity than a snake of the same size that is in its third of fourth year.

Condition – IMHO there is an optimal range for breeders. Too fat is just as bad as too thin.

Hibernation – Some forms require longer and colder hibernation cycles and failure to provide this often has negative effects.

Timing – Some forms ovulate right out of hibernation. If you do the classic thing and wait till the after the first shed to introduce the male you can miss a very narrow window of opportunity. Seem to remember this being documented in speckled kings.

The best way to learn what is affecting poor fecundity is to keep good records and compare notes with other breeder. Even then without testing you still just have antidotal evidence. In the end all we can do is stick with what works.

As for morphs and fertility, I’m unaware of a single case where poor fecundity is directly associated with a morph. IMHO, when there is an indication of poor breeding performance it can usually be attributed to what I call the opportunity factor. This is where we tend to feel the need to produce while the price is still high. As a result we power feed and end up trying to breed animals that are too young, over conditioned and haven’t been adequately cycled. Not to say that this can’t be done its just that we shouldn’t be surprised when things don’t go as well as we’d planned.