A discussion arose in a group I became a part of this week concerning maternal incubation versus using an incubator. It’s accepted as it were, this practice with colubrid snakes won’t work. While some colubrid snakes may stay with the eggs for a few days, they’re not known to attempt maternal incubation. I don’t have the knowledge as to why this is, although there’s been some documentation on colubrid snakes through phylogenetic transitions becoming viviparous (live bearing) over oviparous (egg laying). It’s said the snakes do this in a tropical environment to insure survival of the young. This still leaves us with more ancient lineages of snakes known as Pythons and Boas

While colubrids don’t practice maternal incubation in the same way as pythons and boas, there is evidence of maternal care within the superfamily of Colubroidea within the family Viperidae. Some rattlesnakes being studied have shown what might be considered maternal behavior. You can read more about this and form your own opinion by reviewing the work of Melissa Amarello who authors the site Social Snakes. We’ve also had the pleasure of interviewing Melissa regarding her work within the Reptile Living Room. Another and one of the most well known snakes to exhibit maternal behavior is the King Cobra (Ophiophagus hannah). King cobra (Ophiophagus hannah) are known to build a nest before oviposition (egg laying). It’s also stated in Greene (affiliate link) Snakes: The Evolution of Mystery in Nature (Director’s Circle Book of the Associates of the University o) that the Diamond Python (Morelia spilota spilota) also builds a nest and will leave the nest to bask returning when she’s warm to the eggs and sharing her warmth by coiling her body around clutch. Referring again to Greene we discover Oviparous crotalines staying with their eggs and even some becoming more aggressive during incubation. Some of these don’t leave the young after they’ve hatched but wait until the neonate sheds and then moves off on its own before leaving the site.

Boas and Pythons

Taxonomically speaking the boa and python families are considered less evolved in comparison with colubrids. Therefore, maternal incubation in snakes might appear as a less desirable trait and one lost for the reason(s) of its ineffectiveness. There’s been a lot of varying opinions on the subject of maternal incubation and its inherent benefits to the hatchlings (baby snakes).

Here again, Not all pythons and boas will behave the same way to incubate their eggs which is a factor requiring your own research.

Risk and Reward

Everything we do as part of the animal kingdom is based in risk versus reward. We don’t place our hand in a flame because we learn by experience (parents know nothing) is hot and painful to touch. The same could be said for boas and pythons at albeit a different level. The snakes do behave in a maternal manner, they’re sacrificing themselves to care for their young.

It’s quite well known today; gravid (pregnant) snakes be they oviparous or viviparous will often go off feeding when it comes close to time to give birth. Pythons and boas take this one step further in wrapping themselves about the clutch of eggs to warm them. Some will then will shiver through controlled muscular spasms to keep the eggs warm.

It’s also been noted in various texts of boas and pythons leaving their clutch of eggs to bask or even to collect water upon their bodies. Then returning to the eggs to share the resource(s) with their clutch. Eggs being semi-permeable are in fact capable of absorbing moisture both from the air and the droplets which might present on mother after bathing.

Does this show knowledge of the snake(s) being aware of the need for parental supervision? Are the snake(s) staying with the clutch to prevent predation? These factors are anyones guess.

It’s been documented numerous times; if a female snake is removed from her clutch of eggs, via human intervention she’ll often not return to incubate the clutch once she’s returned to them. Does this show us she’s operating on base instinct ingrained into her brain through millions of years of evolution? The answers still elude us or at least me anyway.

In my observations, I’d lean towards the idea of the snakes being very aware of their behavior and being cognizant of the inherent risks involved, knowingly place themselves in harms way to insure the success of their offspring. They are making a choice are they not.

While fight or flight may be an inborn reflexive instinct. Would the snake not ‘choose’ to flee in the face of peril rather than defend their unborn?

Secondarily female snakes are known to fast both prior to oviposition and maternal incubation as was mentioned above. The possible reason for this, could be, eating would require further time basking. Due to the oviposition site being selected for specific hydric (moisture) and thermal conditions this might leave the clutch unguarded from predation or allow the temperature to fall below the necessary parameters which they determine to be appropriate where pythons and boas are concerned. It may also place female snake(s) in peril prior to oviposition. She’d be much easier ‘caught’ by a potential predator as she will be, not only full with ova but also a meal recently consumed. This combination of factors would then elevate the risk versus reward factor to a level the snake determines to be unsatisfactory. As Hugh Laurie stated so succinctly in the television show House, M.D.

‘Dying changes everything.’

The mother by her behavior would seem to ‘understand’ these factors taking the variables into consideration and weighing out the risk(s). As we recently learned in the following link, snakes do seem to possess self awareness to the point where they understand potential danger.

Maternal Incubation Success

At least one paper published in Evolutionary Ecology Research, 2005 stated the success rate of maternal incubation versus artificial incubation. The paper concluded maternal incubation as being more successful when compared to a artificial incubation. I’ve not read of any other success rates when comparing artificial to maternal incubation. There’s also numerous factors within the study which might play a role in your personal experience should you decide to try maternal incubation.

The biggest factor, the snakes used were wild caught. Wild caught snakes have various bacterial flora which are, for the most part unknown in a captive environment but may play a role in the snakes ontogeny. Add to this, human intervention for genetic selection of color morphs, some of which can have extremely detrimental impacts. For more on the genetic development of color morphs please see the piece by Rob Pettipas Morphs: Have we gone too far?

It would seem in my experience, if the reptiles have survived the millions years of evolution without human intervention then nature has figured out what works and what doesn’t. If this is the case, we must ask ourselves why do breeders continue to use incubators instead of allowing nature to take it’s NATURAL course. The answer is very simple and one most won’t admit to or like.

‘Greed’

The all consuming factor of money associated with and often the case for some of us beginning our journey into herpetoculture, myself included, is MONEY. Anyone who’s asked knows, I began my journey in herpetoculture when I literally saw the amount of money that can and does change hands during a herpetoculture sale. Within a few years, I realized there was much more to these incredible creatures than money. I also became aware of how many others some with decades of experience, I’d have to ‘compete’ against. I then turned my efforts to education, and haven’t looked back since. As we all know or should be aware of at the least, the amount of reptile pets abandoned or poorly cared for is astronomical.

I don’t agree with all the practices of some breeders, be they commercial breeders selling exclusively wholesale, or one of the smaller breeders out there. I understand their desires, techniques, etc. I chose a different route is all. When you’re dealing with reptiles which can bring in tens of thousands of dollars for one reptile, you want to protect said reptile. To protect these ‘investments’ humans use the technological resources available in order to insure healthy viable offspring. Does that mean those who do are some evil cult bent on the destruction of the reptile market for their own nefarious reasons? I believe otherwise.

However, an old boss once stated something to me and it’s always stuck with me.

‘Even the stupid ones survive in captivity.’

This might seem a harsh thing to say, when we give it the context of the numerous morphs and the obvious genetic deficiencies, some to the point where quality of life is diminished, then I think it very apparent where the motivations of those breeders lay. I look forward to hearing your thoughts regarding maternal incubation versus artificial incubation over on our Facebook fan page.