By Ryan Dumas
Every year I have a select few pairs of herpetofauna I attempt to reproduce. Planning and executing a synthetic cycle of events that trigger them to do so is not always easy. But observing the process is not only rewarding for myself, but is enriching to the herps themselves and, in my opinion, is good welfare when done correctly and at natural frequencies.
My favorite species has always been the Coastal Carpet Python (Morelia spilota mcdowelli). I’ve bred them a handful of times over the past 7 years and each experience had its ups and downs. For instance, in 2017 a female deposited 26 (that’s a LOT) eggs! All went well until the day they started hatching. Unfortunately, two were fully developed, but had expired in the egg. As luck would have it though, two other eggs contained twins! We’ll call that net zero, haha. But this is an example of how quickly one can experience a euphoric feeling of elation and a gut punch of sorrow in a relatively short time span.
Recently, my most anticipated pairing was between two locality type Coastal Carpet Pythons, Rockhampton Coastals. Rockhampton Coastals are found in Queensland, along the east coast of Australia. In appearance, they are extremely variable in the wild. However, the line developed and available in the United States has some distinct traits. They are typically a lovely slate gray base color with a black, banded pattern and shades of white. They have a head pattern (colloquially termed “head stamp”) that is distinctively different from other subspecies and localities of carpet pythons in the United States. They are not incredibly rare, but they are not common animals; and to my knowledge only a handful of keepers/breeders are working to produce some. My animals are 6 years old and are classic examples of the US Rockhampton line. The male in particular, is beautifully banded.
The breeding season begins in the Fall. After feeding a little more heavily in late August and September, both animals were fasted for the entirety of October. I do this to ensure they pass all their bowels before being exposed to a cool down period that triggers breeding behaviors in this species. The cool down begins in November. Night temperatures drop as low as 65F with no supplemental heat and the ambient day temperatures do not exceed 72F (although there is supplemental heat during the day). I begin to put the animals together around Thanksgiving, leaving them together for a week or two at a time and providing a week’s break before introducing them again. Neither are typically offered food during this process. This is why I fed more heavily leading into the cool down.
I did not observe any breeding behavior until the new year. In January I saw the first confirmed copulation, a “lock”. Tails were wrapped for hours, a good indication of successful copulation. Over the next several weeks and into the end of February, I noted several more locks. Signs were good. The next indicator I would be looking for is the female entering a shed cycle (ecdysis). This happens after a female ovulates. Building follicles either resorb back into the body or separate from the body wall and travel down the oviduct to become “shelled”. After an ovulation, a female will enter a shed cycle. Once a female carpet pythons sheds, eggs will be imminent; normally between 21-28 days. In early March, I observed this female with the classic, cloudy blue eyes that meant she was in a shed cycle! I removed the male and kept them both individually, this time until the next breeding season.
The female shed her skin in March. On 28 March, I observed her in the iconic “beehive” formation. This is a term describing the body position around a freshly laid clutch of eggs! Carpet Pythons are an egg brooding species, meaning they incubate their own eggs! It is truly a wonderful process to observe, which I have done a few times. This time, however, I decided to artificially incubate so that I could have greater control over the outcome. Because they are egg brooders, they can aggressively defend their eggs. If you get to a freshly laid clutch quickly enough, they are usually too exhausted to defend them. I did not get to these eggs quickly enough! After some misdirection, and some strikes that missed their mark, I was able to collect the eggs. I would later go back and thoroughly clean her enclosure. This includes a complete change of substrate and disinfection of the decor. If the smell of eggs persists, the female may continue to “ghost brood”, using a lot of energy to attempt incubation on eggs that are not there.
After collecting eggs, my moment of elation quickly subsided. This female had laid 16 eggs, of which only 3 were surely fertile, with one questionable. A total of 12 eggs were slugs, infertile and misshapen eggs. They were discarded and four eggs were set up in the incubator using the Suspended Incubation Method (SIM). This is a process by which the eggs are suspended above a very wet/moist substrate. The idea is to keep the eggs dry while allowing for 90% relative humidity necessary for healthy egg development. It is a tried and true method I’ve used for many of my snake clutches. After 3 weeks, the questionable egg went bad. It turned green, fuzzy and smelled particularly bad. It was discarded and the other three eggs continued their incubation at 86F. At this temperature, I anticipated a hatch date around 65-70 days.
I would check on the eggs once daily. Sometimes just a quick look, other times I would candle them (hold a light to them so I could see inside a bit) and check for vein development. All three remaining eggs continued to look good. This was all taking place during the onset of the Coronavirus. My work schedule changed and there were days I, quite honestly, did not check on the eggs. After a three day stretch of work in which I had been plain exhausted, I checked on the eggs. As soon as the incubator door opened I caught a whiff of a terrible smell. Not good. I opened the container of Rockhampton eggs and found that two of the three eggs had gone very bad.
They were green and smelled terrible. Even though the signs pointed to rotten eggs, I had seen and experienced bad looking eggs that went on to hatch. Because of this, I left the two bad ones in there for another week, just to be sure. Bad eggs should not negatively affect good eggs. After a week, they were clearly dead. I removed them and cut one open out of curiosity. What I found was a very early developed snake. These eggs had likely died weeks ago, but took some time to decay and breakdown. Ugh. Now there was only one egg left. It continued to show strong vein development and I could see the embryo moving around inside.
On 10 June, after coming home from work I noticed a small incision in the top of the egg, the snake had pipped! In my experience, once the snake pips using its egg tooth it will sit inside the egg for the next day or two while absorbing the remaining yolk. Afterwards it will emerge. That was not the case for me. The next morning the snake had not pipped any further and I did not notice movement. I cut the egg open a little more and I could see an absolutely stunning miniature replica of the sire of the clutch, a nicely banded, Rockhampton Coastal Carpet Python. I did not, however, observe much movement. Unfortunately I was out of time and had to leave for work. When I arrived home that evening, I checked on the animal and confirmed what I had suspected. It was dead in the egg. All I can gather is that this little one was not strong enough to fully pip and therefore drowned in the egg. A gut punch indeed.
I’m sharing this story with you because when you work with living things, unpredictable and, at times, sad things happen. When these things happen, you have choices to make; how do you react and move forward. In this case, I could sit in sorrow, or stew in anger and wonder why it was unfair or I could use this as a teachable moment for learning. As unfortunate as it is, what will I take away from the experience? I moved my entire collection from one room to another in October, just before the onset of the breeding season. Could that have played a role? Did I feed my female enough before the breeding season? I tend to be a minimalist feeder (it’s more natural) so it’s very possible she did not have enough reserves to properly nourish the development of the eggs. I will need to adjust.
The parents of the clutch were first time breeders. Perhaps inexperience played a role? Did the temperatures drop enough to trigger proper reproductive processes in both individuals? I think my point is clear. The most wonderful aspect to owning and working with living things is observing, keeping records and learning. Animals have so much to teach and we should always be ready to take notes and learn so we can better prepare ourselves for the next attempt! Maybe I’ll have better luck next year!
