By Casey Cannon
Bredl’s Pythons are from the harsh environment of central Australia. The canyons of the MacDonnell Ranges, where this species calls home, commonly has summertime highs over 100F and occasional wintertime lows below freezing. Because of this Bredl’s have adapted their reproductive strategy to breed after the warm up in the springtime. Unlike many python species which breed in the wintertime.
This article is based off of the notes that I look back on every year to see where my Bredl’s females are in the egg development stage. When I was first learning this species I wished a breeding pictorial like the one Marcus Jayne had made for ball pythons existed for spring breeder Morelia. I hope this helps someone out but really it’s a lot for my own benefit having easy access to this information.
Pre-Cooling- In the months leading up to the winter cooling the behaviors of my snakes typically change. Adult Bredl’s that used to be calm and easy to handle suddenly want to lunge at anything that enters their enclosure. That is because they are hungry and are trying to get proper fat reserves for winter like they would in nature. I like to give my snakes larger meals in August and September and stop feeding entirely in October. During October I drop the light cycle in the room from 12.5 hours to 8 hours of daylight.
Cooling– When I cool my Bredl’s I like to drop them down to the 50s at night for November and December. I do this by moving them into a colder room at night and back to their warmer enclosures during the day. During this period females are beginning to grow follicles in their ovaries and the males are beginning to grow viable sperm. I have never seen mating in the wintertime from my Bredl’s.
Warm up/Breeding– After the cooling period I will bring the light cycle back up to 12.5 hours. I will offer a mouse or other small meal a week and a half after temps have returned to normal. I do this to jumpstart the females digestive system. A week or so after the first meal I offer her a very large meal, typically a retired breeder rat. I also feed my males a meal or two if they want it. After this large meal the female will go into shed. When the shed happens the female seems to produce pheromones that attract the males. The males will become restless, moving around their cages trying to get to the females.
I see most locks in late January through April. During introductions males will tease the females with the spurs they have by their cloaca. Locks can last for an entire day and occur several times a week during the peak breeding season.
Ovulation– During ovulation mature unfertilized follicles move from the ovaries into the oviducts where they are fertilized. I do not own an ultrasound yet but typically in pythons follicles reach 40-45 millimeters when they are ready to ovulate. Eggs are typically laid 50-65 days after ovulation.
Ovulation is pretty easy to miss because it typically lasts less than 24 hours. Usually females swell considerably on the last third or so of the body. It has been described by many breeders as “like she swallowed a football”. I’ve also noticed a yellowish pudding-like excrement comes out of the female after ovulation. Pairs do occasionally lock after ovulation.
Prelay Shed- 15-30 days after ovulation the female will go through a shed cycle. After this shed eggs should arrive in 25-40 days.
Building Eggs- During the egg building process the female will start to swell on the back half of the body. She will start to lay on her sides and back. These positions will sometimes get more extreme as the eggs get larger many breeders call these positioning “Pretzeling”. The late stages of the egg building process the female will typically look skinnier in the head and neck and become more restless and agitated.
Egg laying- Right before eggs are laid the female will be pretzeling in the nest box regularly. She will begin to have deep, heavy breathing and coil up in the chosen spot. I’ve been lucky enough to be nearby when a female began to lay eggs. It is important during this process to leave her alone (I’ve definitely been guilty of over checking and now make sure I leave the house entirely).
Fertile eggs are large and white and infertile eggs are misshapen, yellow and small. Occasionally eggs will have an imperfection and I think it is best to incubate them and see if they hatch.
After egg laying the female will look deflated and exhausted. Most will wrap their eggs in a perfect beehive but a lot of my personal animals have scattered their eggs all over the enclosure.
Eggs– I’ve never had a female successfully do maternal incubation, but many others have. When I set my eggs up I use a mixture of slightly wet perlite and vermiculite as a substrate and have a light diffuser over it to place the eggs. I use plastic tubs with air-holes drilled into the sides and place them into an incubator set to 87F. The first baby usually pips out of the egg around day 55 and the rest usually come out over the next week or so.
It’s not uncommon for a few eggs to go bad about 2 weeks into incubation. Possibly those eggs were never viable to begin with.As eggs get closer to hatching they will begin to sweat and generate heat. As they lose water they take on a dented appearance.
Bredl’s are awesome!