Chapter 13 of 13 · Ball Python Breeding Guide
Sources and credits
Disclaimer: I'm not a veterinarian and I don't hold a degree in animal science or animal care. This is a guide I compiled and use for my own ball pythons. For a sick or egg-bound snake, a reptile vet is the authority.
How we rank them
Published studies and veterinary references first. Most of the hard numbers in this guide come from a handful of ball python studies: a 129-female ultrasound study, a facility record of 783 clutches, a follicle-cycle study, and older work on metabolism and maternal brooding. Breeder and keeper sources next, marked as such in every chapter; they carry the most hands-on experience but rarely publish data. Our practice is what we do in our room now; our plan is how we have set up the parts of breeding we haven't reported results for yet.
Every chapter ends with its own numbered list. This page collects the core set.
Ball python studies
- Bertocchi, M. et al. (2018), reproductive ultrasound and fecal hormones in 129 ball pythons, PLOS ONE 13(6): e0199377, doi:10.1371/journal.pone.0199377
- Morrill, B. H. et al. (2011), Herpetological Review 42: 226–231, 783 clutches, summary at Conservation Evidence
- Journal of Herpetological Medicine and Surgery 26(3–4) (2016), follicular cycle in ball pythons
- Ellis, T. M. and Chappell, M. A. (1987), Journal of Comparative Physiology B 157: 393–402, PDF
- Aubret, F. et al. (2003, 2005), clutch size and maternal brooding, 2003 summary, 2005 abstract (archived)
- University of Pisa veterinary thesis (2024), abstract
Genetics and morph health
- García-Elfring, A. et al. (2025), Clown and Cryptic in MC1R, PDF; VPI Axanthic and gch2, OMIA
- Brown, A. R. et al. (2022), albinism genes, PLOS ONE 17(10): e0276376, doi:10.1371/journal.pone.0276376
- Gamble, T. et al. (2017), XY sex chromosomes in pythons, doi:10.1016/j.cub.2017.06.010; Mallery and Carrillo (2016), sex-linked Coral Glow, journal article
- Rose and Williams (2014), doi:10.1053/j.jepm.2014.06.002; Starck et al. (2022), doi:10.1371/journal.pone.0262788; Schrenk et al. (2022), LMU
- MorphMarket Morphpedia, community lists and RGI testing pages (hobby references; cited chapter by chapter)
Veterinary and health
- Merck / MSD Veterinary Manual: reproductive, viral and parasitic diseases of reptiles
- Morel, M. et al. (2025), egg-binding (dystocia) in reptiles, PMC12846459
- Hoon-Hanks et al. (2019), serpentovirus in US snakes; Blahak et al. (2020), nidovirus in ball pythons; Boon et al. (2023), serpentovirus review
- AVMA Guidelines for the Euthanasia of Animals, 2020, PDF
Related species (context only)
- Children's python thermoregulation (Lorioux et al. 2012, PDF); egg turning in water snakes (Aubret et al. 2015, PMC4543940); pine snake incubation (Burger et al. 1987, PDF); rattlesnake sperm storage (Levine et al. 2021, PMC8177532); Burmese python paternity (Skelton et al. 2021, USGS)
Breeders and keepers
- Northwest Reptiles, Bob Clark, Breeder's Circle, AME Exotics, VPI (Barker), ReptiFiles, MoreReptiles, FurryCritter, ball-pythons.net and the MorphMarket Community, each cited where used.
Shipping and law
- MorphMarket Support, USARK, FedEx, UPS and USPS Publication 52 on shipping; 9 CFR §1.1 (Animal Welfare Act); Federal Register 2015 and US Fish and Wildlife Service on the Lacey Act; Hawaii Department of Agriculture; New York Environmental Conservation Law §11-0103.
Where the evidence is thin
No published study covers, for ball pythons specifically: whether cooling improves ovulation, the ideal moment to introduce a male, laying-box design, how long hatchlings can safely go without food, egg cutting, or a rest-year rule. Those parts of the guide are breeder practice and are marked that way.