A ball python at the St. Louis Zoo left keepers gobsmacked when they recently found it coiled around a clutch of eggs after not having contact with a male for at least 15 years.
However, it wasn't necessarily the snake reproducing asexually that stunned zookeepers—while uncommon, it isn't impossible for female ball pythons to lay eggs all on their own—it was the fact that the reptile is nearly 62 years old and has managed to reproduce! According to Mark Wanner, zoological manager of herpetology at the St. Louis Zoo, ball pythons—the smallest of the species—usually only live for 30 to 40 years. So housing a snake that's lived roughly three decades longer is "kind of crazy."
The St. Louis Zoo's ball python is now the oldest documented snake in the world following the death of a male snake of the same species at the Philadelphia Zoo which died at age 47.
"It's not normal to see a snake live to that age," Wanner told the New York Times in an article published Sunday. "That makes it even more incredible that she laid a clutch of eggs."
Zookeepers discovered seven eggs in the snake's cage back in July. Two of the eggs did not survive while two others are set for genetic sampling, which will help scientist determine whether the snake babies were created sexually or asexually.
Three eggs are currently incubating at the zoo's herpetarium where all the other snakes, lizards, frogs and amphibians reside. They are expected to hatch sometime in October.
Although female snakes are capable of storing sperm from males and fertilizing their eggs long after mating, the sperm typically only lasts for seven years, according to Wanner, which would rule that evolutionary trait out. More than likely, the snake endured a "virgin birth" otherwise known as parthenogenesis, a method of asexual reproduction that occurs when unfertilized eggs develop.
It has long been documented that some species of fish, sharks and lizards that are capable of parthenogenesis, but some biologist believe the phenomenon is more common in snakes that what was initially believed. A group of scientists published a whole study on it in 2012 in the Biological Journal of the Linnean Society and determined that asexual reproduction typically occurred when females were unable to find a mate and need to put their eggs to use.
"We hope that this review will show that parthenogenesis is not rare. In fact, it appears widespread within snakes, and within certain species, it is common," Dr. Warren Booth, a molecular ecologist at the University of Tulsa and co-author on the review, told CBS News in a 2016 interview. "As such, we hope to shift that paradigm away from this being a rare, captive syndrome, to something that is potentially an important aspect of vertebrate evolution, and occurring potentially in populations not far from our very doorsteps. Given that it can occur, we should be thinking how it may impact populations that are small or endangered."
