This snake gave birth without a male: How common is parthenogenesis?

A snake gave birth after living alone for eight years, demonstrating parthenogenesis, a rare phenomenon that scientists are realizing may happen more frequently than expected. 

Candice Davis/Missouri Department of Conservation/AP
A female yellow-bellied water snake at the Cape Girardeau, Mo., Conservation Nature Center, for the second time in two years, has given birth without any help from a male member of the species, conservationists say. The offspring did not survive this summer, but they did in 2014. It is believed to be the first documented cases in the species of parthenogenesis, or asexual reproduction.

A rare case of parthenogenesis has been discovered in a water snake that has given "virgin birth" without contact from a male in eight years.

This birth from a single female is another piece in the puzzle of a phenomenon known as parthenogenesis, as researchers are more frequently finding animals that reproduce singly.

The discovery that a female yellow-bellied water snake at a nature center in Missouri had given birth surprised an intern who was making a routine check of the animals.

This snake gave birth last summer – also without any fertilization from a male – and the two offspring are on display at a nature center in St. Louis. The batch born this summer did not survive.

"Virgin birth" is common in insects, but it also occurs in reptiles, fish, birds, and amphibians. It does not occur in mammals. The snakelets in Missouri are the first example of parthenogenesis observed in a yellow-bellied water snake.

Parthenogenesis was discovered in the 1800s with domesticated birds, according to an article by Royal Society Publishing. The first studies involved turkeys. Many parthenogenetic offspring were born with abnormalities, but some could live and reproduce normally.

On a cellular level, parthenogenesis occurs when smaller cells produced alongside an egg fertilize the egg rather than decaying normally.

Experts once thought parthenogenesis was an adaptation of animals in captivity, since that is where it had been observed, but in 2012, researchers found cases of single-parent fish in the wild. Andrew Fields of Stony Brook University and his colleagues were sequencing the genome of 190 endangered sawfish, and they found seven whose "parents" were genetically identical – meaning both parents were the same fish.

As interesting as the discovery was, Warren Booth of the University of Tulsa told The Christian Science Monitor it was not helping the species. "Essentially you are eliminating all variation across the genome so it’s a very deleterious, a very bad thing to occur."

It is possible that the female snake had been storing sperm inside her since her potentially more amorous past in the wild. However, Robert Powell, a biology professor at Avila University, said this is unlikely, however, because animals can usually store sperm for only a year, or three at most. This new mother had lived alone for eight years.

This report includes material from the Associated Press.

You've read  of  free articles. Subscribe to continue.
Real news can be honest, hopeful, credible, constructive.
What is the Monitor difference? Tackling the tough headlines – with humanity. Listening to sources – with respect. Seeing the story that others are missing by reporting what so often gets overlooked: the values that connect us. That’s Monitor reporting – news that changes how you see the world.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to

QR Code to This snake gave birth without a male: How common is parthenogenesis?
Read this article in
QR Code to Subscription page
Start your subscription today