A Kenyan sand boa in Britain named Dolores pulled off an exceptionally rare biological feat after living alone for 20 years: She gave birth to nine babies without ever mating.
Dolores, part of the animal collection at Merrist Wood College and University Centre near Guildford, reproduced through parthenogenesis, an asexual process in which her eggs developed without fertilization, according to the Farnham Herald.
Here's what to know
Dolores is part of the animal collection at Merrist Wood College and University Centre near Guildford.
The nine healthy young arrived on what staff said was her fifth "virgin birth" attempt since 2018.
Typically, sperm from a male fertilizes a female's egg. With parthenogenesis, no such fertilization occurs, but the egg may still develop into an embryo.
Scientists have recorded the process in some snakes, although it is rare.
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Before this successful litter, Merrist Wood said, Dolores had gone through four failed attempts.
More background
Parthenogenesis is not unique to snakes: certain sharks, lizards, and insects can also reproduce this way.
Among snakes, reports include several boa and python species, and others, though the phenomenon remains uncommon.
Researchers are still working to understand why it happens.
It has been seen in females that had access to males, so it cannot be explained simply as a response to isolation. But when males are scarce or absent, it can help ensure reproduction.
That ability can help animals spread quickly into new habitats. Dolores' litter adds another example to a still-developing area of research on animal reproduction.
A comparable boa case surfaced in March.
The BBC reported that Ronaldo — a 14-year-old Brazilian rainbow boa constrictor at the City of Portsmouth College — produced 12 offspring without mating after similar virgin births two years earlier, despite once being believed to be male.
What's being done?
At the animal management center nursery, staff have placed the nine baby sand boas in warm, protected spaces to closely monitor their health and development.
Because this was Dolores' fifth documented attempt since 2018, the college's animal collection team spent years observing a pattern that shifted from unsuccessful outcomes to a healthy litter.
Keepers are caring for an adult snake while responding in real time to an uncommon reproductive event. Dolores' case is now both a husbandry challenge and a teaching opportunity for the college.
"There's never a dull moment working with animals; they fuel our passion and ensure we are always learning," said Taggie Gatchell, Merrist Wood's head of animal collections, per the Farnham Herald.
Where can I learn more?
For more on unusual animal reproduction, these stories look at other unexpected births and hatchings. They include a crocodile's parthenogenesis, a pet snake's surprise egg, and rare breeding events involving tortoises and geese.
• At a Costa Rican reptile park, a crocodile produced a virgin birth, stunning researchers.
• In a new pet owner's home, a rough green snake laid a surprise egg.
• At the Philadelphia Zoo, Galápagos tortoises bred in a once-in-a-lifetime event.
• In Oregon, park rangers watched bizarre hybrid eggs hatch after an unexpected pairing.
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