Mourning Geckos: Reptiles That Reproduce Without Males
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A gecko native to Southeast Asia that is extremely common around human dwellings, the Mourning gecko, Lepidodactylus lugubris, can reproduce without males. Thus, the species is almost entirely parthenogenetic females.
Even though Mourning geckos don’t breed with males, gregarious females do breed with each other. When females copulate, they encourage each other to produce eggs. Then, they lag the adhesive eggs in a communal nesting site.
What is Parthenogenesis?
Parthenogenesis is an evolutionary reproductive strategy, which allows the development of a sex cell called a gamete without fertilization. Most of the time, the gamete is a female cell, but sometimes a rare male develops. It’s a common strategy for invertebrates like ants, aphids, and bees. However, it’s rare in higher vertebrates like geckos.
The term parthenogenesis translates to virgin origin in Greek, which means we’re talking about virgin births. In theory, even humans could be capable of parthenogenesis. However, the odds are extremely low of that happening in real life. Plus, parthenogenesis never produces viable embryos, though it can’t be ruled out completely.
Scientists have discovered these so-called virgin births in reptiles, including snakes like pit vipers and pythons. Also, the phenomenon has been noted in amphibians, birds, and fish, including sharks.
Male Mourning Geckos are Infertile
In the Mourning gecko species, males are occasionally produced. However, researchers determined the males are infertile, although otherwise perfect.
While the males are capable of producing spermatozoa, they are largely deformed. Meanwhile, females can create fertile eggs without another male or female. However, copulation with females encourages egg production.
Mourning Geckos Thrive Near Humans
These Amazons of the reptile world thrive near human structures and have spread from Asia to tropical islands, the Americas, and Australia. Thus, they are one of the most widely distributed reptiles in the world. Hiding out on boats, they have even made it to remote islands like the Galápagos and Hawaii. Interestingly, their eggs are resistant to saltwater, which no doubt has helped the species spread.
There, they thrive by taking up residence on building walls, hiding out in any crevice. At night, they also take advantage of human dwellings by capturing bugs attracted to nighttime lights.
Human structures provide a hunting territory and hideout for the geckos. Within any crevice, they can find the perfect spot to lay their eggs. Like many other geckos, they will drop their tail if captured. Then, they can grow the tail back later.
Mourning Geckos Don’t Mourn Life Without Males
The Latin for lugubris is “Mournful,” and, rather amusingly, it’s thought the name came from the idea that the females mourned life without males. However, these geckos do just fine, producing only infertile males.
At night, these geckos are vocal, making chirping sounds. Listen carefully, and you can hear them chirping in the video below:
Notably, these geckos can live for ten years in captivity, with some reports of as much as 15 years. However, they stay small, usually at no more than three and a half to four inches in adult length.
They Like to Eat Each Other’s Eggs and Hatchlings
Although they may nest communally, Mourning Geckos don’t object to eating freshly-laid soft eggs or hatchlings. The tiny hatchlings are less than an inch long and highly vulnerable. Fortunately, the adults may sometimes leave them alone.
Generally, two eggs are laid every month or so, and they hatch in about two months. When they hatch, a tiny female clone of the mother comes into the world, aside from a few rare males.
Although they may eat babies and eggs, the females usually tolerate each other. Often, pet keepers have a few females together, and they will develop a pecking order. Another bonus is their small size, which means they can live in a small enclosure.
One Gecko Can Produce Offspring
If you obtain a Mourning gecko female, she can produce fertile eggs. Thus, the species is one of the easiest to breed, requiring only one animal. However, Mourning geckos are not the only reptiles that can pull off this neat trick. Another example is one of the world’s largest reptiles, the Komodo dragon, known to have given virgin births in UK zoos.
Although it’s a fascinating ability, parthenogenesis can also lead to lower genetic diversity. Scientists aren’t sure why virgin births are fairly common in many species. Notably, asexual reproduction has not been found naturally in mammals but has been artificially facilitated in genetically engineered mice.
Interestingly, Mourning geckos do vary in appearance, depending on their geography. Thus, there is some genetic diversity, even though they are clones of their mothers.