According to a new a study, when it comes to parenting among bearded dragon lizards, it’s dads who make the best moms. That sentence may seem a bit confusing, but bearded dragon lizards are can change gender when they’re inside the egg and it’s those who go from male to female who kill it when it comes to maternal instinct. Known as “sex reversal,” this is the first time anything like this has been witnessed in a reptile in the wild.
The study by the University of Canberra found that in bearded dragon lizards their chromosomes don’t exactly line up. What this means is that male lizards, although they look male and are genetically so, act like female lizards. The lizards live their whole life like this, and are even able to reproduce, making them “completely functional females.” Lizards who have gone from male to female are also more fit than those who are regular females, and thanks to their male sex chromosomes, they also lay two times the amount of eggs as a regular female. It’s like they're super women, because they have the best of both worlds in some ways.
Although scientists can’t be sure as to why this is the case, they do think that climate change could be playing a part in it, because just over the course of the study the rate of sex reversal among animals had increased. They think it's an over exposure to heat that can cause a male species to lose his Y chromosome while an egg is developing, resulting in this sex reversal process.
While bearded dragon lizards may be the first species where scientists have been able to demonstrate this phenomenon in a controlled experiment, they're certainly not the only ones out there in the wild kingdom. From changing sex completely to reversing traditional sex roles, here are seven other animals who switch it up.
1. African Topi Antelopes
Completely opposite to how we think a female "should" act when it comes to mating, the females of the African topi antelopes are the ones on the prowl looking for a mate. In this particular species, the males play hard to get while the ladies go in for the kill with as many males as possible. The viciousness of the female antelope to get all the action she can sometimes even results in males being attacked when they’re spending too much time with one female antelope.
Also, the ladies only have one day a year to get sh*t done, so it makes sense that they’d be a little overzealous.
In one of the most refreshing sex role reversals out there is the fact that male seahorses are the ones who get pregnant. YES. Although their pregnancy is for only 10 to 25 days, the dad-to-be sometimes lugs around a belly full of up to 2,000 babies. How this happens is that the female seahorse drops off her eggs in the male’s pouch, which then fertilizes the eggs.
When it comes to being a stay-at-home dad, the jacanas, a tropical bird, have that covered. It’s after the female lays her eggs, that the male steps in to keep them warm, nurture them, then eventually raises the chicks to be proper adults. Where’s the female during all this? Well, she’s flown the coop, literally. After a female jacanas has laid her eggs she high-tails it out of there to find herself a new man.
4. Spotted Hyenas
According to National Geographic, not only are female spotted hyenas larger and more aggressive, but they have a penis, too… sort of. Actually the clitoris of a female hyena is so large that it’s even bigger than the penises of male spotted hyenas and it gets erect, too. But that’s not where the fun stops ― females also have something that looks very similar to a scrotum, making it hard to tell who’s male and female.
Although all clownfish start as male, they can easily change into female if necessary. If a female clownfish within a community dies, the most dominant male clownfish will turn into a female, while another male clownfish steps into the dominant role. Apparently this isn’t totally uncommon among fish, as parrotfish, hawkfish, and pipefish also switch up their sexes.
A 2011 study by Yale found that when female caterpillars are raised in cool and dry environments, they end up being man-chasing butterflies, as opposed to playing the coy traditional role of female butterflies. These female butterflies also take on the colors that would normally belong to the males of a species. Because the female butterflies want to survive into the next season, they’re overly aggressive in trying to procure sperm, so all the male butterflies have to do is sit back and wait, getting to be as picky as they want, especially because once they give up their sperm, their lives are cut short.
7. Emperor Penguin
Similarly to the jacanas bird, the male emperor penguin is the one who sits on his partner’s egg while she goes off and does her thing. While the female emperor penguin only leaves so she can score some food, as opposed to moving on to another male, the male penguin does his duty right up to nursing. Once the baby has hatched, the male provides milk for it via a gland that in his esophagus.