Virgin Birth, Double Uteri, and Other Wondrous Female Abilities

In nature, some female "superpowers" rival those of Wonder Woman.

Wonder Woman certainly got her due at the box office, but many female animals have superpowers that we seldom hear about.

Here are some of our favourites, including—no kidding—a magic lasso.

DOUBLE THE UTERUS

These cartoonish predators, found mainly in New South Wales, Australia, aren't true worms—instead they're relatives of arthropods, a huge group that includes insects and spiders.

Velvet worms live in female-dominated groups of about 15 individuals. When it's time to mate, several males will place sperm packets on any part of the larger female’s skin, which she absorbs and stores separately—according to the male—in her sperm receptacle. (See "6 Fierce Animal Moms That Go to Extremes For Their Young.")

Storing sperm from various males makes for more genetically diverse—and thus healthier—offspring. They also have two uteri, and so can develop two batches of embryos at different rates.

Males and females hunt together, shooting out a gooey lasso of a protein and water to capture prey such as termites, beetles, and spiders.

The dominant female then eats before everyone else. #Obvs.

SIREN SONGS

Female Barbary macaques of Morocco, Algeria, and Gibraltar lure males with calls made while mating with other males—which means they often copulate with every male in their group.

Not only that, but a 2008 study found that the females' calls during mating increase the likelihood of male ejaculation.


A mother Barbary macaque holds her infant in Morocco's Atlas Mountains.
PHOTOGRAPH BY CYRIL RUOSO, MINDEN PICTURES/NATIONAL GEOGRAPHIC CREATIVE

Both of these techniques enhance sperm competition, making it hard to tell whose infants are whose—and increasing the likelihood males will care for all infants. (See "Why It Matters Who Females Choose to Have Sex With.")

READY FOR BATTLE

There’s an idea that among territorial species "that females are less aggressive,” says Aaron Reedy, a biologist at the University of Virginia.

Not so among brown anoles of Florida.


Two tagged female brown anoles engaged in battle—a relatively rare event.
PHOTOGRAPH BY AMBIKA KAMATH, NATIONAL GEOGRAPHIC CREATIVE

In a study published this week, Reedy and colleagues found both male and female anoles attack intruder anoles with equal frequency—but “females attack more quickly and with less behavioural display."

Reedy and his team—comprised largely of high school science teachers in the Evolution Education program—suspect males have more to lose by getting physical.

Males' much stronger jaws can inflict damage on their rivals, so it might be that a bit of proverbial chest-beating is less risky than "jumping straight into a fight," Reedy says.

VIRGIN BIRTH

Nature tends to prefer sexual reproduction because the mix of genes creates healthier animals.

But some sharks, rays, bony fishes, and reptiles don’t need sperm—they practice what's called parthenogenesis, or virgin birth.


Spotted eagle rays (pictured, an animal in Belize's Hol Chan Marine Reserve) can have virgin birth.
PHOTOGRAPH BY BRIAN SKERRY, NATIONAL GEOGRAPHIC CREATIVE

Virgin birth can occur when males are not present—particularly in captive settings, such as aquariums. (Related: "Shark Surprises Aquarium with Rare Virgin Birth.")

In these situations, virgin birth could be an animal's biological response "to keep the species going," notes George Burgess, an ichthyologist at the Florida Museum of Natural History.

The exact biological triggers for parthenogenesis are unknown, he adds.


Endangered shark gives rare "virgin birth".

THE POWER TO DISMEMBER

Many females are larger than males because they need room for reproductive hardware, or “to carry the young to birthing size,” Burgess says.


A female violet blanket octopus, Tremoctopus violaceus, sails the open sea. Male blanket octopi are about the size of a walnut.
PHOTOGRAPH BY STEPHEN FRINK, ALAMY

Female blanket octopi of the Atlantic and Mediterranean, for instance, get up to four feet long. Walnut-size males are “basically swimming sperm banks for the female,” he says.

These tiny males transfer their sperm via a hectocoylus: An arm that he yanks off his own body and gives to her.

That's some serious pull—and female blanket octopuses do it all without a cape.

Have a question about the weird and wild world? Tweet me or find me on Facebook. Weird Animal Question of the Week answers your questions every Saturday.

Header Image: A Tallaganda velvet worm called Euperipatoides rowelli seems surprised to see the photographer. PHOTOGRAPH BY ANDRAS KESZEI. 

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