Romeo and Juliet: A Marsupial Love Story

In the animal kingdom there is one romance so tragic, it puts even Shakespeare’s finest work to shame.

That romance is the life of the antechinus. If you’re not sure what an antechinus is, imagine a shrew, but prettier. Actually that’s a picture of an antechinus down there, so maybe just look at that.

A shrew but prettier. Image credit: Mel Williams (Wikimedia Commons)

These animals live a cycle of love at first sight(s), followed by a sad and unfortunate death. So keep reading and I will recount to you the tale of two tragic lovers.

Act I: Love at first sight… and second, and third, and then a few more

The day would start out like almost any other for our dear Romeo, with one exception, his testosterone levels are beginning to skyrocket. The breeding season has begun.

Romeo goes on the prowl. Heart pumping and mind racing, he searches for a partner. That’s when he sees her, his true love. Romeo dashes to Juliet, fighting off all opponents who stand in his way. Flirting is brief; copulation on the other hand, goes for a full 14 hours.

You don't need to see this part. So just enjoy a picture of the beautiful night sky while we let Romeo enjoy... his thing... Image credit: Dave Hensley (Flickr)

When he finishes Romeo just trots off, already in search of his next “true love”. He’ll do this many times over the next two weeks. Competition is fierce, and Romeo wants to mate with as many females as possible in that short amount of time he has left. During this time Romeo will neither eat nor sleep. This little marsupial only has one thing on his mind till the day he dies.

Act II: The painful death part

When the mating season ends it all starts to go downhill for Romeo. None of the females want him around anymore. Desperate, he runs back to Juliet, but even she shuns him. Female antechinuses are strict on the breeding deadline.

Worse is still come for Romeo. He now has a mere fortnight left to live (at most).

It’s all thanks to a side effect of the spiked testosterone levels. Testosterone frees up the stress hormone cortisol. Initially this was a bonus because cortisol breaks down proteins and other molecules, giving Romeo the energy he needed to go all night long without a snack break.

Unfortunately this also means that muscles are being broken down, withering away into uselessness. But that’s not the only problem. Cortisol also shuts off the immune system, meaning Romeo left himself a sitting duck for parasites and infection.

Cortisol - The stress hormone. Image credit: Benjah-bmm27 (Wikimedia Commons)

Now you may be starting to feel sorry for our lovestruck protagonist at this point.

Well don’t. Romeo brought this on himself. This is exactly what you get for forgetting to eat and turning off your body’s defence system for three weeks straight.

Blinded and riddled with pestilent ulcers, Romeo passes away alone. Which just begs the question, ‘was it worth it?’

Well surprisingly, yes. This was his only chance to pass on his genes anyway, so it’s go hard or go home really.

Act III: Children!… and then more dying

Now is Juliet’s turn to shine. With the sperm from her many suitors stored for up to two weeks, it’s finally time for Juliet to fertilise her eggs. If Romeo is lucky she might even choose to use his sperm. Yes you read that right, female antechinuses are able to select sperm that are genetically compatible with their eggs.

Then, on a lovely spring morning, the children arrive. But lovely birdsong and sweet spring air aren’t on their minds in the slightest. The race has already begun.

Newborns sprint to latch onto a teat. These spots are limited and not everyone will make it. They push and they tug, a newborn called Shylock even whines out to his mother “Ouch! MUUUUUMMM!!! Antonio pushed me” (I’m hoping some of you catch the Shakespeare reference here).

Shylock will not make it, this race is no place for cry-babies, and only the strong (like Antonio) will survive.

These antechinuses don't have time to sniff the flowers. Image credit: Anita Martinz (Wikimedia Commons)

This was their first test.

For their mother however, this will be the final test. After raising her young she perishes. Maybe she was struck by heartbreak for her beloved Romeo… more likely though it was due to feeding a litter of offspring three times her weight.

Here our tale ends. A tragic story of loss and woe, with fewer survivors than a season finale of Game of Thrones. But you know what? This species will probably just go and do it all again next year.