Five Gross Facts About Koalas

Five Gross Facts About Koalas

Posted: November 26, 2015

Think koalas are cute? Think again. Here are five gross facts about koalas.

I’m Anna Rothschild, and this is Gross Science.

Number 1. Baby koalas, called joeys, eat their mothers’ poop. For the first six months or so after they’re born, they drink milk from a teat in their mom’s pouch. But then, for several weeks, they eat…fecal matter. The joey sticks its head out its mom’s pouch and nuzzles her butt. She releases some normal poop pellets, followed by a runnier, protein-rich substance, called pap. The pap helps the baby grow, and is full of the mom’s gut bacteria, which could help prepare the joey for its adult diet of eucalyptus leaves.

Number 2. Like many other marsupials, the penises of male koalas have two prongs. But, that’s nothing compared to the female, which has two vaginas and what’s called a vaginal cul-de-sac. Sperm travels up the vaginas on either side, and babies leave through the cul-de-sac, actually breaking through the bottom. After birth, the cul-de-sac heals.

Number 3. Males use a loud belching noise called a bellow for attracting mates and for other communication. A unique vocal organ at the back of their throats makes their calls extremely low. In fact, the koala’s bellow is about 20 times lower than it should be for an animal of its size.

Number 4. A mature male koala has a scent gland on his chest, which oozes dark, smelly gunk that he rubs on trees. No one’s entirely sure what the gunk’s for, but it could be to signal that he’s ready to mate, or to mark his territory. Koalas aren’t known to be super territorial, but that’s not always the case…

Number 5. Wild koalas in Australia face some major threats, like habitat destruction, brushfires, an HIV-like virus that suppresses their immune system, and even chlamydia. The strains that infect koalas are different from the sexually transmitted disease we get. But koala chlamydia also spreads through mating, and mothers can transmit it to their joeys. It can make the animals blind, incontinent, infertile, and even kill them. And it’s pretty prevalent—in some places up to 90% of the koala population has been infected.

Now, it’s not clear exactly how critical koalas are to maintaining stability in the ecosystem. But personally, I don’t want to risk it. We simply don’t know what losing these guys to disease or habitat disruption could mean for eucalyptus forests. And besides, koalas are deeply important cultural icons—think about it, they’re basically synonymous with “Australia”…along with kangaroos and vegemite. So, no matter how strange these animals are, I for one wanna save them.

I guess you’re still kinda cute. Ew.

PRODUCTION CREDITS

Host, Producer, Editor, Animator, Additional Research

Anna Rothschild

Researcher, Writer

Elizabeth Preston

DP, Sound, Additional Research

Ceri Riley

Perfectly B

Music Provided by APM

IMAGES AND VIDEO

Original Footage

©WGBH Educational Foundation 2015

Audio and video of Koala Velar Vocal Fold Vibrations

Courtesy Dr. Benjamin Charlton

A video recording of a bellowing male koala (Phascolarctos cinereus) (called Andy) at Lone Pine Koala Sanctuary.

Movie S1 from: Charlton, B. D., Ellis, W. A. H., McKinnon, A. J., Brumm, J., Nilsson, K., & Fitch, W. T. (2011). Perception of Male Caller Identity in Koalas (Phascolarctos cinereus): Acoustic Analysis and Playback Experiments. PLoS ONE, 6(5), e20329. http://doi.org/10.1371/journal.pone.0020329

Koala (Phascolarctos cinereus) newborn in pouch, Australia

Getty Images/Roland Seitre

young joey in pouch eating pap

Shutterstock/WF

Portrait of male Koala bear, Phascolarctos cinereus, 3 years old, in front of white background, studio shot

Pond5/lifeonwhite_photos

Koala chases girl riding an ATV and attacks

Ebony Churchill/ViralHog.com
http://bit.ly/1HPYrO5

Brushfire

Pond5/EcoMedia

Cutest Koala

Wikimedia Commons/Erik Veland

Phascolarctos cinereus -ZooParc de Beauval, France -upper body- 8a

Wikimedia Commons/frank wouters

Baby Koala

Wikimedia Commons/حسان هواري

Koala with young

Wikimedia Commons/Brian Dell Bdell555

Koala Eating

Wikimedia Commons/(--Pumpmeup)

Friendly Male Koala

Wikimedia Commons/Quartl

Koala

Wikimedia Commons/Summi

A cranky-looking koala, sitting beside the road on the way to Apollo Bay

Flickr/Shiny Things
(used with permission from author)

Koala02

Wikimedia Commons/Mike R

The World Factbook - Australia - Flickr - The Central Intelligence Agency (19)

Wikimedia Commons/The Central Intelligence Agency

Koala being treated for chlamydia

Ari Daniel/WGBH Educational Foundation

Koala and joey

Wikimedia Commons/Benjamint444

Koala Eating (3337014192)

Wikimedia Commons/Rennett Stowe from USA

Australia satellite plane

Wikimedia Commons/Reto Stöckl / NASA Goddard Space Flight Center

Macropus rufus in ZOO Plock

Wikimedia Commons/Bardrock

Vegemiteontoast large

Wikimedia Commons/Tristanb

SFX

Cockroaches

Freesound/StateAardvark­
(used with permission from author)

Squeak Pack/squeak_10

Freesound/Corsica_S

Swishes

Freesound/Pogotron

Produced by WGBH for PBS Digital Studios

POSTER IMAGE

Cutest Koala

Wikimedia Commons/Erik Veland

Want more info?

Additional info about the koala life cycle:
http://bit.ly/1HPTmW4

Info on the koala reproductive system:
http://bit.ly/1HPPVi8

Primary literature on the koala’s unique vocal organ (article behind paywall):
http://bit.ly/1HPTQLW

Nature article on the koala’s bellow:
http://bit.ly/1HPTZ1P

NOVA/PRI’s The World report on koala chlamydia:
http://to.pbs.org/1HPUdWP