Kangaroo joeys are the cutest, but there’s more to this adorable marsupial than you think.
Fact 1. Kangaroo joeys drink milk tailored to their age group.
Imagine having an affectionate, private nutritionist making you a breakfast shake every day formulated to your needs.
The formulation of kangaroo milk changes constantly over the year+ a joey nurses. Its complex, so to summarise: Tiny newborn joeys get a watery, high protein and simple carb, immunity-rich milk; older pouch joeys get high carb, high protein and some fat; big joeys at foot get massive fat and protein and low carbs.
But wait, there’s more. When a mother roo has two joeys of different ages – which is always (read next point) – she has two unique milk compositions coming out of different nipples at the same time.
Fact 2. Two kangaroo joeys can use the pouch at the same time.
It gets crowded in there.
It’s a general fact that kangaroos don’t have twin joeys. But they do have joeys 9-12 months apart*. Big sister joey @1 year old will leave the pouch just before her little sister is born. Little sister climbs up into the pouch, finds a small teat (there are four, but only three are small enough for her to gobble) and hangs on tight.
Big sister joey shoves her head in the pouch to suckle from ‘her’ nipple. It is huge by this time – the nipple stretches as the joey grows – and sometimes even hangs out of the pouch. Big sister will nurse until she’s about 18 months old.
Guess what age big sister joey breeds?
So that’s six months of sharing an increasingly tiny bedroom with big sister. No wonder kangaroo girls have the occasional disagreement.
Fact 3. A kangaroo joey is toilet trained from birth.
In fact, they don’t poo or wee until mum tells them to. A boon for a fastidious working mum.
You will often see a kangaroo mother put her head into her own pouch. She is keeping it clean. She licks it out regularly to ensure no dirt accumulates. While she’s at it, she gives joey a thorough wash.
Small joeys can’t urinate or defecate until they feel their mother’s tongue. So while mum is washing them, they do a tiny poo-wee straight onto her tongue. It might sound a bit gross, but keep in mind that a 3cm milk-fed joey produces a droplet of waste only.
Fact 4. Kangaroo pouches are big and floppy one minute, and tight as a drum the next.
Oh, what would we give for that sort of elasticity?
On a warm day, a large macropod joey swings around in an airy hammock-like pouch for most of the day. Legs, tail and ears spill out in all directions as joey snoozes. But everything changes when mum hops!
Suddenly, the airy hammock becomes a pressure bandage. Kangaroo mothers have powerful muscles around the pouch, which can tighten quickly or relax completely. If mum needs to hop fast to escape danger, she can’t have a big loose load on her undercarriage – so she tightens her pouch muscles and presses joey hard against her belly.
It makes sense – if you were holding a baby loosely in your arms and suddenly had to run, you’d do the same. Hold the precious cargo firmly.
Fact 5. If there’s danger, a kangaroo joey somersaults head-first into the pouch at speed.
Joeys see the pouch as their personal property, and treat it with the same respect as a teenager’s bedroom. None.
Imagine this peaceful view: Kangaroo mum grazing calmly with young joey at foot. Suddenly mum’s head goes up, ears pricked: danger! She barks a soft call, leans down with pouch open and joey scoots straight at the pouch. Bound, bound, somersault!
As joey’s head enters the pouch, the final hop sends the head and body in a downward circular motion. A few kicks and squirms and joey is right-way up.
Here’s a funny video of a kangaroo joey getting into the pouch:
The skin of the pouch stretches at crazy angles. That was a foot. That was an elbow. Ouch.
Mum didn’t wait for joey to settle. All this happened at 64km per hour.
Come and watch all this happen live on our Sunset Koalas & Kangaroos tour
One bonus fact to finish: Kangaroos are amazing.
REFERENCES & NOTES:
* the frequency of joey birth depends on species. Eastern Grey Kangaroos can have a joey every