Fighting is dangerous – even minor fights can lead to injury, and most fights require focus, which distracts the animal from watching out for predators.
Many male animals use body language or bluff to avoid fighting. Male kangaroos use expressive gestures to show other male kangaroos how strong they are, and thus avoid fighting unnecessarily.
Kangaroo bluff display consists of these moves, usually in this order:
Exaggerated pentapedal walking
Kangaroos ‘walk’ by moving their front legs forward, then balancing on their tails for a moment to shift their back legs forward. Its called the pentapedal walk (penta = five, pedal = feet, including the tail). When displaying a male kangaroo will exaggerate this walk by pushing his shoulders and forearms forward, highlighting his muscles. He will arch his back and balance on his tail for longer than normal.
Ball handling and exaggerated grooming
Kangaroos scratch themselves a lot, just as a part of normal grooming. But a male kangaroo avoiding a fight will groom to an extreme degree – its a great way to show nonchalance, but also how pronounced and large their muscles are.
When watching others males display or fight, some male kangaroos will groom their testicles a lot by holding them in their hands and stroking them repeatedly. This doesn’t appear to be masturbation – I haven’t seen it lead to an erection.
During the pentapedal walk, male kangaroos will pause to rub their chest against the ground, by dropping one shoulder to the ground and rubbing back and forth. This spreads their scent and alerts other males to their presence.
Also during a pause in the pentapedal walk, a male kangaroo will grab a tuft of grass in his hand and pull it out and throw it away. This shows off his strength (and probably his arrogance). He will also claw at the ground and throw dust in the air.
This is the most extreme of displays and requires great strength. The kangaroo will raise his body to a normal upright position, then extend on to his tip toes. Its the same thing they do to hop, but more vertical, and held for longer. This position can give a kangaroo an extra 40cm of height.
Only very large, strong kangaroos can maintain high standing for long durations. It is the supreme demonstration of their fitness and strength. A rival male seeing this might avoid fighting if he can’t high-stand for as long.
Kangaroos in the wild are fascinating social animals. Watching male kangaroos avoid fighting is just as interesting as watching kangaroos fight.
The earliest kangaroo-like animals – Nambaroo gillespieae – were ranging around northwest Queensland 25 million years ago. Another couple of kangaroos Balbaroo fangaroo and Cookeroo hortusensis have been found as 15-23 million year old fossils at Riversleigh in Queensland.
Mungo, in south-western New South Wales, is also a rich source of fossils. The site is famous for human history, but it is also significant for megafauna fossils.
Procoptodon goliah, the largest kangaroo to have ever lived, has been found in Mungo sediments. This slow giant was 2.2m tall and weighed around 200 kg. It had huge long arms and large curved claws for grasping tree branches to get to the leaves it ate.
Some Aboriginal People in NSW have oral history of a huge kangaroo with long arms that was dangerous to people. It is possible that Procoptodon lived with Aboriginal People for as long as 30,000 years. Read more here
A large extinct wallaby, Protemnodon, has also been found at Mungo. Fossils of Sthenurus – a large browsing kangaroo – have also been found close by.
Two large extinct macropods (I can’t find their exact species yet) also lived at Mungo. They may have been Macropus pearsoni – who had a large range extending from Cape York and the Darling Downs in Qld to Lake Kanunka in the far north of SA ; and Macropus titan – who ranged from Wellington Caves, NSW, Naracoorte Caves, SA to near Melbourne VIC – who looked like a much larger Eastern Grey Kangaroo.
How did Procoptodon and Protemnodon die out? It is one of the great debates that has raged in Australia for decades. Mungo may have provided the answer.
Griffith University researchers searched for megafauna fossils in areas that also showed continuous occupation by Aboriginal People. Mungo was the perfect location, with a known timeline of Aboriginal occupation going back 50,000 years. They found megafauna surviving 33,000 years ago – at least 17,000 years after the arrival of Aboriginal People.
1. Baby koalas are called Joeys. All marsupial babies are called joeys – kangaroos, wallabies, wombats, tasmanian devils, possums & bilbys. The meaning/origin is unknown – it’s possibly just a diminutive used at that time for any small animal. Joey as a baby marsupial was first recorded in use in 1839.
The use of the word joey may have started with the word being applied for a British fourpenny coin. Politician Joseph Hume promoted the use of the fourpenny, thus the coin developed the slang name joey after him.
2. The first time you see a koala joey it is already 6 months old. Koala joeys are born as tiny naked creatures that don’t look anything like a koala. They move straight into the pouch, and remain unseen until they emerge at around 6 months old.
Actual emergence takes time. The joey first pokes his head out of the pouch at 5.5 months, and fully emerges at 6 to 7 months. By 8 to 9 months the joey becomes too large to get into the pouch, and spends all his time on his mother’s belly or back.
3. Koalas invented pro-biotics. Koala joeys eat ‘pap’ – a special substance produced by their mother that looks like poo and acts like a probiotic. It contains gut flora that the joey needs to process eucalyptus leaves. The mother koala produces it from her caecum (a special chamber in her large intestine) and delivers it from her cloaca, so though it looks a bit like poo, its not.
Pap is absolutely essential to a koala’s health. Wildlife Carers with orphaned koala joeys will frequently ask the wildlife care community for a postal delivery of pap from a koala mother – any koala mother will do, the closer the better but any is better than none. Imagine receiving that package of squishy green slurry in the mail!
4. Koala joeys are born out of their mother’s central vagina. Female koalas have three vaginas.
Why? Its complicated, and deserves a complete blog on the subject. Suffice to say that the two lateral (side) vaginae are for the passage of sperm to the uteri, and the median (central) vagina is for birth.
5. Koala joeys are born high in a tree. There is no danger of them falling to the ground – they are so tiny they get trapped in their mother’s fur. At birth a koala joey weighs only 1 gram – as much as a single sultana/raisin – and is only 2cm long.
It’s Koala Joey Season in the state of Victoria right now. All over the state wild koalas can be seen with joeys – hotspots are The You Yangs near Melbourne, the Great Ocean Road and Raymond Island, East Gippsland.
Echidna Walkabout runs the following tours to see koalas in the wild – with a high chance of seeing koala joeys each year from September to November:
Its #EasternGreyKangaroo week! Watching, and walking with these beautiful animals – in the wild – is something we never tire of.
The social interaction of kangaroos is fascinating to watch. Mothers and female joeys have a deep, strong bond, which they maintain even into adulthood. Most females stay with their mothers their whole lives.
Eastern Grey Kangaroo joeys stay in the pouch for about a year, which is much longer than other types of kangaroos. For the first five months, the joey is small, has no fur and cannot be seen from the outside except as a bulging pouch. At around six months the joey has developed a light coat of fur, and starts to poke its head out of the pouch for short periods.
At 9 to 10 months, an Eastern Grey joey takes its first journey outside of the pouch. The first time is usually an accident: joey falls out while mum’s pouch is loose. In shock, joey usually clambers straight back in to the safety and warmth!
Over the next 2 to 3 months, joey takes more and longer trips out of the pouch. Even with experience, though, getting back into the pouch can be complicated – watch this terrific little video to see how: https://youtu.be/pAnSftUVvoA
Mother kangaroos have a lot of control over their pouch – they can relax or contract the muscles around the pouch, and by standing up or leaning over they can control joey’s access to the pouch. If a mother wants to encourage her 9 month old joey to take their first steps outside, she will let her pouch muscles relax and lean over, allowing joey to tumble out. If she then stands up and contracts the pouch muscles, joey cannot get back in, no matter how hard they try. If there’s danger she will quickly lean forward, relax the pouch, and call to the joey, who immediately rushes back in.
One day when joey is about 11 – 12 months old, mother kangaroo will decide that its time for joey to vacate the pouch permanently. Next time joey is out, mum simply stands up, closes her pouch and that’s it. No more pouch for joey! Joey never seems happy about this arrangement, and will clutch at the pouch repeatedly, trying to get in. But mum must stay firm – she often has another joey ready to be born, and she can’t have two in the same pouch!
Eastern Greys nurse their joeys until they are 18 months old. For the first 9 months, suckling happens when the baby’s whole body is in the pouch. After final pouch exit at 11 – 12 months, joey suckles by putting just their head into the pouch.
Easy guide to age Eastern Grey joeys seen in the wild:
Joey’s head out of pouch: joey is between 6 months and 12 months
Joey gets in or out of pouch: joey is between 9 months and 12 months
Joey is outside, putting head in pouch: joey is between 9 months and 18 months.
Watch out next week for one of our favourite Aussie birds – the famous kookaburra! #LaughingKookaburra week!
Dawson, Terence J. “Kangaroos: Biology of the Largest Marsupials” 1998 pp 78-83
Yesterday as we watched a wild mob of Eastern Grey Kangaroos happily eating and socialising, we noticed a mother with a huge pouch. Shortly after, this tiny joey tumbled out!
Eastern Grey Kangaroo joeys stay in their mothers pouch for 11 months, and in the last few months, as this video https://youtu.be/jnLXuVAre3c shows, the joey comes out of the pouch for increasingly longer periods and learns to balance, hop, groom, eat grass and socialise.
The bond between kangaroo mothers and joeys is strong and long-lasting. The joey in the video is about 9-10 months old, and if she is female, she will probably live with her mother her entire life.
This joey is a little older, probably about 12 months. She still suckles from her mother’s pouch, and will do so until she is 18 months old. While she suckles, her mother takes the opportunity to groom her.
In nature, everything is connected. But some of the affinities between koalas and other animals might surprise you!
Honeyeaters, like this Eastern Spinebill, pollinate trees. Without honeyeaters, new trees will struggle to grow. No trees = no koalas.
If Flame Robins didn’t eat insects, plants would suffer from insect overpopulation. Insects eat the leaves of many plants, eucalyptus included. Too many insects = no leaves on trees for koalas to eat.
Even butterflies are important to koalas. Butterflies, like this Common Brown, pollinate native plants when they search for nectar to drink. Unlike bees, who pollinate a small area very effectively, butterflies can carry pollen large distances, which means they can bring new plants to an area and ensure an even spread of a diversity of plants. Plant diversity at the ground level helps other animals like wallabies thrive.
Caterpillars, the babies of butterflies, eat plants. The caterpillar of the Common Brown eats grasses like Kangaroo Grass (Themeda triandra), which has a tendency to become too dominant in an area if not managed. Aboriginal People managed kangaroo grass with regular small fires, but now that is not happening, we are lucky to have Common Brown caterpillars!
Macropods (kangaroos, wallabies) make tracks through thick undergrowth as they search for food and water. When the undergrowth is thick, koalas use the tracks of kangaroos and wallabies to move around from tree to tree every day. If there are no tracks through thick undergrowth, a koala is in danger of predation by dogs, and they find it much harder to push through. Too much energy expended means a koala has less energy to breed.
Grass-seed eaters, like Long-billed Corellas, spread the seeds of grasses and help control weeds like Onion Grass. Grassy woodlands are perfect habitat for koalas, providing easy movement from tree to tree.
Koalas also benefit other species. Black-chinned Honeyeaters are a threatened small bird. They take fur from koalas to line their nests. Without koalas, who will the Black-chinned Honeyeaters get fur from? Wallabies don’t stay still long enough, possums are only out at night. Will baby Black-chinned Honeyeaters get too cold in their nests and die?
Some creatures, like this Painted Honeyeater, have almost disappeared from koala habitat. Could this be why koalas are declining? We just don’t know.
People often ask us why koalas are declining, even in National Parks. Truth is, no-one is really sure. Every region has different challenges, but overall, koalas are declining too rapidly for their long-term survival.
We don’t know the answer to koala decline, but we do know this: everything is connected. When Grey-crowned Babblers disappeared from the You Yangs, did that affect koalas? Maybe only slightly. When Tasmanian Pademelons, Eastern Barred Bandicoots, Brush-tailed Rock-wallabies and Dingoes disappeared did that affect koalas? Slightly+slightly+slightly+slightly = a lot.
Fact is, we have lost insect, bird, reptile and plant species that koalas rely on from koala forests, yet we still expect koalas to breed well (but not too much) and live long healthy lives. It is amazing that they are surviving at all.
Victoria has 103 native extant (living) mammal species. They represent 28 families in 8 orders. Victoria comprises only 3% of Australia’s total area, but is home to nearly 30% of her mammals. Most of the major types of Australian mammals are present in this state: 2 of the 2 monotreme families; 11 of the 17 living marsupial families; 6 of the 8 bat families; 1 of the 1 family of native rodents and 8 of the 10 families of marine mammals.
Conservation Status in Victoria is noted beside each species thus: CR: Critically Endangered EN: Endangered VU: Vulnerable NT: Near Threatened DD: Data Deficient