You’d have to ask a kangaroo why they hop. Their answer (if you could understand roo) would possibly be “because my mum always did”.
So, in the absence of roo input, here are some of the advantages of hopping:
1. Hopping is energy efficient.
This is probably the most important single factor. Hopping uses less energy than four-legged running at the same speed.
It is critical in a dry, unpredictable environment to be efficient with resources. Kangaroos sometimes have to travel long distances, in oppressive heat, with very little water to drink and very poor food in their bellies. Most mammals would not survive.
Kangaroos eat grass. Australian grasses can be fairly low in digestibility, and sparsely cover the ground. The grass dries off quickly, and during summer only the first few millimetres of the grass is green – the rest is dry and golden. So for the whole of summer (and sometimes longer in drought) adult kangaroos have to move around, socialise, breed, and feed their babies on a diet that wouldn’t feed a lamb. Food = energy. Hopping doesn’t use much food energy, compared to other forms of locomotion. So kangaroos can survive on their poor diet.
Like most grazers, kangaroos need to drink water daily. But in their country, surface water can be hard to find and unreliable. When the surface water dries up completely, they have to hop to better watering sites. Exertion depletes the body of water. So an efficient means of movement, like hopping, uses less precious water than other forms of movement.
2. Hopping is quiet.
We can’t find any scientific research to support this, but it is our experience that kangaroos move extremely quietly compared to other animals. Maybe because they are in contact with the ground so little, or because their feet are soft (like a dog or cat’s), or maybe because they have only two feet to worry about they can place their feet carefully. Whatever the reason, a large mob of kangaroos can move very quickly without much sound at all, even through Bush full of sticks and dry leaves.
The stride length of a kangaroo hopping at speed is long – 6 metres at 50km/hr. That means they are only touching the ground 2 times a second. In contrast, a galloping horse touches the ground four times in each stride, and has a foot in contact with the ground at all times creating a constant drumming sound. At the same speed a horse touches the ground 8 times a second.
Why is this useful? Kangaroos’ natural predator is humans. Being able to escape quietly could mean the difference between life and death.
3. Hopping is flexible and allows for sudden changes of direction.
Kangaroos have an amazing ability to turn quickly! They can achieve a 180 degree turn in a single hop.
Hopping as a means of locomotion probably gives kangaroos an ability to turn “on a pinhead” which would be very useful for escaping predators. We don’t know of any terrestrial mammal that can turn as sharply as a macropod. With the centre of gravity at the pelvis, the kangaroo is a pivot that can almost turn on a point. Most land-based mammals have a long body, with their weight centred between the front and back legs. The length of the body limits the turning circle. In a way, they have to wait for their back legs to catch up. Also, the speed limits the turn – the faster they go, the harder it is for them to turn, and the more stress it puts on their legs, ankles and feet. We suggest that even at speed a kangaroo could turn very sharply without damaging their legs because most of the turn is executed while airborne.
Kangaroos live all over Australia, in grasslands, in mountains – hopping allows them to move quickly over any surface, no matter how rough, steep or uneven.
4. Kangaroos have evolved from possum-like ancestors who bounded along tree branches and the ground. Hopping could be just an adjustment on four-footed bounding.
Small macropods, like the Musky Rat-kangaroo, bound along the ground using their front feet a bit. Brushtail Possums can bound or run, and sometimes sit up on their back legs just like a small kangaroo. So it’s not hard to imagine the possum-like ancestors of kangaroos – bounding on the ground, running along branches. Over time they got bigger, moved into the grasslands where there were no branches to clamber along, and their ability to bound got them out of danger quickly. Over time their ability to run ceased altogether.
It is interesting to note though that kangaroos can use their legs independently in an alternating fashion. But only when they swim!
We came to Marlo for a quick break. No plans, just relaxing. This place is so amazing that in four days, four easy walks, while having a rest and not even trying, we’ve already seen:
Emus (including one baby)
White-eyed Duck (Hardhead)
Australian Wood Duck
Pacific Black Duck
Australian White Ibis
Little Pied Cormorant
Little Black Cormorant
Australian Pied Oystercatcher
New Holland Honeyeater
Eastern Yellow Robin
Not only that, the weather has been so lovely here – better than Melbourne! Sunny days every day!
Thanks to Glenn Herbert from Snowy River Homestead B&B, and Len Axen from BirdLife East Gippsland for advice, suggestions and your time showing us around! Thanks too, to Tanya and Chris at Tabbara Lodge for a lovely relaxing stay.
Every continent has it’s biodiversity hotspots. One of ours is East Gippsland – the far eastern corner of Victoria, in south-eastern Australia. On this corner of the mainland the warm South Pacific Ocean meets the cold Southern Ocean, ocean currents collide and marine life abounds. The warm easterly winds of Australia’s east coast meet the cold south-westerlies of the south coast, so weather patterns are a mish-mash of both systems.
Australia’s highest mountains brush the edge of East Gippsland, and two of Australia’s “big” rivers – the Murray and the Snowy, start in the Kosciusko highlands just to the north. The Snowy runs through East Gippsland, first through dry rainshadow woodland, and then onto a fertile swampy floodplain.
In this region there is a bit of everything: warm and cool-temperate rainforest, wildflower-filled coastal heaths, 600 year old tall eucalyptus forest, stunted dry woodland, alpine meadows and some of Australia’s most beautiful beaches. 340+ species of birds, most of our large iconic mammals, reptiles, butterflies and a host of frogs live or have been recorded here.
Red-necked and Swamp Wallabies
Strangely, all this has been found in a region barely known to science, birdwatchers or naturalists. Many parts of East Gippsland are rarely visited. We’ve just scratched the surface of this incredible hotspot. There’s more there just waiting to be found!
Stay tuned for more articles about this fascinating region!
Have you ever watched a pair of Rainbow Lorikeets snuggling together on a branch? They nuzzle each other, their whole bodies touching even in hot weather. The one being groomed closes their eyes with a look of pure contentment.
When you know that this is a pair that has been together for many years, and that they do this several times a day, you know it’s more than just “grooming”. This is an activity they indulge in as often as they can, always with their partner. They are a married couple.
When they have children, they look after them with affection. They snuggle with their young, and groom them too. But there’s something special about the interaction between a mated pair.
Sometimes love is felt most keenly when one of the pair dies. Rainbow Lorikeets, along with many parrots, will stand beside the body of their mate killed on the road, some for hours. They don’t seem to know what to do – they refuse to leave their side, often in danger themselves from passing cars. We don’t see all the manifestations of grief – most of that would happen quietly in the trees. We do see this though.
If that’s not love, what is it?
We believe that it’s best to assume that every single wild animal on this earth is loved by another of their own kind. Some species make it obvious – like Rainbows. Some are more subtle. We’ve seen signs of Koala love, love between Kangaroos, magpies, ravens, flying-foxes. We don’t know whether insects, spiders or fish feel it, but how would we know? Even if they don’t, isn’t it best to respect all life?
Which animals have you seen loving each other?
There are many reasons to save the planet from human-induced climate change. This is just one of them. Every single Rainbow Lorikeet that dies of heat stress, starvation, fatigue or bushfire leaves behind another Rainbow Lorikeet who grieves for them.
Start 2014 off in a positive, rewarding way by helping a great Aussie character – a wild koala!
Volunteer a few hours of your time on a weekend, create habitat for a wild koala, learn about koalas from an experienced Koala Researcher and meet some of Melbourne’s world-famous wild koalas.
Click this link to see how & when:
Which do you need more: food for the soul, or food for the stomach? On our last trip to the Top End we had to choose.
One of the strange joys of a Darwin trip is the sparrow’s fart arrival. Planes come into Darwin at odd times. So we always find ourselves at Darwin International Airport as the sun is rising, or well after it has set. It’s a fine welcome – night is possibly the best part of a day in the tropics. The warmth is pleasant, the smells are enhanced, there is softness in the air that contrasts strongly with the eye-blinding, walk-into-a-pizza-oven heat of a Darwin dry-season day.
Brown Honeyeaters and Red-collared Lorikeets called as we picked up our hire car. We drove away from the dawn. Hours to kill before hotel check in, but East Point always provides entertainment before late breakfast at Fannie Bay.
Darwin is a west-facing city. It is a city of sunsets, not sunrises. West of the Darwin peninsula is the sea: beaches, parks, markets, places to eat. East of Darwin is a vast swathe of flatness, all the way to the Arnhem Land escarpment 300km away.
Darwin’s most fascinating large park is East Point Reserve. In true Top End fashion, you drive north, then west to get to it. It’s a peninsula poking out into Beagle Gulf. The name takes you back to another time, when cities and land transport were not the focus – the sea was. East Point marks the eastern beacon of one of the few safe harbours of the wild Top End, from a sailors point of view. Imagine the relief they would have felt seeing that promontory during a tropical storm, or after a long sea journey where supplies ran low.
That morning, as the eastern headland woke up we listened to Bar-shouldered and Peaceful Doves, Olive-backed & Yellow Orioles & Figbirds, Trillers, Brown, Rufous-banded and White-gaped Honeyeaters, Forest & Sacred Kingfishers. Orange-footed Scrubfowls scratched in the undergrowth, dolphins played in the shallows and a group of Grey-tailed Tattlers rested on a rock. But it was someone else that gave us the soul-food we will remember always.
Some silhouettes are unmistakeable. The Beach Stone-curlew is one of those. Elegant – no. Delicate – certainly not. Comic – yes, that’s getting closer. A bird embarrassed by its huge, unwieldly beak, further complicated by unfortunate splotches of yellow. Even never having seen one before, we knew it immediately. And it was BEAUTIFUL!
As if ashamed by his appearance, the male* appeared to be hiding, standing in plain sight on the beach. In fact, his camouflage was so excellent that we could easily have missed him on the featureless sand. He watched us, we watched him, thrilled with our discovery.
Unsatisfied with our view, we tried another angle back down the track. Relocating him was tricky – he was even harder to see with the light in our eyes. There he was, higher up on the sand amongst the rocks and driftwood. He’d moved. Or had he? Moments later another Beach Stone-curlew flew in from the sea and landed where the male had been earlier! Whatever, now we had two. It’s incredibly special to have your first sighting of a species, a lifer, and have two of them in view for extended moments.
Some lifers are unforgettable. You just want to stare at them forever, drinking in every tiny detail. Its like you need to imprint them on your brain so that the creature is a part of you. Our eyes grew strained from peering through the binoculars. For relief, I took bad photo after bad photo knowing I had a big delete session coming on but doing it anyway.
The staring marathon paid off – a chick emerged from the detritus! Playfully he walked towards his parent, who was carrying something. The chick’s beak was smaller, almost like a normal bird’s, and he lacked the bold yellow, black & white patterning around the head. After feeding, the chick sat down amongst a pile of sticks and then it was an effort to locate him after each blink.
One parent (let’s say the mother, though there’s no way we could tell) walked up the beach a little out of our view. The ‘father’ flew back out to sea. Left alone, the chick got up and started to play with the debris around his hiding spot. He pulled out a whippy stick – the stick fought back! An hilarious tussle ensued. Each time the stick caught on the sand the chick would subdue it and wrestle it back into submission, when of course the stick would rise again! Birds can be very funny. Finally he walked up the beach to his mum and disappeared from our view.
Lucky for us. Our souls were well fed, but our stomachs were rumbling! Breakfast at Fannie Bay was hours overdue, and if that baby Beach Stone-curlew had kept playing we might have starved happily watching him!
Postscript: Beach Stone-curlews have a small population – only around 6,000 worldwide. Most of these are along Australia’s north coast. They are threatened by beach disturbance – people walking along beaches especially with dogs, residential development along the coast, increased feral predators that come with humans, entanglement in fishing line and nets left by human activities. They only have one chick per year, so each baby is precious. For more go to BirdLife Australia: http://www.birdlife.org.au/bird-profile/beach-stone-curlew and see their listing on the IUCN Red List: http://www.iucnredlist.org/details/22728621/0
*there seems to be no way of telling Beach Stone-curlew sexes apart, so this is just for the sake of the story