About Saltwater Crocodiles

About Saltwater Crocodiles

Saltwater Crocodiles are the world’s largest reptile.  The largest individuals can exceed 7 metres (10metres has even been suggested) and weigh over 1 tonne.  They can live over 100 years.

About saltwater crocodiles

“Salties” live in Australia’s wild Top End (the northern parts of the Northern Territory, Queensland and Western Australia), and throughout south-east Asia.  The Mary River in the Northern Territory has the largest density of crocodiles of any waterway in the world.

Read more about the crocodiles of the Mary River here: Crocodiles are beautiful

Australia has another species of crocodile too – the Freshwater Crocodile.

identify freshwater crocodiles from saltwater crocodiles

This is how to identify a freshwater crocodile from a saltwater crocodile. You can tell them apart usually from their size (freshies rarely grow as large as salties).  But if you see a big one – like this one in the picture below – you’ll see that freshwater crocs have a slimmer snout than saltwater crocs, and behind the eyes there is a triangular growth that is large and pronounced in salties, and low and flat in freshies.   Salties have rows of pointed scutes*(2) (osteoderms) on their head and back, freshies have flatter scutes. Compare the two pics below:

how to identify a freshwater crocodile

how to tell a saltwater crocodile from a freshwater crocodile

Crocodiles are the most intelligent of reptiles, with an extraordinary ability to learn quickly.  They are famous for picking up on the habits of their prey: fishermen in Arnhemland are warned not to use the same fishing spot too regularly.  They have also been recorded using tools* (1), an attribute shared with primates, dolphins, elephants and crows, and considered one of the signs of high intelligence.

Mother crocodiles tend and guard their nest for the whole time the eggs are growing.  She will even splash water over the nest to cool it on hot days.  After the eggs hatch and the babies start calling, she breaks open the nest and assists them to disperse by carrying them gently in her mouth. She will even help open eggs that are struggling to hatch.

You can see them on Echidna Walkabout’s 6 day Wild Top End wildlife tour Australia which runs every August.

 

*1 https://www.livescience.com/41898-alligators-crocodiles-use-tools.html

*2 Scutes: special non-overlapping scale-like structures that clad a crocodile’s body.  Scutes have a bony structure.  They are shed in small pieces, not as one continuous skin like snakes’ scales.

What do jabirus do for fun?

What do children do if they don’t have toys? They make them!  Baby animals are just the same as human children in some respects. They play with what they have.

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Three Jabiru chicks were walking with their parent across a Top End, Northern Territory floodplain on a hot September day. We were lucky enough to be driving past, and did a quick U turn to watch.

Their cautious parent took them into the bushes upon seeing us, but after a few minutes the kids lost interest in hiding and started looking for some fun. A small tree on the open floodplain was calling them: “Come and pull me apart, why don’t you?” The temptation was too much.

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Adult male Jabiru flying

Out they marched, one chick the ringleader. She ambled up to the small tree and grabbed hold of a dangly bit of branch and pulled. Her brother and sister looked on, uncertainly. The ringleader pulled and twisted until finally, the branch broke free. What fun! Brother and sister decided to try some for themselves.

All three chicks gave the tree hell for several minutes. It was so funny to watch.  They pulled, they prodded, they grabbed high and low.  Of course, when siblings play it often ends up in a squabble. “You stole my branch, bro! Give it back, or I’ll peck you!  Ooooh, you’re asking for it…Give it back NOW”

Watch the video here:  Baby animals play youtube video

 

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Adult male Jabiru (Black-necked Stork)

But there’s a serious side to play. Baby animals play in ways that teach them how to use their bodies for serious adult life. Jabirus use their beaks for catching, killing and eating fish and carrion. So of course they must learn to use their beaks as babies. That sounds easy, doesn’t it? But think of how long it takes human infants to learn to use their hands to eat, or write! Motor skills take time to develop.

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Adult male Jabiru – note the large, strong beak

Watch this kind of animal play on our Wild Top End trip – every August!

Australia still has megafauna!

Big animals impress. But what are ‘big animals’ – elephants, rhinos, moose? How about kangaroos, emus, wedge-tailed eagles and goannas?

Goanna/Lace Monitor

Australia has its share of megafauna, but we Aussies sometimes make the mistake of overlooking our big natives.

Goanna/Lace Monitor

On a steamy, sizzling hot January day in far East Gippsland I took a mixed group of nature photography & wildlife biology students walking in Croajingolong National Park, near Mallacoota. It was funny trying to keep them together – the wildlife students would stand for ten minutes identifying every small bird and lizard we came across, while the photography students yawned and fiddled with their camera settings. Minutes later, the photography students would be in raptures over a rock formation, snapping from strange positions, then comparing histograms – while the wildlife students wandered off in search of obscure insects.

But one sight kept them all fascinated for twenty minutes. It was a goanna (Lace Monitor), and a big one – 2 metres long.

Goanna/Lace Monitor

Single-minded, she swaggered out of the mat rush, crossing our path with only a glance in our direction. From her straight path and speed we could tell she was on a scent and getting close. None of us could smell anything, but a human’s sense of smell is embarassingly poor and anyway, we don’t have Jacobson’s organs*.

She was close to her quarry, and seized it moments later. It didn’t fight back. In fact, it hadn’t moved for weeks. A very large, long-dead, dessicated Flathead fish was her dinner and our highlight of the day.

Monitor Lizards, of which the eastern Australian goanna, or Lace Monitor, is a member, can eat anything. If its meat and its immobile, a goanna will eat it. If its meat and can be caught, a goanna will eat it. If you’re an egg, or a baby bird unable to fly, just hope that no goannas come by. You can’t hide from an indestructible, patient predator with a sense of smell that makes every bloodhound look like they have a head cold.

Goanna/Lace Monitor

Our goanna wrapped her jaws around the flathead and tossed it around until she could get a good angle. Head first she started to swallow it whole. Gulp, gulp, slowly, almost painfully she eased the stiff old fish into her throat, like a sword-swallower. You could see the outline of the fish inside her chest. Ouch!

Goanna/Lace Monitor

The photographers went wild! The shutter-clicks were like distant machine gun fire. The wildlife students watched in awe, no binoculars necessary for this close encounter with megafauna. You can hear their hushed excitement on this video: (video to come)

After swallowing her meal, she climbed slowly onto a fallen tree, eased her belly down, relaxed her legs, laid her chin on the tree and snoozed. Not even a hammock and a cocktail could have made her happier. She was one blissful reptile.

Goanna/Lace Monitor

Keep an eye out for the megafauna in the wilder parts of Australia – goannas live everywhere in Australia except for the cities and built-up areas (and the island of Tasmania). They are most active when temperatures are warm but not too hot (20C – 30C). We often see them on our 4 day Wildlife Journey to East Gippsland (where this story occurred) and occasionally on our Mungo Outback Journey and Wild Top End trips.

*Jacobson’s Organ – an odour-tasting organ in the mouth of monitor lizards and snakes

 

A bird of stardust: the Chestnut-quilled Rock-Pigeon of Australia’s Top End

In the Top End there’s a bird made of shadows and stardust.

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He is Doddorok*, the Chestnut-quilled Rock-Pigeon. He is one of those people that you remember, but you don’t know why. Every glimpse of his subtle form is burned into my mind, even eclipsing the equally momentous Sandstone Shrike-thrush and White-lined Honeyeater seen nearby. Its like the stars that have sprinkled his plumage have also gifted him with touch of cool magic.

As a long-time lover of pigeons and doves, I wanted to meet him so badly.

On our first visit to Kakadu we had underestimated the Swedish sauna heat of a September day and had started the Gubara Pools walk late – around 10am. Its only 6km. Allow 3 hours, ‘they’ say. 3 hours!!?? Is everyone a birder up here? Well, ‘they’ were right – by the time we reached the thin monsoon forest strip where the Gubara Pools hide we were knackered and all our water was gone.

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the walk into Gubara Pools

But the pools were peaceful, shady and fair dinkum it had to be 10 degrees cooler beside them. So we loafed there for several hours, letting our bodies renew and the heat subside.

After an hour or so we started exploring – shady spots only! At one point Roger came rushing back from high in the rocks, waving and shushing me – he had found a pool, and a resident big dark pigeon. He thought it might be Doddorok but, good man that he is, he came to get me so we could make the discovery together. We had to go quietly he said, and hope that the bird hadn’t been disturbed.

You’ve never seen two people climb so furtively as we did. Step, look around, step again, like an overacted old movie. Doddorok would have been chuckling: “look at these two southerner idiots. They think I can’t hear them!”

Eons later (it seemed) we reached the pool. We sat. We waited, looking up at the shady shelf where Roger had first seen him. Doddorok tested our patience a little. Did we respect him? Had we paid our ‘ top end time tax’ to the spirits of Gubara? Eventually we passed the test and a dark head appeared and looked at us.

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Don’t be fooled by pictures showing a drab, dark bird. This pigeon has the loveliness of a tropical night. His dark head and neck is splashed with stars. Bluish eyelids close over dark eyes as he enjoys the silence in his shady enclave. A splash of the red rocks of his escarpment home shows in his wings when he flies.

The second time we saw him was powerful again. We had discovered that Nanguluwur, a short walk to a rarely-visited art site near Nourlangie, could be accessed very early. The walk is charming. Tropical savannah grasslands with pandanus and fern-leaved grevillea forest are visited by yabbering Grey-crowned Babblers, wisps of finches and red-backed fairywrens, singing Pied Butcherbirds and the occasional Diamond Dove. The forest rings with the maniacal calls of friarbirds and lorikeets.

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a tiny Diamond Dove on the walk in to Nawurlandja

On reaching the art site, the birds went quiet. I developed itchy feet, so on a whim, took off my shoes and made the final climb barefooted. It was like walking into a cathedral and removing one’s hat.

We whispered, pointing out the ancient and post-contact art on the overhang, not wanting to damage our tender connection with history. There’s something about being alone at an Aboriginal Rock Art site – the very silence makes you realise you’re not alone at all. We were being watched by at least one being. On an outcrop above our heads he sat, framed by red ochre paintings. He wasn’t disturbed. This is his place. Doddorok – the pigeon of the rock.

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Each time we go we look at every faded splash of red ochre and every diamond-spattered rock hoping to see him again. We can imagine his dark calm eyes watching, through a curtain of stars.

Chestnut-quilled Rock-Pigeons Petrophassa rufipennis live in the sandstone country of Kakadu and Arnhemland in the Northern Territory’s Top End. The population size is not known, but they appear to be stable in their preferred habitat, much of which is protected.

*Doddorok is the Kunwinjku, Gundjeihmi and Kuninjku language name for the Chestnut-quilled Rock-Pigeon. To say the name go to this wonderful site of Bininj names of plants and animals: http://mayh-dja-kundulk.bininjgunwok.org.au/plant_or_animals/chestnut-quilled-rock-pigeon

The people of the sky – in the flight path of the Flying-foxes

We felt them before we saw them.  I don’t know if it was a change in air pressure, or just that feeling that you are not alone, but we sensed something on a primeval level.  Even after hundreds of generations of urban living, we are not disconnected from nature.

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It was the fruit bats.  Thousands of them.  On a summer evening, in Mallacoota in far eastern Victoria, we were standing on the verandah enjoying the last shreds of the dying sun.  Something made us look up, and for the next twenty minutes we couldn’t move.  The sky was full of Grey-headed Flying-foxes.  Full, seriously, full.  Every part of the sky from horizon to horizon had a megabat in it.  Sometimes there was a bat-length between them, sometimes less.  Watch:

The magic of the experience was partly the silence.  It was like every other creature held their breath out of respect for these magical beings.  Watch: https://youtu.be/jLEpevbVX8c

In many ways, bats are like people.  Many of them live in high-rise “cities” – crowded, noisy places with complaining neighbours.  They commute long distances to “work”.  They love mangoes and apricots (fruit-bats do anyway – the little ones love mosquitoes, which is an area in which they differ to us!)  They have a highly advanced brain, that is quite similar to ours.  Some scientists have suggested that they may have evolved from primates.

We had the same feeling coming down from sundowners on Nawurlandja, in Kakadu National Park, last August.  It was a balmy still evening and we had stayed well past the sunset.  As we came out of the rocks into the carpark we felt it again and looked up.  This time it was Little Red Flying-foxes, with a few, larger, Black Flying-foxes amongst them.  The Blacks were swirling around, but the Little Reds were on a mission – flying directly north in silent masses.  Little Reds can congregate into camps of one million animals.  We saw tens of thousands that night.

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In Australia, you can see fruit-bats/flying-foxes in many places.  We have them in Melbourne, Bairnsdale and Mallacoota in Victoria.  They live in Sydney and Brisbane.  They are most numerous in the warm tropical places like Cairns and Darwin.  Listen for them in their daytime cities (roosts/camps) – they sound a bit like children laughing, squealing and crying all at once.  At night, look up.  If you are under their flight path you will enjoy a moment of pure wonder.

Join us in East Gippsland or Darwin/Kakadu sometime and see this wonder for yourself.

Please help!  Join or follow the Australasian Bat Society: http://ausbats.org.au or FB: www.facebook.com/AustralasianBatSociety

Background:  bats are some of the most threatened mammals on the planet.  Grey-headed Flying-foxes, for example, have had most of their natural foraging habitat destroyed by farming, land clearing and housing.  They hang on in patches of natural bushland, and sometimes have to resort to eating fruit from orchards.  Unfortunately, this brings them into conflict with the farmers.

Bats also suffer from a public relations problem – some people are scared of them.  Bats have been used to symbolize darkness and evil in books and movies.  Nothing could be further from the truth.  99.98% of bats eat insects or fruit.  They don’t, and can’t, drink blood.  They are completely harmless to humans, and do their best to stay away from us. 3 species out of 1,240 do drink blood, but never enough to harm their prey.

Wildlife of the Top End, Northern Territory Australia

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Karndayh – female Antilopine Kangaroo

Here’s a full list of the mammals, reptiles and birds we’ve managed to see in our trips to the Top End since 2008. Most of these animals can be seen on our Wild Top End 6 day trip to Kakadu and Mary River National Parks:

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Badbong – Wilkins Rock Wallaby

MAMMALS

Dingo
Rock-wallaby – Wilkins (formerly Short-eared)
Wallaby – Agile
Kangaroo – Antilopine
Possum – Northern Brushtail
Flying-fox – Black
Flying-fox – Little Red

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Kornobolo – Agile Wallaby

REPTILES

Crocodile – Saltwater (Estuarine)
Crocodile – Freshwater
Python – Water
Snake – Slaty Grey
Snake – Common Tree
Dragon – Gilbert’s (Ta-ta Lizard)
Water Monitor – Mertens

Burarr - Mertens Water Monitor
Burarr – Mertens Water Monitor

Goanna – Gould’s

BIRDS

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Wandering & Manbarladjidji – Plumed Whistling-ducks and Manimunak – Magpie Geese

Goose – Magpie

Duck – Plumed Whistling-Duck

Manbarladjidji - Plumed Whistling-ducks
Manbarladjidji – Plumed Whistling-ducks

Duck – Wandering Whistling-Duck
Duck – Radjah Shelduck
Goose – Green Pygmy-goose
Duck – Pacific Black
Duck – Grey Teal
Duck – Pink-eared
Scrubfowl – Orange-footed
*Quail – Brown
Grebe – Australasian
Jabiru (Black-necked Stork)
Cormorant – Little Black
Cormorant – Pied
Cormorant – Little Pied
Darter
Pelican – Australian
Bittern – Black
Heron – White-necked (Pacific)
Egret – Great
Egret – Intermediate

Djakarna - Black-necked Stork (Jabiru)
Djakarna – Black-necked Stork (Jabiru)

Heron – White-faced
Egret – Little
Egret – Eastern Reef
Heron – Pied
Egret – Cattle
Heron – Striated
Heron – Nankeen Night
Ibis – Glossy
Ibis – Australian White
Ibis – Straw-necked
Spoonbill – Royal
Spoonbill – Yellow-billed
Osprey
Kite – Black-shouldered
Buzzard – Black-breasted
Eagle – Little
Eagle – Wedge-tailed
Harrier – Swamp

*Goshawk – Grey
Goshawk – Brown
Sparrowhawk – Collared
Kite – Black
Kite – Whistling
Kite – Brahminy
Sea-Eagle – White-bellied
Bustard – Australian
Rail – Buff-banded
Swamphen – Purple
Brolga

Ngalkordow - Brolgas
Ngalkordow – Brolgas

Stone-curlew – Bush
Stone-curlew – Beach
Stilt – Black-winged
Avocet – Red-necked
Oystercatcher – Australian Pied
Lapwing – Masked
Dotterel – Black-fronted
Dotterel – Red-kneed
Jacana – Comb-crested
Sandpiper – Common
Tattler – Grey-tailed
Greenshank – Common
Curlew – Eastern
Whimbrel
Plover – Pacific Golden
Grey Plover poss
Godwilt – Bar-tailed

Doddorok - Chestnut-quilled Rock Pigeon
Doddorok – Chestnut-quilled Rock Pigeon

Pratincole – Australian
Gull – Silver
Tern – Gull-billed
Tern – Caspian
Tern – Whiskered
Dove – Emerald
Pigeon – Crested
Pigeon – Partridge
Pigeon – Chestnut-quilled Rock-
Dove – Diamond
Dove – Peaceful
Dove – Bar-shouldered
Dove – Rose-crowned Fruit-Dove
Dove – Banded Fruit-Dove
Pigeon – Torresian Imperial
Cuckoo – Brush

Azure Kingfisher
Azure Kingfisher

Bronze-cuckoo – Little
Koel – Common
Cuckoo – Channel-billed
Coucal – Pheasant
Owl – Rufous
Owl – Barking
Boobook – Southern
Nightjar – Large-tailed
Kingfisher – Azure
Kingfisher – Little
Kookaburra – Blue-winged
Kingfisher – Forest
Kingfisher – Collared
Kingfisher – Sacred
Kingfisher – Collared
Bee-eater – Rainbow

Rainbow Bee-eater
Rainbow Bee-eater

Dollarbird
Kestrel – Nankeen
Hobby – Australian
Falcon – Brown
Falcon – Black
Black-cockatoo – Red-tailed
Galah
Corella – Little
Cockatoo – Sulphur-crested
Parrot – Red-winged
Rosella – Northern
Lorikeet – Red-collared (Rainbow)

Karnamarr - Red-tailed Black Cockatoo
Karnamarr – Red-tailed Black Cockatoo

Lorikeet – Varied
Pitta – Rainbow

Ngalelek - Little Corellas
Ngalelek – Little Corellas

Bowerbird – Great
Treecreeper – Black-tailed
Fairy-wren – Red-backed
Honeyeater – White-lined

Honeyeater – White-gaped
Miner – Yellow-throated
Honeyeater – Bar-breasted
Honeyeater – Rufous-banded
Honeyeater – Rufous-throated
Honeyeater – Dusky
Honeyeater – Red-headed
Honeyeater – Banded
Honeyeater – Brown
Honeyeater – White-throated
Honeyeater – Blue-faced
Friarbird – Little
Friarbird – Helmeted
Friarbird – Silver-crowned
Pardalote – Striated
Weebill
Gerygone – Green-backed
Gerygone – Large-billed
Gerygone – Mangrove
Babbler – Grey-crowned
Woodswallow – White-breasted
Woodswallow – Little
Butcherbird – Pied
Cuckoo-shrike – Black-faced
Cuckoo-shrike – White-bellied
Triller – White-winged
Triller – Varied
Shrike-thrush – Little
Shrike-thrush – Sandstone
Shrike-thrush – Grey
Whistler – Grey
Whistler – Rufous
Oriole – Olive-backed
Oriole – Yellow
Figbird

Australasian Figbird
Australasian Figbird

Drongo – Spangled
Fantail – Northern
Willie Wagtail
Fantail – Arafura (Rufous)
Mudlark (Magpie-lark)
Flycatcher – Leaden
Flycatcher – Broad-billed

Broad-billed Flycatcher
Broad-billed Flycatcher

Flycatcher – Paperbark
Flycatcher – Shining
Crow – Torresian
Flycatcher – Lemon-bellied
Martin – Tree
Reed-warbler – Australian
Grassbird – Tawny
Cisticola – Golden-headed
White-eye – Yellow
Mistletoebird
Finch – Crimson
Finch – Double-barred
Finch – Masked
Finch – Long-tailed
Mannikin – Chestnut-breasted