Corroboree Billabong - Mary River Wetlands Cruise

Lying just over 100km south of Darwin, on the way to Kakadu National Park in Australia’s Northern Territory, Mary River Wetlands is one of the most diverse ecosystems in Australia, teaming with birdlife and home to the largest concentration of saltwater crocodiles in the world.

Its proximity to Darwin makes Mary River a convenient day trip from Darwin, unlike Kakadu which is 300 km away and is best explored in two or three days.

I visited Mary River wetlands twice: once at the end of the wet season (April) as part of an epic Adelaide to Darwin road trip and, more recently, on a day trip from Darwin at the end of the dry season (September).

Staying at Mary River

The first time, we stayed at Point Stuart Wilderness Lodge and explored the wetland on land and on a cruise. The lodge offers a 4WD floodplain safari, which is a good opportunity to see and photograph land-dwelling mammals like Agile wallabies, Water buffalo, wild pigs, and Dingos.

The cruise from Point Stuart Wilderness Lodge goes along Rockhole Billabong, which joins Corroborree Billabong, all part of the enormous Mary River wetlands.

Mary River wetlands cruise from Darwin

Rufous night heron on corroboree billabong — Rufous (Nankeen) night heron perched on pandanus palm

The second time I visited Corroboree Billabong on an organized tour from Darwin that combines Fogg Dam and Mary River wetlands.

This is a good option if you are short on time and not planning to take the Yellow Water Billabong cruise in Kakadu National Park. The tour includes a visit to Fogg Dam, another lovely wetland not far from Darwin, and a stop at an iconic Outback pub.

The best thing about the tour is the accompanying commentary by the guide. I’ve learned more about Darwin’s natural, cultural, and indigenous history on the drive to the billabong than I had in all my research prior to the trip.

Corroboree Billabong vs Yellow Water Billabong cruise

If you are wondering whether to take the Mary River cruise or the Yellow Water Billabong cruise in Kakadu, here are a few tips to help you choose.

Kakadu National Park is spectacular. But it is 300 km away from Darwin. Ideally, you should set aside 2 or 3 days to properly explore Kakadu. It is possible to visit Kakadu on a day trip if you are prepared to spend 8 hrs in the car for a couple of hours in the park. There are also several (expensive) day tours on offer. If you do decide to take one, choose the tour that includes the Yellow Water Billabong cruise, which is the best opportunity to see the park’s wildlife.

If you don’t have the time to take the Yellow Water billabong cruise in Kakadu, the Corroboree Billabong cruise in the Mary River wetlands is your chance to see the crocodiles and the birds, only a 90-minute drive from Darwin. It is a much better option for a day trip, and you’ll see practically the same wildlife species in either billabong.

Mary River wetlands cruise is also a more relaxed (and cheaper) experience. The cruise in Kakadu is a big business enterprise, while the Mary River cruise feels much more low-key.

Mary River Wetlands Cruise on Corroboree Billabong

Forest kingfisher on billabong — Forest kingfisher

Mary River wetlands are a permanent wetland area that provides a breeding habitat for an extraordinary number of crocodiles, birds, fish, and amphibians. In fact, I haven’t seen a Freshwater crocodile in my three cruises on Yellow Water Billabong, and on Mary River, I’ve seen 3 in one cruise.

Here are some of the animals you can expect to see on a Corroboree Billabong cruise.

Crocodiles

saltwater crocodile on corroboree billabong — Saltwater crocodile

The two species of crocs are very different. Saltwater crocodiles are enormous, and their broad snouts deliver the strongest bite of any creature on Earth. The biggest saltie on record was shot in Queensland and measured 8.64 meters, which is a little longer than the boat that takes you on a cruise. Male Saltwater crocodiles never stop growing, and they can live up to 100 years.

However, life is not always peachy, even for such a formidable predator. Only about 1% of all hatchlings reach adulthood. The rest fall prey to fish, birds, monitor lizards and other crocodiles. Although, those that do mature have a lifespan similar to ours.

Saltwater crocodiles are one of few species of carnivorous animals that intentionally prey on humans. Their powerful tails can propel them out of the water, enabling the croc to cover up to 4 meters in a second. That’s why you never want to be anywhere near the water’s edge in crocodile habitat.

As I mentioned, Mary River wetlands are home to the world’s largest concentration of saltwater crocodiles. You’ll see both species of crocodiles on your cruise, often at a very close range.

Freshwater crocodile on Mary River, Australia — Freshwater crocodile

Freshwater crocodiles grow to about 2.5-3 meters. They have very narrow snouts filled with razor-sharp teeth, perfect for catching fish, aquatic vertebrates, small birds, and mammals. These crocodiles are endemic to Australia. They are much smaller than Salties and are not known to attack people. However, they do sometimes fall prey to their saltwater cousins.

Jabiru

The striking Jabiru is the only species of stork native to Australia. It stands over 1.3 meters tall, with a wingspan exceeding 2 meters. Its iridescent black neck and head contrast with its white body and vividly red long, slender legs. Both sexes appear similar, but females have yellow irises, compared to the male’s darker eyes.

As opportunistic feeders, Jabirus hunt a wide variety of prey, including fish, frogs, small reptiles, and even small mammals or birds. You might see them use their sharp, spear-like bills to catch prey in shallow water. You might also spot their massive nests high up in the trees.

Interestingly, the name Jabiru is a misnomer. True jabirus occur in Latin America. I’ve seen them in Costa Rica and Brazil. To distinguish Australian jabirus, scientists have given them an unimaginative name of Black-necked storks. Not surprisingly, they are commonly still referred to as jabirus in Australia.

Comb-crested Jacana

The dainty Comb-created jacana is one of my favourite birds in the Top End. They look very cute, especially the males with their striking red combs atop their heads. But it’s their enormous feet that steal the show. Those feet with exceptionally long toes allow the jacanas to walk on floating vegetation (of which there is plenty in Corroboree billabong!) by distributing the bird’s weight across lily pads and other aquatic plants.

Another curiosity about jacanas is that it’s the male who incubates the eggs and cares for the chicks. He even carries his chick around under his wings so that all you see is a bird with a tangle of large feet sticking from its wings.

White-bellied Sea Eagle

Marry River wetlands are also a great place to see nesting White-bellied sea eagles. The second largest raptor in Australia (after the Wedge-tail eagle), they are magnificent birds to see up close.

White-bellied sea eagles mate for life and often return to the same nest each year. Funny enough, sometimes a male would construct a nest (a massive construction of branches and twigs) and the female would reject it making him start the process all over again. This is effectively quality control. The nest needs to be solid enough to last for many years and to withstand yearly renovations.

Whistling Kite & Australasian Darter

One of the most common birds you’ll see on your Mary River wetlands cruise is the Australasian darter. These birds are common in coastal Australia, but at Mary River, you might see their interactions with Whistling kites, another common raptor in the billabongs.

Darters catch fish by spearing them with their long, sharp beaks. And then, they have to get the fish off their beak so they can swallow it. The kites have figured out that it takes the darter some time and effort to get the fish ready for swallowing, and they often steal the fish from the poor darter before it can get it into its mouth.

We’ve watched Whistling kites swooping at the darters when they surfaced above water, but haven’t witness a robbery.

Magpie Geese

A common bird in the Top End, the Magpie geese are not actually geese. They belong to their own unique family, Anseranatidae, and have characteristics of both ducks and geese.

They are social birds and generally travel in flocks or in a mini-harem consisting of a male and two females. The trio even raise the chicks together.

Plumed Whistling Ducks

As the name suggests, these ducks give a whistling sound and have protruding cream-coloured plumes on their flanks. Despite their fairly striking plumage, they blend surprisingly well with the muddy bank vegetation.

Unlike most other ducks that feed on aquatic vegetation, Whistling ducks feed on grass on land. So you are likely to see them on the banks of the billabong rather than in the water.

Radjah Shelducks

Radjah (or Raja) Shelducks are another species that form long-term bonded pairs. They travel either in pairs or in small flocks and they are easily distinguished by their mostly white plumage with dark wings and tails.

A curious fact about Radjah shelducks is that males, like humans, tend to become very irritable during the wet season and can even attack their mates. Turns out “going tropo” is not unique to our species. Ducks get it too.

Egrets and Herons

Pied heron along Arnhem highway, Australia — Pied heron

You are also likely to see several species of egrets and herons which thrive in this rich ecosystem. There are three egret species that differ mostly in size, all with white plumage: Great Egret, Intermediate Egret and Little Egret. And several species of herons, including the Rufous night heron, White-necked heron, and Pied heron.

The wetlands provide abundant feeding and nesting opportunities for these birds, making them a vital part of the wetlands’ ecological balance.

Azure Kingfisher

If you see a flash of vivid colour in the pandanus trees along the banks of the billabong, it may be an Azure kingfisher – the most strikingly colourful of Australian kingfishes. With its vivid blue upperparts, orange belly, and distinctive white spot in front of its eyes, the Azure kingfisher is unmistakable.

These little guys grow to all of 16-19 cm. They typically sit quietly near water watching the water intently for their prey.

If you are lucky, you might see them darting into the water to catch a fish. They often return on the same perch to consume their catch.

Rainbow Bee-eater

Slightly larger than the kingfisher is the vibrant Rainbow bee-eater. You might see them perched on the branches overhanging the water.

These slender, graceful birds are phenomenal aerial hunters, snatching insects mid-flight with remarkable precision. As their name suggests, they specialize in catching bees, wasps, and other flying insects. And while they are immune to bee stings they have a clever method to avoid being stung—they will repeatedly strike their prey against a branch to remove the stinger before consuming it.

Surprisingly, Rainbow bee-eaters nest on the ground. They excavate tunnel-like nests in sandy banks, sometimes up to a meter deep.

Water Buffalo

The biggest animal you’ll see in Mary River wetlands is the Water buffalo. They were brought to Australia from Indonesia in the early 1800s to be used for their meat and very tough hide. Once they were no longer wanted, the buffalos were left to wonder on their own and they took to the Australian habitat like fish to water. Apart from large male saltwater crocs they have virtually no natural enemies.

They are formidable animals to encounter in the billabongs. Unlike cattle, buffalos are bold animals. In the Brazilian Pantanal, where jaguars often kill cattle calves, farmers put a few buffalos in the paddock with the cattle and they stand their ground when jaguars attack, keeping the cattle and their young safe from the big cats.

On Corroboree billabong you mostly get distant views of the buffalo, but occasionally you might encounter one very close to the water giving you an opportunity to appreciate the animals’s size and its huge horns.

Agile Wallaby

Agile wallabies on Corroboree billabong — Agile wallabies

The most common macropod in the Top End is the Agile wallaby (there are no kangaroos this far north). They are easy to see on a 4WD floodplain safari, but occasionally, you can spot them from the boat as well. We spotted this little guy on our Corroboree Billabong cruise.

One curious fact is that these wallabies are excellent swimmers, often using their swimming ability to escape predators by heading into rivers or swamps.

Another interesting trait is their ability to go without water for extended periods, surviving on the moisture from grasses and plants – an essential survival skill for the dry season. Their name “agile” refers to their quick and nimble movements, which they put to good use to evade predators in the open grassland habitats.

Final Thoughts on Corroboree Billabong Cruise

I hope I have convinced you that a billabong cruise is a must-do if you enjoy seeing wild animals in their natural habitat. The billabong itself is a very serene environment regardless of the season. And one of the best things about a boat cruise is that it brings you much closer to the animals than a land-based adventure. Water acts like a natural barrier and the animals are much more relaxed about our presence on the water.

If you are interested, check the availability of the Mary River Wetlands tour from Darwin for your dates.