The Top End (part 8)

Day 5, morning – second day in Kakadu, Yellow Water wetland cruise

Was it yesterday we encountered a group of cyclists while queuing for a ‘comfort stop’ after visiting the termite mounds? At the queue for the loo, I chatted with one of the men. They were being taken to tourist spots in a big bus in the mornings, then after lunch they took their bicycles from their support vehicle to cycle 80 km in the afternoons. Rinse and repeat for a couple of weeks. Such stamina in 33 degrees C!

Let’s hope they didn’t encounter the things that apply to this permit. Luckily we didn’t.

Issued by the Official Australian Un-dead Response Unit

Every day the very organised Candice and Tom provided us with plenty of cooked and uncooked breakfast options and prepared the troopie for the day’s activities. They provided lunches, too, and dinners every night. Such energy! On the road, we occasionally dropped into petrol stations that also supplied various kinds of alcohol to buy (this is not usual in the eastern states of Australia where alcohol must come from a separate store).

First up this morning was a two-hour boat trip across the Yellow Water (Ngurrungurrudjba) freshwater wetland.

The whole of Kakadu is a Ramsar site, designated an internationally important wetland under the Ramsar Convention on Wetlands of International Importance Especially as Waterfowl Habitat. According to Wikipedia:

A wetland can be considered internationally important if any of the following nine criteria apply:

  • Criterion 1: ‘it contains a representative, rare, or unique example of a natural or near-natural wetland type found within the appropriate biogeographic region.’

  • Criterion 2: ‘it supports vulnerable, endangered, or critically endangered species or threatened ecological communities.’

  • Criterion 3: ‘it supports populations of plant and/or animal species important for maintaining the biological diversity of a particular biogeographic region.’

  • Criterion 4: ‘it supports plant and/or animal species at a critical stage in their life cycles, or provides refuge during adverse conditions.’

  • Criterion 5: ‘it regularly supports 20,000 or more waterbirds.’

  • Criterion 6: ‘it regularly supports 1% of the individuals in a population of one species or subspecies of waterbird.’

  • Criterion 7: ‘it supports a significant proportion of indigenous fish subspecies, species or families, life-history stages, species interactions and/or populations that are representative of wetland benefits and/or values and thereby contributes to global biological diversity.’

  • Criterion 8: ‘it is an important source of food for fishes, spawning ground, nursery and/or migration path on which fish stocks, either within the wetland or elsewhere, depend.’

  • Criterion 9: ‘it regularly supports 1% of the individuals in a population of one species or subspecies of wetland-dependent non-avian animal species.’

I suspect that Kakadu covers all of those criteria.

The place was drying out – water levels can drop as much as four metres from the heights of the wet season – and as the dry progresses, the birds and animals crowd together in or near the remaining water sources. There were lots of saltwater crocs resting on the river’s edges and flocks of birds of different species feeding in the still-soggy vegetation away from the river. All the wildlife is used to lots of human boat traffic, so didn’t take much notice of us. The captions on the photos below give the names. ‘TICK’ indicates the first time I’ve see the species in the wild.

Brolga (Grus rubicundus) (photo by Bruce Moore) TICK

Brolga pair

Juvenile rufus night heron (Nycticorax caledonicus) TICK

Little pied cormorant (Phalacrocorax melanoleucos)

Rajah shelducks (Tadorna radjah) at the back. TICK

Plumed whistling ducks (Dendrocygna eytoni) (photo by Bruce Moore) TICK

There may have been some wandering whistling ducks (Dendrocygna arcuata) with the plumed whistling ducks above, but it was too hard to differentiate them at the time.

White-bellied sea eagle (Haliaeetus leucogaster)

Strictly speaking, we should call the bird below the black-necked stork since the common name ‘jabiru’ belongs to a South American stork, but all the birdos I know would immediately say ‘jabiru’.

Jabiru (Ephippiorhynchus asiaticus) (photo by Bruce Moore) TICK

The next bird is also known as the ‘Jesus bird’ or ‘lily trotter’ for its apparent ability to walk on water. It has very long toes that allow it to spread its weight on big waterlily leaves. We saw several very cute, fluffy chicks near the adults, too.

Comb-crested jacana (Irediparra gallinacea) (photo by Bruce Moore) TICK

Little corellas (Cacatua sanguinea) (photo by Bruce Moore)

Mostly royal spoonbills (Platalea regia) (photo by Bruce Moore) TICK

Pied heron (Ardea picata) TICK

Black kite (Milvus migrans)? A bit hard to tell, but certainly a raptor. TICK

There were numerous egrets – great, intermediate and little (Ardea alba, Ardea intermedia and Ardea garzetta).

The kink-necked birds are the egrets (great egret on the far right); jabiru at the back.

Great egret (left); royal spoonbill (right)

Australian white ibis (left, Threskiornis molucca) has a long, curved, black bill.

I’ve neglected the water plants. Apologies if I have the IDs wrong – let me know and I will change them.

Water lily (Nymphaeae violacea), looking somewhat Monet

Lotus lily (Nelumbo nucifera)

The humans weren’t the only ones feeling the heat. Crocs cool down by resting in shallow water and/or opening their mouths to let the body heat escape.

A saltie cooling off

We saw some natural crocodile feeding action, too – one of the crocs in the shallows curled its tail tighter and tighter to form a small pond around the fish. At the last minute the fish jumped! – and the croc snapped at it but missed. You won’t see this in a zoo.

Photo by Bruce Moore

I found it an altogether satisfying cruise supplying a lot of TICKS.

The Marrawuddi Art Gallery was unexpectedly closed so we couldn’t see that. A rock art gallery walk was scheduled for the afternoon but I chose to miss it. I had noticed there was a nice-looking (artificial) pool at the campground so decided to go for a swim to cool off and stretch my back. Next to it was a bar and bistro, open only at night, all terribly civilised but a bit incongruous considering where we were. In the pool I chatted with a woman from Melbourne. She was a lawyer and was really enjoying her first holiday in two and a half years – Melbourne had been in extreme lockdown for most of that time.

I’ll let others tell the story of Nourlangie in the next post.

The Top End (part 5)

Day 3Northern Territory Museum and Art Gallery

After the rest had motored off for their all-day trip, I took some painkillers, strapped on the borrowed back-support belt and sat in the park by the sea across from the hotel. Kath had leant me Penny van Oosterzee’s 2014 book, A Natural History and Field Guide to Australia’s Top End and I was determined to get in some research before Kakadu. The park was peaceful and I had never seen so many peewees (magpie larks, Grallina cyanoleuca) in one spot – there were at least 40 pecking for insects to eat.

Magpie lark; photo by SuperJew, Wikimedia Commons

The weather felt a bit cooler. Anglo folks currently name only two seasons in the Top End, but apparently the ‘build-up’ to the ‘wet season’ is soon to be recognised as a third season. The Aboriginal peoples sensibly recognise six seasons. We were in Wurrgeng, which spans early June to mid-August.

The Indigenous six seasons are marked by ‘calendar plants’ and events – for example, the blooming of certain flowers indicates other changes in the environment such as the availability of certain foods (plants or animals). This extensive and intricate knowledge has been worked out and passed down over more than 60,000 years and enables good living off the land. There are academic arguments over this figure, but it still means a couple of thousand human generations. The humidity is relatively low with daytime temperatures to around 30˚C (it was 33 to 36 while we were there) and night around 17˚C (it was mostly 23 for us). This is the period when most creeks stop flowing and the floodplains dry out. Traditional Indigenous burning, which starts in the previous season (Yegge), is continued. Birds and animals converge on the shrinking billabongs.

Birds gathering around a billabong; artwork at the museum

After a while, I felt able to go for a walk so I got a map from the hotel desk clerk and wandered to the nearby mall, where I spotted an independent bookshop called, well, “The Bookshop”. Here I bought Brock’s Native Plants of Northern Australia (2022), which gave me another overview of the ecosystems and a field guide to the plants.

Since I had the whole day at my own pace, I decided to go to the Museum and Art Gallery of the Northern Territory, which wasn’t on our official itinerary. I normally would have walked there to get a sense of the city, and it’s amazing what you can stumble across, but decided that would be asking too much of myself. So I walked to the nearby Information Centre where a staffer gave me a bus map, told me to flash my Seniors Card, which would give me a free trip, at the driver, and directed me to the bus depot around the corner.

While waiting for the bus, I chatted to a very helpful local and a couple of other tourists (recognisable because of them clutching the same bus map). Having driven from Perth (4,000 km or 2,500 miles away), they were having their RV serviced before driving back, and using the time by going to the museum. This couple confirmed what I’d heard on the media – that very many people were travelling post-covid lockdowns (although we’re still far from post-covid). They said that they could usually be very flexible and book accommodation in the morning for that night, but now they had to book several days ahead and if they didn’t turn up at the hour they said they would, their room would be given to someone else.

As a former museum staffer (scientific officer, Marine Invertebrates, South Australian Museum) and sometime museum volunteer, I am still a museum enthusiast. This museum concentrates on Northern Territory and nearby birds and animals of the tropics. I avoided the Cyclone Tracy rooms – been there, done that, lost the T-shirt and most other things. I could hear the recording of the shrieking winds and it still gave me a shiver.

Model of a cathedral termite mound with Territory bird and fish taxidermies in the background

Model of nest of the great bowerbird (Chlamydera nuchalis); the male maker is on the left

The strange and unique Australian lungfish (Neoceratodus forsteri)

Various kinds of box jellyfish – you don’t want to encounter any of them while swimming

Green turtle skeleton

Sawfish

The basement display of large wooden fishing vessels – local ones and some from nearby islands and Indonesia – was very impressive. You can tell I like boats and ships by the number of photos I took. It’s a shame I usually get so seasick – thanks, Dad, for not giving me your seasickness-proof gene (I love you anyway). The shop was better than the usual, with little of the plastic tat seen in most museum shops. I bought two books – the one that Kath had leant me and Lindley McKay’s 2017 A Guide to Wildlife and Protected Areas of the Top End. The latter was the most detailed book I’d seen, with sections on all sorts of invertebrates as well as the expected frogs, mammals, birds and reptiles, and I leapt on it with great glee. Research!

After a couple of hours perusing the galleries that were open – some were closed for refurbishment – I walked back to the bus stop where I chatted to a couple more tourists who had just finished a multi-day coach trip from Perth. They mentioned that covid was rife on the coaches, but fortunately their bus hadn’t had it. They were flying back later that day. I don’t think I could stand such a long bus trip, even without covid.

Back at the hotel, I took a rest and waited for the group to come back from Berry Springs and the community gardens. I’ll write about them next.

On the rocks

Rock walls are harsh environments. The sun beats down, the rain pelts down, the wind blasts through and over the rocks and, at the North Wall at Ballina, the river and ocean waters take turns, depending on the tide, to deliver spray. It’s hot, cold, wet, dry, salty and fresh, sometimes in short order and over and over again. You have to be a tough, resilient animal or plant to live there.

The North Wall is an artificial wall, built from 1889-1912 along with the South Wall. It was planned to stabilise the mouth of the Richmond River and help provide safe passage for ships from Sydney (and other east coast ports) that were transporting people and goods to Ballina. From there, smaller boats shunted back and forth to Lismore and small towns in between. Rileys Hill quarry down south provided the rocks, which were brought up the coast by barge. Prior to the walls being built, the mouth of the river moved over time and so did the sandbars, which were dangerous to shipping. It’s still a dangerous bar with fast-flowing water.

In 2016, structural repairs were carried out in the form of hanbars. Like many, I thought these blocks were very ugly, until Cape Town friend Jane pointed out that the structures are somewhat similar to the dolosse concrete blocks invented in South Africa, based on a kind of traditional knucklebone game. After that, I felt they looked more interesting.

View of the cyclone-tossed sea from North Wall, Ballina – hanbars and Rileys Hill quarry rocks in the foreground

The path on the wall is popular for walking, jogging, cycling and pooch walking. It also gives great views of the beaches to the north and south, of breaching whales while they are migrating up and down the east coast, and of pods of dolphins exploring the waters for a feed. In a decent storm, there’s almost nobody there and the waves are spectacular.

One of the tough animals commonly spotted is the eastern water dragon (Intellagama lesueurii). You might see a dozen of these, of all sizes, on a 10-minute amble along the wall, sunning themselves. They can grow up to 90 cm long (nose tip to very-long-tail tip). They eat small reptiles, worms, frogs, insects, vegetation, fruit, small mammals and molluscs, all of which would be available in rock crevices or on the nearby sand dunes.

The skin texture is marvellous – Andrew took some close-ups of some medium-sized ones yesterday.

We were able to see another tough reptile living on the wall – a carpet python (Morelia spilota). We’d only seen this one once before, last week. I guess it was warming up. They usually feed at night, on rats, possums and birds – and maybe small lizards?

The python would have been as long as I am tall – and very healthy looking.

Meanwhile north of the wall on the windy Lighthouse Beach, a willy wagtail (Rhipidura leucophrys) was following us, possibly watching out for any insects we might dislodge as we picked up plastic from the tide wrack – not much, thankfully.

The cyclonic seas had washed up the usual suspects that often come in from far offshore together – glaucus, porpita and bluebottles. The only thing missing was velella.

You really want to avoid the ‘pearls of pain’ – nematocysts – of the bluebottle, even on the sand. They can still be triggered by contact with your skin.

You never know what you’ll find on a walk on the wild side.

A snowball in warm weather

Friend Christa sent me a photo of this colourful beastie – it’s a mealybug, in this case a snowball mealybug, Monophlebulus species. It was about the length of a thumbnail and found in disturbed earth in a garden.

Snowball mealybug, Monophlebulus species; photo by Christa Schwoebel

The body has a white, waxy layer, which is thought to control water loss and provide some disguise from the ladybird beetles and parasitic wasps that keep their population under control. The larvae are all-white and fluffy, but the adults (like the one in the photo) lose the wax layer and their colours are revealed.

There are about 200 species in Australia. They feed, using their straw-like mouthparts, on the sap of eucalypts and callistemons, and some are considered to be agricultural pests on commercial crops and in gardens.

Brisbaneinsects has good photos of both the shaggy larvae and the adults.

The Coffs Harbour Butterfly House also has good photos, including one being attended by an ant:

They are often attended by ants as they exude excess sugar syrup. The syrup is also deposited on the leaves, which then can become mouldy, reducing the light reaching the leaves. The mould, the loss of nutrients, and the injection of poisons into the plant all damage infected plants.

The ants will naturally protect their source of honeydew.

According to the WA Department of Agriculture:

Most mealybugs have a number of often overlapping generations per year. Their development is dependent on temperature. Temperatures of about 25°C and a high relative humidity are optimum for mealybugs and, like aphids, their populations reach peaks in spring and autumn.

Eggs can be laid singly or in clusters, and female long-tailed mealybugs have been recorded laying as many as 200 eggs in a lifetime. Egg clusters are usually embedded in a cocoon of waxy filaments.

After hatching, the juveniles (crawlers) search for suitable feeding sites in sheltered areas. Crawlers can be dispersed by wind and progress through five moults before reaching adulthood. For males, the last juvenile stage pupates in a silk cocoon, and emerges as a winged adult. Adult males do not feed, having no mouthparts — their sole purpose is to mate with females.

Here is a photo from friend Roselene (Beyond Nature) of what looks like the same beastie caught in the sap of a eucalypt tree.

Mealybug caught in eucalypt sap; photo by Roselene Cusack

I agree with Christa that, pest or not, “It looks truely weird.” Fortunately, I like “weird”.

Beetling about

This little one was wandering about in full daylight, and by chance I was able to get the species name from the October 2021 edition of ANICdotes from the Australian National Insect Collection. ANIC’s beetle was from Lamington National Park, not so far from us.

It is the pie-dish beetle, one of the Pterohelaeus species. This beetle is also found in Brisbane, as Brisbaneinsects shows.

Pie-dish beetle, Pterohelaeus sp.

Pie-dish beetles feed mainly  on decaying vegetation, actively foraging on the ground at night. The hard flanges of the ‘pie dish’ on the back protect against attacks by spiders, scorpions, ants and other beetles.

During the day they shelter under bark, wood, stones or leaf litter.

Adults may live up to a year.

The common name for the taxonomic family is ‘darking beetles’, which is amusing as we were originally going to call our property ‘Darkling Wood’. It was ‘Castle Undulant’ for a while before we got the main house re-stumped. Maybe we should go back to ‘Darkling Wood’!

A study in contrast

The weather has warmed up and snakes are on the move. Here on Bundjalung Country, late July and August are called ‘Coming Out Season‘:

Getting dryer and can be strong winds, first hint of northerly winds. Birds starting to sing and build nests. Turtles and echidnas start moving around and are fat. Old people say don’t eat the first echidna after winter. Coastal acacia peak flowering, some heaths begin flowering. Banksias still flowering, river red gum peak flowering. Grey mangrove mass ripe fruit.

We’ve had our first echidna sighting and it looked pretty fat already, but it will get fatter.

On the roof, a young carpet python (Morelia spilota) was exploring.

A friend sent the photo below of another python (who she calls Skinnyfang) exploring at her place last week – you can clearly see the pit organs on the lower jaw. These organs detect infrared radiation (heat) from the bodies of possums, birds and rodents and other warm-blooded prey. The snake ambushes the prey, throws its body in coils around it and suffocates it before swallowing it down.

Carpet pythons are not venomous but a bite would be painful, and a tetanus shot is recommended if you are bitten. You don’t know where that mouth has been!

Spring may be the season of renewal, but not everything survives. The freshly dead body of this rainbow lorikeet (Trichoglossus moluccanus) allowed me to have a close-up look at its beautiful colours.

Such a contrast in colours and patterns, and both beautiful in their own way.

The introduced Mexican beetle

This pretty little beetle was in the backyard last week.

The leaf beetle, Zygogramma bicolorata

I couldn’t find it in my reference books or on the ‘net so I asked the ever-helpful Queensland Museum, who identified it as the parthenium or Mexican beetle, Zygogramma bicolorata. It was introduced from Mexico into Australia and India in the 1980s, to control parthenium, an agricultural weed of national significance. It seems to have been successful, eating the leaves down so much that the plant eventually dies off.

It’s nice to hear a successful biological control story for a change.

The reptile and the monotreme

I heard the first boobook of the season the other night, and the first cicada. The mulberry tree’s leaves are growing back, and the whipbirds are going nuts with their call-and-response mating calls. Some frogs are even calling, and soon the fireflies will be out. Methinks the season is turning.

Andrew’s sharp ears picked up rustling out front of the house yesterday afternoon and, lo and behold, there was our second sighting of an echidna (short-beaked echidna, Tachyglossus aculeatus) here in 20 years.

What do reptiles have in common with monotremes? One thing is they both lay eggs – but monotremes (echidnas and platypuses) are mammals, and that’s peculiar.

The monotreme

The echidna is named after the Greek mythical monster, Echidna, who was half woman and half snake. The animal was originally perceived to have both reptile and mammal characteristics.

The female lays a single egg each year, and places it in her pouch. It is soft-shelled and leathery, and will hatch into a puggle (don’t you just love that word?) in 10 days or so. It is hairless and laps milk from two areas in the pouch – no teats on an echidna. After 45-55 days, it starts developing soft spines. The mother then digs a den and puts the puggle in it, goes off to feed and returns to ‘suckle’ the baby every few days until it is weaned at about seven months. It may stay in the den up to a year.

The first photo shows lots of dig sites – the echidna was vigorously throwing dirt out of the way with its back-facing front feet, then thrusting its nose into the dirt. The nose has electrosensors in its snout to detect ants and termites. Andrew said he could hear snorting as the echidna cleared dirt from its nose.   This is a short-beaked echidna and although the snout is pretty long, the long-beaked echidna from New Guinea does have a longer beak and overall looks very different.

The dark spot in the photo below – a vertical ellipse behind the eye –  is one of the ears. Hearing is excellent. Andrew managed to quietly sneak up for close-ups, and it at first threw itself against the earth, spines up, then, when he didn’t move, went back to digging madly shortly after.

The spines are actually tough, hollow hair follicles – you can see a broken one towards the bottom front in the photo below.

As the sun went down, we left it to its business.

The reptile

Although the echidna’s spines are pretty spiky and it hunkers down to defend itself, goannas can still make short work of them. There’s an exhibit at the Queensland Museum of a mummified pair – a perentie (Australia’s largest goanna) who tried to eat an echidna, then died and was preserved in the desert conditions. The echidna is still stuck in its mouth.

Photo by Bloopitybloop, Wikimedia Commons

Our goanna, seen resting under the hoop pine near where the echidna was digging, is a lace monitor (Varanus varius). It’s also called the tree goanna from its habit of scooting up trees, for defence and also to check out bird nests for eggs and chicks.

This one is probably making our brush turkey nervous, too, as it will dig out and eat the eggs from the turkey’s brood mound if it gets a chance.

It is always such a delight to see these animals in the wild.

The swamp rat

Sometimes it is educational to see a dead body, and sometimes it is just sad.

I found this native swamp rat (Rattus lutreolus) at the front of my house. The body was very fresh and just the head had been munched.

Swamp rats are kinda cute and furry when alive. I’m sorry I didn’t get the chance to see it in that state.

Eastern swamp rat (Rattus lutreolus); photo by Catching The Eye, Wikimedia Commons

They are active both day and night, preferring to live in dense vegetation in swamps or next to streams. They tunnel through the vegetation, eating seeds, stems, insects and fungi.

Puzzling over how it died, I asked around. The general consensus, especially from a friend who is a wildlife carer, is that a cat got it. She has seen sugar gliders with only their heads bitten off by cats.

This makes sense because there were cat footprints on my back deck that day. (There are some advantages to not sweeping.)

Cat footprints

Australia has a huge feral cat problem, with one estimate of 1.7 billion native animals killed each year. I just can’t see how such a scale can be resolved, but I try to do my little bit.

I’ve put my cat trap out but had no success yet. Moggies beware, I’m gonna get you.

 

Not your average Christmas reindeer

Svalbard reindeer (Rangifer tarandus platyrhynchus) are endemic to Svalbard and are the smallest subspecies of reindeer – about half the weight of other reindeers. They sure do look small with their short legs and pot bellies.

You polar bear? No? That’s all right then. (Svalbard reindeer; photo by Bruce Moore)

We saw several small family groups feeding on the short vegetation in the tundra (actually, there’s no other sort). The closer ones weren’t at all afraid and, after looking at us, put their heads down to feed again. They must eat as much as possible during the short summer, stockpiling fat to see them through the winter. Their strong hooves scrape snow off buried vegetation, but if ice forms over it they can find it difficult to break through. Starvation is the main threat since polar bears prefer to eat ringed seals, but since polar bears eat pretty much what they can catch, eating of reindeer is known to happen.

The reindeers feed on all types of vegetation, generally in small herds

Photo by Bruce Moore

Photo by Bruce Moore

Photo by Bruce Moore

Photo by Bruce Moore

Back in the day, they, like so many other animals, were overhunted and practically extinct by 1925, but with protection numbers have increased. The current total population size is not known, but estimated by the Norwegian Polar Institute to be 400-1,200 over  the period 1979 to 2013 in the valley that runs past Longyearbyen, the main city. (To clarify, this means annual surveys were done and the numbers found varied year by year, the minimum being 400 and the maximum 1,200. There will be many more in the whole archipelago. The archipelago is difficult to survey and the Russian areas aren’t always surveyed either. Breeding depends on the harshness or otherwise of the seasons, which vary hugely in the Arctic year by year.) A small number are still shot (with permits) each year, providing some Longyearbyen restaurants with game and some hunters with income.

Bones take a long time to break down in the Arctic cold

My foot gives scale

Expected lifespan is about 10 years. Males grow their antlers from April to July (Northern Hemisphere spring and summer), losing them at the beginning of winter after the mating season. But females grow their antlers beginning in June and keep them for a year, including over the winter.  So the Santa’s reindeers have got to be females. Hey Rudolph, is some re-naming required?