Monthly Archives: August 2015

Australian adders

Common Death Adder, Acanthophis antarcticus, Bruce Thomson.

Common Death Adder (Acanthophis antarcticus), Bringalily State Forest. Photo by Bruce Thomson.

The Death Adder is one of Australia’s more unusual snakes. This post presents some recent photos of this reptile from around Queensland and northern New South Wales.

Maree Cali from Mackay spotted one of these highly venomous elapids close to her campsite. Says Maree, “I was excited to accidentally set up camp over the Easter break next to this cool customer and was blown away by its laid back nature, camouflaging ability and beauty — and I’m not particularly into snakes.”

A master of camouflage, waiting for a meal to pass by. Photograph by Maree Cali.

On the move! Photograph by Maree Cali.

Gerry Swan and Steve Wilson give an overview of Death Adders in their book What Snake Is That?

Australia is the only continent with no vipers, family Viperidae. In their absence, some elapid snakes of the genus Acanthophis have evolved to fill a similar niche. These sluggish, well-camouflaged and sedentary snakes lie concealed in leaf litter or under low shrubs and grasses. Important features of this group are a short, thick body, a broad head distinct from the neck and an abruptly slender tail.

Their similarity to vipers was not lost on early settlers, who were reminded of the Adder (Vipera berus) from Britain and Europe. They named the Australian snakes ‘death adders’ because of the high mortality from bites before anti-venom became available. The corruption ‘deaf adders’ may derive from their reluctance to move away when disturbed.

Death Adders are ambush predators that feed on a variety of vertebrates. The slender tail has a segmented tip and soft spine, and they lie with this resting near the head, When prey is detected, the snake wriggles the tail convulsively, mimicking a grub or worm to lure the animal within striking distance. Its ability to strike so suddenly and with such mind-boggling speed is unnerving to witness, particularly considering the snake is slow moving and prone to lie motionless for days on end. The strike is accurate and lethal, as a powerful venom is injected deeply through long fangs.

Death Adder, with strikingly patterned head strategically positioned near its tail (aka caudal lure!). Captive specimen, photograph R. Ashdown.

Common Death Adder. From The Snakes of Australia, by Gerard Krefft, 1869. Death Adders are not true ‘adders’, belonging instead to the same family as other venomous Australian snakes, the elapids. Their similarity to adders, which are actually members of the viper family, has evolved in response to the species’ environment and their ‘sit and wait’ style of life, which does not require a snake to be long and agile but short and muscular for a quick strike when necessary.

Kate Steel encountered a Death Adder near her back verandah of her house in northern New South Wales. Kate relocated the snake in a sack, grabbing a few photos on the way. She posted on Facebook, “Just caught this slithery under the verandah, there was a Willy Wagtail giving warning and then Lyly the alarm dog. Hope the photos are not too shaky cos my hand is!”

A Death Adder being relocated from near the back verandah to somewhere less likely to be trodden on by bare feet. Photo by Kate Steel.

Queensland Parks and Wildlife Service (QPWS) Rangers often encounter snakes as part of their daily work. Ranger Stuart Fyfe took the following photos of a Northern Death Adder (Acanthophis praelongus) in far northern Queensland.

“I found this Death Adder pretty late one night outside the barracks common room, (around 11pm), so took a few photos then put him in a bucket to relocate him in the morning. We have a couple of families on base with small kids, so we tend to relocate these guys down the track.

When I first found him he was quite docile, and didn’t puff up even when I put him in the bucket, but when I released him in the morning he was all fired up — they tend to puff up like that when they are being defensive. He must not have liked being in the bucket overnight.”

Photo by Stuart Fyfe.

Death Adder scale patterns. Photo Stuart Fyfe.

Death Adder moving out of grass to escape a controlled burn on national park. “This was one of the biggest we’ve seen up here. Based on the width of the Rake Hoe I estimate he was about 42cm long.” — Stuart Fyfe. Photo by David Delahoy, QPWS.

How dangerous are death adders to humans? From a Wikipedia article that lists details of deaths due to ‘unprovoked bites by snakes’ in Australia:

The estimated incidence of snakebites annually in Australia is between 3 and 18 per 100,000 with an average mortality rate of 0.03 per 100,000 per year. Between 1979 and 1998 there were 53 deaths from snakes, according to data obtained from the Australian Bureau of Statistics.

Between 1942 and 1950 there were 56 deaths from snakebite recorded in Australia. Of 28 deaths in the 1945-49 period, 18 occurred in Queensland, 6 in New South Wales, 3 in Western Australia and 1 in Tasmania. The majority of snake bites occur when people handle snakes in an attempt to relocate or kill them.

Australia is the only continent where venomous snakes constitute the majority of species. Snake bites in Australia that cause deaths are less common than they once were, because of increased medical knowledge and anti-venom that is better and more available. Around half of all deaths from snakebites are thought to be caused by brown snakes, perhaps as many as 60% of deaths caused by snakebite.

Unlike other snakes that flee from approaching humans crashing through the undergrowth, common death adders are more likely to sit tight and risk being stepped on, making them potentially more dangerous to the unwary bushwalker.

However, they are reported to be reluctant to bite. Richard Shine, in Australian Snakes, a Natural History, describes this apparent reticence:

There are many stories testifying to this docility, perhaps the most famous being of two men cutting sugarcane in a paddock. They spent the day working at the job, carrying loads of the crop frequently out of the gate to their nearby truck. It was late in the day that one of the workers noticed a large Death Adder coiled in the dust in the middle of the path, right beside the gate, The dust showed hundreds of footprints from their bare feet within a few centimetres of the snake’s head.

Ranger Andrew Young recalls a family Death Adder encounter when he was a lad growing up on the family farm at Stanwell, west of Rockhampton, in the 1960s. He remembers lots of yelling, and dancing about, associated with this particular snake sighting.

“My Dad had sent the farm-hand out to our other property at Ridgelands where he was to plough up some paddocks for planting sorghum. When he was finished he drove the tractor back to our Stanwell farm for some more work we had there. The farms were about 40 minutes drive apart by car so a good couple of hours by tractor.

When he arrived home that evening we all went to meet him and hear how he went. During the discussion, he said, “Oh, and I found a great legless lizard today!” He opened the tool box on the side of the tractor and hauled out this Death Adder! Dad shouted “Drop it!” and we all leapt back — as you might imagine! I shall not recount the snake’s fate …

But I have always thought that the snake was indeed laid back as it didn’t bite when it was ploughed out of the soil nor when grabbed out of the tool box that it had been jiggling around in all day.”

In its element. A Death Adder photographed in the Mount Moffatt section of Carnarvon National Park by QPWS Ranger Brent Tangey.

Many bites from Death Adders proved fatal before the introduction of antivenom. Death Adder venom contains a type of neurotoxin which causes loss of motor and sensory function, including respiration, which can result in paralysis and death. Deaths from bites are still common in New Guinea.

How dangerous are humans to death adders in Australia? In reality, this snake is perhaps more endangered than dangerous. Despite being labelled ‘common’, the Common Death Adder is becoming increasingly less so. Gerry Swan and Steve Wilson write:

Death Adders have declined in many areas. They can be regarded as biological indicators of environmental quality as they appear extremely susceptible to degraded conditions. Weeds, altered fire regimes, introduced predators and toxic prey in the form of the introduced Cane Toad all play a part in the demise of these snakes from sites where they were once extremely common.

As Steve, who has pursued reptiles across the continent for decades, said to me when talking about Common Death Adders, “I defy anyone to call them ‘common’.”

Reptiles are beautiful and fascinating creatures. They are a fundamental part of Australia’s wonderful biodiversity — something that is under constant siege. Says Steve:

The loss of native vegetation has been the most substantial and urgent problem facing Queensland’s reptiles and other fauna. The estimated annual toll from broad-scale clearing between 1997 and 1999 was a staggering 89 million reptiles, a figure no doubt matched today as hundreds of thousands of the state’s extraordinarily complex natural heritage is bulldozed, heaped and burnt. Apart from the immediate individual casualties, the loss and fragmentation of habitat has implications at population and species levels. With the spectre of increased clearing for expanding coal and gas exports and the push for more northern development, it is critical that habitat continuity be prioritised.

I’m yet to encounter one of these snakes in the wild, but hope the chance to do so will be there for a while yet.

northern death adder, kuranda, north queensland HDR (Large)

There are five currently recognised species of Death Adder found in Queensland, though several distinct populations may prove to be valid new species. Between these species, Death Adders can be found over most of mainland Australia, except Victoria. All are live bearers, with litters of over 30 young recorded. This is a Northern Death Adder (Acanthophis praelongus). Photographer Greg Watson photographed this captive specimen at Kuranda (within the species’ range and of an animal with a size and the pattern consistent with the location).

Common Death Adder (Acanthophis antarcticus). Photographed on a QPWS fauna survey of Bringalily State Forest by Bruce Thomson

A strikingly patterned Common Death Adder. Photo by Steve K Wilson.

A strikingly patterned Common Death Adder from central Queensland. Photo by Steve K Wilson.

For more information on the five Death Adder species found in Queensland, see A Field Guide to Reptiles of Queensland (second edition) by Steve K Wilson. The book contains some beautiful images of these snakes by Steve and fellow reptile photographers Angus Emmott and Gary Stephenson.

[Safety note: Death Adders are dangerously venomous. All photos on this post were taken at a safe distance. It’s not a good idea to test a Death Adder’s mood by touching one or getting too close with a camera. Seek professional assistance in relocating a snake if you need to move one.]

Thanks to:

Greg Watson (gregwatsonphotography.com.au)
Bruce Thomson (www.auswildlife.com)
Maree Cali
Stuart Fyfe
Brent Tangey
Kate Steel
Andrew Young
Rennie Fletcher
David Delahoy
Steve K Wilson (www.stevekwilsonreptiles.com.au)

Around the place

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A gallery of various recent images. Click on any image for a closer look.

Life on the edge

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Grey Mangroves (Avicennia marina) at dawn, Lota, Brisbane. All photographs Robert Ashdown.

One perceives a forest of jagged, gnarled trees protruding from the surface of the sea, roots anchored in deep, black mud, verdant crowns arching toward a blazing sun. Here is where land and sea intertwine, where the line dividing ocean and continent blurs. — Klause Rutzler and Ilka C. Feller

If there are no mangroves, then the sea will have no meaning. It is like having a tree without roots, for the mangroves are the roots of the sea. — Attributed to a fisherman from the Andaman Sea

The sun has just risen above Moreton Bay and the sky is catching fire. I’m standing in the incoming tide, in that edge zone where land meets sea. The waking suburbs are less than a kilometre away, but I can’t see or hear anyone. The rising sun doesn’t have my attention. I’m looking the opposite direction, back into a tangled mangrove forest, as the first rays of the sun hit the gnarled grey trunks. Everything in front of me has come together in a brief, quiet spectacle of light and shade, and I’m transfixed by the scene.

———

The edges of things are fascinating places to naturalists and photographers. Ecologists use the word ecotone to describe the edge zone between ecosystems. Landscape photographers revel in edges, the places where the land meets the sky, the ocean meets the shore — where lines draw the viewer into the scene.

Exploring the edge of land and bay. Amity, Stradbroke Island.

With 125km of boundary (stretching from Caloundra to the Gold Coast), Moreton Bay has plenty of edges between land and water. These are diverse places, reflecting the bay’s beauty and contrasts — with mysterious mangrove forests, mud-flats full of life and sandy island beaches. Where the bay stops the growing city of Brisbane in its tracks, the human-built environment swallows these places in walls of concrete or canal estates.

Known as Quandamooka to Aboriginal people, Moreton Bay lies close to one of Australia’s largest cities.

Known as Quandamooka to Aboriginal people, Moreton Bay lies close to Brisbane, one of Australia’s largest cities.

Bushfires cloak the Glasshouse Mountains, at the northern end of Moreton Bay.

Some of the bay’s natural edges have been replaced by the geometric patterns of canal estates. It is thought that about 20 per cent of the bay’s mangroves have been lost since European settlement.

Some of the bay’s gloriously ragged natural edges have been replaced by the geometric patterns of canal estates. It is thought that about 20 per cent of the bay’s mangroves have been lost since European settlement.

Luckily, there are places in Moreton Bay where the zone between sea and land is as it has been for millennia — blurred and hard to define. In 1799 Matthew Flinders couldn’t find the entrance to the Brisbane River because it was obscured by a wall of grey-green mangroves, plants which thrive in the shallow water and mud flats of this island-sheltered bay.

The word mangrove refers to a range of plants growing in the intertidal zone. This is an orange mangrove (Bruguiera gymnorrhiza), Coochiemudlo Island.

The word mangrove refers to a range of plants growing in the intertidal zone. Orange Mangrove (Bruguiera gymnorrhiza), Coochiemudlo Island.

Mangroves are, of course, important places — as home to marine life, crucial nurseries for the sea creatures our fisheries depend on, and buffer zones to storms and the power of the sea.

Important is a word that just doesn’t begin to cut it. It’s baffling then when we are reminded that some still seem to despise them, as when those who have claimed their patch of real estate by the bay see mangroves as an impediment to their view. Some even destroy them to improve their outlook, killing part of the thing they seek to enjoy, not understanding the basic truth that the bay is a vast living system, with many parts, not just some pretty vista captured within a window frame.

Australia is surrounded by approximately 11,000 km of mangrove-lined coast — around 18% of the coastline, and nearly half of this is found in Queensland. There are about 13,500 ha of mangroves on the edges of the Moreton Bay. Most are found near river mouths and in other areas protected from waves.

A grey mangrove seedling. Nearly 70 per cent of the prawns, crabs and fish we eat depend on the mangrove habitat for at least part of their lifecycle.

Many probably still see mangrove forests as smelly, horrible places crawling with mozzies, snakes, spiders and crocodiles. Explore one though, and light and time slip away. As the sounds of the land fade, other noises are heard — clicks, splashes, the clear piping of a mangrove kingfisher or the sweet, falling leaf call of a mangrove gerygone. There’s a gradual realisation that these muddy, shadowed places are full of life.

A Soldier Crab displays its maroon knees.

The highly venomous, but charmingly beautiful Blue-lined Octopus.

Blue swimmer, Moreton Bay.

So where does the sea actually start or end in a mangrove zone? There’s no set spot of course, this is the intertidal zone, where the water ebbs and flows with the endless tides.

At low tide, old mangroves look like stranded, strange creatures, patterned by lichens and ringed by water-marks. They are partially consumed each day as the incoming tide pushes past them toward the land beyond. In king tides and storms the sea reaches beyond them to saltmarshes and samphire flats, sometimes even popping up in the drains and streets of bayside suburbs like some kind of unwelcome intruder.

On this morning I have waded out before dawn into the mangroves, carrying a camera and binoculars. I’m close to the suburbs but may as well be lost somewhere on Australia’s vast northern coastline, sent back in time to when there were no cities chewing up the bush beyond.
I’ve gone as far as I can, having pushed out beyond the edge of the mangroves.

As the sun rises and the first orange light hits the wall of mangroves, the wind drops and calm descends on the scene, allowing glowing reflections a brief window of life. Realising that this will only last a minute or two, I steady my camera on a shaky, mud-stuck tripod and capture one long exposure. Then, the wind rises, the moment vanishes, and a restless movement fills the mangrove forest as a new day takes over.

A dragonfly is warmed to life by the sun’s first light. Lota Creek mangroves.

Man, boat and pelicans, dawn, Wynnum.

Weeks later I get the developed slides back and realise that this single sunrise mangrove image (the first image on this blog post) will be a favourite photograph of mine, one that will have the power to transport me from the stress of busy life to the quiet wildness of the mangroves, still there I hope, greeting each day amid the endless rhythm of the tides, home to myriad creatures, important — and just being its mysterious, magical self.

Mangroves at dawn, Wynnum North boardwalk

A full moon rising over St Helena Island is framed by a Grey Mangrove. Wynnum North.

Wildlife of the Lockyer Valley calendar 2016

Brachychitons by night

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My photographic exploration of these intriguing trees continues.

On a cool evening at Highwoods on the Darling Downs I watched the fading light soak into textured bark. As eerie silhouettes against a starlit sky, these trees seem otherworldly and ancient, reaching silently toward the Milky Way.

[Click on the images for a larger view]

Thanks to Martin, Rod and Mark. See also: Bottle Trees at Highwoods, Brachychiton survivors and Brachychitons Part 2.

The Simpson revisited

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The Simpson Desert. All photos in this post by Robert Ashdown.

The scene was awfully fearful, dear Charlotte. A kind of dread (and I am not subject to such feelings) came over me as I gazed upon it. It looked like the entrance into Hell.
[Explorer Charles Sturt on encountering the edge of the Simpson Desert, September 1845.]

In 1996 I spent some time on the edge of the Simpson Desert. Not much time, and not far into the desert, but it was a memorable adventure.

As an image I’d taken on that trip was recently chosen for the cover of a book on macroevolution (the evolutionary and ecological processes responsible for generating patterns of biodiversity), it seemed like a good opportunity to post some slide scans, accompanied by a few words written for an article published in the Summer 1996 edition of Wildlife Australia.

Looking west across the Simpson Desert as the light fades.

The Simpson Desert. To some the name may conjure images of lifeless sand dunes, of a stark and deadly landscape. To visiting naturalists, the Simpson is a place of subtlety, surprises, life, colour and great contrasts.

The Simpson Desert covers part of three states at the arid centre of Australia. More than 1,000 parallel sand ridges, often running unbroken for great distances, form a unique landscape. It is one of the world’s great sandy deserts.

Lobed Spinifex (Triodia basedowii) forms hummocks on dune crests. It provides refuge for many species of desert fauna.

Ctenotus pantherinus ,one of many species of beautiful reptiles that call this arid area home.

Parakeelya.

Central Military Dragon (Ctenophorus isolepis).

Canegrass dragon (Diporophora winneckei) playing dead.

Aboriginal people lived in this desert for countless generations, basing their lives around wells and an intimate contact with the desert plants and animals. Early Europeans saw it as a dead zone — devoid of flora and fauna of any real value.

Vegetation in the swale areas between sand ridges.

Brown falcon.

The Desert Grevillea (Grevillea juncifolia) is one of the many desert plants that can survive long periods without rain. I watched Black Honeyeaters coming over the sand ridges to land in them for a brief nectar refuel.

Ghost Gum and spinifex in afternoon light.

These notions faded as expeditions and surveys revealed an astonishing biodiversity. Far from being a monotonous and lifeless wasteland, the Simpson Desert encompasses a variety of constantly changing land-forms, each providing habitat for many superbly adapted plants and animals. New and exciting biological discoveries are continually being made.

To the visiting photographer, the Simpson is overwhelming. The vast, silent landscapes do not easily reveal their secrets. In a dry creek bed between sand ridges, we share the midday shade with a host of birds.

The dry bed of Gnallan-a-gea Creek, Simpson Desert.

Flowering bloodwood, Gnallan-a-gea Creek.

Flowering bloodwood, full of birds. Gnallan-a-gea Creek.

Tangled Mulla Mulla.

Grasshopper and desert sand.

The change from afternoon into night is soft and magical. As the sun sinks, the red sand on the ridges glows with a luminous intensity. The shadows of the wildflowers and other plants lengthen.

Silence returns and cloaks everything with a palpable intensity, The dome of the sky sweeps down to invade the ground as the twilight colours fade and the horizon vanishes, Another day in this remarkable place has ended.