Tag Archives: Ravensbourne National Park

Blue, red and green

Three images from guest photographer Brett Roberts.

Ravensbourne National Park. Photo by Brett Roberts.

Ravensbourne National Park. Photo by Brett Roberts. Click on an image for a closer look.

Brett, a colleague in the Queensland Parks and Wildlife Service, is a photographer who combines a technical mastery of the camera with an eye for arresting composition and abstract expression. Here are three sublime glimpses of the shimmering, ever-shifting patterns and colours of nature.

Fire, Girraween National Park. Photo by Brett Roberts.

Bushfire, Girraween National Park. Photo by Brett Roberts.

Reflections at the Cascades. Crows Nest National Park. Photo by Brett Roberts.

Reflections at the Cascades, Crows Nest National Park. Photo by Brett Roberts.

‘To take photographs is to hold one’s breath when all faculties converge to capture fleeting reality. It’s at that precise moment that mastering an image becomes a great physical and intellectual joy.’ Henri Cartier-Bresson, The Mind’s Eye: Writings on Photography and Photographers

‘Mysteries lie all around us, even in the most familiar things, waiting only to be perceived.’  Wynn Bullock

Red Triangle Slugs on the rampage

It’s a mid-winter night in Toowoomba, raining and cold. I step outside and my bare foot squishes something cold — cold, but very much alive.

Red Triangle Slug Triboniophorus graeffei.

The Red Triangle Slug (Triboniophorus graeffei), an air-breathing native slug. Photo R. Ashdown.

Oh no! I’ve trodden on a favourite invertebrate, one of a host of unusual creatures that come out to play in the suburbs at night. It’s a Red Triangle Slug — creator of the strange rows of circular marks covering fences and trees throughout town. It’s a wonderful wet night, perfect for them to rampage about the backyard.

Feeding marks of Red Triangle Slug Triboniophorus graeffei on fence.

The grazing marks of Red Triangle Slugs on a Toowoomba fence. Photo R. Ashdown.

These colourful native animals are one of approximately 1,500 species of land snails and slugs found across eastern Australia, a number that includes both native and introduced species. Most of the slugs and snails found throughout the gardens of towns such as this one are introduced, as native species have not coped well with the changes that urbanisation have brought to their original habitat. Red Triangle slugs, however, are an exception — survivors and adaptors, turning up all over the place.

Red Triangle Slug, Triboniophorus graeffei, Ravensbourne NP

A Red Triangle Slug in rainforest at Ravensbourne National Park. Photo R. Ashdown.

What type of creature are these Red Triangle Slugs, named for the … well, red triangle … on their backs? They are “terrestrial pulmonate gastropod molluscs from the family Athoracorphoridae”, the leaf-veined slugs.

Molluscs are soft-bodied invertebrates that usually have a shell for protection from human toes and other problems. They have a ventral foot for locomotion and, in aquatic species, gills for respiration. Their digestive and reproductive tissues are located together to form a visceral mass inside their bodies. An extensive fold of tissue, known as a mantle, covers them and is a protective sleeve for the head and gills. In snails it produces the shell. In the Triangle Slugs, it is reduced to the red-bordered patch on their backs.

Slugs and snails belong to the class of molluscs known as gastropods, which includes marine, freshwater and land snails (mostly with coiled shells) and slugs (without shells).

Red Triangle Slug, Triboniophorus graeffei,

The eyes have it. Simple eyes, on tentacles. Optical tentacles, if you like. Slugs can only ‘see’ light and dark, and the eyes are not able to focus. Photo R. Ashdown.

Growing to a length of 14 cm, the Red Triangle Slug is One of Australia’s largest native slugs. Found in coastal forests (and some towns) from around Wollongong New South Wales north to Mossman in northern Queensland, they graze on the microscopic algae that grow on tree bark, footpaths, posts and fences, among other things. Naturalist Martyn Robinson discovered that if given the chance these slugs will also remove bathroom mould!

Feeding marks of Red Triangle Slug Triboniophorus graeffei on fence.

The circular feeding marks of Red Triangle Slugs on a Spotted Gum. Photo R. Ashdown.

Red Triangle Slug, Triboniophorus graeffei, on camphor laurel

Late afternoon on a dark, wet day. A Triangle Slug roams a Camphor Laurel next to the Clive Berghoffer Stadium. Photo R. Ashdown.

Red Triangle Slug, Triboniophorus graeffei, eating algae on back steps

Alas, our stairs are in poor shape. Any remains of paint have been replaced by algae. Perfect, however, for a rampaging slug looking for a feast. Photo R. Ashdown.

Red Triangle Slug, Triboniophorus graeffei, eating algae on glass window

Doesn’t say much for the state of the back-door’s glass either! This slug runs amok in search of algae, or seeks a view of what the humans get up to at night. Photo R. Ashdown.

Red-triangle Slugs come in different colours. While the most common colour form is a creamy white animal with a prominent red triangular mantle shield, all-red and all-yellow animals can be found at Cunninghams Gap (south of Toowoomba). Future molecular studies may reveal that some of these colour forms are actually distinct species.

Red Triangle Slug, Mt Mitchell NP, Cunninghams Gap.

An orange form of the Red Triangle Slug, at Mt Mitchell NP, Cunninghams Gap. The hole inside the red triangle is the animal’s respiratory opening, known as a pneumostome, or breathing pore. This is a feature of all air-breathing land slugs and snails. Photo Harry Ashdown.

Photographing a Red Triangle Slug, Mt Mitchell, Cunninghams Gap.

Photographing a Red Triangle Slug, Mt Mitchell, Cunninghams Gap. Photo R. Ashdown.

Red Triangle Slug, Toowoomba

Toowoomba resident Jane alerted me to the presence of a beautiful red form of the slug in her Toowoomba backyard. Here are several curled up in a log in her great garden. Photo R. Ashdown.

Colour variations in Red Triangle Slugs

Colour variations in Red Triangle Slugs, from Australian Land Snails, Volume 1, by John Stanisic, Michael Shea, Darryl Potter and Owen Griffiths — gastropod gurus! Courtesy Darryl Potter.

If you have read this far you are probably not the kind of person who finds slugs disgusting. So, I don’t need to finish this post with a monologue about the important role native slugs and snails play in our ecosystems, as they go about recycling nutrients and offering themselves up as (sticky) food for many other critters.

I’ll just end by saying that it’s always great to see these little slow-motion beasties on wet nights, but not so great to feel them between your toes!

Red Triangle Slug on footpath, Toowoomba.

A Red Triangle Slug motors slowly along the footpath outside our place near midnight as cars swish past. A splash of colour on a drab, dark night in the ‘burbs. Photo R. Ashdown.

Slugs on the web:

Summer singers

A Cherrynose Cicada (Macrotristria angularis), a spectacular, large Australian cicada. I had to capture this one to photograph it so closely, as the males are exceptionally wary when on trees. Its call is a tinkling and reverberating song. The ‘nose’ is actually a postclypeus, which has nothing to do with breathing — it houses the muscles for the feeding system. Photograph R. Ashdown.

Cicadas are amazing creatures. A long life as an underground-dwelling nymph is followed by a wonderful transformation to adult winged treetop dweller. At the moment the air is alive with the sounds of cicadas. As I write this a Clanger (Psaltoda claripennis) is rattling and clanging away on a jacaranda tree on the footpath. Come twilight, the sound of traffic is completely drowned out by the rumbling drone of the Bladder Cicada (Cystosoma saundersii). In nearby eucalypt woodlands the roar of Razor Grinders, Cherrynoses and Double Drummers is truly overpowering.

These are the loudest insects on the planet. The Green Grocer, Yellow Monday and the Double Drummer produce noise intensity greater than 120dB at close range — a sound approaching the pain threshold of the human ear. A large Razor Grinder in full song can cause permanent hearing loss if held close to the human ear (great idea, eh?).

Entomologist Chris Burwell from the Queensland Museum explains cicada song in Wildlife of Greater Brisbane. Designed to attract females, the song of the male cicada unfortunately alerts predators, particularly birds,  to its presence. As a result calling male cicadas usually take flight as soon as you approach them (making them quite hard to photgraph). Calling males often form huge groups, and there is evidence that this ‘wall of noise’ actually repels birds, because it is so painful to their ears!

Their interesting songs, striking appearance and sudden summer arrival (including their mysterious abandoned nymph cases) has brought these harmless insects lots of fans. As a child I marveled over the images of emerging cicadas by the astonishing Densey Clyne, and as a photographer always enjoyed trying to capture them on film – which can be quite challenging. Photographing the emergence of adults from the nymph stage is always fun. This happens under cover of night (although some species will emerge during the day).

While walking at Ravensboune National Park recently we stumbled upon this emerging adult cicada. After watching it for a while we concluded that it was stuck, and had been so for a few hours. Putting aside my ‘don’t interfere with nature’ rule  for a moment, I moved the insect up so that it could grab the branch. Over the next 20 minutes we were transfixed by the entire process — with unfolding wings and the changing body colour, a fascinating transformation.

While walking at Ravensbourne National Park we came across this large emerging cicada. After watching it struggle without result for  a fair while we concluded that it was completely stuck, so we intervened, carefully tilting it up so that it could grab the trunk. Photograph R. Ashdown.

Within ten minutes the cicada’s wings were unfolding and its body colour was changing. This is the third and final stage of the cicada’s life. After emerging from an egg, the nymph climbs down to the soil and spends six or seven years underground. Cicada expert Dr Max Moulds has said that their underground sojourn can take anything from nine months to 17 years or more depending on the species. Photo R. Ashdown.

The cicada’s wings are unfolding as fluid is pumped through the veins. The delicate structures will need to harden before flight can be successful. It is usually several days before the cicada starts singing. Photo R. Ashdown.

The wings are moving with the breeze. By the next day I hope it was joining the raucous and joyful chorus with its mates — such an Australian bush sound. Photo R. Ashdown.

Ecologist Greg Ford has just sent me this wonderful image of an adult Double Drummer (Thopha saccata), photographed at Crows Nest National Park. I’d hazard a guess that our young cicada is one of these — the patterns certainly match, and its colour would have darkened during the day. Photograph courtesy Greg Ford.

Another place, another stunning cicada. This nymph has emerged during rain at Amity, on Stradbroke Island, using a verandah railing as the perfect emergence spot. I back-lit this one with a torch to bring out the delicate wing details. Photo R. Ashdown.

Shimmering new blue wings. Photo R. Ashdown.

For lots of information about cicadas, see the wonderful web work of Lindsay Popple.

Here are some other great links for information about cicadas: