I was taking a couple minute break away from work and the computer screen and wandered outside into a beautiful day. The sun was shining past puffy white clouds as they raced along the blue sky highway. Out of the corner of my eye I noticed something zipping about one of the emu bushes. Immediately I knew it was a Blue-banded Bee. The day before, quite possibly the same bee was buzzing around the same bush. Its movement so fast it almost looked like it teleported between spaces. At the purple tube flowers, the bee stopped midair to inspect, its body so motionless that everything else seemed to orbit around it and that it had stopped in time. So still it seemed, at least momentarily, that you could lean in close and inspect every last detail of its intricate features. All except the wings of course, which beating unfathomably, were barely a blurry distortion of space.
I extended my break and sat down to watch the bee for a while, a bee that appeared to bend the laws of physics and had harnessed quantum mechanics for its own accord. After a little while I noticed a pattern in it behavior. When the sun shone through the clouds the bee was out assessing flowers, occasionally stopping in for a visit. When the clouds came over the bee seemingly disappeared. For one of these brief moments of cloud cover, I saw the bee settle on a kangaroo grass stem, mandibles firmly clamped to the stem, legs and body lifted touching only but itself. The sun returned and the bee vanished into the air.
I did a bit of reading and found that foraging activity in bees may be related to several factors including light levels and temperature. There was certainly a reduction in light when clouds passed and temperature dropped noticeably. So it seems as though the light and/or temperature levels where fluctuating above and below the threshold for foraging in this bee. This too may explain the recent phenomenon of finding Honey Bees on the ground. This summer has been comparatively mild and many days have been cool, though sunny. Maybe these Honey Bees are also getting caught out on their foraging expeditions by a brief cold snap grounding them temporarily.
Compared to previous years there is an apparent lowness to the numbers of Blue-banded Bees in the garden. This, I suspect, has a lot to do with the lack of tomato plants, which have been hubs in previous years. So next year I’ll endeavor to both bump up the veggie harvest and provide these intriguing and lightening fast bees with more flowers to forage at.
Early on Christmas Eve day I was in the driveway about to drop my son off at his grandmother’s and was vaguely aware of an anomaly in the soundscape that surrounded me. I was too preoccupied to stand around and search for who was making the sound, but around lunch time I arrived home and noticed the sound again. This time, with my mind no longer swimming with things I had to do, I stood with my son by the fence of the paddock across the road listening to the out of place sound. I could hear an occasional bzzrrrt from the large gum trees in the paddock, though after a little while I could no longer hear the call nor see the animal making it. We went back inside, and I did a few jobs around the house and put my son down for a sleep.
I suspected the orator of this new call might be a Restless Flycatcher, though I was more familiar with the scissor-grinder call they use while foraging. Flycatchers are fabled in my mind, a rare, beautiful bird gleaming with a dark blue-black iridescent sheen, and having slightly anomalous features like a wide-based bill and little crest which deviate from the norms of similar sized birds in the area. The flycatchers have suffered greatly from habitat clearance in the Adelaide Hills and are now Endangered in the region. In half a dozen years birding in the hills, I’ve only seen them a few times in one small reserve containing remnant native vegetation. To add to their intrigue, while doing my undergraduate degree, I remember one of the lectures suggesting the scissor-grinder call caused spiders and possibly other tasty morsels to flee from cover so the flycatcher could swoop down and collect them.
Jobs complete and attention undivided, I went back out into the driveway to search again for the mystery singer. To my surprise I could hear the bzzrrrting and the scissor-grinder call being emitted from a tree not 15 meters from me! I bobbed and ducked with my binoculars until I got a clear view of the luminous flycatcher. Having got a good view, I raced inside to get my camera. I couldn’t let a momentous event such as a flycatcher at home be left to my word and memories without conclusive proof. Camera in hand, back into the hallway, I flicked the camera on. Damn, no memory card. Back to the study for the card, then back outside. Mercifully, the flycatcher had not moved far. It was perching in young river red gums and hawking above the dry yellow grass projecting the scissor-grinder call down to the ground with an open beak. I snapped a few photos. Then, moments later, an indignant Willy Wagtail swooped in and chased the newcomer away. I was ecstatic at having seen the flycatcher and a warm glow sat within me, though a little resentful of the Willy Wagtail for chasing it away. However, what more could be expected from the original angry bird, one with the grit to assault a hawk much larger than themselves that would surely eat them if it got the chance.
The next morning, Christmas morning, I awoke to a burgeoning of bird song. Among the peeps of honeyeaters, the lonesome treecreeper and the chatter of parrots, was the incongruity of the bzzrrrting flycatcher. I went outside to find the sunlight as brilliant beams of soft lemon flowing lowly across the hills igniting the dry grass. Very nearby the flycatcher dipped and swooped between our yard and the paddock across the road, perching briefly and illuminated by the gentle sunlight, its satin shimmering. The moment was again shattered by the local residents, White-plumed Honeyeaters who vehemently chased the flycatcher away. Although I’ve seen the white-plumes chase other birds away, often New Holland Honeyeaters, these chases seem less sustained or primed with emotion. Why the flycatcher is so disliked by the other local birds I do not know. This matter will remain a mystery to me and a subject of my mere speculation, though, perhaps not to the honeyeaters and wagtail.
A gentle positive warmth from seeing this lovely creature lingered in my soul for more than a day, a feeling that I lapped up. I am so lucky to have had this encounter, and I hope that someday the flycatchers will return.
When I first got into birding many years ago, I would travel around Adelaide visiting different reserves and parks looking for birds I had not seen before. It was such a thrill to see something new. Back in those early days of birding my cousin mentioned a little patch of remnant vegetation out in the Murraylands called Talbots Reserve. My Uncle had been there with a group which was led by a knowledgeable birder. This birder had shown them several interesting and rare birds, many of which we had not seen before. So, without hesitation we decided to visit.
The reserve was fascinating and packed with about six dozen native plant species. There were patches of Southern Cypress Pine rich in greens and standing in their lovely pinnate form. South Australian Blue Gums and Mallee Box Gums thrust their leaves to the sky on twisted and bent branches, though some weighed down by the lurking and uncanny mistletoes which hung their red and green flowers among their own fleshy leaves. The flowers of Sticky Hop-bushes would draw a multitude of insects and the doo-le doo-do of calling Peaceful Doves would waft calmly through the warm air. The reserve did indeed have birds that we had not seen before, particularly species which occupy drier habitats away from the more mesic Adelaide Hills where I spent most of my time. Diamond Firetail Finches with their scarlet rumps, white diamonds on their black flanks and their red becks coupled with a tiny black mask were one of the most beautiful and delicate of the new bird prizes. Then the Restless Flycatcher, attired with a dark satin sheen on the upper parts with brilliant white on the lower, projecting their scissor-grinder call to their yet unseen prey.
The most memorable new bird I saw was the White-browed Babbler. I remember a group of these peculiar birds jumping around in low dense shrubs with big tails and decurved beaks making an array of interesting noises. Once I got a good look at one, I said to my cousin, “I think that’s a babbler”. At the time I did not fully understand how I knew that. I was not the sort who went through the field guide and knew every bird I could possibly see before I went out into the field. I would go out, see what birds I saw, and check back with the field guide after the fact. When I was five, I got a field guide from my cousin’s family for my birthday. Back then I looked at a few birds in the backyard but did not delve deeply into the avian world. In hindsight, what I think happened that day was that I dredged up information deposited deep in my mind from flicking through the pages of that field guide when I was five, around 15 years earlier. Nowadays, babblers still bring me joy and curiosity when I see them, and sometimes I ponder the workings of my own mind.
I did multiple trips to the reserve over the years and it was only after perhaps half a dozen trips that I began seeing only birds I had seen before. As well as the reserve containing the interesting and new birds, other aspects of the reserve began to catch my attention. The array of plants of various forms, the large ant holes a few centimetres in diameter punctuating the sandy soils at frequent intervals, ferns and occasionally orchids nestled into rocky crevices on granite outcrops, and interesting wasps and other busy insects visiting bushes flush with flowers.
Over these trips something else developed within me. A peacefulness, something almost spiritual related to this place. I found I could stand among the trees listening to the gentle whooshing of the breeze through the leaves and the calls of the plentiful birds and my mind could rest. This place could provide respite from daily life and the ordinary churnings of my mind. I’ve been to plenty of wild places and only a few have really provided me this sensation. I have pondered why this is, and there are several facets.
People: I have never seen another person walking around in the reserve that I do not know. I have some level of social anxiety, particularly in large crowds but also when I am out in the bush and there is someone else walking around that I don’t know. The barriers I put up within myself to deal with social interactions, or the potential of, are costly. To let these barriers fall away is a huge relief.
Space and composition: Talbots Reserve and the reserve across the road are only about 22 ha combined, but I can stand within them on the sides of the low hills and imagine what the whole landscape looked like before much of the land was cleared for agriculture. This is something that is pretty special in these parts as most of the areas have been cleared, at least at some stage.
And finally, sound: the sound of an environment is something that often gets forgotten about, or at least the less conspicuous things, like the rustle of a skink in the leaves or the buzz of an insect flying by. But sound to me is as vivid as sight and often it tells me more about what is going on in a place. At the reserve there are very few sounds that can be attributed to humans. There is a dirt road, though cars pass infrequently. This may seem relatively unremarkable. If you get far enough away surely there are not human derived sounds. However, there could be the rubble of a car off in the distance on some remote track, a plane flying high in the sky or even the vibrating of a wire fence in the wind. It is amazing how far sound travels particularly from highways. On a clear night I hear trucks on the freeway over 2 km from my home. In the bush, I can pick out the high-pitched calls of secretive birds from among the calls of other birds and the wind that others cannot hear. However, my perception of soundscapes has boundaries. In a crowded restaurant, I have difficulty holding conversations because my brain cannot separate the background conversations from those of the people I am conversing with. This can make for some awkward situations and why nightclubs were never a good place for me to meet people when I was younger. At Talbots, though, I can sit and listen to the wind through the trees, the birds calling, with whistles of a Crested Pigeon’s wings as it flutters from its perch, the buzzing of a little black wasp as it inspects a stick, without intrusion.
I recently went back to the reserve after several years of not visiting and the magic has not worn off. Not only were interesting birds doing interesting things, but still I got my moments of peace and tranquillity to recharge. A group of Varied Sitellas fluttered around in their frantic way with their almost needle like upturned beaks collecting food for a nestling that sat in its tiny nest in the V of a dead branch silhouetted against the overcast sky. A female Purple-backed Fairy-wren popped into its nest in a pile of sticks on the ground surrounded by dry grass. Two coloured males diligently bringing food. A juvenile Hooded Robin perched on an old dead tree trunk, which, grey with age, was topped with lime green lichen. And one of the Brown Treecreepers loudly protested our presence.
Wild places do not always have to be great swathes of untouched wilderness, not to say these places should not be protected, or even created. But small reserves like Talbots can provide many of the sensations and feelings that wilderness can provide. Additionally, and most importantly, they provide a refuge for the plants, animals and other organisms that live there, a growing necessity in our current world.
It’s the first really nice day we’ve had in a while. It’s a La Nina year and the weather’s been pretty cool and wet for some months now. Normally it’s warmer and drier this late in the year, but everything needs respite and an opportunity to grow and thrive after the hot dry few years we’ve had.
I’m sitting outside by the spinach plant, who’s tiny green flowers are just starting to crack open revealing yellow pollen clad anthers. The air is thick with moisture and a fragrant botanical smell wafts through the air. Among the sun and shade of the foliage, sitting on leaves and stems, or zipping about, are flies. The flies are incredibly variable, perhaps spanning 100 orders of magnitude in mass. The largest, a bulky and clumsy fly maybe a centimeter long with a dark bronzed abdomen and black hairs. Slightly smaller are the iridescent dark green flies with deep red eyes (from the right angle), which are meticulously checking the tiny flowers. Inspecting one of these beauties up close, so close my eyes can only just focus, I see tiny pollen grains stuck to the hairs on its body. Next down the line are the hoverflies, who’s wings, when grounded, sit out like a fighter jet’s, while their yellow and black stripped abdomen bobs up and down. There are smaller hoverflies too, much the same. A brightly coloured lady beetle catches my attention for a moment. Further down the size scale is the darkly iridescent gold fly whose apparent role is to bother the bigger flies by zipping about then landing on them. Its abdomen is a slightly stubby bullet shape which I can’t quite comprehend. I shift my legs to shade myself from the sun to find a much larger fly than any I have seen yet resting on my foot. After a moment’s hesitation, it flees at the disturbance. This fly’s wings sit in a triangular shape above the gunmetal blue abdomen. I focus back on the spinach plant. There are numerous tiny flies as varied as the big ones which include some fruit flies and flies that are as big as two dots made by the pen I am writing with. I can barely see their form, let alone colour, though a fruit fly lands close in view revealing its cream body and racing stripes running down its length.
Some may want to rid the world of flies, and sometimes I do too. Well at least the ones that get into my eyes. However, these flies on the spinach plant are not the ones I have qualms with. These flies give me joy at their antics, wonder at their fine details and beautiful colours, and make me ponder the diversity of life. If half a dozen species of fly can exist in this microcosm of a spinach plant in this one moment of time, the number of other species that exist in the world now and throughout history is incomprehensible. These flies shine a tiny light on the interconnectedness of the world. They sip the nectar from the flowers and plant that has sucked energy from the sun. They transport the pollen to fertilise another flower, and then, if unlucky enough, might get snapped into the bill of a fairy-wren, which then feeds the fly to its nestling who may one day grow old and snap flies of their own.
During the time we’ve lived here I’ve got many short glimpses of hawks. They occasionally land in trees in the backyard, or drift and swirl through the air, wings unmoving, before disappearing as promptly as they came. I would scramble to get my camera or binoculars so I could confirm their exact identity, but never fast enough. There are two possible hawks in the area, the Collared Sparrowhawk and Brown Goshawk. They look remarkably similar especially when getting only distant views. Although female goshawks are much larger than either the males or sparrowhawks, the diagnostic differences between species come down to things like position of the first knuckle of the middle toe, the shape of the tail and where the powder blue is on the beak. There are people out there who can tell the different between the narrow silhouette of this or that raptor in the dwindling evening light from a mile off, but I’m not one of those people. However, this month was more fruitful for my hawk identification attempts.
In the evening of New Year’s Day, while sitting in the lounge room I heard the rising franticness of alarm calls which signals the arrival of a hawk. Often the hawks fly over before disappearing down the valley, while the chorus of alarm travels with it. Every bird valuing its continued existence and of a size that would make a delectable dinner dive into the depths of a bush or tree. Today though, the alarms remained, along with the occasional “kek” emitted by a hawk. I postponed my dinner to investigate. I found up in the branches of a stately old elder gum, a hawk pulling the feathers off a decapitated, bloodied bird carcass. I thought the ill-fated bird may have been a Crested Pigeon but couldn’t be sure as they were so high up in the tree. Even with some distant photos, the hawk’s identity could not be resolved. I consulted a friend who suggested that if the unfortunate bird was a Crested Pigeon then this was a female goshawk. The Crested Pigeons had nested in the backyard and had a bundle of sticks, which suffices as their nest, hidden in a bush not far away. The Willy Wagtails were none too happy and were complaining fiercely, ensuring the hawk was under no illusions about that fact. The wagtails were game enough to thrust their sharp claws into the hawks back, ruffling and removing some of the nicely manicured feathers. The wagtails were such a pestilence that the hawk moved to another perch in a lumbering flight hauling its meal. The New Holland Honeyeaters, not as game as the wagtails, sat carefully watching the lethal predator, keeping a safe distance.
A couple of weeks later, on a beautiful evening the hawk alarm calls began again. This time the identity of the perpetrator was more obvious, as the hawk landed on a low branch in the backyard with its prize. This was a Sparrowhawk and much smaller than the bird I’d seen previously, confirming that both hawk species stalk the skies above our house. This time a young White-plumbed Honeyeater was the hawk’s sustenance, feathers plucked before the meal began. The Willy Wagtails were again making their disdain felt. Even a Black-faced Cuckoo-shrike joined in the beratement of the hawk, swooping low above its head.
Though the scene of a hawk with dead bird in its talons maybe challenging to some, like seeing a pride of lions take down a wildebeest on the African plains. These animals are symbols of strength, agility, speed, cunning and determination in human culture. We should not forget why these animals have come to symbolise these attributes, and remember that the powerful predatory symbols we idolise are not the compassionate hawks who let their meals fly away.
On the morning of the 20th of December a bushfire broke out in catastrophic weather conditions approximately 20 km from our home. The fire moved quickly razing much in its path including trees, bushland, houses, sheds and animals. By early afternoon we had evacuated our home as the fire headed directly for our town. Fortunately for us, but not so for many others, the wind changed direction and took the fire with it. My uncle’s farm was not so fortunate, and the wind took the fire there and beyond. Luckily, they were safe, as well as the house, sheds, hay, and by some extraordinary luck, the sheep and cattle.
After a couple of days I made my way into the fire ground to help fix fences to keep stock in. One thing that struck me was the number of big ancient-looking gumtrees that caught fire and collapsed, or were still on fire. The fire had got into the exposed heartwood and in some cases smouldered or burnt for weeks. Many of the younger gums remained relatively unscathed (I’m unsure if some may die later). One smouldering River Red Gum stood out to me. Broad-based, narrow topped, very gnarled. It had half a dozen small hollows on the side I could see.
In the canopy, a pair of Crested Shrike-tits foraged among its parched leaves. Shrike-tits are fascinating birds. They sport a little black and white crest which becomes erect when something catches their attention or they are in a dispute with some other bird. Though this is not to say they get into raucous encounters often. Most of the time they are unobtrusive, flitting through the canopy looking for food. Sometimes the only reason you know they are there is because you hear them tearing bark off trees with their can opener-like beaks. We have a pair that lives around our house and I know when they are about because I hear their little giggling or chuckling-like call. If you aren’t paying attention to the soundscape you could easily miss them. In addition to their fancy head and crest, they have a black or olive bib (depending on whether male or female, respectively), a yellow belly, and an olive back and wings making them a rather striking looking bird. Shrike-tits are vulnerable in the Mt Lofty Ranges and I’ve been told they have home ranges as large as 100 ha, so even if you are within their territory you still might not come across them often. They are no doubt my favorite backyard bird and I always get a thrill from their presence, no matter if I just hear them giggling or see them up close splashing in the birdbath.
Pondering the smoldering tree with the shrike-tits reminds me of the gumtree in our backyard. So many things happen on that one tree. Tiny psyllid insects sit on the leaves producing their waxy sugary little domes (lerps). The lerps attract Striated Pardalotes, who specialise in such delicacies and have nested every year in a small hollow in one of the branches. When its been a good year and the tree is flush with leaves the White-plumbed Honeyeaters build their nest within the green drooping masses. Willy wagtails, more confident in their ability to fend off undesirable company, place their nest on a exposed dead stick. Ants march up and down the trunk. Spiders face off with each other on a sunny day, seeking refuge under the bark when disturbed. And of course the shrike-tits ripping bark off to find a juicy invertebrate. By night Ring-tailed and Brushtail Possums stride along its branches looking for a vegetarian feast, where a Boobook or Tawny Frogmouth may have alighted only moments before. There are so many interactions between this one tree and the organisms around that it could be someones life’s work to record all such interactions and never record all that there is to record.
These fires, by burning down these trees, are erasing the history of the landscape, and with increasing frequency and intensity of fires our landscape will become poorer and poorer. With each tree lost we lose the history each tells in it gnarls, twists and hollows. It represents the disappearance of a node in a complex web of interactions that each tree has. When we loose hundreds of these magnificent trees in one brief inferno, it immeasurably increases the value of those that are left. We should cherish and protect those that are left, and help propagate more of these scribes of the landscape and nodes of complexity.
This year has been a busy year, with our son arriving, and plenty of travel and work. This busyness resulted in the garden being somewhat neglected and weeds in some areas reaching lofty heights. Towards the end of the year we got onto most areas except one of the slopes by the back veranda. We noticed a couple of months ago the Superb Fairy-wrens collecting nesting material and taking it into the weed patch. The fairy-wrens did indeed build a nest and successfully fledged three chicks, resulting in the weed patch being conserved temporarily. In December, the fairy-wrens built another nest, and were again successful in fledging chicks.
As well as providing refuge for the fairy-wrens, the patch also acted as a fort in which a rabbit, dubbed the “Nibbler”, made its home. The Nibbler has damaged new plants we put in and, along with blackbirds, dug small holes in the garden. The Nibbler remains at large, but in the hot weather I have called a truce and I have ceased my attempts to catch it.
Grasses make up the greatest proportion of the weeds in the weed patch, and have matured and dried producing copious seeds. A few weeks ago I noticed the appearance of mouse holes nearby. Given most other areas in our yard and in the paddocks next door have been mown or grazed, the weed patch probably has a higher abundance of seeds than elsewhere. Good encouragement for mice to move in. The next logical resident to appear in the weed patch is one to keep the mice in check.
One day, in the throngs of a heatwave, I was outside trying to keep plants hydrated, and the fairy-wrens and New Holland Honeyeaters alerted me to the arrival of the new weed patch resident. I went to investigate the peeping alarm call, which is less frantic than the one used for a hawk. I peered under the bushes and over the weeds, looking at where the birds where looking. It wasn’t long before I found a meter-long brown snake sliding up against the fence, which promptly disappeared at my arrival. There have now been four occasions that fairy-wrens, mainly, and New Holland Honeyeaters, have alerted me to the presence of snakes.
Always listen to what fairy-wrens have to say, your life might depend on it.
Bool lagoon in South Australia’s South East bustles with life. Thousands of waterbirds were floating, flying, or walking through the water. Magpie Geese were honking away in the vast swathes of Water-ribbons, while Whiskered Terns scouted the narrow water-filled channels looking for a tasty tadpole meal. Fairy-wrens and Southern Emu-wrens sung from dense vegetation at the water’s edge and Lowland Copperhead snakes slid off the warm roads to make way for cars. Bool Lagoon Game Reserve is about 360 km south east of Adelaide and is a large freshwater lagoon system that provides a refuge for diverse fauna including many rare and vulnerable species of birds, fish, reptiles and amphibians. I have rarely seen such an abundance of wildlife in one place and it is awe-inspiring.
As day turns to night and the Magpie Geese honk less often, a different cohort of animals become active. Fluttering about in the half-light, silhouetted against the evening sky, small bats emerge and begin catching insects. High pitched chirps appear from every direction from what could be Lesser Long-eared bats or Chocolate Wattled Bats. As I am getting nestled down in my sleeping bag I hear a plonk on the side of the swag. Moments later another plonk! I unzip my swag and grab my torch to investigate. Illuminated in the torchlight is a large green frog, a Southern Bell Frog. A short walk around camp reveals many more of these spectacular amphibians making their way through the night.
Southern Bell Frogs, also called Growling Grass Frogs, are fairly large frogs reaching about 11 cm long. They have green bodies with brown markings and golden stripes on the upper edge of the flanks with a green stripe running from their head down their back. They are quite variable with some individuals being darker green and more brown while others have very little brown and are light green. The bell frogs are nocturnal ambush predators and sit and wait for their prey to stroll within striking distance. Unfortunate souls may be beetles, insect larvae, bugs, termites and sometimes small frogs including others of their own species.
Southern Bell Frogs were once common throughout south-eastern Australia however they have declined considerably in recent years and are now listed as vulnerable nationally. This has been linked to a number of potential factors including habitat fragmentation and degradation, barriers to movement, disease, pollution, as well as other influences which have led to the loss of some populations and the isolation of others.
Southern Bell Frogs occur in areas with permanent or near permanent water such as lagoons, lakes, slow flowing creeks, dams, channels and rice crops. Permanent water, or close to it, is important because the frogs breed during spring and summer and it enables the eggs and tadpoles to develop fully without the risk of the water drying up. The adults can be found in thick vegetation in or near the water’s edge, or in ground debris and soil cracks. They are however sometimes found a considerable distance from the water.
Bell frogs are wonderful, charismatic animals with beautiful and variable colours and are definitely an amphibian to keep an eye out for. Bool lagoon is a stronghold for the Southern Bell Frog in South Australia and is worth a visit not only for the frogs but also for the vast array of other fascinating creatures that live at and use the lagoon system as a refuge.
I am going to start this post a little differently today because there is a little more back story to this encounter. Part of my PhD research involves investigating the relationships between size, metabolic rate and dive characteristics in Diving Beetles, the family Dytiscidae. Diving beetles, of which there are more than 4,000 described species, are found in most freshwater habitats and are often the top predators in fishless environments. Both the larvae, sometimes called water tigers, and the adults beetles have veracious appetites with some of the larger species being know to attack tadpoles and small fish.
To investigate the relationships between size, metabolism and dive characteristics I needed to collect a number of diving beetle species across a wide range of sizes, so I travelled to three areas in South Australia. Initially I had to travel away from Adelaide to the South East of South Australia and into the Flinders Ranges to collect the large species, then small beetles could be collected in the Adelaide Hills. This post describes collecting in the South East.
We arrived at the edge of a road to be greeted by a swamp partly surrounded by teatree and reeds. Near the swamp large cryptically coloured grasshoppers leapt from the ground flashing their bright yellow wings, which were hidden while sitting on their blade of grass munching away. There was a small opening on one side of the swamp where we could get to the water’s edge. It was a beautiful sunny day, and a dragonfly was sitting on a stem of the incredibly diverse aquatic vegetation just after it had emerged from its nymphal stage, still soft and not ready to fly.
Despite the beauty we had to get to work and placed a few bottle traps into the water with a little bit of fish as bait. Within minutes large dark figures begun to zip around near the traps in the tea coloured water, some almost as big as your thumb. Moments later diving beetles were appearing in the traps and were voraciously consuming the bits of fish.
We pulled up the traps to find two species of diving beetle, Onychohydrus scutellaris, a whopper of a beetles at almost 3 cm long and either in iridescent emerald green or sometimes brown, and Hyderodes shuckardii which was about 2 cm long and much darker in colour. These two species represent two of the three largest diving beetles in South Australia.
It was not until you looked at H. shuckardii up close that you could see their more subtle beauty. The surfaces of the wing covers (elytra) on the males were smooth and dark green in colour and their legs a dark amber. The females on the other hand were not smooth, instead their wing covers and pronotum (bit between the head and wing covers) were rough showing mottled green and amber. These females are the “granulose form” of females. The other type of female looks like the males with smooth wing covers and pronotum.
This granulose condition in the females is thought to give the females more control over which male to mate with. The males have pads on their forelegs with heaps of tiny suckers that they use to grab onto and hold onto the females. The roughness of the granulose females’ surfaces reduce the number of suckers that can attach and makes it easier for her to get away from the male if she wants to. The ratio of the smooth and granulose females in an environment may relate to the mating intensity, and all of the females we caught were the granulose form suggesting mating intensity was high in that particular swamp.
As with other insects, diving beetles have an air filled respiratory system, like ours but instead of lungs they have a network of branching tubes running from holes on the outside of their bodies (spiracles) to the cells where the oxygen is needed and carbon dioxide is produced. Diving beetles overcome this problem of having a gas filled respiratory system in water by holding a bubble of air collected from the water’s surface underneath their wing covers which supplies oxygen for them while they dive. This is where my research comes in. I’m trying to find out how much air different sized beetles can hold, how quickly they consume oxygen from the bubble and how this effects the time the beetles can stay underwater.
Diving beetles are very widespread and can often be found in freshwater habitats all over Australia and the world in various sizes from a few millimetres to several centimetres. They are fascinating creatures for more reasons than I have included here, so keep an eye out for them, either while dabbing around your local pond with a net or you may find them flying around lights at night.
Brachina Gorge in the Flinders Rangers in South Australia is absolutely stunning and, I think, a quintessentially Australian landscape. In the middle of the gorge, old worn down quartzite hills tower into the sky, rich in earthy oranges, yellows and creamy whites. The hills are speckled with sparse green-grey vegetation. In the bottom of the gorge are massive ancient river red gums that rise up from the creek bed which is filled with rounded river pebbles and gravels in a variety of greys, reds, purples and almost blues. Each stone has white marks from being plonked into each other in the infrequent deluges that cause the creek to fill with water.
We were driving through Brachina Gorge as a scenic route for our journey heading further north. As the car suspension was bounding up and down over the pebbles we came to a section of creek with small puddles of water. The water was encouraging plant growth in the river bed which was in turn attracting an iconic resident of Brachina Gorge, the Yellow-footed Rock-wallaby. After enjoying watching these wonderful animals for some time, something caught our attention making its way through the plants and sticks near the edge of the creek. Boldly strolling along was an echidna, occasionally poking its long snout into crevices and holes. It is unusual to see native Australia mammals so unfazed by the presence of humans, but when you are covered in an armament of spines you can be pretty confident that not too many creatures will mess with you. The spines had a light base and tapered to their points that were sometimes dark coloured. From underneath the spines poked a face with puny dark eyes and a long moist snout. Propelling the spiny beast along were a set of robust legs with strong claws and feet.
Echidnas are an iconic Australian animal and draw attention for a several reasons. They are one of only two kinds of egg laying mammals, along with platypus. They use their strong forelimbs to dig into hard ground, ant or termite nests, and use their sticky long tongue to slurp up ants, termites and other insects from the crevices and holes. During winter echidnas go into torpor, a period where the animal becomes inactive and lowers its metabolic rate and body temperature. When active and regulating its body temperature echidnas are at about 32°C, but when in torpor the body temperature declines to close to that of the surrounding soil temperature that they maybe buried in. So in cold areas this may mean a body temperature as low as 4°C. During these periods of torpor echidnas may only breath once every three minutes.
Echidnas also provide an example of convergent evolution where two unrelated species of animals evolve similar characteristics due to similar selective pressures from their environment. Both echidnas and hedgehogs have the same defensive strategy, being covered in spines, but are unrelated to each other. Echidnas are monotremes, whereas hedgehogs are eutherian mammals that give live birth rather than have eggs like monotremes.
Echidnas are found throughout Australia, and during summer can be found foraging in the bush during the day or night. They are fascinating animals to watch, and you are more likely to get a good view of these interesting animals than many other Australian mammals. So if you are in the Australian bush keep an eye out for these wonderful and curious creatures.