Sunday, July 30, 2006

Ask and you shall receive

Snail commented on my previous post:

"Have you spotted any temnocephalans on your animals? They're pretty cute."
This made me look twice and I found a couple looking very photogenic on the side of the first segment of the tail. Whipped out the camera and extension tubes and took this photo (which is fairly high magnification as you may be able to tell). Then I did a bit of research.

Temnocephalans (or Temnocephalids) are a type of flatworm (phylum Platyhelminthes), in the same class (Turbellaria) as things like Dugesia and Caenoplana. Unlike those 'roving' flatworms, Temnocephalans have a posterior sucker with which they anchor themselves, and a crown of tentacles (presumably for food capture?). As far as I know these guys don't do any harm to the crayfish they are found upon. Oh, and like Dugesia, you can see the eyespots of these critters giving them a cartoon-character appearance. To me, anyway. Posted by Picasa

Saturday, July 29, 2006

The Deep Blue

Excitement here as a couple of new arrivals have been added to the household. I spent a bit of time cleaning up a fishtank of mine, pulling up algae, adding some logs and doing a water change. I originally planned to put a handful of feeder yabbies in the tank (these are small Cherax destructor) and are very entertaining, but in making enquiries about them I was told of some cheap Marrons so snatched them up.

The Marron is Cherax tenuimanus ('slender hands'), a species of freshwater crayfish from the rivers of south-western Western Australia (that hotspot of biodiversity). Marrons are generally dark brown to black, but apparently this brilliant blue form occasionally occurs and has been bred for aquaria. The species is farmed for the table too, supposedly nicer than yabbies or redclaws.

Crayfish make very good aquarium animals. They do interesting things, like climb around, fight, attempt to escape, bulldoze the gravel, moult their exoskeletons and eat snails. A slightly more annoying trait is their tendency to tear up any plants and eat them, causing quite a mess.

The pair turned out to be both males, so I'll probably be in the market for a female at some stage. I'm a bit worried about the damage to the telson/uropods that one of them has experienced, as I've lost redclaws in the past to tail infections. Did you know that you can sex crayfish by examining the bases of their legs? On the base of the rear-most pair, each leg has a little projection in males (just visible on the photo to the right). Females lack this but have a couple of pores on the next pair of legs to the front). Upon mating, the male deposits a spermatophore between the female's last pair of legs, and she subsequently releases eggs and has them pass through the sperm on their way to the underside of the tail where they are held during development.

Hope these guys enjoy their new home and do well in it. Maybe one day I'll try to get hold of some Euastacus australasiensis for a bit of a contrast. Posted by Picasa

Friday, July 28, 2006

Glider-on-glider action!

... also known as the saga of the sugar-glider nestbox spycam (codename: possumporn).

You're probably bewildered so I'll start at the beginning, back in 2003 from memory. In my garden I had an Acacia elata which is a large wattle tree species, and during my nocturnal surveys of the garden I discovered that it was being visited by a small and very cute marsupial possum that I identified as the sugar glider (Petaurus breviceps). Excited to have these visitors, I constructed a nestbox for them, in order to provide an 'artificial hollow' as daytime retreat. Soon, gliders started using the box and I would watch them exit the box in the evening, glide to the nearest tree and disappear for a night's foraging (they feed on sap, manna, flowers and nectar etc.).

I got the idea of being able to see these animals inside the nestbox, so bought a small spycam, took the box out of the tree after the gliders had left, fitted the spycam in a top corner and rigged up a cable leading to a computer with motion-detection software. Later that night one of the gliders returned to the box and from then on I was able to see the goings-ons inside.

It was great - there were up to three gliders visiting regularly, sleeping, scuffling, scratching, coming and going; the real excitement begun in Spring 2003. The female lay on her back, pouch exposed, and I could see movement within! I then got glimpses of the two babies (very cute!) and eventually the female left them on their own in the nest while she foraged (till then she'd taken them with her). Soon after that, disaster struck.

Feral honeybees moved in. The audio from the box was a constant buzz and the gliders appeared terrified by the intruders. On that first day, it seemed to be 'scout' bees visiting, and probably from different hives too as they were fighting. The gliders scarpered (in daylight, which is a big risk), the female gathering up her young and taking them with her. The next day, the swarm moved in.

I poisoned the bees, cleaned up the box and replaced it. I'd also lined the roof and some of the sides with carpet as this supposedly doesn't give a stable substratum for the bees to build. The gliders must have been spooked and didn't return save for a few odd visits. The box got invaded again, but after a while the bees left. A second box that was given to me also got invaded. The camera cable broke. I was a bit slow to clean up the original box, until a few weeks ago.

I climbed the tree, lowered the box down, took the lid off, only to find a little glider face blinking up at me! It looked around then went back to sleep! I cleaned the camera, removed a bit of wax that was attached to the carpet, and once more put the box in the tree and connected it up.

So the glidercam is back up! There are two (a male and a female) that are regularly staying and visiting the box now. I've attempted to embed a short video that shows the male rubbing the 'ladder' with his forehead then climbing up to exit the box. There is a scent gland on the head (you can see it in the photo above) that is presumably used for territorial marking. A couple of days ago I saw the male rubbing head-to-head with the female! Hopefully the pair are more than just friends and we'll see some babies appearing in the warmer months!

Tuesday, July 25, 2006

Biting off more than you can chew

Just a quick post for today, to prove that I still exist (after a week-long field-trip followed by the whole beginning of a new semester thing).

Ever seen beautifully regular circles and ovals cut out of leaves in your garden? Maybe they looked like something had been eating very tidily, but those bits are not actually being eaten, but neatly snipped out and carried away by a type of bee called a Leafcutter (Megachile sp. such as the pictured M. serricauda). The females (ever the workers in the solitary bee world) snip two shapes (small circles and larger ovals) from leaves, carry them to a hole or crack (I've found nests in those little gaps you find between bricks in walls, bamboo canes are also apparently also used) and use them to construct the brood chambers. If you see those shapes in your garden you'd do well to watch them closely on a nice warm morning and hope a leafcutter comes around. They land in a few places and eventually select a good leaf (maybe by tenderness?), then astonishingly fast snip their way through the shape (as seen in the photo on the left). As the leaf cutout is removed it's curled between the bee's legs and as the last piece is severed the bee and leaf fall together into the air, whereupon the bee flies off too fast to follow in the direction of its nest.

As is generally the case with bees, the females collect pollen, moisten it with little nectar to form 'bee bread' upon which they lay an egg. For the leafcutter bees, this bee bread is made within a crack or hole that they've lined, with the oval leaf pieces, and is subsequently sealed, with the circular ones. Often a single hole has multiple cells constructed within it in a linear fashion (though I wonder if the first bee to emerge then chews through the rest of the cells to reach the entrance?).

Incidentally, the bee on the right is one that I encountered on a miserable and cold morning, and it appeared to have been caught out in the cold so to speak, and didn't make any effort to fly away.

Saturday, July 15, 2006

A Cool(oola) frog

Picture this - you've been tramping through hot and sticky Queensland rainforest on a summer's night, climbing up and down the sandy dune substrate. Suddenly, the path leads you out into a large open space, the moon illuminates the scene before you. You see virgin white sand ringing a large lake, Melaleuca trees scattered here and there on the banks, reeds emerging from the shallows. The sound-scape is equally rich; the frogs are out in force tonight. You hear the yapping of two types of rocket frog: the fast call of the slender and streamlined Litoria nasuta and the slightly slower call of the Wallum Rocket frog Litoria freycineti. There's another call at a higher frequency, sounding something like the squeak of a reluctant cork coming out of a bottle.

It's the species that is producing this noise that was so exciting to me on that night in December a couple of years ago. It's the Cooloola Sedge Frog, Litoria cooloolensis. Fitting name, considering Cooloola was the setting; it's just south of Fraser Island and has the same sort of environment as is found on that sandy isle. A lot of that area, between the dunes, is 'wallum', which is a type of boggy heathy environment often with Melaleuca; it's a habitat that occurs only in south-east Queensland and north-east NSW. These freshwater lakes are another great feature of the area, perfect for a moonlit swim.

So, to the frog! It's one of the most beautiful little treefrogs in my opinion. Quite similar to the Dwarf Treefrog Litoria fallax in size (~25mm), shape and call, though the green dorsum is finely speckled with black, and a quite obvious yellow is present on the flanks and legs. The flash colouration of this species is lovely - the thighs show a purple and an orange streak, and the armpit may have a bit of reddish orange too.

Revisiting the lake in the daylight, some of the frogs were basking on the emergent reeds. Like the one in the photo on the right, they would rest vertically on the stems and shuffle around the reed to stay on the opposite side to me!

Though on that night at that lake, the species was abundant, it's future may not be secure. IUCN lists this species as endangered:

"Listed as Endangered because its extent of occurrence is less than 5,000 km², its distribution is severely fragmented, and there is continuing decline in the extent and quality of its habitat in southeastern Queensland."

Hines, H., Meyer, E., Hero, J.-M., Newell, D. & Clarke, J. 2004. Litoria cooloolensis. In: IUCN 2006. 2006 IUCN Red List of Threatened Species. <>. Downloaded on 05 July 2006.

Litoria cooloolensis on the Frogs Australia network Posted by Picasa

Friday, July 14, 2006

Snake Pits

Just a quick photo without too much of a story for today; this is a Diamond python (Morelia spilota spilota) from the mid-north coast of NSW. Apart from its striking colouration and general good looks, pay special attention to the pits on the lower jaw below the eye - these are heat-sensing pits that the snake uses to locate its warm-blooded prey. Snakes in general don't have great eyesight, perhaps due to a fossorial ancestry. Posted by Picasa

Thursday, July 13, 2006

Mighty Mite

And now for something I know nothing about! I've tried before to get this critter identified, without any luck. All I can say is that it's a mite, and a pretty spectacular one at that. This one was under the bark of a blue-gum's trunk, a spot where I've seen them before in the past.

The lower photo is on 1 mm grid paper, indicating that the opisthosoma alone is around 5 mm in length, while the total span is just over 15 mm!

This animal is very active, constantly tapping and probing with the first pair of legs and running around. I have no idea what it eats - does it actively hunt invertebrate prey or does it quietly eat bits of the tree it lives on?

I'll have another go at getting an ID of this species; I'll update this post if anyone can shed any light on it. Posted by Picasa

Edit 14-07-06: Well folks, that was quick and easy, I've got an ID thanks to Bruce Halliday at CSIRO:
Your mite is indeed spectacular. It is a member of the family Erythraeidae (Prostigmata). I think it might be Rainbowia imperator (Hirst 1928) or a related species. These are beneficial predators in the garden, eating aphids and other small insects. The larval stage of the mite is a red parasite that attacks insects and spiders. Other related genera are Erythrites, Paratrombium, Caenotrombium.
Thanks Bruce!

Wednesday, July 12, 2006

More homeless bees

This group of bees is homeless for a completely different reason. Unlike the male Lipotriches, even the females of this species don't build nests. They don't collect pollen (the bee in the photo is just taking a drink of nectar for some energy). They don't raise their offspring at all. In fact, the lifestyle of these bees is completely different to what most people think of when bees are mentioned. These bees have taken a page - and a title - from the book of a peculiar group of birds: the cuckoos.

We all know how cuckoo birds lay their eggs in the nests of other birds. Cuckoo bees do the same thing, laying their eggs in the freshly provisioned nests of bees such as Blue banded bees and Teddy bear bees (Amegilla spp). This phenomenon is known as kleptoparasitism (i.e. parasitism by theft).

So that's why the bee on the left has to sit all alone out in the cold. I've once come across a dead shrub that was used as a night-time roost by half a dozen or so cuckoo bees. During the day they patrol areas visited by Amegilla bees (and in sunlight the blue really stands out and they can be seen from a long distance), then follow them to their burrow and eventually enter it (presumably when the host is absent) and lay an egg inside. Some cuckoo bees are equipped special mandibles used to kill any host offspring already present. Strangely enough, there have been reports that the host offspring isn't always killed, and it can make it through to adulthood - though it's malnourished and emerges at 1/4 of the size of a normal individual.

Apparently in bees this sort of thing is relatively common - up to 20% of all bees may be kleptoparasites. Australia has about 24 known species including this particular one, Thyreus nitidulus (other genera include Coelioxys and Inquilina which parasitise leafcutter bees and reed bees respectively though I've not seen these guys). Other Thyreus species have similar colourations - startling blue or white patches on a black background. Why such bold colourations in a creature that relies on stealth in order to follow its host and avoid detection? One hypothesis is that the colouration helps the bees maintain territories by being able to recognise conspecifics. Personally I've come up with another theory, though it requires some explanation.

Bees and other insects have completely different vision to us mammals. In fact, without going too much into it, they have two separate visual systems that kick in depending on the angle subtended by the object. But that's not important, what matters is how these vision systems lead to perception and recognition by the bee. There's been some interesting research done by scientists in Thaiwan on perception of Golden Orb-weaving spiders by bees. To cut a long story short, all those bright coloured spots you see on the spider may be the only thing the bee sees contrasting with the spider's background, which doesn't present a spider-shaped image, which means the bee doesn't recognise it as a danger, which leads to it blundering into the spider's web. That's a gross simplification, so read the original paper.

My point is, it's possible that there is a similar system at work here - if the bee only sees a few disconnected dots, it may not be able to recognise the cuckoo bee for what it is. The point is that it's important not to assume that what we see as blaringly obvious colouration may look completely different to a bee.

Well, this article has gone way over my word limit. Time for some refs then I'll call it a day.


Tso, I. M., Lin, C.-W. and Yang, E.-C. (2004). Colourful orb-weaving spiders, Nephila pilipes, through a bee's eyes. Journal of Experimental Biology 207(15): 2631-2637.

Dollin, A. (1999). The cloak and dagger cuckoo bees - "the bad relations". Aussie Bee 10: 4-5. Posted by Picasa

Edit: I should point out is that there is even another group of hymenopteran kleptoparasites: the cuckoo wasps (family Chrysididae). These creatures are brightly coloured too, with spectacular metallic colouration. Check out for the eye candy if nothing else.

Tuesday, July 11, 2006

A pile of ...

The image on the right is one which doesn't look like it would inspire a lot of excitement, does it? Presumably you can tell what it looks like: a little pile of bird droppings sitting on a lemon leaf.

Zoom in however (image below), and it tuns out to be not to be a present from an avian visitor but a superbly cryptic arachnid. It's known as the Bird-dropping spider (Celaenia sp.). By night it's an ambush predator, sitting with waiting arms to grab moths that fly by. By day it's a pile of crap - glamourous alter-ego isn't it? You can see how silk is used to anchor the abdomen to the leaf as well as to add some white to the disguise to mimic the pale uric acid excreted by birds. The purpose of this deceit is obvious - nothing really wants to munch on anything that's already been digested by something else (well, except dung beetles).

Oh - and those moths it feeds on; it turns out that they don't just flutter past by accident; the spider actually mimics the pheromone of the female in order to lure males! Read more on the Australian Museum's page on these critters.

Sunday, July 09, 2006

Bees on a twig

This little native bee species, Lipotriches excellens, turns up somewhere in my garden in the warm months of every year. Like many solitary bee species, the females have burrows in the ground somewhere, while the males live out in the wilds seemingly spending most of their time doing nothing, just hanging around in a big cluster on a dead twig somewhere. Sometimes there's the odd female in amongst the cluster with them; she's slightly larger and has more more gold colouration in the bands on the abdomen (Closely related species in the group are called "Green and Gold bees" for their colours)

Come spring, I'll be on the lookout for the new generation of males, they tend to use the one spot for the whole season. Posted by Picasa

Saturday, July 08, 2006

First Frog

Just realised that (shock, horror) I'd made it this far in my blog without a single frog photo! For those of you who aren't aware, frogs have always been one of my passions and a relatively frequent photographic subject. So, enter one of my favourite frogs. Doesn't it look ridiculous?

The pictured frog is Philoria kundagungan, commonly called the Yellow-bellied Mountain Frog. I found this individual at Cunningham's Gap in south-east Queensland and its distribution doesn't take it far afield from there. The group of frogs, 'Mountain frogs' that includes this species, is a bit strange; nowadays they all have small distributions and are associated with mountain tops, but fossils have been found at Riversleigh (in north-west Queensland), suggesting that these frogs had a larger distribution back in the day.

These frogs inhabit really wet leaf-litter habitats in and around mountain creek-beds, from whence you can hear their fart-like call. I was lucky to find this guy as my family and I were just passing through Cunningham's Gap and took a bushwalk during the day with the vague hope of finding one; this male obliged by calling as we were walking past. Posted by Picasa

Bibionid flies mating

One from this summer: a pair of flies (family Bibionidae) spotted mating in my garden. Quite a spectacular degree of sexual dimorphism - the female is the large colourful one with the small head, compared with the skinny male with the big head/eyes. Females can be quite conspicuous in the warmer months, flying slowly around lawns (the larvae feed on grass roots among other things). Posted by Picasa

Red Triangle Slug

Triboniophorus graefii, a common native slug around Sydney; it extends north into southern Queensland and has some isolated populations here and there; for example it's famous at Mt Kaputar where it occurs in a pink form. Other forms are bright red, and a particularly beautiful form is mango yellow with a red triangle. Years ago, before I knew what it was, I found a yellow form in my garden and the memory of it has really stuck with me.
Posted by Picasa

Friday, July 07, 2006

Spinifex with backdrop

That darned rock again; Uluru at sunrise with spinifex seed-spikes in the foreground. Apologies for all the desert shots. Posted by Picasa

Strange Neuropteran

Heoclisis fulvaThis is a weird bugger (I suspect it's in the insect order Neuroptera, thus being related to lacewings) also spotted on my desert trip. An owlfly perhaps? Posted by Picasa

Edit 24-08-06: Got an ID from Dr David Britton at the Australian Museum:

"It is an antlion, probably Heoclisis fulva, which is a large common and widespread species across Australia. It is a very hairy species which comes freely to light."

Thanks David!

That rock

Okay, I know we've all seen photos of Uluru, and judging by the number of tourists present, half the world has watched it as the sun sets, bathing the rock in its golden glow, changing its colours etc. etc... However, I consider myself priveleged to have seen the full moon rise from behind the rock. Posted by Picasa

Kings Canyon Morning

Heading out of Kings Canyon in central Australia, looking out over the plains on a cool winter's morning.

Tracks and traces

Just something I thought was cool when I saw it at Yulara near Uluru.