David Nelson's Photoblog

On the road again...

2008-12-03T12:03:00.001+11:00

Hey guys, I'm currently on the road, living out of my car and driving around Australia. Check out my adventures here

What happened?

2008-10-05T17:00:00.002+11:00

I'm going to put this out as a reader challenge while I do some research myself. I came across this somewhat disturbing spectacle in a local bit of bushland. The spider (which was on a vertical trunk as it happens) appears to be a huntsman which has been/is being consumed by some sort of parasitic fungus. It certainly makes me shudder. Apologies for the photo quality, I only had my happy snap camera with me at the time.

This one's done...

2008-10-05T16:47:00.000+11:00

I'd heard about these and seen photos, but last night was the first time I'd seen the Blue Mountains form of the Sydney Crayfish (Euastacus australasiensis)... truly an astonishing colour.

Sydney Crayfish, Euastacus australasiensis

Assorted Simpson desert photos

2008-09-30T19:43:00.001+10:00

I mentioned that I've done a bit of volunteer work in the Simpson recently - without further ado, here are a selection of photos. Remember to check out the rest of the album for any photos I've deemed less... publishable!

Varanus gilleni, Pygmy mulga monitor

Nephrurus laevis, Knob-tailed gecko

Ctenophorus nuchalis, Central netted dragon

Morethia ruficauda, Fire-tailed skink

Ctenotus pantherinus, Panther skink

Varanus brevicauda, Short-tailed pygmy monitor - smallest monitor in the world

Ctenophorus isolepis - Military dragon

Rhynchoedura ornata - Beaked Gecko

Ningaui rideii

Varanus gouldii, Gould's sand goanna

Scorpion

Varanus eremius, Spinifex goanna

Mantid

Sand tracks - lizard

Tenebrionid & tracks

Moon and spnifex clump

Moonrise in the Gidgee

Strzelecki Gibber

2008-09-29T15:32:00.001+10:00

Spent a bit of time out around Lyndhurst (the start of the Strzelecki track) in South Australia recently. Saw a couple of herps.

Sleepy lizard / Bobtail / Shingleback / Pine-cone lizard (Tiliqua rugosa)

Pebble-mimic dragon, Tympanocryptis sp.

Marbled Gecko, Christinus marmoratus.

Curracabundi

2008-09-29T09:05:00.001+10:00

I was recently lucky enough to visit Curracabundi National Park - located out past Gloucester near Nowendoc. The park has been acquired fairly recently, largely for its value as a stronghold for the endangered Brush-tailed Rock Wallaby. I was on a trip studying this species so got to get some great looks at them and spend some time observing and photographing a colony. As always there were lots of other interesting things to see.

N.B. I'm experimenting with a different system of posting images whereby I upload a picasa web album (in this case 17 images) and then embed a selection of the best photos in the blog post itself. Each image you see will link to the photo in the album, from where you can view the rest of the photos. I'm trying this out as a way of making more photos available for viewing - not just the best ones that I want to put in a post. Let me know if you like/dislike/have problems with the system.

Greenhood

Lace Monitor, Varanus varius - this big animal was causing some consternation amongst the rock wallabies.

Brush-tailed Rock Wallaby

Brush-tailed Rock Wallabies with pouch joey

Rock wallabies spend their days on rocky outcrops, often basking in the sun and squabbling over the best positions on the rocks. When evening comes the wallabies venture out from their refugia to feed.

Monkeycot Bluff & Barnard River

Egernia striolata living in the rocky crevices

Tongue Orchid, Dendrobium linguiforme

Quick pic: Aphid close-up

2008-09-02T03:03:00.003+10:00

Donkey orchid

2008-07-28T12:50:00.001+10:00

Diuris maculata, I believe.

Simpson desert trip highlight

2008-07-21T11:46:00.003+10:00

Together with the frogs, of course, this thorny devil (Moloch horridus) was one of the stars of the trip...

Simpson Desert part 2: Frogs!

2008-07-08T13:08:00.003+10:00

I've just got back after another trip into the Simpson. Luckily there was a bit of rain out there before we arrived which resulted in a couple of frogs being active!

The first I found on the trip out there when we stopped for the night - between Nyngan and Bourke. It's Neobatrachus sudelli, the Painted Burrowing Frog. I could hear frogs calling but they were a long way off.

In the Simpson there was only about 15 mm, enough to wet the sand but not enough to fill clay pans where frogs would breed. I searched at night but it was actually thanks to our pitfall traps that we caught two frogs.

One was the beautiful Notaden nichollsi, the Desert Spadefoot Toad (a close relative of N. bennetti, the Holy Cross Toad). Of course these frogs aren't real toads, but rather ground frogs in the Myobatrachid family.

The other was a Neobatrachus species like the first I saw, but it's N. centralis this time, the Trilling Frog. Check out the vertical pupil!

These desert frogs are all burrowers - they dig downwards through the sand and sit out the dry periods. With a bit of rain they surface, feed (largely on termites and ants), breed if they can, then dig themselves back under the sand to wait.

I was very happy to see these gorgeous little frogs - there are many desert adapted species in Australia that I've heard a lot about but this was the first time I'd seen any.

Broad headed snakes rock on

2008-06-05T09:38:00.003+10:00

I've just been out at Yengo helping a fellow student with some field work - you can read about the project in today's Sydney Morning Herald article here. It was a real treat to see my first broad-head (Hoplocephalus bungaroides): this one was nestled in a rock crevice.

Another highlight was this Thick tailed (or Barking) gecko (Underwoodisaurus milli) which we found under a piece of tin. He put on this impressive threat display and even barked and lunged at me a few times as I took his picture.

Trip report: Simpson desert, part 1

2008-05-29T10:14:00.007+10:00

Back in April, immediately after handing in my thesis, I bought myself a swag and headed out to the Simpson desert. I was a volunteer on a trip run by the "Dickman Lab" aka the Institute of Wildlife Research at Sydney Uni. This group of researchers carries out a range of ecological studies in the arid zone, from the effects of feral cats and foxes, fire ecology, population dynamics and the effects of grazing. Chris Dickman has been leading research the particular study area that I was visiting in the Simpson for around 20 years.

It was great to see the country change - dry up - flatten out - as we headed out of Sydney, through the mountains and across the western plains. Through Bourke, Cunnamulla, Charleville, Windorah and Bedourie. Lying under the starry sky on the first night, just over the NSW-Queensland border, I could feel the tension of weeks in front of a computer in the city slide off me.

Highlights of the drive:
- first nights under the stars
- Mulga (King brown) snake on the road (above)
- channel country
- Wedge-tailed eagle nest (below)

After two and a half days on the road we had arrived!

Miscellaneous update

2008-05-27T10:37:00.002+10:00

Assuming there are still some people that either subscribe or occasionally check this blog for updates, I thought I'd provide a brief rundown of my activities recently.

Honours is all handed in and I'm awaiting my mark. My vague ambition for the next year or so is to see as much of Australia as possible (road trip!), do some volunteer work, and maybe think about what I want to do next (PhD? Work? Continue avoiding either?).

Since handing in I've been on some field trips - to the Simpson desert, the Warrumbungles and out to Wellington caves. I'll post some photos from the desert along with some comments in the near future.

I also have a backlog of photos (e.g. from the top end and some frogging trips here in Sydney) that I may get around to posting.

Coat of many colours

2008-02-27T15:57:00.000+11:00

I'm back in Sydney! I have lots of photos from the top end that I'll probably throw up from time to time, though I'm rather busy for the moment with uni work.

Almost immediately after getting back I went for a trip up to the mid-north coast. On the way, picnicing at Karuah, I spotted this lovely moth.

A quick look on Don Herbison-Evans' site revealed what it was - Agarista agricola, 'Joseph's coat moth' (Noctuidae).

This one is a male - and it was very flighty though always returned to this creeper (I assume a food plant). It finally stayed put and I snuck up with guerilla stealth. A fraction of a second after I took this shot it was suddenly off again - this time because a female had turned up and he was in pursuit!

The pair fluttered around for a while though the female seemed to show no interest in her suitor. She did however lead me to another food plant in the area.

This vine was almost entirely defoliated, and I spotted the caterpillar below as well as a few of the same species that had only hatched recently.

Not great photos, happy-snaps only, though I was very impressed with the colouration on both the adult and the larval forms.

Night Tiger

2008-02-01T15:52:00.000+11:00

This snake is a real beauty - it's the brown tree snake, Boiga irregularis. You might recall it's the species that has caused ecological havoc on Guam where it's introduced. In Australia however, it's native, and up here in the top end we have the so-called 'night tiger' form.

Big, scary arthropods

2008-01-28T21:29:00.000+11:00

Saw these two impressive creatures on the road last night.

Possibly this one could be called a bird-eating spider?

Scutigeromorph centipede:

Busy Buildup

2007-12-14T13:00:00.000+11:00

The rains have only been tantalising so far - puddles form then dry up in the baking sun of the following day. Frogs breed only to have their progeny fossilised in mud as it dries. Lightning fills the horizon as a storm approaches, but it is reduced to nothing but a breeze by the time it gets here.

There are plenty of animals out and about but I haven't been too active with the camera so far. The sight of these blue-triangle butterflies today inspired me to grab a photo.

Back in the Top End

2007-11-13T18:19:00.000+11:00

As of about a week ago I've been back up in the Northern Territory. I'm up here to conduct my honours field work and will be returning south in mid-february.

It's nice to be re-acquainted with the heat, the storms, frogs, reptiles, plants and birds that I became used to during my last stay up here, though there are lots of other exciting things that I'm experiencing now that I didn't encounter then. The landscape has definitely changed in my absence and it's fascinating to see the biological changes that are driven by the seasons.

Below are a few photos from the last couple of days. Hopefully I'll keep the blog updated intermittently while I'm up here though I expect that as time goes on (and runs out) that I'll have few spare minutes to do so.

Litoria meiriana, the Rockhole Frog, from Litchfield National Park.

Spiny-tailed Gecko, Strophrurus ciliaris.

Frill-Necked Lizard, Chlamydosaurus kingii.

Harlequin

2007-10-22T22:15:00.000+10:00

Ah, the things that excite me... A group of harlequin bugs (family Scutellidae) are growing up on my rosella bush this year. These insects seem to have a particular disposition for members of the hibiscus family (Malvacae), so they're often found on things like cotton plants and cow-itch trees.

Mantispid

2007-10-18T11:33:00.001+10:00

Just spotted this little insect in the garden. It's a mantispid or mantis-fly. I'd forgive you if, after a casual glance, you were to call it a mantid, however it actually belongs in an entirely different order - Neuroptera - which contains the lacewings. I was going to write more info on these critters however the annotated budak has already done so. So click the link to see another species and find out more.

Another successful field trip

2007-10-15T18:19:00.000+10:00

Had the weekend away up in the vicinity of Smith's Lake - I normally go up there a couple of times a year and spend some time frogging, herping, insecting, birding etc. and generally see at least something of note. The trip this time was particularly noteworthy for two quite interesting reptiles.

The first was this dragon - the southern forest or angle-headed dragon (Hypsilurus spinipes). I'd never seen one of these before so was stoked to discover it in a patch of rainforest. It's a species that can be quite hard to spot due to its good camouflague and arboreal habits, luckily this one was just at knee-height clinging to a small tree-trunk.

The second reptile of note was a rough-scaled snake (Tropidechis carinatus), another 'lifer'* for me. This snake is known to be very venomous and is known to have caused human mortalities. We came across this individual sitting on a palm-frond just beside a pond - it's likely that it was sitting in wait for a frog to hop past.

This is the red-eyed treefrog (Litoria chloris). Only when it rains a lot does this species suddenly appear, breed, and disappear again. I suspect it lives the majority of its life in the canopy. Luckily we had some good rain and a few individuals showed up despite the somewhat cool temperatures.

Photographed here is Litoria barringtonensis, one of the frogs in that confusing group of green stream frogs. The black spots distinguish this species from...

... Litoria phyllochroa. Interesting to get these two species together at the one site. Despite their similar appearance they do have distinctive calls.

Finally, a photograph of a spawn mass of the tusked frog (Adelotus brevis). Unlike the more familiar spawn of Limnodynastes species, the eggs of Adelotus are entirely unpigmented.

Inside the hive

2007-10-09T09:45:00.000+10:00

I got my colony of the native stingless bee Trigona carbonaria in late November last year. The housing for Trigona is two half-boxes on top of each other, (an optional small third box can be placed on top for honey), so when a colony is doing well it can be 'split' by separating the two boxes and placing them on corresponding empty boxes.

My colony was a 'split', so it was composed of a full bottom box and an empty top box and 'honey super' on top, and seemed to be going very strong from the activity around the entrance. So, I thought I'd take the honey box off and see how the inner workings of the hive were going. Here are some photos from the event.

This is the main cavity of the box - you can see that it's nearly full of brood (the spiral structure up the top of the photo), pollen and nectar pots. Close-ups to follow.

This is the 'honey super' which sits on top. The piece of board in the photo below sits between this and the rest of the box cavity with small spaces at each end - the idea is that the brood spiral doesn't extend into the honey box, but honey and pollen are stored here, so the honey can be harvested without damaging the brood.

Divider board with amazing wax structure.

Pollen pots with some spilt honey.

The spiral brood. Each little pot, when sealed, contains an egg or larva and enough supplies for it to develop into an adult. You can see some of the pots around the edges are open, still being stocked or waiting for the queen to oviposit.

Looks like the colony's doing very well - I expect they will stock the honey super more in the coming months, and it will be ready for a split before too long.

Update... Pectinate...

2007-09-20T11:36:00.000+10:00

Okay, it's been a shockingly long time since updates of any regularity. I've been back down here in (cold) Sydney since early July, starting honours. I'll be heading up to the top end again in about a month for honours field-work. Coming back mid-February, writing up for about a month, then I'll be free. Now that will feel weird!

As for the future of this blog... well for now I don't see any point in shutting it down despite the fact that posts are likely to be rather infrequent. We'll see what happens.

Got a photo published in the Sydney Morning Herald recently, thanks to my supervisor.

Had a photo used in a recent publication - remember that big beautiful mite, well turns out that similar looking things were around in the Early Cretaceous.

Dunlop J. A. (2007) A large parasitengonid mite (Acari, Erythraeoidea) from the Early Cretaceous Crato Formation of Brazil. Fossil Record 10, 91-8. doi: 10.1002/mmng.200700001

Took the camera out a couple of days ago, it's been hibernating since being back in Sydney. Snapped this shot of a beetle's antennae. Not a technically great photo but I thought I'd share it anyway as the structure ('pectinate' meaning comb-shaped) is quite impressive.

Fire!

2007-06-25T23:45:00.000+10:00

Just thought this one taken tonight by the side of the road was apt, following the previous post on Macrozamias resprouting.

Assorted

2007-06-19T21:12:00.000+10:00

A biting fly was annoying me as I walked along a fenceline a couple of weeks ago. I paused to photograph this Nephila and the fly blundered into the web! Bonus! You can see that the spider was actually already eating something.

A Rainbow Bee Eater. I've never seen them down in Sydney and have really fallen in love with their colours, voices, flight and tail-feathers (hidden in this shot).

Macrozamias - Fire - Regrowth

2007-06-17T22:28:00.000+10:00

It seems like fire is a huge ecological force everywhere in Australia, and the Top End is no exception. You can imagine how the massive amounts of vegetation generated in the wet season can lead to huge fuel loads and intense fires. The question up here is the same as it is in Sydney where I'm from - how often should areas be burnt to maintain biodiversity? I don't know enough about this topic to discuss it intelligently, but it's definitely something that it's not easy to forget as smoke fills the air on a daily basis and roadside fires are a common sight.

One such roadside fire was burning a few weeks ago, and the flora has shown its ability to regenerate with great enthusiasm. The plants that really catch my eye are the cycads - Macrozamias. So without further ado, here is a series of photos illustrating the regrowth of these plants.

New camera - new photos!

2007-05-22T22:43:00.000+10:00

New toy arrived today, and after the infuriating initial battery charge, I managed to get out in the last few minutes of sunlight to have a quick play. Nothing special. But I'm a very happy chappy!

The new camera is the Pentax K10D by the way. First impression is that I'll have a lot of fun with it!

Bizzare File Snakes and the Runoff

2007-05-21T21:49:00.001+10:00

We all know about the seasons in the wet-dry tropics, right? There's the Wet, and there's the Dry. True, but there's also Buildup (aka suicide season - I've not experienced it but it's apparently hot, humid, yet infuriatingly it doesn't rain), and when the rain has finished, Runoff. It's called that for an obvious reason - there's so much water around from the amount of rain that has fallen, and it's all got to go somewhere... creeks, rivers, dams etcetera all continue to flow for quite some time following the last of the rains.

As the water recedes, many aquatic organisms risk becoming trapped, and desperately try to travel upstream to permanent water. At a nearby creek, just such an event has been occurring recently. In addition to the millions of fish, shrimp and crayfish, the most exciting inhabitants of the waterway are the entirely aquatic file snakes occurring there in amazing numbers, trying to cross the culvert under the road where the water flows swiftly.

File snakes are a very small family - the Acrochordidae, comprising three species. The species around here is Acrochordus arafurae, the Arafura file snake. The family gets its name from the characteristic rasp like skin - though to aid in capturing the slippery fish that these snakes prey upon. From this skin, which is loose and baggy, to its bull-dog face; its thin bifurcated tongue to the way it can hardly move out of the water (the classic analogy compares this snake with a wet sock) - this is a snake that is simply unlike any other I've ever come across.

They're almost completely harmless. Non-venomous and they don't bite. I say almost, though. Apparently, these snakes may eat catfish, and the venomous spines of the latter may pierce the snake's skin and pose a danger when handling them! I've heard that they adopt a 'fishing pose' - the tail is anchored in some tree or pandanus roots while the body and head lolls in the current, hoping to detect a fish as it brushes by seeking shelter. The low metabolism of the species means it doesn't need to surface very frequently to breathe.

Trivia: they're supposedly quite a tasty dish in indigenous culture!

Litoria dahlii, Dahl's Aquatic Frog

2007-05-12T19:22:00.000+10:00

Visitors to Fogg Dam that know a bit about herps generally try to see two animals that are almost icons of the place. One of these is the Water Python, Liasis mackloti. These snakes occur at incredibly high densities in the floodplains of this region, feasting on the staggeringly abundant Dusky Rats (Rattus colletti). The biomass of these two species is said to exceed that of an equal area of the Serengeti plains. But I digress.

The other animal that this area is 'famous' for is the subject of this post, Litoria dahlii, Dahl's Aquatic Frog. Again, this species is one of the most conspicuous animals of the floodplains. On wet nights the Arnhem Highway can be absolutely covered in them. To me, this frog is one of the more interesting in the area, there are some aspects of its ecology that are quite unique.

But firstly, who was Dahl? A bit of googling turned up a Knut Dahl, a native of Norway, who did some exploring and collecting in this part of Australia, including Arnhem land, in the late 19th century. Not sure of his connection to the species' describer, George Boulenger (who seems to have been quite a clever character), though I suppose that it's possible Knut was the collector of the species.

The other part of this species' common name is also quite correct; one of the peculiar things about this species is that it's largely aquatic. Although they do seem to travel considerable distances over land by night, their main place of habitation tends to be in water around the edges of dams and ponds, where they are often spotted clinging to or sitting on top of aquatic vegetation such as lilly pads or algal mats on the surface. Their aquatic nature goes further - they are one of the few species of frog in Australia that are known to feed on underwater items. I've seen them eat things whilst both they and their prey are floating on the surface by lunging forward by means of a thrust of those back legs with their webbed toes.

You might recognise some similarities to other Australian frogs - the 'complex' of frogs that this species belongs to is the Bell Frogs, containing things like Sydney's endangered Green and Golden Bell frog (Litoria aurea) and the Motorbike frog of WA (Litoria moorei). All the frogs in this rough group seem to be rather aquatic, though if I'm not mistaken L. dahlii is the most so. A further trait of the group is some daytime activity, and this is true of L. dahlii too - I've seen them basking in the afternoon sun out at Fogg dam.

Another interesting thing about the species is its diet. The menu includes frogs, either of the same species or another. At places where the species is abundant, the scream of a young frog as it's eaten by a larger individual is a sound that may be heard occasionally. I suspect that small fish are taken as they doze in the shallows at night. Tadpoles are definitely eaten too. There's even an account in the literature of a frog trying to eat a roadkilled death adder! That's one reference I'll have to try to track down!

Apologies for the nearly month-long absence of posts, I'll try to post something else tomorrow!

Whuuuut?

2007-04-19T00:27:00.000+10:00

I'm sure they're actually very intelligent animals...

The definition of cute...

2007-04-14T15:57:00.000+10:00

...has to be a frog that can sit on the nail of my little-finger, with plenty of room to spare...

It's a metamorph of Litoria microbelos, the smallest Australian treefrog.

Snake vs Frog Round II

2007-04-12T22:31:00.000+10:00

As I was traipsing along a bush track the other day, a young Roth's Treefrog (Litoria rothii) suddenly leapt out from beside the track, with a Golden Tree-snake (Dendrelaphis punctulata) in hot pursuit. They both noticed me in the same instant and the three of us froze - the frog halted its hopping, the snake slid to a stop just past the frog (which was superbly camoflagued against the sand), my hand reaching for the camera being my only movement.

The snake regained its composure, and began tongue-flicking and moving its head backwards, forwards and side-to-side, trying to pick up the scent of its quarry. The frog remained petrified, but to no avail. The snake closed in, spotted the frog, and quickly struck.

The consumption of this frog was much faster than the last one I witnessed, a mere mouthful to the snake. Interestingly, you can see from the photos that this snake has something wrong with its eye - it's dark and clouded and I suspect it could not see out of this eye very well, if at all. Indeed, as I moved around to the other side of the snake for a photo of its good eye, it suddenly realised I was there and made haste into the bush.

Both of these animals are largely tree-dwelling, and it's my guess that the snake, upon coming across the frog in a tree or pandanus, then had to pursue it after it jumped to the ground.

Something tells me it's not really a fair fight...

Afternoon of dragonflies

2007-04-06T22:37:00.000+10:00

Set out towards Fogg Dam tonight with the camera and the intention to take some photos. Ended up shooting nothing but dragonflies, as the light faded (so depth of field and shutter-speed were real issues).

Got a couple of keepers, thought they made a nice little series. Dragonflies are in incredible abundance up here. But then, everything is!

More photos, less text

2007-04-01T16:32:00.000+10:00

The beautiful tadpole of Litoria tornieri.

Barn owl. Impressive talons!

Not a commonly encountered snake around here - the White-bellied mangrove snake (Fordonia leucobalia). Apparently a crab specialist!

The skink-eating Lialis burtonis, Burton's Legless Lizard. Check out how the jaws hinge far behind the eye!

Snake: 1, Frog: 0

2007-03-31T22:07:00.000+10:00

These photos (somewhat gory to some people's tastes) really speak for themselves. Suffice to say that I heard the screaming of the frog, located the pair and proceeded to photograph the whole process. The snake is a Keelback, Tropidonophis mairii, and the frog is a Cyclorana australis, the Giant Burrowing frog.

Random images...

2007-03-18T19:47:00.000+11:00

Quiet Monday night here, thought I'd put some images up (I've been photographing some cool things up here, may as well share some shots).

That's the famous Litoria caerulea, the Green Treefrog. They're an animal of the forest around here, venturing out into flooded areas on forest margins to breed when it's really wet.

As the sun sets over Fogg Dam, a Pied Heron poses with its breeding-plumage-ponytails.

Well, they call them floodplains for a reason... you can see a couple of Jabiru on the edge of what used to be a road.

And here's a closer look at that Northern Territory icon, the Jabiru, or Black Necked Stork to some people (but it's not black at all!).

These guys are male Black Whip-snakes, fighting. It's a mating thing, I'm told; trying to tire the other guy out so he can't mate with a nearby female. Whip-snakes are frighteningly fast creatures.

More to come, eventually...

Update, two months on

2007-03-12T00:57:00.000+11:00

Well it's been a while since I've typed into this little box and published it for the world to see. The lack of posts is due to my being pretty busy, the somewhat limited computing facilities, and the fact that, being in a place that's so biodiverse and full of life, I'm generally trying to get out and see things in my free time.

So, what's been going on up here? We got some real rain for a few days about two weeks ago, caused by the tropical low that then turned into cyclone George (which hit to the west of here). The sheer amount of water that fell absolutely saturated the area; the floodplains are absolutely, well, flooded. The Arnhem Highway is closed not far from here at the Adelaide River (despite being raised above the floodplains, the water was well over the road).

I have to go to bed, so I'll wrap up with a recent panorama of the famous (at least in some circles) Fogg Dam. The dam is on the left (the road runs over the three-metre-high dam wall), on the right are the floodplains. Oh, and that big green clump of vegetation on the road was a floating island of grass that tore off and drifted onto the wall... A heap of birds - egrets, herons, cormorants, spoonbills and the odd Jabiru (night herons at night) have been hanging around the where the water is coming over, making easy meals of the fish travelling between the dam and floodplains. And then there are the crocs...

Uncertain future...

2007-01-01T23:32:00.000+11:00

I'm not sure what will happen to my blogging over the next few months.

On the 4th of January, I'll be leaving Sydney to work as a research assistant near Fogg Dam, south-east of Darwin. To me this is super-exciting, I'll be able to see so many great things as well as begin to immerse myself in the world of research.

I don't know what to expect in terms of computer and internet access when I'm there, though I'm sure I'll be taking heaps of blog-worthy photos and discovering new things. I'm considering starting a separate blog in order to share these things as well as record what I'm doing and how I'm going up there for whoever would be interested in that (friends and family mainly I suppose). Alternatively, I might just stick the odd piece up here and not bother with a new blog. Or I might not even be able or inclined to blog while I'm away, in that case you'll hear from me when I get back.

So... stay tuned. Not too sure what's going to happen, but if I do start something separate I shall announce it here.

'Tis the season for giving and receivin'

2007-01-01T23:14:00.000+11:00

I was trying to chase down some specific info on this subject to accompany these shots that I took a few days ago, but haven't managed to find what I was after. So I'll post them with just a short explanation.

What you're seeing are the larvae - caterpillars - of the Imperial Blue butterfly, Jalmenus evagoras being fussed over by ants. The ants get a heap of nutritious substances which are exuded especially for them by the caterpillars (and, from memory, some drug-like substances that modify their behaviour), and in return these ants will quickly dispatch of anything that comes near their defenseless charges or even lands nearby on the plant (Acacia decurrens, the Sydney Green Wattle in this case, though A. longifolia is another favourite).

The attention given by the ants seems to reach a frenzied peak leading up to pupation, and the ants even protect pupae quite vigorously.

Bad bee photos

2006-12-20T09:19:00.000+11:00

Took some quick snaps of the variety of native bees visiting some flowering Angophora bakeri yesterday morning. Nothing I was really too proud of in the bunch, but I thought I'd share a few of the photos anyway. My main problems were lack of sharpness (too much sunlight - so the flash no longer froze the motion of the bees and camera shake) and lack of good poses (well that's what I get for spending so little time on the job).

The only IDs I'll attempt are:
No. 3: Lipotriches sp.
No. 4: Yellow-spot bee (family Colletidae, Amphylaeus, Hylaeus or Meroglossa sp.) plus ~~one of the red bees, Lasioglossum sp.~~ a Homalictus species, possibly H. brisbanensis.

Camera batteries are charged and I'll have another go when the weather fines up.

Didymuria violescens

2006-12-19T09:46:00.000+11:00

The phasmid species that I wrote about that showed phase change appears to be Didymuria violescens. This photo is of an adult male - I also have some females that have just reached adulthood.

This page lists 'purple winged stick insect' and 'spur-legged stick insect' as common names. I've actually induced one of the males to do a defensive/startle display where it spreads its wings, showing off the purple membranous hind-wings. The habitat seems to match; the page also reports that the species tends to be found at high elevations.

Leaping larvae

2006-12-18T18:08:00.000+11:00

Snail mentioned "cheese-skippers", the jumping maggots of the carrion flies (Piophilidae).

It's slightly less obvious why piophilids are called cheese-skippers. You need to see the maggots at work before the common name makes sense. When disturbed, they curl up, grabbing their ... ahem ...anal papillae with their mouthparts. And then they let go, springing several centimetres into the air. Boo!

Jumping in dipteran larvae additionally occurs in several other, taxonomically diverse families. These include Tephritidae (fruit-flies), Cecidomyiidae (gall midges), Agromyzidae (leaf miner flies), Clusiidae (umm...?) and Phoridae (scuttle flies). (Phew, those are a few fly families that you don't come across very often! I wouldn't know a cecidomyiid from Adam!).

Additionally, jumping has been noticed in the Neriidae (long-legged flies). The neriid that occurs in Sydney is Telostylinus angusticollis. This animal is cultured at UNSW and used for studies of sexual selection and aging, as the males have exaggerated features and fight for resources and access to females.

That's a female pictured on the left; males are more slender and elongate. They fight head-to-head, striking each-other with their front legs, heads and antennae. Males also put those long legs to use standing guard over a female - literally.

Larvae of the species, pictured top and bottom, develop in rotting bark, such as that of Acacia longifolia. When they are close to pupation, they evacuate the gut, emerge from their substrate, and at this stage are thought to use jumping as a way of getting off their tree and getting to the soil where they are thought to pupate.

This photo shows what a larva looks like before (left) and after (right) evacuating its gut. Only when it's done this does it gain the ability to jump.

You can see the mechanism in the top photo - the maggot reaches around, grabs a 'ledge' between its last two abdominal segments using its oral hooks, then it contracts its longitudinal muscles. This builds up tension which is then released when the oral hooks are disengaged. Pop!

They're not terribly good jumpers. Not like piophilids which can jump about 50 cm from the surface of a corpse. No, these guys have a lot of trouble jumping from a horizontal surface. They actually do it best if they're upside down - they'll hang off, suspended by their rear ends, before reaching up and jumping downwards off the surface. But put one on a dry surface and crawling doesn't work, so it will wriggle around and try to jump. Normally it doesn't work so well (as in the top photo), as the larva will be lying on its side and therefore not have a great deal to push off.

Jumping in fly larvae is a novel solution to the problem of moving fast and far if you're a small soft-bodied organism. The place where the larva grows up, be it rotting bark, a piece of fruit or a decaying corpse, is generally not a great place to pupate. And a juicy maggot in the open is vulnerable to predation, parasitism, dessication... With a couple of quick jumps, a larva can get away from its food source without crawling laboriously over its surface, settle down and start the business of metamorphosis.

Friday Frog - Amplexus

2006-12-15T23:08:00.000+11:00

This image was taken a couple of months ago of a species called the Whirring Treefrog, Litoria revelata, from the mid-north coast, where it's relatively abundant in some areas, though it's not a commonly encountered frog in general.

This photo shows, of course, the hold called 'amplexus' where the male (the little yellow fellow in this case) grasps the female in preparation for oviposition. The poor female then has to drag the male around to the spawning site(s) she chooses. Amplexus is either axillary (the male grasps the female in the armpits) as in this species, or inguinal (around the waist).

Male Litoria, at least in my experience, often seem to take on yellow colouration when they're trying to find mates. A classic example is of course the ground dwelling species L. lesueuri and similar. I wonder if it's some sort of advertisement?

Litoria revelata has a high-pitched whirring call, sort of like a sped-up version of the closely related L. verreauxii. At the site where these two were photographed, they can occur in huge numbers, and it's absolutely ear-splitting when the frogs are really going for it. It also seems as if the other species that occur at the site just give up - and shut up - rather than try to compete over the din.

Jumping Spider (quick photo)

2006-12-09T19:38:00.000+11:00

Go

2006-12-09T15:18:00.000+11:00

check out the new Circus of the Spineless - #15!

Broughton Island

2006-12-09T11:12:00.000+11:00

Looking South-east from Pinker Top.

Broughton Island, sized a couple of kilometres across, sticks out of the ocean north-east of Nelson Bay. I recently paid it a visit to do some volunteer work for an ongoing frog project that's being conducted on the island. It was a great place to visit, truly the location made the work much more pleasant.

Esmeralda cove

The island is part of the Myall Lakes National park, but there are several shacks looking out over Esmeralda cove, owned by fishing clubs and leased from the park. No-one's supposed to live there permanently, but some of the blokes seem to spend a good part of the year on the island.

Flat rock

Believe it or not, this photo above is of the best frog site on the island, and it's home to several hundred Green and Golden Bell Frogs (Litoria aurea), the endangered frog that caused venue headaches during the planning of the Sydney Olympics after it turned up in the Homebush Brickpit. There are numerous small ponds on that rock platform, fed by seeps of fresh water. Every now and then a big wave inundates the ponds, killing any tadpoles and other aquatic life. It's a crazy place for frogs to survive, but bell frogs are notorious for doing well in habitats with regimes of regular disturbance, in fact they often seem to be out-competed in static ponds.

Green and Golden Bell Frog (Litoria aurea) on prickly pear

Bell frog on algal mat

Apart from bell frogs, the other species of frog that's on the island is the Striped Marsh Frog. Stripeys are a very common species in suburban Sydney, but are in lower numbers than the bell frogs on this island. There's a handful of reptiles on the island, introduced rats and rabbits, and a nice array of sea-birds. The little penguin colony that exists there is the northern-most population of the species. Numerous Mutton-birds call from their burrows at night, and seem very confused when encountered on the paths that cross the top of the island.

Little (fairy) penguin

Sooty Oystercatcher

Looking back towards Esmeralda cove

One final bell frog

Panoramas compiled using Autostitch v.2.186

Just a phase

2006-11-20T15:02:00.000+11:00

These two phasmids (stick insects) are the same species. In fact they're probably siblings. And surprisingly, they're about three years old.

I keep another species of phasmid, the spiny leaf insect (Extatosoma tiaratum), and I was quite surprised a few weeks ago when I had hatchlings emerging from the container with this species in it that were obviously not Extatosoma. Thinking back, the only source of the eggs of this species that I can think of was from some adults I collected from the snowy mountains in the summer of 2003. I must have just thrown the eggs in with my Extatosoma eggs, and now, three years on, they've decided to hatch. Unfortunately I don't know what species they are - when they become adults I should be able to find out.

The really interesting thing about these nymphs is that they show what's referred to as 'kentromorphic' phase change. If an individual grows up in isolation or low density, it will display a cryptic uniform green colouration. If it's in high density however, it turns the colour of the one on the right above - that is highly contrasting black, yellow and white. That's classic warning colouration.

Locusts show a similar phenomenon. Green when solitary, yellow and black when crowded. The interesting thing is that both locusts and some phasmid species (including the ones showing kentromorphic phases) plague. That is to say the population occasionally skyrockets and you've got a swarm of hungry locusts or phasmids on the move as they deplete local food sources.

So these insects seem to use their colours in quite different ways. When the population density is low, being conspicuous isn't a good idea - predators may not encounter the insects often enough to learn to avoid the aposematic signal, so it's better to remain camoflagued. But when there are heaps of conspecifics around, predators will get the message pretty quickly and there's a real benefit to advertising unpalatability.

References:
Key, K. H. L. 1957. Kentromorphic phases in three species of phasmatodea. Australian Journal of Zoology 5:247-284.

http://home.swiftdsl.com.au/~pmiller/stick_insects/papers/key1957/index.html

Friday Frog - Metamorph

2006-11-17T22:50:00.000+11:00

Spotted this tiny fellow hanging on between a couple of blades of grass/sedge by the edge of a large pond a few weeks back. It was in the process of metamorphosing and still had a significant tail.

Too small to really tell what it is at ~1 cm long, though I suspect it's a Common Eastern Froglet (Crinia signifera). Given where it was however, there are a few other species that are possibilities.

At this stage in a frog's life, it generally doesn't eat at all. Its gut is still in the transitional stage between the long spiral-shaped gut it required for its herbivorous diet as a tadpole and the relatively short gut it will need to digest invertebrates. Plus the gape is still widening to give it a big froggy grin, and isn't much use in grabbing prey. So a lot of the energy the metamorph gains is from the resorption of the tail. Numerous other changes are going on; the transition to land involves the switch from using gills to lungs and skin for oxygen absorption, plus the skin needs to toughen up and get ready for retaining moisture.

Ancient insects

2006-11-13T22:17:00.000+11:00

Funnily enough, today in my house I came across two of these insects, called Silverfish (order Thysanura), in separate rooms. They quite often occur in human habitations, though I've never seen them before in mine. Was it just a coincidence that I saw my first and second on the same day, or am I witnessing the overrunning of the whole house?

These insects, together with the similar looking bristletails (Archaeognatha), are generally thought of as 'primitive' insects. Looking at the phylogeny of insects (e.g. here at tolweb.org) it's obvious that the two groups branched off quite early from the rest of the insects. Silverfish and bristletails were originally collectively called the 'Apterygota' (without wings), though this grouping is now considered artificial in the sense that the two orders diverged separately, so do not constitute a clade.

So they're thought to have characters pretty similar to whatever the ancestral insect was. And they seem to survive pretty well by sticking to their guns, dated as they are.

They can eat almost anything, and this keeps them happy places we might think are pretty nutrient poor. Take human houses, libraries, museums; silverfish happily eat book binding glue, paper, photos, fabrics (natural and synthetic)... nothing I'd enjoy munching on.

I sort invertebrate pitfall trap contents brought back from the Simpson Desert, a fairly inhospitable part of the earth. Thysanura turn up regularly in the samples; they obviously don't mind the hot, dry conditions where nutrients aren't a thing to waste.

So I won't be too worried if these things have taken a hold in my house. Hopefully they won't eat through all my books. Moreover, it's fun to see something that looks like it just crawled out of the ocean living happily in our world of processed and synthetic materials.

Further Reading:
Wikipedia: Silverfish
Wikipedia: Insect Evolution

More cute frogginess

2006-11-11T10:17:00.000+11:00

Need I say more?

Friday Frog - Yum!

2006-11-10T11:58:00.000+11:00

We get a yearly plague of Grapevine moth caterpillars on our ornamental grape. I spotted this Peron's Treefrog (Litoria peronii) just outside our front door just a few minutes ago chowing down on one of the little guys.

Personally I reckon this image should qualify for cute overload, what do you think?

(I have some other images of the frog acting very clumsily but endearingly if you think they'd be better...)

Portrait of a dwarf treefrog

2006-11-08T14:06:00.000+11:00

This little guy came in yesterday through the frog rescue service. They're commonly transported around the country in fruit and vegetables.

They're also exceedingly cute little frogs. Their diminutive size of only around 25 mm earns them the common name of 'Dwarf Treefrogs'. There are two species that look almost identical: Litoria fallax and L. bicolor, the former occurring up the east coast to Cairns, the latter from there around the north coast and into WA. I'm not entirely confident about what species this one is, though I can supposedly measure the head width: body length ratio to find out for sure.

Sunday squamate

2006-11-05T22:37:00.000+11:00

A couple of reptile images from that field trip I mentioned that took place a month or so ago.

It looks a bit like a blue-tongue only its tongue is pink. So guess what it's called?

Yup, a pink tongue. Hemisphaeriodon gerrardii to be precise. It's a nocturnal, largely arboreal skink with impressive hooked claws and a flexible tail for climbing. During frogging forays they are occasionally spotted hanging on happily a few metres up a tree trunk.

They've reputedly got a tremendous amount of bite force, used in separating snail shells from their owners (don't tell Snail!).

Glider babies

2006-11-04T16:11:00.000+11:00

Here's a short video from the nestbox camera from a couple of nights ago.

The adults hadn't been visiting for a couple of weeks but now they're back and the mum has revealed her couple of cute little secrets to the world.

Paralysis tick follow-up

2006-11-04T12:00:00.000+11:00

In a previous post I showed a photo that, it turns out, is of an adult female paralysis tick, Ixodes holocyclus.

I realised how little I knew about these guys - everyone's heard of the name and has some sort of fear of getting one, but what's the actual danger?

It tuns out that there's three things that may be problematic. The first is the obvious one - paralysis.

When the tick feeds, it releases a toxin from its salivary glands that spreads from the site of the tick bite. This toxin interferes with the motor neurones and the signals they send to the muscles. So the muscles can't contract - paralysis.

Remove the tick and the problem goes away quite quickly. But it may have left behind some nasty pathogens.

There's rickettsia - a bacterium-like organism that causes 'tick typhus' or 'spotted fever'. Doesn't sound too terrible: rashes, fever and flu-like symptoms.

Another possible problem is Lyme disease, caused by a bacterium, though it's not actually confirmed in Australia. Both of these diseases can be treated with antibiotics.

The final thing that ticks may cause is an allergic reaction, and this may be pretty severe, even life-threatening in the case of anaphylaxis.

Take a look at these links on paralysis ticks for more information:
Sydney uni medical entomology
Tick Alert Group Support

Circus 14 and a nice link

2006-11-03T19:07:00.000+11:00

The Halloween edition of Circus of the Spineless is out over at the neurophilosopher's weblog.

Also I stumbled by chance upon cool page that some of you may be interested in. You may remember a couple of years ago a story hit the news about a new insect order being discovered/described. Confined to Africa, the Mantophasmatodea is a strange group looking like something halfway between a mantid (Mantodea) and a phasmid/stick insect (Phasmatodea). I seem to remember at the time one of the common names being used was 'gladiators' and another is apparently 'heelwalkers' due to the way the feet are positioned.

Anyway I remember that trying to find information at the time was pretty fruitless, so it was good to finally get some info and photos via some museums in South Africa. Check it out

What's that dunny bug?

2006-11-01T15:07:00.000+11:00

Ever been annoyed in the shower by tiny little flying things?

Ever actually tried to work out what they are, only to be baffled by a combination of their tiny size and confusing features?

Well I have. These things are tiny - the ones in my bathroom (ahem... yep it needs cleaning) have a wingspan of only 2-3 mm. There's a larger species (the one in the photo) that I sometimes see which is about 5 mm. In case you're wondering, I actually nabbed this one from a bathroom and brought it home for some photos, which seems somehow wrong...

And what are they? My first thought was a moth. Scaly-looking wings, hairy etc. But the antennae don't look right. And there's apparently only one set of wings.

Turns out they're a fly (order Diptera). They live in the suborder of flies called Nematocera (thread-like antennae) along with things like mosquitos, the other suborder being the Brachycera (short antennae) which are the more typical houseflies, robberflies etcetera.
And the family of these guys? Psychodidae.

They've got a variety of common names - washroom flies, drain-flies (reflecting their frequent use of bathrooms) and moth-flies.

They apparently like that gunk of fungus and god knows what else that accumulates in shower drains and the like. I wouldn't be surprised if they did well in sewer environments too.

What's more, my species looks awfully like what is identified as Clogmia albipunctata on this page (go there to see some other funky species too). That's in Japan; the species also appears common in America. I wonder where they're originally from?

Links:
http://en.wikipedia.org/wiki/Psychodidae

Yawn

2006-10-31T22:29:00.000+11:00

I'm sleepy. Just an image for tonight. It's a small species of native bee that visits my garden frequently, one of the Lipotriches species. I think it's L. excellens, though flavoviridus is another possibility. It's foraging on a Lobelia flower.

I should start searching for groups of males hanging around in the garden.

Beauty and deceit...

2006-10-29T13:54:00.000+11:00

I've been having great fun with my combination of extension tubes (70mm or so) plus my 50mm macro lens racked out to minimum focus. Total reproduction ratio is 2.4:1 on the sensor, meaning that the full frame covers about 10 x 6.5 mm.

Impressive figures, but what I love is that the photos that result give me something of the feeling I get from peering down a dissecting microscope. The minute beauty of nature's tiny creatures is apparent in a way that's well beyond the limits of the unassisted eye.

And so to the subject of this post, the emerald cuckoo wasp (family Chrysididae). I'm sure that most people don't realise how common these are. I'll bet they'd turn a few more heads if they were over five millimetres in length. If you want to see some for yourself, just keep your eyes on a brick wall (corners seem to be preferred) in the sun on a warm day.

What they're after are the nests of other wasps. Things like mud-dauber wasps I'll bet, though I've never actually seen one have any success in its search. Like the cuckoo bees that I've written about in the past, these wasps are kleptoparasites, laying their eggs in the nests of other wasps whereupon the larvae eat the provisions and/or the host's larva.

Have a look at chrysis.net for more information and some great pics of cuckoo wasps from all over the world. There's a great part of the story that I gleamed from that page. After the cuckoo wasp makes a hole in the mud structure of its host, it lays its egg inside, then seals the hole back up! Apparently this is to stop mould getting in and wreaking havoc.

And of course, the metallic iridescence that characterises most of the group is another example of structural colour, rather than pigmental.

More of the blues...

2006-10-21T19:11:00.000+10:00

Well that was unbelievably lucky.

I just went out into the garden to attempt to find an animal called Caenoplana coerulea or the Blue Planarian (family Geoplanidae). I rarely see it around, occasionally on wet nights I suppose. One recent observation of it was seeing one preying upon a portugese millipede (Ommatoiulus moreleti).

Anyway, I didn't have high hopes but I was after a couple of photos so thought I'd wander around and try to find one. I sometimes see them under rocks and logs and the odd plant pot.

I lifted a single paver and there one was! Got my photos then went out again and continued searching, but with no luck this time around.

The bottom photo indicates how this creature got its common name and species epithet. The undersurface is a lovely blue colour (coerulea or caerulea means blue).

Interestingly there's another similar geoplanid species called Bipalium kewense, the shovel-headed garden worm. Check out the AustMus page for some pics and info. I bring it up because it was originally described in England from Kew gardens (hence kewense), and occurs all over the globe including in Sydney but is now thought to have originated somewhere in Indo-China, and spread from there in pot plant soil and the like.

I bring it up because I've now found out that Caenoplana is a good traveller too! When it was found in California in the fourties, it got described as a new species, Geoplana vaga, before the mistake was discovered. Now Ogren says: "Other localities are known in Tallahassee, Florida (1961); Statesboro, Georgia (1972); San Antonio, Texas (1978) and James Island, Charleston, [South Carolina]". And North Carolina. And Iowa, as of 1999.

I wonder where else it's got to? And what's the secret to the success of this species and Bipalium?

Reference:
Ogren, R.E. (1989). Redescription and a new name for the blue land planarian Geoplana vaga Hyman now considered conspecific with Caenoplana coerulea Moseley from Australia (Turbellaria: Tricladida: Geoplanidae). Journal of the Pennsylvania Academy of Science 63, 135-142.

Blue on Black

2006-10-21T10:08:00.000+10:00

Blue on black,
tears on a river
Push on a shove,
it don't mean much
- 'Blue on Black', Kenny Wayne Shepherd Band

Don't mean much? Take a look at the colours of the Ulysses butterfly (Papilio ulysses) from Australia's tropics and say that again. The amazing contrast between the two regions of this butterfly's wings is actually teaching us some things about optics that we didn't realise.

The butterflies are actually doing two separate things - creating not only the brightest blue, but also the blackest black to make the contrast as strong as possible.

You can just see the tiny scales that coat the surfaces of the wings in the photo on the right. But each of those scales is covered with further structures so minute that they actually do strange things with the light that hits the scale. Take a look at the structure of those matt black scales.

From Vukusic et al. (2004, Figure 2b). This is a scanning electron micrograph of the ridges and latticing on a scale (bar represents 2 μm). While there's black pigment on the surfaces and interspersed throughout the material, this pigment can only absorb so much light. The rest is reflected. But the structure is such that the light actually seems to bounce around in those pits (which are tiny; a thousandth of a millimetre across by my estimate) and get scattered towards the absorbing pigment, some of it getting absorbed each time it encounters the pigment. The end result is an absorbance as high as 95%. This is actually the first time that the use of microstructures to create black colouration has been demonstrated.

Now take a look at the fine structure of the blue scales (right; from Vukusic et al, 2001; fig. 3; scale bars: a: 1 μm, b: 20 μm). Those ridges are still there though the complex pits within them are not. So it's not really the surface structure that's responsible for the brilliant azure.

Also from Vukusic et al, (2001, figure 5, scale bars from top: 3 μm, 1 μm and 1 μm), this final figure shows some cross-sections through the scale. The physics is a bit complicated and I don't understand it fully myself, but from what I gather, the 3D matrix of air-filled spaces (often referred to as a 'multilayer nanostructure') within the scale leads to a phenomenon called 'coherent scattering'. So some wavelengths undergo interference and are 'cancelled out' while others are reinforced (i.e. the blue).

So there it is. A great illustration of two completely different types of structural colour and how they are used to produce a conspicuous distinction between a bright colour and its background. Blue on black never looked so amazing.

References:
Prum, R. O., T. Quinn, and R. H. Torres. 2005. Anatomically diverse butterfly scales all produce structural colours by coherent scattering. The Journal of Experimental Biology 209:748-765.
Vukusic, P., J. R. Sambles, and C. R. Lawrence. 2004. Structurally assisted blackness in butterfly scales. Proceedings of the Royal Society of London Series B (Biological Sciences), Biology Letters 271:S237-S239.
Vukusic, P., R. Sambles, C. R. Lawrence, and G. Wakeley. 2001. Sculpted-multilayer optical effects in two species of Papilio butterfly. Applied Optics 40:1116-1125.

Hang on a Tick...

2006-10-19T20:33:00.000+10:00

Just a novelty image that I took of a huge tick that I noticed clinging to me while I was out on a walk whilst out in the field.

No doubt it was preparing to have a go at me, luckily I noticed it first.

Following the leader

2006-10-18T23:25:00.000+10:00

Found a couple of these cool animals on a field trip recently. No, it's not an earthworm, it's actually a young Blackish Blind Snake (Ramphotyphlops nigrescens). I was reminded of the following great story concerning these beasts.

They're a highly specialised snake species - while we occasionally get them at the surface at night, a large proportion of a blind snake's life is spent underground (and hence the reduction of the eyes to small pigment spots). And the diet of these creatures? Ants - specifically they get into the galleries and feast on the larvae and pupae. Obviously ants aren't always the most obliging of creatures and this may explain the smooth surface of the blind snake that offers no purchase for a set of angry ant mandibles.

As it turns out, at least one of the way these guys find their food is by following the scent trails of worker ants! Even trails a week old are still followed. When one encounters an ant trail, it stops, tongue flicks the trail before following it, tongue-flicking as it goes. Eventually it hopefully ends up at the ant nest where it feasts on the developing young.

But the story doesn't end there.

There's a species of snake called the Bandy Bandy (Vermicella annulata) which feeds pretty much exclusively on blind snakes. It's a beautiful creature (though I've not seen one), boldly annulated in black and white. Offer it a scent trail of a blind snake and lo and behold it's transfixed; progressing along the trail while flicking its tongue. Trails of non-prey species are ignored.

So if you ever see a bandy bandy or a blind snake making its way along the ground with a determined look in its eye, think about the way in which both these snakes are specialised to use their olfactory environment to track down their hard-to-find prey.

References:
Greenlees, M., J. K. Webb, and R. Shine. 2005. Led by the blind: bandy bandy snakes Vermicella annulata (Elapidae) follow blindsnake chemical trails. Copeia 2005:184-187.

Webb, J. K., and R. Shine. 1992. To find an ant: trail-following behaviour in the eastern Australian blindsnake Rhamphotyphlops nigrescens. Animal Behaviour 43:941-948.

Wee buggers

2006-10-18T23:20:00.000+10:00

These newly-hatched plant bug nymphs were found aggregating on a lemon leaf in the garden and I decided to try illuminating them through the leaf.

Don't think I really got the composition perfect though I think it's still an interesting enough image.

On the nose

2006-10-13T16:50:00.000+10:00

It's a busy time of the year with end of semester projects being wrapped up and assignment due dates looming. Don't even mention exams.

Took a break from research to grab some photos of a planthopper that I noticed in the garden. I believe this is a Dictyopharid planthopper in the superfamily Fulgoroidea. You really expect to find nostrils on the end of that snout, don't you?

Used the 50mm macro with extra extension to get this 'portrait' of a bug that's only about 10mm long.

Orchids of spring

2006-10-04T22:26:00.000+10:00

I had a great long weekend in the field - spending some time up on the mid-north coast around Smith's Lake. Lots of interesting animals and even a few plants that I had to admit were very attractive and interesting.

I saw these four species of orchid within a few hours while on a walk first skirting then within some dry sclerophyll forest. The first one to catch my eye was the Sun Orchid (Thelymitra sp.) poking up through some grass.

Next a species which always thoroughly amazes me. It's the aptly named Flying Duck Orchid (Caleana sp., possibly C. major). I've seen these guys only once before but was happy to find them again, their flower stalks sprouting out of the disused 4WD track.

In similar places to the duck orchids were a few Beard Orchids (Calochilus sp.)

Finally, somewhat inconspicuous in amongst the grass, these tiny onion orchids (Microtis sp.) were in good numbers. Each of those little blooms is tiny, less than a centimetre long!

As I have time I'll slowly put up some more photos and information of other things I saw and photographed - it was quite a rich weekend sightings-wise.

Embryo-thon

2006-09-27T21:53:00.000+10:00

For today, not only do we have another Litoria peronii embryo (left), but a rather smaller beastie.

This afternoon I spotted the little guy on the right attached to some weed in one of my aquaria, so fished it out and put in on a microscope slide to try to get a photo, seeing as embryography seems to be my current obsession.

It's an egg of the Crimson Spotted Rainbowfish, Melanotaenia duboulayi. Close to hatching too. You can see a photo of a newly hatched larva here.

Now we're talking about something of a different scale to the frog embryos here. My estimate for the diameter of the frog eggs at this stage is 4 mm. The rainbowfish egg is about 1mm. To photograph it I used a 28mm lens reversed on bellows with about 13 cm of extension. It's a bit hard to see how the fish is arranged in the capsule, but basically it's got its body and tail coiled around its head. Those eyes even swivel at this stage.

Roll up!

2006-09-26T19:18:00.000+10:00

The circus is in town again this time courtesy of Deep Sea News.

Another tiny tot

2006-09-26T16:11:00.000+10:00

Well here's another little embryo photo, taken today. I'm really getting into this! For the record this is Litoria peronii, the Perons Treefrog. Read earlier post.

Bit tricky getting the capsule to show up, required some experimentation with the lighting and positioning to get it right, but I think it paid off.

If you look closely you can see the external gill filaments - little fingery projections behind where the operculum is forming. You can see the eye developing too.

I'm going to call this stage 22.

Photography info

2006-09-26T13:43:00.000+10:00

I've had a few requests to describe my photographic set-up, in particular the gear I used for Development in the duckweed.

My camera is a 6 megapixel digital SLR, the Pentax *ist D. It's a few years old now but still does a good job and has served me well. I think that in particular its big bright viewfinder is great for critical focusing, and the ability to use older lenses is a good thing for the student budget. I shoot only RAW these days, it really can't be beaten for the ability to change parameters like exposure, white balance, correct tints etc.

My two macro lenses are the brilliant Pentax FA 50mm f/2.8 macro and the cult classic Kiron 105mm f/2.8 macro. I use the latter for most of my flash work and with animals where the extra working distance is required. The 50mm comes in handy for high magnification stuff such as the frog egg photos where I used extension tubes for about 2:1 reproduction. Both of these lenses go down to 1:1 magnification but are frequently used for non-macro work too.

I try to use available light when possible but it becomes increasingly frustrating with camera shake at high magnification, subject movement, light loss... so I have the Pentax AF360FGZ flash which I use in off-camera conjunction with the onboard flash for things like frog photos. For higher magnification work I have an old battered manual ring flash with a PC sync connection which I just handold either around the lens or slightly to one side (used this for the egg photos). Generally the soft lighting it gives isn't ideal but it's the best thing I have for getting light onto subjects only centimetres from the lens.

(Edit: I've now started using my normal flash just handheld for the photos and prefer the results)

I don't use a tripod very often but for the egg photos I did set the camera up and just went and took a photo every now and then after positioning the flash. One frustration was reflection of the flash off the water's surface. I just had to play around with the angle of the camera and flash to avoid it.

My general bit of advice for photographers is to play around with things. Try different combinations, don't be afraid to use older lenses and extension tubes, bellows, reversing rings, close-up filters etc. Even compact cameras without interchangable lenses can deliver stunning and high quality results when paired with close-up filters or similar. Of course this sort of photography involves a lot of trial and error, but critically examine your 'dud' photos to decide what went wrong and try to improve things for next time. Practice on mundane subjects so you know what you're doing when something exciting comes along. And always try to get a photo of the interesting things you see, even if it's a relatively boring 'record' shot. Don't be reluctant to get the camera out of the bag, I know bitterly from experience how much you'll regret it later.

For the record, my other equipment:
Pentax A* 300mm f/4
Pentax K 55mm f/1.8
Pentax A 50mm f/2
Pentax A 28mm f/2
Pentax A 24mm f/2.8
Zenitar 16mm f/2.8 fisheye

Pentax manual bellows
CompactDrive Portable hard drive for storage
Manfrotto 190D tripod with 486 ball head
Manfrotto 679B monopod

Development in the duckweed

2006-09-25T15:50:00.000+10:00

A few nights ago the Perons Treefrogs (Litoria peronii) in my garden spawned for the first time this season. Two years ago when they spawned I took a few photos of the developing eggs in their early stages, and a few minutes ago I took a few more shots of a later developmental stage. What the early shots in particular show is to me quite amazing.

So it all begins one warm night when a female decides on the man she wants and they embrace in amplexus. She deposits the eggs singly or in small clumps and he immediately fertilises them.

I check the pond at 7:45 in the morning and find this. The eggs are only at the 4-cell stage labelled Stage 4 (modified Gosner stage from Anstis 2002). That means there have only been two cell divisions. Now that is cool.

An hour later, 8:35, and another cell division has occurred. The eggs are now at stage 5 and consist of eight cells. You can clearly see the division between the animal (top) and vegetal (bottom) poles.

It's 9:20 now, and stage 6 (16 cell)

10:30 and the cells are getting smaller and smaller (stage 7-8ish)

The cells are scarcely distinguishable from each other at midday

The surface is now almost entirely smooth at 4:45 in the afternoon, after stage 9. Next stop, gastrulation! But I don't have photos of it. So there's a big gap between now and the next photo.

So this is the stage of the little guys in the tubs outside now as I type (stage 19ish). They're already capable of doing a bit of wriggling within the egg, and will hatch over the next few days. Interestingly, there's often what appears to be a bit of staggered development. So some of the embryos are more advanced than these ones, and will probably hatch sooner. Some stay in the capsules for ages.

Reference: Anstis, M. 2002. Tadpoles of South-eastern Australia: A guide with keys. Reed New Holland (Australia).

Holy jumpin' flatworms batman!

2006-09-23T11:17:00.000+10:00

Saw this big monster in a creek last night along with a heap of its smaller brethren.

It's the Sydney Crayfish, Euastacus australasiensis. Wouldn't want to try to pick that guy up, even if I avoided those nasty claws there are still those painful looking spikes to contend with. Truly a well defended beast.

Close inspection pays off as usual, you can see those funny looking oval things on its carapace and claws - zoom in on the photo and what do you see?

Temnocephalans of course.

Friday Frog?

2006-09-22T00:19:00.000+10:00

I've considered making a weekly frog theme, with an anuran species or photo 'featured'. But I probably couldn't be bothered to make sure I do it every week. So for (probably) today only, enjoy your frog of the week. (Golly, this is three frog posts and four vertebrate posts in a row!)

This frog is Litoria phyllochroa, the Leaf Green Treefrog. It's a small creek and stream dweller that I'm lucky enough to have quite near in my area. They call in the warmer months from vegetation fringing the water.

The taxonomy of the species and its close relatives are a bit confused at the moment. The problem is frogs in this group occur up the coast from right down south up into southern Queensland. And there have historically been problems with the names and type specimens and all that. There's nudidigitus in there somewhere. Fingers must be naked I suppose. There's pearsoniana floating around too. And don't forget barringtonensis.

Truth is I can't remember which is which (or if its resolved or not) and a quick literature search didn't give me the instant joy I was hoping for. I'll give it a bit more searching and try to get the picture straight.

But I'm pretty sure this one is phyllochroa. The type locality for phyllochroa is Sydney, so that helps.

In the meantime, enjoy your froggy friday.

Toadally awesome!

2006-09-19T18:16:00.000+10:00

I won't say much at this juncture, other than to say that I see the animal on the right in my future if all goes according to plan...

Want to know more? Never kissed a toad? Never heard of Team Bufo? All shall be revealed in time.

Another from last night

2006-09-15T23:24:00.000+10:00

These little frogs (Pseudophryne australis, Red-crowned Toadlets) were calling in small numbers last night. This one wouldn't stay still for a photo shoot, but the upside is that I have some good photos showing how these frogs crawl rather than hop (similar to toads, giving them the 'toadlet' moniker).

Little cuties!

Previous post on the species

Playing possum

2006-09-15T10:19:00.000+10:00

I was very lucky last night while on a wander in the bush to come across one of these critters - it's an Eastern Pygmy Possum, Cercartetus nanus.

It's one of those animals where it's very hard to say how common they are, because even where they are in good numbers you just don't see them.

I spotted its eyeshine off in the heath and thought it was a treefrog, but moving in closer I was able to get a good look.

These little guys eat mainly nectar and pollen, though with some insects too depending on abundance. I liked this comment from here

"C. nanus is able to catch flying insects with one paw"

I'd like to see that!

Hovering visit

2006-09-12T19:20:00.000+10:00

Just a quickie today, bit busy with uni work and all that. Thought I would post an image, so here's something I've always thought was quite pretty. It's a hoverfly/dronefly (family Syrphidae) that I occasionally see in the warmer months though it doesn't generally hang around to be photographed. I found it at night for this photo.

The eyes of this beast impress me greatly. Pretty. Oh, and if anyone could tell me what that thing on its back (to the rear of the thorax, looks transparent?) is I'd be much obliged.

Darn it, I've got all these great blog posts lined up in my mind (for example, the story of the teaser creature) but don't have the time right now to write them. They will come eventally, I promise!

More sponging off a certain other blog

2006-09-03T23:09:00.000+10:00

Yet again, A Snail's Eye View has a nice post, this time on Helicarionid 'semi-slugs' and I'm just posting a picture of mine and handing you over to Snail for the info.

This one was spotted in the Myall Lakes region of the NSW mid-north coast.

Orange things

2006-09-03T13:03:00.000+10:00

A walk in the bush last night turned up quite a few interesting things and a few good photos too.

On the left is a velvet mite, a teensy little leaf-litter predator. They've got a great soft felty appearance. Generally I see them in scarlet but this one as you can see is mottled orange and red.

The next little critter I happened upon is a type of beetle that I haven't run into before. As you can see it has a bold orange and black colouration, but whats more it lives on and in a bright orange bracket fungus! This raises the question of whether the colouration in this case is aposematic (warning colouration) or camoflague! Or, I wonder, is the beetle sequestering both the pigment and the toxins from its fungus food?

It was surprisingly easy to get a family ID. They're family Erotylidae, having the common name of 'Pleasing Fungus Beetles". Pleasing indeed.

As you can see from the photos, they appear to be quite, erm, social. You can also see the holes in which I presume they live. Oh, and you can also make out their bright orange frass.

Deep-Sea News omission?

2006-09-02T17:56:00.000+10:00

Did this mysterious creature turn up gasping for water after being dragged up from its ocean trench home?

No, it's living happily in my fishtank along with about a dozen of its siblings. It's a days-old Crimson-spotted Rainbowfish (Melanotaenia duboulayi).

These guys are small! Only a matter of millimetres long and less than a millimetre wide. So photography is quite a challenge as you could imagine.

Day at the circus

2006-09-02T10:21:00.000+10:00

For those of you who don't follow Circus of the Spineless, the twelfth circus is up at Sunbeams from Cucumbers. So have a look at some of the interesting inverts from around the world. Including Sydney, Australia funnily enough...

Rust and ash

2006-08-30T23:12:00.000+10:00

Was just about to go to bed when this cute image caught my eye. It's two different colourations of the red-backed toadlet Pseudophryne coriacea. Nice little frogs.

Wandering where to pupate?

2006-08-29T23:21:00.000+10:00

Snail over at A Snail's Eye View has written about Danaus plexippus, the Monarch or Wanderer butterfly here. What better opportunity to post a photo of the lovely larva! It's sitting on the seed pod of one of the species' host plants, Gomphocarpus, the swan plant, and appears to be in some sort of stand-off with a hemipteran of some description.

It's not a species I'm overly familiar with and in fact I think this is one of the only times I've ever seen the caterpillar.

Teaser III

2006-08-29T20:21:00.000+10:00

So what's our little beastie doing here? And what are those funny looking things on its back? You may wonder... All shall be revealed in good time my friends.

Teaser II

2006-08-29T19:59:00.000+10:00

This image probably won't help anyone very much, but it's sort of inspired by darky's comments regarding the mouthparts of the beetle.

That said, you could probably actually get down to species from this photo if you knew where to look.

Oh, and if anyone's interested, I've upgraded to blogger beta which turns out to be a mixed blessing. It appears to be no longer compatible with Picasa. And the new template tools looked promising but unfortunately were too rudimentary and inflexible for my needs.

Teaser - Subterranean beast

2006-08-27T14:04:00.000+10:00

While on a walk at night recently I came upon a little beastie that happened to be active. It's a species that has a really interesting story to it, which I'll be spreading out over several posts. Or, at least, I'll show a few photos to get your interest up before revealing what it is. Unless someone guesses before that... Feel free to have a go.

Frog in the hole

2006-08-22T08:14:00.000+10:00

This is a photo that I always find rather cute. It shows three Peron's Treefrogs (Litoria peronii) peeking out of their daytime shelter prior to moving out and commencing the night's foraging.

I've always had this species in my garden though recently they seem to be having great success. The main 'source' population for the area has historically been a golf-course pond about a kilometre away, from which the frogs disperse into the suburbs (in some cases I've found tiny little frogs still with tail stubs appearing in my garden in late summer after making the mammoth journey).

The last two seasons, however, the frogs have bred in my garden, in bathtubs and other containers of water lying around. So there are more cute little baby frogs around than usual.

The shelter is a big hit with them; it's actually a hanging pot that has a separate reservoir on the bottom for holding water and keeping the soil moist. The frogs come and go through that little hole and spend their days nestled up in the crevice at the top.

Personally I find it pretty unlikely that all the frogs that found this spot did so independently (and in a count a couple of days ago there were something like four adults and three juveniles like the one at the top of the photo). So I'll be doing a bit of an investigation in my garden and elsewhere to try to determine whether these frogs are using some sort of scent-cue to locate shelters used by other frogs. I'm also interested in whether these frogs will choose to aggregate given the opportunity to spread themselves out in plenty of shelters.

So stay tuned, these frogs are going to become active in another couple of weeks and they're likely to do other interesting things like call, pair up and breed.

Red and yellow and green and blue and...

2006-08-19T14:47:00.000+10:00

Shock! A vertebrate and it's not a frog! No story today, just a purty birdie doing its thing.

Rain, spring and slugs

2006-08-16T21:59:00.000+10:00

I'm not sure whether these slugs are active in winter, but last night I spotted this little blighter wandering across a wet leaf, and I'm going to take it as another 'sign of spring'. Yep, it's a Red-Triangle Slug (Triboniophorus graefei); I've shown some photos of the species in the past.

The difference is that this one's a juvenile which is in the process of losing the three dark longitudinal lines (juvenile colouration) and gaining the red triangle that's seen in adults.

Oh, and another sign of warmer weather here tonight - the sound of a little microbat flying over.

Common as mud Eastern Froglet

2006-08-15T20:53:00.000+10:00

If you live in coastal south-eastern Australia, chances are you've encountered at least one frog species. And this is probably it. It's the Common Eastern Froglet, Crinia signifera. You've probably at least heard its call - vocalised even in the day, all year round. Curiously, individual or groups of males call in concert and out of phase with other individuals/groups. Hard to explain, but basically the classic 'call' that you hear of this frog is made up of at least two frogs at different pitches.

I found the frog on the left (photographed semi-submerged in water) when out in the bush a couple of weeks ago - it appeared swimming around in a small pool in a stream. Despite my presence, it kept its vocal sac semi-inflated.

It reminded me of a C. signifera that I found a few years ago (pictured right). This frog stayed completely inflated despite being handled, prodded and photographed!

Casting the net

2006-08-13T09:50:00.000+10:00

While I was out frogging a couple of weeks ago I was surprised to find a certain spider that I'm familiar with, Deinopis subrufa or the Net-Casting Spider. Surprised because it was the middle of Winter, when most honest invertebrates are dead, inactive or overwintering as eggs. So, an opportunity to show some photos and describe the species. Of course, a lot of you would have already learnt about this critter from Life in the Undergrowth (funnily enough it was actually I who suggested it for inclusion in the series to one of the BBC team's researchers).

As you can see, Deinopis doesn't build a web. Rather, it creates the small rectangular net out of a wooly bluish silk (below left), and holds the corners as it hangs from silken infrastructure at night. When an unsuspecting prey item trundles past below it, the spider stretches the net out and down over its victim. The spider relies heavily on its vision to spot its prey, and to do this has some spectacular eyes.

I found out something interesting about this animal's eyes recently. Photoreceptor cells have photopigments residing on their membranes, so a high surface area is required to pack in lots of pigment and absorb lots of light. This is achieved by having cilia or microvilli (rhabdomeres).

So you'd expect a creature like Deinopis to have receptors packed with rhabdomeres. However, if you were to grab a spider in the daytime and have a look at its photoreceptors, you'd find that its receptors had only about 15% of their space occupied by rhabdomeres - not too impressive. But during the daytime, the spider just rests and doesn't need to see very well; plus there's a lot more light available. In the night-time, when it's ready for ambush, if you looked at its receptors again, you'd find that a whopping 90% of each receptor's space is filled with rhabdomeres. That increase translates to a 74% photon catch at night-time compared with 6% in the day! About 2 hours after sunrise, the spider is actually destroying the (presumably costly) surplus membrane and then rebuilding it at dusk.

Oh - and another tidbit about the eyes of this animal: they're single-lensed, just like ours and unlike the compound eyes of insects. And for the photographers out there that drool over lenses that are f/1.2, consider the F-number of the eyes of this spider: f/0.58! Human eyes come in much more poorly at about f/2.1 in the dark and f/8.3 in bright light.

References:

Blest, A. D., 1978. The rapid synthesis and destruction of photoreceptor membrane by a dinopid spider: a daily cycle. Proceedings of the Royal Society of London Series B. 200:463-483.

Clever frog puts eggs in multiple baskets

2006-08-12T21:00:00.000+10:00

It's that time of the year where I'm about sick of the cold. It's depressing to look around and find so few invertebrates active. I start telling myself that it's just about spring-time already. Actually today was quite nice in Sydney, the sun shone and it was t-shirt weather for most of the day. Yesterday I saw a Spring Bee (Trichocolletes venustus) on the first Hardenbergia to flower. A couple of Perons Treefrogs have cackled preparatorily from their hideouts during the daytime. So spring is well and truly on the way, in my mind at least. A couple of weeks ago it was still pretty optimistic for me to be going frogging, but I had a bit of cabin fever and had an idea that the species I was after wouldn't disappoint.

Most frogs breed in spring and summer, though in a country like Australia there's a fair bit of uncertainty about when the rain will fall, if at all, so a lot of frogs are pretty opportunistic. Some frogs will breed only in winter however, for example the Jervis Bay Treefrog (Litoria jervisiensis). This strategy always seems pretty crazy to me. Frogs don't regulate their body temperature physiologically, and it's surprising to me at least that winter-breeders manage to have enough energy to call at low temperatures. Then there's the investment that spawning takes! Winter is a time to save your resources, not chuck them in a pond! You rarely see most snakes and lizards in winter, but these frogs are at their most conspicuous at these times! Forgive my rant, it's just that these little squishy frogs are made of much sterner stuff than a lot of people would think. Oh, one last example. Another winter-breeding treefrog, Litoria littlejohnni (not named after our PM, BTW, but Murray Littlejohn), has been recorded down at Barren Grounds calling at just three degrees above zero!

Time to cut to the chase, I think. The frog I was after two weeks ago isn't really a winter-breeding frog, but atypically, more of an all-year-round frog. It's the Red-Crowned Toadlet, Pseudophryne australis. This species is pretty special in many aspects. It's a very relevant frog to Sydneysiders as it is tightly linked to the Hawkesbury sandstone of the area and isn't found outside the greater Sydney Basin. It's a striking frog, like many Pseudophryne species (the genus includes the two species of stunning Corroborree frogs), and its colouration hints at its toxic nature. That red that looks so obvious doesn't actually make the frog that noticeable, however, as wet fallen Eucalyptus leaves that make up the leaf litter it inhabits often show a similar colour.

This little frog is believed to have declined quite considerably from the numbers it once existed in. A large part of the story of its decline is probably urbanisation. Building, clearing, pollution, bush-rock removal - the same tale of a lot of Sydney's declining wildlife. I quote Richard Wells (2002), a herper in Sydney, describing his experiences with this frog from 1965:

"They were just so common that I thought that everything about their life history would have been long ago recorded and usually I just about ignored them"

Jump forward to the present:

"...the little frog I found once so commonly 35 years ago is now thought by some to be at risk of extinction. If someone had told me that this could happen to that species back in 1965 I would have laughed in their face."

A sobering tale. This species really appears to live life on the edge, and in more ways than one. Some recent work by Karen Thumm for her PhD (supervised by Mike Mahony) had some interesting findings and implications for the natural history of the frog. Basically, after the frog oviposits (the clutch is laid on land in moist leaf-litter, then when the tadpoles hatch they develop further in small pools), the eggs within a single brood take a variable amount of time to hatch, and tadpoles hatch at various stages of development. Why? The hypothesis is that the frog is 'bet-hedging' in the face of Sydney's particularly unpredictable rainfall (Thumm & Mahony 2002).

"Rain does not fall in a wet season or in any predictable pattern in the Sydney Basin. The advantage or disadvantage of delaying hatching depends on unpredictable future rain conditions.A strategy for optimal hatching times cannot evolve. If all embryos hatched at the same time, there would be a high chance of total reproductive failure. It appears that in the absence of a clear environmental signal, hatching is staggered in order to spread risk."

I've done a bit of a hopeless job of explaining very much about this frog, but this post is long enough already, so I recommend you read some of the below sources. Or I may blog about it again in the future.

References and further reading:
Thumm, K. & Mahony, M. (2002). Hatching dynamics and bet-hedging in a temperate frog, Pseudophryne australis (Anura: Myobatrachidae). Amphibia-Reptilia 23, 433-444.

Wells, R. (2002). Notes on the Red-crowned Toadlet Pseudophryne (Pseudophryne) australis (Gray, 1835) - an endangered frog from the Sydney Basin of New South Wales. Australian Biodiversity Record (4), 1-28. Link (well worth a read): http://forum.kingsnake.com/tax/messages/1027.html

Red-Crowned Toadlet Threatened Species information at National Parks: http://www.nationalparks.nsw.gov.au/PDFs/tsprofile_redcrowned_toadlet.pdf

Ask and you shall receive

2006-07-30T17:44:00.000+10:00

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.

The Deep Blue

2006-07-29T16:28:00.000+10:00

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.

Glider-on-glider action!

2006-07-28T14:46:00.000+10:00

... 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!

Biting off more than you can chew

2006-07-25T20:48:00.000+10:00

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.

A Cool(oola) frog

2006-07-15T20:27:00.000+10:00

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."

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

Litoria cooloolensis on the Frogs Australia network

Snake Pits

2006-07-14T20:34:00.000+10:00

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.

Mighty Mite

2006-07-13T20:40:00.000+10:00

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.

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!

More homeless bees

2006-07-12T13:13:00.000+10:00

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.

References

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.

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 chrysis.net for the eye candy if nothing else.