When I was at the Barren Grounds yesterday, with a group of birdwatchers, we were distracted by a strange looking Ant-like creature walking (almost running) all around the picnic table in the shelter shed there.
I could not get a good fix on what kind of creature this was, at the time. It moved fast, by walking quickly on its distinctively long legs. It looked like an Ant. But was it? Could it have been a wasp? Or even a Spider? There are
Ant-mimicking Spiders, after all.
Just in case it might have been an aberrant Spider we decided to check the number of legs, and came up with an odd number - literally an odd number. It appeared to have only 5 legs, and that always makes it hard to work out what kind of creature it is, for obviously it has been damaged, as often happens in Nature. I recall a Phasmid (Stick Insect) I once found which is famous for having a
"sacrificial" strategy, of losing limbs, or parts thereof, in order to allow the insect to survive attacks by birds - a similar strategy is used by Skinks, of course, which readily shed their tail tip, but can survive such an attack and even re-grow a new tip of the tail.
As someone who once thought seriously about buying a 5 cylinder Audi, I am always intrigued by such seeming imbalance. But I digress.
The clue to the identity of this creature is here. At full resolution the head shot shows a distinctive shadow (from the flash).
See what I mean? The v-shaped protrusion is typical of a Fly. As a matter of fact, you can even check out
David's wonderful shot of a Hoverfly, and see a similar antenna structure on its face. As soon as I spotted that v-shaped shadow, I checked the positive image itself, and realised I was staring a fly's face. Even the red eyes on each side of the head became obvious as typical fly eyes (obvious once you work out what you are looking at).
But it was the shadow of the short antennae which swung it for me. You see wasps and bees (related creatures - Hymenoptera) both have prominent mid-sized
antennae which are distinctively bent ("elbowed" as Peter Chew refers to it). By contrast, Flies (Diptera) have
very short, straight antennae - which is what I had noticed.
From that moment on, it was simply a question of searching the available internet references.
I started with the wonderful
Chew Family's Insects and Spiders of Brisbane. That took me to the prospect of it being a
"Stilt-legged Fly". I followed a further link to
Nick Monaghan's "Life Unseen" website. and I found that it was indeed a "Stilt-legged Fly" - indeed he has a 'dead ringer' for my insect, under the name of
Metopochetus sp.
So, that reminds me of the old joke: "When is a fly, not a fly? When it is a Walk!"
In all the time we watched this creature, running around the picnic table, crossing large gaps between the rustic boards on the table, etc, it never attempted to fly. That's why we thought it was an Ant. Indeed its transparent wings were held so close to the body (not widely spread, as in many flies), that the wings simply looked like a metallic sheen on the body of the insect.
Just to help clarify the shape of the insect, I spent some time on Photoshop, removing the shadows (because I had photographed it with the flash, on a Macro setting). In a sense it was just as well I did, as it was the shadow which gave me the clue as to the identity of this creature, as I mentioned. But the true shape of the insect is more clearly visible now, once the shadows have been removed.
I still think it looks like an Ant - but I am convinced that it is indeed a Stilt-legged Fly.
But with 5 legs, it might just be an "Audi-fly".
By the way, it was almost impossible for me to get a really clear focus on this creature, as it ran around the picnic table. These days, I only have manual controls on my Micro lens (A control ring on the Micro lens has broken). So just consider how amazing is David's achievement to snap that hoverfly in perfect focus, when in flight? No wonder his blog is called
"Focus on Nature".
Here is an opening flower of the Lambertia formosa. These seven long tubular buds split open, and the four sides of the perianth tube roll backwards, to about one fifth of the length of the flower. That leaves a long style protruding from each flower. As you can see here, the "style" is still covered when the bud is still unopened. These flowers are the brightest flowers in the Sandstone bush around the Southern Highlands at present. The Honeyeaters and the Rosellas and Gang Gang Cockatoos love these flowers which are full of nectar.
This juvenile Eastern Spinebill, was sitting very quietly in a shrub beside the track. Unfortunately my photo was not very clear. But it was unusual enough that I felt it worthwhile showing at small size. The adults have very different markings, with a white throat, black "v" shaped mark on the chest. The white tail feathers (on the outside edge of the tail) are clearly visible. Spinebills (a type of Honeyeater) are very common in this patch of sandstone scrub. 
Here is a photo of a single flower of Fieldia australis which was growing underneath the waterfall. It superficially resembles a correa flower, but it is not closely related to those plants. It is related to Gloxinias, and African Violets.
Here is a photo of a half-opened Banksia paludosa flower head (inflorescence). There are several points of interest. The most obvious thing is that the individual flowers open from the bottom upwards, sequentially. The brownish "match-heads" are the unopened tepals of the flowers. These flower buds are in pairs, arising from a common point on the stem. The fine points of the brush at the lower part of the flower are the "styles" in the opened flowers. They are all bright yellow, still being fresh with pollen. In this species these "stules" are straight, except for a slight bend near the point. By contrast, the commonest Banksia species in this area, Banksia cunninghamii, (generally referred to as B. spinulosa) has what are referred to as "hairpin" shaped styles. Note the Honey Bee enjoying the rich source of nectar.
This is a Red Spider Ant (Leptomyrmex rufipes) (or else a closely related species). There were several of these ants running around on the Banksia flower, which clearly was producing lots of nectar. You can see that the flower head was in the process of opening - and so the flowers were clearly very fresh. These Ants are distinctive in that they have very long legs, and they hold their black abdomen reversed, held high over their thorax. The red head is distinctive. These ants were moving very quickly, using their long legs to run over the top of the buds of the unopened flowers. Half a dozen of these ants had left the flower by the time I had changed lenses to get a close shot. This ant left the flower before I could get a second (clearer) shot. That is a fast moving ant.
While we had lunch down beside the river, below the waterfall, some members of our group found this leech, which climbed onto this piece of wire. The red and yellow markings become much more prominent, if the Leech manages to attach itself to a "victim" and engorges itself.
We had all prepared ourselves for Leech attacks, as my colleague Alan had taken home a Leech with him, just a few days previously. Nobody wants to be bitten by a Leech, except a recent shark attack victim.
