Wednesday 17 January 2018

Tailed Emperor Caterpillars


As summer has warmed up and butterflies have become more abundant in the garden I have been watching for Tailed Emperor Charaxes sempronius females visiting or laying eggs on the Persian Silk Tree in the garden. I found a hatched butterfly there last year, so wanted to see any caterpillars.

See: the adult here

I haven't seen any butterflies yet this year, but at least one has laid eggs while I wasn't watching. I found chewed leaves the other day and I have been out at night watching the caterpillars since. They are mostly nocturnal feeders. Although I did see one feeding at about 1100 hr one day.


There are six of these caterpillars on the tree at the moment and they are all at this large stage. I never noticed any chewed leaves when they were small yellow instars.


There are many species of caterpillar which adopt defensive postures, curl up, or drop off their branch whenever they are approached by a potential predator, like me, but these didn't do that. They simply carried on eating or walking along a branch while I watched them. The four pairs of prolegs on the abdomen can be clearly seen in this photograph, with the pair of claspers on the last tail segment. The prolegs have tiny, tiny hooks on their tips for hanging onto vegetation.


Their heads are adorned with these marvelous horns. I watched an ant wander close to one and it faced it off, presenting its horned head-plate at the ant, tracing its path as it passed. Not that the ant probably noticed, they follow scents more than vision. But the horns might deter bird predators. And what are those two little horns in the centre. Anyone know?


In this photograph one pair of the true legs on the thorax can be clearly seen, they are segmented with little claws on the end. This caterpillar carried on munching as I clicked away, its mandibles chomping sideways at the leaf with quite astonishing speed and efficiency.


Once they have fed enough, they crawl back along their branches to pre-formed beds. These are silken pads spread on a leaf, or used to hold two or three leaves together. The silk is sticky, and firm on the leaf, and the caterpillars can hold onto it easily. This is important to help the caterpillars stay attached to the leaf when the wind blows. For they certainly bounced about one windy day when I was watching them. They held on effortlessly.



And there they sleep and grow for much of the rest of the night and most of the day, curled up safely camouflaged and with a firm grip of their leaf bed. Isn't it amazing what goes on in the garden.

Monday 1 January 2018

Wet Scales



First day of the year and a grand day.

I went to Tidbinbilla Nature Reserve outside Canberra to wander around the wetlands. Well, specifically to see platypus as they are such gorgeous animals. That was as good as ever, so then on for a general look around and experience the wildlife.

While scanning the water surface of the ponds, I noticed a little ripple crossing from bank to bank. It was far too small for a platypus wake. It was a little lizard, about 15 cm long, a species of skink I have yet to identify - anyone know?



The lizard swam with a serpentine motion, waving from side to side with its legs tucked into its flanks, not used to paddle.



Farther on I saw another scaly creature in the water, a Red-bellied Black Snake. A beautiful snake and a marvelously adapted predator. This one was creeping up on another small lizard which was basking on the bank. It never got near enough to strike, or perhaps it did not really want to catch the lizard. That snake carried on slowly patrolling along the edge of the water. Then I noticed two more snakes within ten metres of the first. So I moved slowly and grabbed some shots.



Red-bellies are elapid snakes so are venomous, but they not aggressive and I only watched them, not approached them. They approached me while I kept still.



The red scales on their underside are a rich, yet delicate fiery colour. Their scales are always clean and they shone in the sunshine as the snakes slipped through the grass.



The detailed pattern of how the snakes' scales fit with one another is fascinating, exquisite and no more so than around the head.



They constantly flicked their forked tongues out when hunting, scanning the air for chemical clues of where prey might be lurking.



When seen head on, a victim's last view, they always impress me with their focused attention.