Solid Rock

I refuse to believe it's been 30 years since this song came out, because that would have implications for my age. There's a reason why I'm still living in the 80s, you know. [Ed:—You don't look a year over 65.] [The 80s. Not my 80s. I've still got a long way to go yet.] [Ed:—If you say so.]



Michael Cathcart (ABC Radio National) interviewed Shane Howard about the song and what's been happening since 1982.

Afternoon nap

For those of you who were concerned about Red's welfare after his dust up with an unknown assailant, here are some recent photos of him. He doesn't appear to have suffered any lasting damage.

That spot is a much sought after snoozing place. It has shade, a blanket of fallen leaves to lie on and a moss-covered rock to lean against. Perfect!

Turkeys everywhere!

They really are.

Harry thought it would be hilarious to start building a nesting mound on the patio. (Location, location, location.) But his heart wasn't in it and he soon lost interest.

He has similarly lost interest in fighting with the pademelons. Now they all avoid eye contact.

And he no longer chases away other brush turkeys. As a consequence, the garden is awash with large black birds.

As are the trees. Which is odd because I suspect that brush turkeys are afraid of heights. They are not great perchers and usually only fly into trees to roost.

That's quite enough of that!

Jottings from the Tropics: 19 October 2012

Written late yesterday afternoon...

Once again, the birds had disposed of all the water in the bird bath, so I filled a jug and went out onto the patio to do the house-keeping. And then I saw this fellow.

The Boyd's rainforest dragon sat for a while on the warm pavers and then decided it wanted a drink of water. When a grey-headed robin flew down to take a bath, the dragon rushed at it. A rainforest dragon running across the ground on its hind legs is a fearsome sight. (If you're robin-sized, that is. It's somewhat less frightening if you're human.) The display had its desired effect. The bird scarpered and the dragon had free access to the water dish.

Then a Lewin's honeyeater thought that it would like to take a dip. The dragon extended its saw-toothed dewlap, rose onto its hind legs and lunged at the bird. (In my mind, it also took a swipe at the interloper, but I might be confusing it with Godzilla. You can see why.)

The dragon spent an hour or so, guarding the water bowl from dusty and thirsty birds, periodically drinking with its snout immersed, before it eventually sauntered back into the rainforest.

I didn't take any photos of the dragon in the bowl, but here are some from the patio. Isn't it an amazing lizard?

Jottings from the Tropics: 18 October 2012

Red, the pademelon, has been in a fight. I'm not sure of his adversary. It might have been another pademelon, a dog or a brush turkey. (This last one is not as unlikely as it sounds. I've seen Red and Harry the brush turkey engage in serious interspecies argy-bargy.) Anyway, Red has cuts and puncture wounds on both sides of his head and has been feeling very sorry for himself.

Tuesday

Wednesday

Mind you, he seems to have perked up a bit today. I think he can smell food.

Today

– o – O – o –

Not long to go before the start of cyclone season. The Bureau of Meteorology begins issuing daily cyclone outlook reports on 1 November. The reports keep going through the Wet Season and end on 30 April next year. Fortunately, the Bureau is predicting an average to lower than average number of cyclones this season. That suits me just fine.

I will have to think about cyclone supplies soon. And this time I'm going to buy a fancy tin-opener that doesn't rust and has sharp teeth and a nice wide key so I don't dislocate my fingers trying to get the lid off. And if I can't find a good tin-opener, I will have to train up some white-tailed rats.They can bite right through a baked bean can.

Jottings from the Tropics: 17 October 2012

The prolonged dry spell — 'dry season' actually meaning something this year — has left the rainforest birds with few options when it comes to bathing. Whereas the turkeys make do with shuffling dust through their feathers, those species with more (ahem) dignity prefer to use the bird bath. Grey-headed robins, Lewin's honeyeaters and bridled honeyeaters are now forced to share 'their' water with Atherton scrubwrens (which bathe as a group) and eastern whipbirds (which are such enthusiastic dippers that I have to refill the bath several times per bird).

Emerald doves, brown cuckoo-doves and Victoria's riflebirds drop by to drink bath water during the day. At night, long-nosed bandicoots stand with their front feet in the bowl and spend minutes lapping it up. It might not be a waterhole on the Serengeti, but at least I'm not in danger of encountering a lion. I'm not so confident about dropbears.

– o – O – o –

Sometimes a brush turkey will follow me so closely when I take rubbish down to the bin that it runs into my leg. I don't think many other people have this problem.

– o – O – o –

A huntsman spider made the mistake of taking up residence under the sofa. Now it is covered in so much dust that it looks like an eight-legged angora rabbit. I tried to un-dust it, but it's not easy tidying up a large aggro spider. I suppose it's the arachnid equivalent of mum spitting on the hanky. I might try cleaning under the furniture instead.

Saturday morning music

Still stuck in the 80s.

INXS, What You Need (1984)

Papa-roo-zzi

This pademelon — an adult male that I nicknamed Red because a) he is red and b) I have no imagination — has been here since I bought the place in 2009. That's not to suggest that he was written into the contract. Although I reckon that would be an incentive to buy places like this one: house includes all fittings plus at least one marsupial with a strong personality.

He is the most photographed of 'my' pademelons, which could explain why he puts on this expression whenever I bring out the camera.

He might look unamused, but, you know, he didn't move.

Twilight's home: A new cave-dwelling coral from the western Pacific

Cross-posted to Bioscience Writing & Editing.

Leptoseris corals love the gloom. They grow in shaded nooks and crevices and on the sea floor at depths where many other corals do not thrive. They are particularly common in mesophotic reefs, where the light is muted and all but a few wavelengths are filtered out. Several species live at more than 100 m and one, Leptoseris hawaiiensis, has been recorded at 160 m at Johnston Atoll in the Pacific Ocean.

This low-light lifestyle makes it awkward for the endosymbiotic zooxanthellae that live within the coral's tissue. Zooxanthellae are photosynthetic, requiring a hit of light to drive the chemical reactions that build carbohydrates. Down in the shadows and the perpetual twilight of the mesophotic zone, there's not a lot of illumination to go around. But they make do. Elements of the Leptoseris skeleton — especially the ledge-like menianes that fit in close with the polyp's tissue — are thought to play a part in snaffling light and making it available to the endosymbiotic zooxanthellae. Survival is a team effort.

Until recently, all species were known to be zooxanthellate, but a newly described Leptoseris from the western Pacific breaks that pattern.

Living specimens of L. troglodyta sp. n.
a) Philippines, Cebu Strait, W of Bohol,
NW of Cabilao Island, 10–30 m depth
b) Indonesia, NE Kalimantan, Berau Islands,
S of Derawan Island, 7–10 m. depth
(Image from Hoeksema, 2012)

Leptoseris troglodyta Hoeksema, 2012, lives in marine caves in water between 5 and 35 m deep and has been recorded from sites in eastern Indonesia, the central Philippine Islands, Palau, Guam and the Louisiade Archipelago of Papua New Guinea.

Although this species lacks zooxanthellae, it still possesses the menianes that help to harvest light in other Leptoseris species. This combination raises the question of which came first in Leptoseris — zooxanthellae or no zooxanthellae?

It might be tempting to assume that L. troglodyta had zooxanthellate antecedents and has ditched the endosymbionts as part of its adaptation to cave-dwelling, leaving the menianes as evolutionary hangers on. But research on Dactylotrochus cervicornis, another azooxanthellate and menianes-possessing genus in the same family (Agariciidae) suggests that things might not necessarily have proceeded that way. So the question remains: Did the zooxanthellae precede the menianes or did the menianes precede the zooxanthellae? This, as Dr Hoeksema says, is 'a “chicken or the egg” causality dilemma'.Further research will shed light (ahem) on the conundrum.

References

Hoeksema, BW (2012). Forever in the dark: the cave-dwelling azooxanthellate reef coral Leptoseris troglodyta sp. n. (Scleractinia, Agariciidae). ZooKeys DOI: 10.3897/zookeys.228.3798

Kitahara MV, Stolarski J, Miller DJ, Benzoni F, Stake J, Cairns SD. (2012) The first modern solitary Agariciidae (Anthozoa, Scleractinia) revealed by molecular and microstructural analysis. Invertebrate Systematics 26: 303–315. doi: 10.1071/IS11053

Another hiatus

My computer has been playing up, so it is off to get a stern talking to and some bits and pieces replaced. Maybe in that order. As a consequence, I will be off air for the rest of today and part of tomorrow.

I do have another computer, but it is playing up too. You know, you'd expect the one I'm using now to be a bit temperamental because it's five years old, has travelled a lot and hasn't always been treated with respect. The other one is new and has scarcely been used.

It has scarcely been used because it is a pile of crap. I won't mention the manufacturer, but this is not the first time I've had problems with machines from them. And it's out of feckin' warranty.

Just don't get me started.

Back soon.

_____________________________

Update: Computer now fixed. But, as the computer fixer upperer said, it's quite old and probably won't last too much longer. Well, I think I know how it feels...

Sunday afternoon music

I've been listening to Frank Yamma all morning.

Ngura Watjilpa (2010)


She Cried (2010)

A trick of the tail: How snails avoid snail-eating snakes

Cross-posted to Bioscience Writing & Editing

There's not much chance of a land snail outrunning a predator, so a slow-moving gastropod must rely on other measures to stay out of trouble. The shell is an effective defence, but it's not perfect. Some predators can crush them. Others, such as the song thrush and pitta, smash them open on rocks. Carabid beetles and firefly larvae are small enough to breach the defences by slipping through the only gap in the armour — the shell aperture. Even the best protection has a weak spot.

Not only do snails in some parts of Asia have to survive these usual suspects — brute force crushers and smashers and those sneaky nibblers — but they also have to deal with specialist predators: snail-eating snakes. Iwasakii's snail-eater, Pareas iwasakii, has asymmetrical jaws that are adapted to extract snails from their shells. (Click here to to watch a video of the snake in action.)

Researcher Masaki Hoso of the Naturalis Biodiversity Centre in the Netherlands has discovered that Satsuma caliginosa, a camaenid land snail from Japan, has evolved counter-measures to escape its serpentine hunter.

The range of Satsuma caliginosa partly overlaps that of Iwasaki's snail-eater. Where the two are separate, the interior of the Satsuma shell aperture is smooth, but where predator and prey occur together, the shell aperture is lined with several low barriers that narrow the opening and prevent the snake grabbing hold of the snail and dragging it out. Unfortunately for Satsuma, these barriers only develop in adults.

Masaki Hoso found that Satsuma employs an equally effective but more drastic method of staying alive until the shell barriers develop. When snagged by a snake, the snail sheds its tail. (Really, the hind part of the foot.) Result: predator gets a bite-sized morsel of prey and prey gets to live another day.

(a-c) Foot regeneration in S. caliginosa in the wild.
(a) S. caliginosa caliginosa with an intact, (b) a regenerating and
(c) regenerated foot. (d) proportion of S. caliginosa with
a regenerating or regenerated foot in the wild.
(Image from Hoso, 2012)

But this process of autotomy is costly. Regrowing the shed tail requires a lot of energy and while that is taking place, resources are diverted from shell growth. For immature snails, this involves a trade off between defence mechanisms. Dropping the tail is a life-saver, but delays the development of apertural barriers. Still, dropping the tail means that the snail can survive long enough to grow those apertural barriers.

Reference 
Hoso, Masaki (2012). Cost of autotomy drives ontogenetic switching in antipredator mechanisms under developmental constraints in a land snail. Proceedings of the Royal Society B DOI: 10.1098/rspb.2012.1943