One of these is not like the other ones

From today's Bureau of Meteorology report for Victoria:


Victorian Weather and Warnings

Warnings current:

Coastal Wind Warning West of Cape Otway

Coastal Wind Warning Cape Otway to Wilsons Prom

Coastal Wind Warning East of Wilsons Prom

Coastal Wind Warning Port Phillip and Western Port

Gippsland Lakes Wind Warning

Ocean Wind Warning 2

Victorian Severe Weather Warning

Tsunami

It's not often you get a tsunami warning in Victoria. And we haven't really had one this evening.

Tsunami Warning for Victoria
Issued at 1746 on Sunday the 30th of September 2007 for People in coastal areas of Victoria from Wilsons Promontory to Gabo Island

An earthquake of preliminary magnitude 7.6 occurred at 1523 EST at 49S164E generating a potential Tsunami.

It has been determined that no significant threat exists to coastal communities of Victoria.

There has been a warning issued for southeastern coastal communities of Tasmania.

And the warning for Tasmania:

IDT24000
Top Priority

For all Tasmanian coastal waters

An earthquake of magnitude 7.6 occurred at 03:23 pm EST near the Auckland islands [49.4S 164E] and may have generated a tsunami.

If confirmed, a sea level rise in the order of 35cm is possible about the south and east coasts with possible sea level rises around remaining coastal areas.

Dangerous waves and currents may affect beaches, harbours and rivers for several hours from the time of impact.

The waves can be separated in time by between ten and sixty minutes and the first wave of the series may not be the largest.

The SES advises that people should:

Stay out of the water.
Monitor the local media for updated information.

This Warning will be updated 07:00pm EST.

I was momentarily fascinated by the idea of a 35cm tsunami barging through Port Phillip Heads and hurtling up the Yarra and Maribyrnong rivers. 'Twas not to be.

Still, it makes a change from the usual round of warnings and alerts.

On the street sellers of snails, frogs, worms, snakes, etc

Google Books is a treasure trove.

From Henry Mayhew's (1861) work on London labour and the London poor: Cyclopaedia of the condition and earnings of those that will work, those that cannot work and those that will not work. London street-folk; comprising street sellers, street buyers, street finders, street performers, street artisans, street labourers with numerous illustrations from photographs. Volume II.

I CLASS together these several kinds of live creatures, as they are all "gathered" and sold by the same persons—principally by the men who supply bird-food, of whom I have given accounts in my statements concerning groundsel, chickweed, plaintain, and turf-selling.

The principal snail-sellers, however, are the turf-cutters, who are young and active men, while the groundsel-sellers are often old and infirm and incapable of working all night, as the necessities of the snail-trade often require. Of turf-cutters there were, at the time of my inquiry last winter, 42 in London, and of these full one-third are regular purveyors of snails, such being the daintier diet of the caged blackbirds and thrushes. These men obtain their supply of snails in the market-gardens, the proprietors willingly granting leave to any known or duly recommended person who will rid them of these depredators. Seven-eighths of the quantity gathered are sold to the bird-dealers, to whom the price is 2l. a quart. The other eighth is sold on a street round at from 3d. to 6d. the quart. A quart contains at least 80 snails, not heaped up, their shells being measured along with them. One man told me there were "100 snails to a fair quart."

When it is moonlight at this season of the year, the snail gatherers sometimes work all night ; at other times from an hour before sunset to the decline of daylight, the work being resumed at the dawn. To gather 12 quarts in a night, or a long evening and morning, is accounted a prosperous harvest. Half that quantity is "pretty tidy." An experienced man said to me :—

"The best snail grounds, sir, you may take my word for it, is in Putney and Barnes. It's the 'greys' we go for, the fellows with the shells on 'em ; the black snails or slugs is no good to us. I think snails is the slowest got money of any. I don't suppose they gets scarcer, but there 's good seasons for snails and there's bad. Warm and wet is best. We don't take the little 'uns. They come next year. I may make 1l. a year, or a little more, in snails. In winter there's hardly anything done in them, and the snails is on the ground ; in summer they're on the walls or leaves. They'll keep six months without injury; they'll keep the winter round indeed in a proper place."

I am informed that the 14 snail gatherers on the average gather six dozen quarts each in a year, which supplies a total of 12,096 quarts, or individually, 1,189,440 snails. The labourers in the gardens, I am informed, may gather somewhat more than an equal quantity,—all being sold to the bird-shops ; so that altogether the supply of snails for the caged thrushes and blackbird» of London is about two millions and a half. Computing them at 24,000 quarts, and only at 2d. a quart, the outlay is 200l. per annum.

The list

I didn't manage to read much over the mid-semester break (although I did write a week's worth of lectures, so I achieved something.) My stack of books is growing at the same pace as the weeds in the back garden.

This is the crop at the moment:

• Barbara Kingsolver, Prodigal summer
• Barbara Kingsolver, The poisonwood bible
• Martin Cruz Smith, Stalin's ghost
• Leonardo Padura, Havana red
• Natalie Angier, The canon: a whirligig tour of the beautiful basics of science
• Christopher Kremmer, The carpet wars
• Jean Fornasiero, Peter Monteath and John West-Sooby, Encountering Terra Australia: the Australian Voyages of Nicolas Baudin and Matthew Flinders (recommended by Sophie)

The following are on their way to join the crop:

• Sean B. Carroll, Endless forms most beautiful
• Mark Cocker, Crow country
• Roger Deakin, Wildwood

And these are about to move from 'to buy' list to the crop:

• Ian Rankin, Exit music
• Val McDermid, Beneath the bleeding
• Lee Child, Killing floor
• William Hague, William Wilberforce

That should keep me quiet for the next few weeks ...

Thanks to Molecule Man (you know who you are!), I am now addicted to Google Reader. I realise that I am probably the last person in the world to adopt it but in case someone out there isn't familiar with it, Google Reader puts all your favourite blog feeds on one page and tells you when they've been updated. They're all there! And you can do other stuff with it, apparently.

Thursday gastropod: Temporena whartoni (Cox 1871)

It might look dull and ordinary but this is one of the shortest of short range endemic snails in Australia. Temporena whartoni (Cox 1871) is restricted to a single small island off the Queensland coast.

Temporena whartoni is a mid-sized snail — average shell width is 36 mm, shell height 25 mm.

Its home — Holbourne Island — is a granite outcrop that was formerly mined for guano. The 34 ha island is now a national park, so the species is presumably doing all right.




Its taxonomy is another matter. It has been shifted around from one genus to another. Originally described as Helix whartoni (in the 1800s, Helix was the catch all genus for large, rounded shells), it was later moved into Temporena, Iredale's (1933) subgenus of Gnarosophia. Then Iredale (1937) elevated Temporena to genus with H. whartoni as type species. Subsequently, it's been shoved into another catch all — Sphaerospira (Smith, 1992). It almost certainly belongs in a different corner from that genus. It shares some conchological and anatomical characteristics with three other species on the adjacent mainland, including the smaller Varohadra macneilli Iredale 1937, which also occurs on granite islands.

So there's a nice little investigation for someone. A bit of DNA analysis, some historical biogeography ... Oh, and Varohadra — another can of taxonomic worms.


References

Cox, J.C. (1871) Descriptions of seven new species of Australian land shells. Proceedings of the Zoological Society of London 1871: 53–55.

Iredale, T. (1933) Systematic notes on Australian land shells. Records of the Australian Museum 19: 37–59.

Iredale, T. (1937) A basic list of the land Mollusca of Australia. Pt II. Australian Zoologist 9: 1–39.

Smith, B.J. (1992). Non-marine Mollusca. In Houston, W.W.K. (ed.) Zoological Catalogue of Australia. Vol. 8. Canberra: Australian Government Publishing Service.

I and the Bird #58

The latest series of Dr Who has finished in Australia but the good Doctor has plenty of things to keep him occupied. He's over at The Nightjar for I and the Bird #58.

Strange but true.

Mark Dapin's forthcoming book 'Fridge magnets are bastards' is a rant in alphabetical order. An excerpt appeared in Saturday's Age.

First, Dapin's definition of bastards:

At best, bastards impersonate the performance of a function and, at worst, they perform the opposite of that function. Financial planners, for instance, pretend to be planning your finances, when they are, in fact, using your finances to plan theirs.

After discussing invisible elephants, executive toys and learning curves, among other weasel words, he turns to the purple cow. Not familiar with the term? Be enlightened.

noun 1. nonexistent animal used to illustrate nonexistent concepts, e.g. originality in marketing.

Bastards love their imaginary menagerie. If they are not preoccupied with finding the invisible elephant, they are often out looking for the purple cow.

Small children like to be taught about the world through the exploits of talking ducks and the like. Executives — who are generally not big readers — also require short, pithy stories about their favourite animals to understand the world around them. Certain brand managers have been known to cry themselves to sleep if they do not hear the story about the purple cow.

The concept of the purple cow came from marketing guru Seth Godin, who had an epiphany while driving through the French countryside. Although he was at first "enchanted" by all the cows in the fields, he soon realised they were "boring". "A purple cow though: now that would really stand out," he wrote, apparently seriously.

So far we've been spared that little zoological wonder in our emails from upstairs. But how much longer until it becomes part of our managerial lexicon? I'm taking bets.

Spring in Melbourne

Melbourne is magic at this time of year. The days are getting longer and the weather is mild and calm with clear blue skies*. And the city is full of beans. Spring is a wonderful time in Melbourne.

The Royal Melbourne Show is on at the moment. The biggest agricultural event in Victoria — yes, even bigger than the legendary Quambatook Tractor Pull — the Show has been running continuously since 1848 under the aegis of the Royal Agricultural Society of Victoria. Of course, it has expanded beyond displays of livestock and rural life but farming is still at the Show's heart.

It's great fun. Except for one thing — the volume. I don't live that close to the Showgrounds — they're about 2 km to the ENE** — but there's a lot of river and flood plain between the grounds and my house. They're on a high spot. I'm on a high spot. I can hear the PA system very clearly. On the whole, I'd rather listen to the sheep and cattle than the over-excited announcer.

The Spring Racing Carnival kicks off next week. Not that I'm interested in horse racing but the street party atmosphere pervades the whole city. By the time the Melbourne Cup rolls around (the first Tuesday in November), no one is paying attention to anything but the horses ***. (Those of you reading this in somewhere other than Australia may be surprised to know that Cup Day is a public holiday in Victoria. Cup Day afternoon might as well be a public holiday in other parts of the country too, for all the work that gets done after the betting and the boozing.)

Unfortunately, the outbreak of equine influenza might put a dampener**** on the Spring Racing Carnival this year.

The most important event on the Melbourne sporting calendar is the AFL Grand Final on Saturday — Geelong vs Port Adelaide. I don't follow the footy either but there is something hugely inclusive and entertaining about it. I love driving past the footy ovals on mid-winter evenings when the floodlights illuminate the ground for players of all ages and standards. They're taking it seriously but they're having fun. I love the Monday morning corridor conversations about the weekend's matches. You better believe they're taking it seriously ... and having fun. And I love the way the city celebrates the Grand Final.

More than 97,000 people packed into the MCG for the 2006 Grand Final. Last week's match between Geelong and Collingwood drew an audience of 98,000. Melbourne doesn't muck around when it comes to footy.

And the close of the footy season means that the start of the cricket season is around the corner.

Oh, and did I mention that the end of semester is only a few weeks away?

______

* Generally. Apparently it's going to rain tomorrow but I'll believe it when I see it.
** Okay, that is reasonably close.
*** Apart from the poor devils who have exams.
**** Or is it damper? I never know.

Williamstown walk

I went for a stroll along the Williamstown waterfront this morning. The weather was glorious — clear, mild and still. I didn't see anything exciting, just the usual array of little black cormorants, little pied cormorants, silver gulls, Pacific gulls, chestnut teal and the occasional crested tern. But no grebes.

I vant to suck your blood ...

Winsome

Black and white

Drying in the sun

Give them an inch ...

My garden is a slug and snail sanctuary. It's not intentional. (No, really.) The greedy gastropods usually confine themselves to decaying vegetation, doing a great job of recycling, but sometimes they get carried away. Now the garden snails have gone too far. They're feeding on my Haemanthus. The bastards!

Supper for snails

Moments before it was launched into the compost heap

Young slugs I: Limax maximus

Young slugs II: Limacus flavus

Chillagoe smelters

Only a trio of crumbling smokestacks remains to hint at Chillagoe's starry past. In the early decades of last century, the smelters processed copper, lead, zinc, silver and gold. Spearheading northern development, the town sustained the country's worst mining disaster, produced two premiers and spawned corruption scandals big enough to bring them both down.

John van Tiggelen, Mango Country

At the turn of the 19th century, Chillagoe was a thriving mining town. The Chillagoe Company — established by mine owners and entrepreneurs John Moffat and J.S. Reid — built a smelter complex and railway line to process ores and carry the refined metals to Mareeba (from where they would be transported to the port of Cairns). But within a few years the company was in severe trouble. Expecting to receive copper, lead, gold and silver ore from mines all over North Queensland, the only regular sources were Redcap and Calcifer. Other mines sent material intermittently, making it difficult to maintain a flow of money.

In 1914, the company approached the government for financial support but was refused. The smelters closed during WW1.

At the end of the war, the Queensland Government acquired the smelters and re-opened the complex. The decline in metal prices meant that it was still not financially viable. A change of state government led to a Royal Commission, which uncovered mismanagement and corruption and finished the careers of Chillagoe miners-turned- state-premiers, Ted Theodore and William McCormack.

Although unprofitable, the smelters provided work for depressed areas of North Queensland. They were kept open until a nationwide review of the base metal industry showed them up as run-down and hopelessly inefficient. In 1943, the equipment was dismantled and sent to Mt Isa Mines (which had just started to produce copper) and Collinsville State Coal Mines. The rest was left to decay.

During a half century or so of on-again, off-again production, the smelters processed 1,250,000 tons of ore. They never made a profit but supported the people of the region. Although the Chillagoe smelters are now ruins, mines continue to operate and exploration has identified profitable amounts of zinc, copper, lead, silver and gold in the area.

Ruins at the site

Copper on the smelter brickwork

Copper on the ground around the site

Strata of slag

Slag has its own kind of charm

Lakes of ... slag

Dispersal of the prettiest

Partula hyalina is a Pacific island tree snail with an odd distribution. It lives on Tahiti but not the other Society Islands and is also found in the Austral and Southern Cook Islands.

The distribution is unusual for several reasons. Most species of Partula are restricted to single islands — they're not good dispersers — yet this one has clearly got around. But if it dispersed from Tahiti under its own volition how (or why) did it skip nearby spots to get to the distant Cook Islands? And to make the story more intriguing why did only one of the multiple colour forms go roaming? So many questions, so few snails.

Diarmaid Ó Foighil of the University of Michigan suggests that the snails were transported around the South Pacific by prehistoric travellers who prized the white shells for their beauty.

The combination of aesthetic preference and fashionability made the unlikely introduction possible.

Read the fascinating story of Partula, pulchritude and Polynesian sea passages at the University of Michigan's web site and in the links kindly provided by Mo (which include the abstract of the paper in Proceedings of the Royal Society B). (Thanks, Mo!)

The Thursday gastropod: the temperate nerites

And if it isn't the name of a band, it should be.

Most species of Nerita live on tropical rocky shores but a few occur in the cooler waters of southern Australia and the North Island of New Zealand. These temperate species have plain black shells, which has led to confusion about their identity. Is there only one species? Two species? Three?

Despite the abundance of Nerita atramentosa Reeve 1855 in southern Australia and New Zealand, it has been largely overlooked as a subject for study. It was assumed that it constituted a single species, which showed some variation in the colour of the operculum (the D-shaped plate that seals the aperture). The variation is not particularly unusual — the operculum ranges from black to tan — but it piqued the interest of researchers in New Zealand (Waters et al., 2005).

Using mitochondrial DNA, they looked at the population structure of N. atramentosa from SE Australia and NZ and found that the 'east' and 'west' populations are distinct. The eastern nerites tend to have tan-coloured opercula and western black opercula. The point where one dominates the other seems to be somewhere around Wilson's Promontory, the southernmost point on mainland Australia, which formed a barrier across Bass Strait at times of lower sea level. (But both types occur on either side of this point.)


Nerita atramentosa: A) Point Peron, Western Australia; B) Marino Rocks, South Australia; C) Wilson's Promotory, Victoria; D) Cape Maria van Diemen, New Zealand; E) Mallacoota, Victoria; F) Cape Conran, Victoria. From Waters et al., 2005


That the tan operculum Nerita also occurs in New Zealand suggests it has undergone at least one long distance dispersal event. But another black-shelled nerite, N. morio Sowerby 1833, from Easter Island, Pitcairn, Gambier and Austral Island in the eastern Pacific also has a tan operculum. Could it be this same species having made an even longer ocean crossing? The mtDNA says yes.

So there's a difference between the east and west populations. Are they different species?

The taxonomy of Nerita atramentosa is a little murky. Spencer et al. (2007) have cleared it up.

Reeve (1855) described N. atramentosa from Swan River, Western Australia and E.A. Smith (1884) proposed the name N. melanotragus for New Zealand specimens that had been misnamed by earlier authors. This latter name was widely applied to shells from both NZ and Australia and N. atramentosa was little used until Iredale and McMichael (1962) turned the tables. From then on, N. atramentosa gained currency.

Just about everyone assumed that there was only one species. They all looked the same, really, and no one was terribly interested in these plain black shells, so why not? As the earlier name, Nerita atramentosa had priority, it was the one that stuck.

When Spencer et al (2007) extended the earlier study of Waters et al (2005) they found that the two species are both valid. N. atramentosa is the black-operculum western species (from WA to central Vic) and N. melanotragus is the tan-operculum eastern species (from central Vic to southern Queensland, Lord Howe and Norfolk Islands, New Zealand and the Kermadec Islands).

Spencer et al. (2007) maintain N. morio as a separate species pending more information. They treat the very similar Easter Island endemic N. lirellata Rehder 1980 in the same way.

It all seemed so simple when we just had the one ...



Nerita species: A) N. atramentosa, Adelaide, South Australia; B) N. lirellata, Easter Island; C) N. melanotragus, Auckland, New Zealand; D) N. morio, Easter Island. From Spencer et al. 2007.


References

Rehder, HA. (1980). The marine mollusks of Easter Island (Isla de Pascua) and Salay y Gomez. Smithsonian Contributions to Zoology 289: 1 – 132.

Spencer, HG, Waters, JM & Eichhorst, TE. (2007). Taxonomy and nomenclature of black nerites (Gastropoda: Neritimorpha: Nerita) from the South Pacific. Invertebrate Systematics 21: 229 – 237.

Waters, JM, King, M, O'Loughlin, M & Spencer, HG. (2005). Phylogeographical disjunction in abundant high-dispersal littoral gastropods. Molecular Ecology 14: 2789 – 2802.

Pirattitude

This scurvy dog don't have enough of it on International Talk Like A Pirate Day.

I thought about deliverin' today's lecture in a Cornish accent (aaarrrr!) while wearin' this here black eye patch but I chickened out. I deserve me pirate name — Cowerin' Annie Slaughter — cos I be a coward.

Not so, Ol' Chumbucket and Cap'n Slappy. Mixin' pirattitude with science, they show how to give a lecture to the bilge rats. If only me topic today had been pirates versus ninjas, I would have been all right. Aaarrr!

This is the way the week begins

... not with a bang but a whimper. Oh, okay, that's not quite what Eliot wrote. But 'The Hollow Men' is clearly about Monday morning in the lecture theatre — as experienced from either side of the lectern.

I've been up to my ear lobes in uni stuff, which is why I've been a bit slow to post. Not that work is going to get less frantic in the next few weeks. And now I look at my diary, I see that 'few' actually mean 'twelve'. Oh, well, that means that things will settle down around mid-December. It'll take a while but they will settle down.

The other thing that's been slowing my blogging activity over the weekend is my sore back. (Yes, I'm feeling very sorry for myself. What's the point of a blog if you can't be self-indulgent?) As much as I would like to blame the house-keeping, I suspect the slouching at the desk (with the computer in front of me) or on the sofa (with the computer on my knees) was the real problem.

But I was on a writing roll (7,000 words over the weekend), so I didn't feel like switching off the laptop while the muse was perched on the edge of the desk. (Bloody writing. Sure, it looks easy ...)

Of course, now I can't sit still for more than a few minutes at a time, so my productivity had plummeted. That'll teach me.

September in the garden

I retrieved the newspaper from the garden on Saturday morning to find that it had been delivered with such enthusiasm it had excavated one Dargon Hill Monarch and scythed off the flowering heads of another. My weekend started on a low note. (As you know, I am very fond of my plants.)

A Dargon Hill Monarch in happier days

Fortunately, my back garden is free of rolled-up newspapers. (Not so free of weeds but that's another story.) These first few weeks of spring have brought out a glorious range of flowers, among them Kennedia beckxiana, which has adopted a pincushion hakea as its climbing frame.

Kennedia beckxiana

Kennedia retrorsa

The modest flowers of Lasiopetalum

Kangaroo apple (Solanum laciniatum)

The business end of a kangaroo apple

The Thursday gastropod: Rhynchotrochus macgillivrayi

Yes, it's another camaenid but we've got plenty to spare. And I'm sure you'll agree this is a rather splendid one*. Rhynchotrochus macgillivrayi (Forbes 1851) is a tree snail from the Wet Tropics of Far North Queensland. It is the only known representative of the genus in Australia. All other species — and there are many — occur in New Guinea and neighbouring islands.

Dunk Island

Naturalist John MacGillivray collected specimens from trees in the Frankland Islands, North Queensland, during the voyage of the HMS Rattlesnake. Edward Forbes named the species in his honour.

Of all Australian Helices, this is perhaps the most curious. Its outline and aspect are singularly like those of a Trochus of the Ziziphinus group. The colour is also very singular, being a yellowish flesh hue deepening on the base to a rich brownish-yellow, and speckled irregularly with minute black dots which are areolated with white, the white ring being largest on the side towards the mouth ... The outer lip of the aperture seems as if it had been dented in two places.

The dent is known as the papuinid notch (after the camaenid subfamily Papuininae to which the genus belongs).

Distribution of R.macgillivrayi

William Clench and Ruth Turner (1966) produced a monograph of Rhynchotrochus but not much has been done on the group since then. It's hardly surprising.

The genus Rhynchotrochus is the most complicated among the elements in the Papuininae ... Our present understanding of the species and forms composing the genus are certainly no more than tentative and will be subject to considerable modification when more material is at hand for study. The most serious handicaps at present are the lack of localized specimens, alcoholic material, and the complete inadequacy of many of the original descriptions.

More than forty years later, the situation has hardly changed.

_____

* If slightly over-exposed. Sorry about that, chief.


References
Clench, WJ & Turner, RD. (1966). Monograph of the genus Rhynchotrochus (Papuininae: Camaenidae). Journal of the Malacological Society of Australia 1(9): 59–95.

Forbes, E. (1851) On the Mollusca collected by Mr. MacGillivray during the voyage of the Rattlesnake in MacGillivray, J. Narrative Of The Voyage Of H.M.S. Rattlesnake, Commanded By The Late Captain Owen Stanley, R.N., F.R.S. Etc. During The Years 1846-1850. Vol. 2. London: T & W Boone.

I've bought a new computer. The one I'm using now is a bit old and slow and there's only room for one old and slow item in my study. I needed a machine with — and I hope I don't lose you with these technical terms — shit loads of memory to cope with big, hungry software. Anyway, I saw a good deal on a laptop with a separate 19" monitor and put in the order. So far, so good.

The shipping company called me on Monday to organise a delivery date. Thursdays are the only days on which I don't have classes, so I decided to take today off to wait at home for the courier. I had a meeting scheduled for the afternoon but I could send my apologies for that, so it wouldn't be a big problem. (And it wouldn't be any sort of problem if the courier dropped by in the morning.)

Still so far, so good. I stayed at home this morning, marking assignments and finishing off the post below. At 11.30 am, the courier company called to organise a time for delivery.

'Aren't you supposed to deliver it today?' I said.

'Sorry. Only just got the paperwork.'

'But I've taken the day off work. I won't be able to do that again until next Thursday.'

'Next Thursday it is, then.'

'But — '

Dead line.

I wasn't happy but there didn't seem to be an alternative solution. And it meant I could go to the meeting. So off I went.

When I emerged from the meeting at a little before 5pm, I received a call from the courier. He was waiting for me outside my house. Fortunately, I was only about half an hour away, so he didn't have to wait too long. But he only had one box to deliver.

I was confused. He was confused. We stood around scratching our heads — until we worked out that the computer and monitor were sent at two different times. Not terribly complicated but it floored us. I have the laptop. The monitor will arrive next Thursday. Maybe. Now I ask myself whether I will be capable of using the computer, considering its mere delivery stumped me.

Fatal attraction?

Dragonflies often roam far from water but they always return to it to lay their eggs. Some species are known to locate water by searching for surfaces that reflect horizontally polarised light. Unfortunately for dragonflies, water isn't the only substance to do this. So do Perspex sheets, discarded oil ... and highly-polished gravestones.

Gábor Horváth and odonatologist colleagues noticed that dragonflies were attracted to gravestones in a Hungarian cemetery. Although a number of species occurred in the area, only darters (Sympetrum species) visited the stones. The dragonflies were very particular in their choice of sites — they preferred large, black or dark grey, polished, horizontal stones clear of overhanging vegetation but with a nearby perching place. When the research team looked at the light reflected from the gravestones, they found it identical to that from other flat, dark surfaces, including still water.

Fig. 1 (a) Male and female dragonflies (Sympetrum sp.) perching on the tips of sunlit iron railings in a cemetery in the Hungarian town Kiskunhalas. (b, c) Males of Sympetrum sp. perching near polished black tombstones. (d) A female Sympetrum sp. displaying touching behaviour at the shiny black plastic sheet used in the double-choice experiments. The photo shows the brief moment when she touches the test surface with her legs and ventral side of her body. (From Horváth et al., 2007)

The study shows that these Sympetrum species are sensitive to polarised light, using it to locate ponds and lakes for courtship and egg-laying. Mistaking gravestones for water every now and then is a small problem, but if it affects the dragonflies' reproductive success then it becomes an ecological trap (Schlaepfer et al., 2002).

The term 'ecological trap' applies to a situation where

in an environment that has been altered suddenly by human activities, an organism makes a maladaptive habitat choice based on formerly reliable environmental cues, despite the availability of higher quality habitat.

Under natural conditions — no puddles of oil, no black plastic sheets, no gleaming gravestones — horizontally polarised light is a dependable indicator of water, a reliable environmental cue. But when humans introduce materials with identical properties, the dragonflies are misled. Their habitat choice is now maladaptive, reducing their reproductive success and ultimately their numbers.

So far, the lure of the gravestones doesn't seem to have had an impact on the five Sympetrum species that frequent the cemetery but other dragonflies are known to lay their eggs on oil, shiny road surfaces and cars.


Reference

Horváth, G, Malik, P, Kriska, G & Wildermuth, H. (2007). Ecological traps for dragonflies in a cemetery: the attraction of Sympetrum species (Odonata: Libuellidae) by horizontally polarizing black gravestones. Freshwater biology 52: 1700–1709.

Schlaepfer, MA, Runge, MC & Sherman, PW. (2002). Ecological and evolutionary traps. Trends in Ecology & Evolution 17: 474–480.

The Moon and Google

Google Moon. Make sure you zoom all the way in.

The original Fabergé egg?

When Phaethon fell to his death from the Chariot of the Sun to the river Eridanus, his sisters wept for him until they transformed into poplars.

Thence tears flow forth; and amber distilling from the new-formed branches, hardens in the sun; which the clear river receives and sends to be worn by the Latian matrons.

Ovid, Metamorphoses

As it seeps from the trunks and branches of injured trees, resin — the tears of legend — traps insects and other small animals. If protected from air, the resin eventually turns into amber. The organisms within are suspended in amber, often preserved so well that they retain internal organs and even DNA.

Poinar, Voisin and Voisin (2007) report a fragment of egg shell preserved in Dominican amber. Although frogs, lizards and bird feathers have been described before, this is the first specimen of a vertebrate egg.

The tiny egg — less than a centimetre long — is thought to belong to a hummingbird. If so, then it also of importance as the earliest known hummingbird in the New World. The amber is of disputed age but is somewhere between 15 and 45 million years old, which makes the shell contemporaneous with hummingbird fossils in Europe but much older than those from the Americas.

Reference
Poinar jr, G., Voisin, C. & Voisin, J-F. (2007). Bird eggshell in Dominican amber. Palaeontology. Published online 4 Sept 2007. doi: 10.1111/j.1475-4983.2007.00713.x.

Going through the motions

It's long been known that freshwater molluscs get spread around the place by all manner of mechanisms, up to and including hitchhiking on fish gills. Recent research in Alaska has demonstrated another way in which they might disperse — tucked away in a fish's tum.

Some species are able to survive the dark and smelly journey through a fish's interior, emerging from the far end apparently none the worse for the experience. In the time taken for the mouthful of mollusc to pass along the digestive tract, the fish might have moved a considerable distance — almost certainly further than an adult mollusc would have made it on its own. When the fish poos, out pops the invertebrate in a completely different location.

Randy Brown, of the U.S. Fish and Wildlife Service in Fairbanks, Alaska, examined poo from wild-caught fish and found that they were filled with live pea clams (Pisidium idahoensis, Sphaeriidae) and valve snails (Valvata sincera, Valvatidae). Although (understandably) quiet at first, once out in fresh water the molluscs soon started moving around.

The number of live molluscs collected from each fish ranged from 312 to 769 pea clams and 432 to 1212 valve snails. Only a single pond snail (Lymnaea atkaensis, Lymnaeidae) made it through alive.

The survivors have at least one thing in common. Both species can seal their shells to protect themselves from a hostile environment. (And, let's face it, the inside of a fish's intestine is probably pretty hostile.) Unlike the valvatids, pond snails lack an operculum, so can't close the door. The fish's digestive enzymes do their work unhindered.

Earlier studies have shown that the tiny hydrobiid snails (which also possess the operculum) survive the journey through flounders and trout. It appears that hydrobiids aren't the only ones to be taken on the tour. Now there's a little project for the holidays.

Reference
Brown, R.J. (2007) Freshwater molluscs survive fish gut passage. Arctic 60(2): 124 –128.

From the Montreal Gazette's review of Tomorrow, the latest book by Graham Smith:

Paula and Mike Hook have what looks like the perfect life. She works in an upscale art gallery, while he, after long years spent in the comically unglamorous field of snail research, has stumbled into success as publisher of a nature magazine called the Living World.

Comically unglamorous? I'm not sure what to say ...

I and the Bird #57

A DC Birding Blog celebrates bird migration in the latest edition of I and the Bird. Flamingos, fairy-wrens, forktails and ... er ... frushes. What are you doing reading this? You should be over there. (But don't forget to come back again.)

Eau de toilette

... or odour toilet. Take your pick. Our visit to the Werribee Sewage Farm (correctly called the Western Treatment Plant) was more Channel than Chanel, but we had a great time.



In his book The Big Twitch, Sean Dooley praised the site:

... a trip to Werribee is one of the most spectacular wildlife experiences this country has to offer. Almost three hundred species of birds have been recorded on the Farm itself, but even more impressive is their sheer abundance. Especially during a drought year, tens of thousands of waterfowl are drawn to the permanent waters of the farm. As they wheel about the lagoons in fluid yet cohesive flocks one is reminded of the accounts of early explorers who wrote of birds in such numbers that they darkened the skies.

We didn't get fluid and cohesive flocks. Not of birds, anyway. The waders are still in Siberia, planning their austral vacation, and the locals are spoiled for choice when it comes to ponds and water races so are distributed over a large area. It was also late afternoon. Put those factors together and I think we were lucky to see as much as we did.



My highlights were three species, all of which are plentiful on the lagoons. But abundance doesn't make them any less fascinating. (Familiarity does not breed contempt when it comes to bird-watching.)

Male musk ducks were displaying to females, other males, passing teal, the odd floating leaf ... Dozens of these big, dark, odd-looking fellows were flaunting their pennants and splashing around like kids at the beach. The females sailed passed, apparently unimpressed.

The ducks did draw the attention of my second highlight — the hoary-headed grebes. Werribee is the centre of the universe for this species. Ornithologist André Konter wrote of his visit to the site in November 1997 in Grebes of our world:

So far I had never seen such big flocks of grebes as at the lagoons of the Werribee Sewage Farm ... Thousands of Hoary-headed Grebes must be wintering there every year and even then, when the breeding season should have started, hundreds of them were still present, partially in breeding, partially in non-breeding plumage.

We didn't see thousands but we saw as many grebes as we did musk ducks. And they're just as tricky to photograph as the Australasian grebes ...



The final highlight was a bird heard more than seen. The vegetation at the edge of the ponds was stuffed with clamorous reed warblers, all belting out their gorgeous melodies.

There were other memorable scenes, including ten or more great cormorants sunning themselves at the water's edge and a pair of black swans with their impossibly cute grey cygnets hitching a lift on their backs. As the swans glided past, one of the cygnets came over shy and buried its face among the black feathers. We saw a little dark eye peep out at us from the safety of mum (or dad's) plumage.

That was our first visit to the Western Treatment Plant. I think we'll have to do this on a regular basis. If only we could shift it closer ...

Thursday gastropod: Thersites Pfeiffer 1855

[Thersites] was the ugliest man of all those that came before Troy — bandy-legged, lame of one foot, with his two shoulders rounded and hunched over his chest. His head ran up to a point, but there was little hair on the top of it.

Pfeiffer should have been red-carded when he used the name of this loathsome character from the Iliad for a genus of three rather fetching camaenid snails from mid-eastern Australia.

Not that Thersites has been without its critics. Iredale (1933) proposed that it be ditched as a generic name and replaced with Annakelea. He didn't suggest this because it was an unfair reflection on the handsomeness of the shells. He argued it on a dodgy taxonomic point.

(Anyone not mesmerised by the minutiae of taxonomy might want to skip down to the pictures. Still reading? Don't say I didn't warn you.)

Pfeiffer (1855) introduced Thersites without nominating a type species. (A type species provides an objective standard of reference for the genus.) Martens (1860) subsequently designated Reeve’s Helix richmondiana as the type. But Iredale (1933: 42), stretching the rules of nomenclature to snapping point, argued that the “tautonymic type of Thersites must be H. thersites Broderip” and, as this was not an Australian species (it was described from Mindoro in the Philippines), deemed the generic name inappropriate. “So Thersites must be dismissed from Australian malacological study,’ Iredale wrote, possibly with an unseemly flourish.

He provided an alternative genus name — Annakelea — retaining H. richmondiana as type species and adding H. novaehollandiae Gray and H. mitchellae Cox.

However, Thersites was perfectly acceptable under the rules of nomenclature. Iredale's argument didn't hold water, so Annakelea bit the dust and entered into synonymy.

Thersites richmondiana (Reeve 1852) is a large species (max. width about 50 mm) from rainforests and wet sclerophyll from southern Queensland to northern New South Wales.

Richmond River, NSW

With a maximum width of 40 mm, T. novaehollandiae (Gray 1834) is the smallest of the three Thersites. It occurs in northern New South Wales from Glen Innes south to Port Stephens.

Dorrigo, NSW

Once common in suitable habitat in northern New South Wales, extensive clearing has restricted T. mitchellae (Cox 1864) to a few locations. The most important of these is Stotts Island in the Tweed River near Murwillumbah.

Byron Bay, NSW

References

Bishop, MJ. (1978) A revision of the genus Thersites Pfeiffer (Pulmonata: Camaenidae). Journal of the Malacological Society of Australia 4(1–2): 9–21.

Iredale, T. (1933) Systematic notes on Australian land shells. Records of the Australian Museum 19: 37–59.

Von Martens, EC. (1860). Nachträge in Albers, JC. Die Heliceen, nach natürlicher Verwandtschaft systematisch geordnet. 2. Leipzig: Wilhelm Engelman.

New South Wales National Parks and Wildlife Service. (2001). Mitchell's rainforest snail Thersites mitchellae (Cox, 1864) recovery plan. NPWS, Hurstville, NSW.

Pfeiffer, L. (1855). Versuch einer Anordnung der Heliceen nach natürlichen Gruppen. Malakozoologische Blätter 2: 112–144.

Sex, flies and lateral gene transfer

Like all parasites, Wolbachia engages in an intimate relationship with its host. After all, getting up close and personal is what parasites do. Wolbachia, a bacterium, is small enough to live inside the reproductive cells of its host, where it causes havoc by interfering with sex determination, killing males and inducing parthenogenesis. (That's havoc for the host, of course. Wolbachia does just fine from the manipulation. It is passed on to subsequent generations in the eggs, which is why it biases host populations towards females. More females, more eggs, more Wolbachia.)

But the relationship between the bacterium and its host is even more intimate than that.

In 2003, a team at the University of Tokyo investigated what they thought were three strains of Wolbachia in adzuki bean beetles (Callosobruchus chinesis). They treated the beetles with antibiotics to rid them of all bacteria but found that only two of the three strains responded. Each time they screened the beetles for the presence of bacterial genes, the results came up positive for the third strain. But it wasn't because this lineage of Wolbachia had developed antibiotic resistance. It hadn't been in the beetles at all during the study. What the team detected was a fragment of Wolbachia genome, which had been incorporated into the X chromosome of its host.

Bacteria swap genes all the time but shifts between bacteria and multicelled organisms are thought to be very rare. Or were thought to be very rare.

Following this discovery, scientists at the University of Rochester and the J. Craig Venter Institute decided to screen host genomes for Wolbachia genes. They weren't quite prepared for what they found. The genome of the fruit fly Drosophila amanassae doesn't simply include the odd foreign gene. It contains what appears to be the whole bacterial genome. At some point, the parasite's genome has become integrated with that of its host.

Wolbachia genes transferring to host's DNA
(Nicolle Rager Fuller, National Science)
Larger image.

Professor Jack Werren (University of Rochester) puts the discovery into evolutionary perspective:

In our very own cells and those of nearly all plants and animals are mitochondria, special structures responsible for generating most of our cells' supply of chemical energy. These were once bacteria that lived inside cells, much like Wolbachia does today. Mitochondria still retain their own, albeit tiny, DNA, and most of the genes moved into the nucleus in the very distant past. Like Wolbachia, they have passively exchanged DNA with their host cells. It's possible Wolbachia may follow in the path of mitochondria, eventually becoming a necessary and useful part of a cell.

So what was once considered exceptional — lateral transfer of genes between bacteria and animals — may turn out to be a common occurrence. Wolbachia infects a wide range of insects, arachnids and crustaceans. How many of those host species have incorporated all or part of the bacterial genome into their genetic make up? And how many of those transferred genes — if any — have a role in their new location?

Read more about the story at the University of Rochester's news page and at news@nature.com.

Chillagoe kurrajong

I made a list of things I wanted to see in Chillagoe. It was a modest inventory: bustards, snails and the Chillagoe kurrajong, Brachychiton chillagoensis. I ticked them all.

Brachychiton is a principally Australian genus, with a few species in Papua New Guinea. It occurs in seasonally dry habitats in eastern, northern and central Western Australia. Most species drop their maple-like leaves when water is scarce, although a few, like B. populneus and B. gregorii hang onto them until severe drought forces them to cast the leaves off.

This kurrajong is endemic to the Chillagoe – Almaden area, where it grows on the fractured, crumbling slopes of rock outcrops. It also occurs in the dry vine thickets that nestle between limestone cliffs, where they're sheltered — a little — from fires. I have a soft spot for kurrajongs, although I know next to nothing about them, so I wasn't going to miss the chance of visiting this one in its home. I'm also fond of short-range endemics — and I know rather more about those — so I was doubly excited by the opportunity.

The tree is recorded as flowering from late May to October, but only a few bell-shaped blossoms clung to the branches of the individuals I saw.

'You're not going to take a photo of that?' one of my friends asked as I scratched away debris to uncover a fallen flower.

'Why, yes. Yes, I am.'

And I got the sort of look that I might have received had I been on the wrong side of the bars at Bedlam.

But I took the photo anyway.

As kurrajongs shed their leaves when they bloom, a tree covered in these blossoms must be a spectacular sight. And I missed it by that much. Next time ...

Fallen flower at Balancing Rock, Chillagoe – Mungana National Park

The last few buds at the side of the road

The leaves have characteristically rounded lobes

New seed pods on a roadside tree

Deeply fissured and tessellated bark

It occurs with another species, the broad-leafed bottle tree (B. australis), which has a much wider range. (This more common species extends from west of Cooktown south to Wide Bay.) The two are readily distinguished on the shape of the leaves and the different bark textures. And no doubt on the flowers too — at the right time of year. Which, I shall note in my diary, is not late July, no matter what the definitive work claims.

Brachychiton australis doing it tough on a limestone outcrop

Really tough ...

The bark is paler and relatively smooth compared with that of B. chillagoensis

The leaves are also more pointed and deeply dissected

Reference
Guymer, GP. (1988). A taxonomic revision of Brachychiton (Sterculiaceae). Australian Systematic Botany 1: 199 – 323.

With 88 weeks and two days* to go before I make the break from my current employer, I thought this might be a good time to develop an alternative career. Rather than invest in a shottie, balaclava and underworld lawyer, I decided to revive my interest in science communication. Sure, it's not as exciting as armed robbery but I can see an up side to that.

Mind you, I'm wondering whether I'll be able to make it all the way through those 88 weeks and two days. I have just about had enough.
_____

* But who's counting?

Harlequin bugs

The last few days of winter were unseasonably warm. (26C, anyone?) And now it's spring — clear, mild and windy.

I took my camera into the garden to photograph hoverflies dancing in the morning sun. Because the autofocus isn't good with small, active objects, I had to wait until a fly settled on a flower. Unfortunately, every time that happened, my target would be dislodged by pairs of harlequin bugs trundling around in copulo. This flower was like Tiberius's palace.


Somewhere, a Dindymus Claudius was hiding behind the arras and documenting the goings on.