Backyard Bit

Fireflies can be a festive sight for a brief period in the latter part of the year along the Toowoomba Range escarpment. Fireflies are beetles (Coleoptera), not flies, and they belong to a family found throughout the world (except for Antarctica) called Lampyridae. There are about 2000 species world-wide, but Australia has only 25 described species, all of them confined to the wetter parts of coastal Northern Territory and eastern Australia, especially in rain forest and mangroves. 

The firefly species seen locally is Atyphella scintillans. The males fly just after dusk emitting a series of controlled flashes from light organs on the underside of their body. This is part of their mating sequence. Females also flash but have not been observed to fly with males. Larvae and pupae are also faintly luminous. Synchronised flashing, which is common in New Guinea species, has also been observed in some north Queensland species. 

The ground-dwelling larvae live in moist leaf litter and are predators on small, soft-bodied invertebrates, especially small land snails and slugs. They inject a paralyzing secretion through their mandibles into their victim. The prey's tissues are dissolved extraorally and the liquified mass is then imbibed by the larvae.

Adult fireflies do not eat and only live for a few days.

(Michael Rooke (information courtesy of Rod Hobson)

Outing Report - 4 Nov, 2018 - Ian and Margaret Clarke's Property “Bundara”, Biddeston

An early start meant that we foregathered at Bundara at 7.00am – just as well, as it was quite a warm day! Ian commenced proceedings by giving us an overview of the history of the property, the existing vegetation and the various plantings that had been put in.

Ian has an interest in oaks and has planted a collection over 30 species in number on the property. During our walk around, we saw but a fraction of these. There was of course an English oak Quercus robur, but I made a note of a few others amongst an impressive array. Q.coccifera, the Kermes oak is from the Mediterranean. It hosts the kermes scale insect from which a red dye called 'crimson' was derived. Another that caught my attention was Q.variabilis, the Chinese Cork Oak, which, like its European counterpart, can produce cork.

The existing native trees are dominated by eucalypts, in particular Eucalyptus orgadophila, the Mountain Cool-ibah, E.tereticornis, the Forest Red Gum, and Corymbia tesselaris, the Carbeen/Moreton Bay Ash. I also noted E.sideroxylon, the Mugga/Red Ironbark, and E.meliodora, the Yellow Gum.

There followed a bewildering array of native plantings with a list running into the hundreds, which is a tremen-dous achievement. I will just comment on a few that caught my eye or piqued my interest. Acacia pendula is the wattle with silvery 'weeping' foliage. Atalaya salicifolia (Scrub Whitewood) was eye-catching due to the winged rachis between the leaflets. We saw three Brachychitons – B.populneus, the Kurrajong, B.discolor, the Lacebark, and B.rupestris, the Bottle Tree.

Ian showed us his pecan tree (USA) Carya illinoiensis, which yields little in the way of nuts for humans because the nuts all get eaten by the cockatoos!

We saw Ian's orchid which was briefly elusive as it was up in the fork of a tree, the orchid being Cymbidium canaliculatum, the Black Orchid/Tiger Orchid. We saw four species of Dodonaea including Dodonaea viscosa, which has in the past surprised us, being native also to Zimbabwe and New Zealand! Amongst the Flindersias we saw (I think there were four) was F.maculosa next to the driveway, in spectacular flower. This is another tree which has an attractive 'weeping' habit.

I was interested in Ian's Wilga, Geijera parvifolia.  I had heard that these can be difficult to propagate, but Ian said that his readily produces seedlings around the trees. The Glochidion ferdinandi (Cheese Tree) obligingly assisted with identification by bearing fruit in the shape of miniature cheese rounds which give it its common name. 

Ian has plantations of olives on the property – Olea europea. But he also has the African Olive, O. africanus (possibly a subspecies of the European olive) and, happily an Australian olive, namely, O.paniculata, the Native Olive. Also in the olive department we saw Notelaea linearis, the Narrow-leafed Mock Olive, which has a common name which I doubt is 'common'!

We saw Ozothamnus diosmifolius, the Rice Flower, so called because the flower buds resemble rice grains. Podocarpus elatus struck a familiar note as Podocarpus is well represented in southern Africa as is also Poly-scias. Ian has P. elegans. Zimbabwe has P. fulva.

A lovely splash of yellow colour was provided behind the dam wall by planted Senna artemisioides and S. coronilloides. Senna was previously 'Cassia', until the taxonomists decided to upset the apple cart and split the genus. The name 'artemisioides' is a reference to the appearance of the foliage which resembles that of Arte-misia absinthium, the notorious wormwood from which absinthe derived its flavour. We don't know if Ian has tried making absinthe from his Senna!

There were too many plantings to comment on all of them, but there was an interesting aside on the subject of planting trees. Ian confirmed that he has used road-kill roos in the planting holes over which the new tree is grown. He was asked if this makes a difference and he assured us that it has the trees 'jumping out of the ground'!

A lovely morning's walk in the garden and property was followed by lunch at the Biddeston School where we inspected the plantings of native trees around the oval in preparation for the school's 100^th anniversary.

Thank you to Ian and Margaret Clarke and to Sharon Wilson, principal at Biddeston School.

(Report by Philip Haxen)

Speaker Report November - Extinction of the Australian Megafauna: What is the Evidence?

(Bryce Barker, Professor of Anthropology, University of Southern Queensland)

The Australian megafauna lived during the time known as the Pleistocene, colloquially termed the Ice Age, which occurred between about 1.7 million to 10000 years ago. The megafauna are the extinct ancestors of species which are today much smaller and were characteristic of the Pleistocene not only in Australia, but also the Americas and Eurasia. North America had mammoths, saber- toothed cats and giant sloths for example, (as per my previous talk about the La Brea tarpits near Los Angeles). Africa is the only continent still inhabited by megafauna.

The Australian representatives included Megalania prisca, a seven metre goanna; Diprotodon, at two metres at the shoulder the largest marsupial to have ever existed; Procoptodon goliah, the short faced kangaroo standing over two metres high; Thylacoleo carnifex, termed the marsupial lion, and many others including seven metre snakes and crocodiles, a 2.5 metre turtle and two toothed platypus species double the size of today's species.

There is ongoing debate and controversy as to the causes of extinction of these animals which occurred world-wide. Professor Barker's presentation clearly examined the likely causes by comparing the Australian research with findings from America and Europe.

Broadly, reasons for the extinctions cover three main theories:

•     The arrival of humans with their superior hunting 
•     The effect of humans on the landscape
•     Climate change   

It is possible that all three could have contributed, but Dr Barker laid out the following points regarding human arrival:

1)      Is there evidence of hunting technology coinciding with extinctions?

2)      Are there remains of megafauna in association with human settlements?

3)      Is there rock art depiction of hunting of megafauna?

All three are found in America, Africa and Eurasia.

In North America the earliest hunting technology is the stone projectile or knife, characterised by the 'Clovis Point', a sharp tool knapped from suitable stone and associated with the Clovis people. There are many bones of megafauna associated with these people, and clear signs of penetration of or cuts to the bones (including those of extinct megafaunal bison). So far, although stone tools are plentiful, there is no confirmed evidence of mega-faunal bones associated with Humans in Australian archaeology. Remains of post megafaunal species are how-ever common.

Eurasia also has many finds associating stone projectiles with remains of extinct megafauna. Depiction of hunting seems universal in rock art and is a feature common to all inhabited continents. The Lascaux and Chauvet caves of France are famous, as are the many and widespread bushmen paintings in Africa. So far there is no Australian rock art confirmed as depicting megafauna. Many paintings previously thought to depict megafauna have been dated to well post-extinction and are considered to be 'dreaming' creatures...possibly passed down over many generations from an ancient memory.

Professor Barker then went on to describe a truly remarkable and unique Australian site of human habituation, the Nawala Gabarnmang Rock Shelter, where he has carried out research. Found only just over 10 years ago by two men overflying a remote area of Arnhem land, Northern Territory, the site seemed almost lost to memory. One elderly man recalled camping there with his father in the 1930s.

The shelter is part of an ancient shallow ocean floor where deposits of sand laid down over time were compressed into sandstone, then harder quartzite. When the structure was raised above the sea, erosion of softer sandstone began, leaving pillars of quartzite supporting a roof. About 50 000 years ago people began to use the shelter. The pillars would have then been about a metre apart, and people began to modify the shelter by chipping away some pillars with stone tools to increase space. This was carried out over many generations and they also began to cover all surfaces with paintings. There is layer after layer of paintings, some confirmed as being 28 000 years old! Blocks of broken pillar have been used for grinding coloured ochres, others piled up as platforms for artists to sit or stand on.

No representations of megafauna or their remains have been found at the site. The thylacine is clearly depicted, but it is known that they occurred on the mainland until about 3 000 years ago (possibly displaced by the dingo). There is a painting at a nearby site, of what appears to be a large flightless bird in which a spear is embedded. Research focused on the giant Genyornis newtoni which became extinct about 40 000 years ago. Humans and the bird may have co-existed for some thousands of years. However, dating of the painting showed it to be only 14 000 years old, so it is probably another 'dreaming' beast. It is now believed that only at most 14 species of the original 90 megafauna species were still extant when humans arrived on this continent. The evidence seems then to suggest that direct contact with humans in Australia is an unlikely megafauna extinction culprit. However, many still assert that hunting wiped out the megafauna.

The scientific research continues with ever more sensitive dating techniques such as Optically Stimulated Luminescence OSL, (which dates sediments by measuring when silica was last exposed to sunlight!) which so far matches the older carbon dating. Meanwhile the controversies continue.

(Report by Cheryl Haxen)