June Butcher, founder of the Kanyana Wildlife Rehabilitation Centre and our member and guest speaker for the general meeting, gave us an insight into the aims and functioning of the rehab centre now located in the now very well rehabilitated wildlife centre at 120 Gilchrist Rd, Lesmurdie. The main thrust of the talk was bilbies – the secret life thereof, until now, for June and her devoted team of volunteers have done much serious scientific research into what goes on in the inner sanctum of the burrows of bilbies.

In the past bilbies could be found across about 70% of Australia. Enter the usual ferals and the percentage drops to around 20% at most and dwindling. Gradually, however, the number of bilbies in the wild is being restored thanks to the breeding programmes being carried out by the likes of Kanyana with DEC, and safe release areas like Peron Peninsula, Dryandra, Loxby Downs etc., which have ‘soft’ release facilities (semi-bush but fully protected) before full release in the same area such as we have at Dryandra and photographed by Mike Griffiths with camera traps recently.

It all started at Kanyana in 1996 when baby Bet-Bet, an emaciated little female bilby was flown down to June. Bet-Bet survived along with Basil from Broome thanks to DEC. From this small beginning the serious business of breeding bilbies for release began under the auspices of DEC and the Central Keeper in S. Australia. At the latter a studbook is kept of all the animals in breeding programmes throughout Australia, enabling monitoring of the exchanges between centres and ensuring that healthy bloodlines are maintained. Kanyana has seen 140 bilbies pass through its doors and has turned out around 100 babies. An average of 15 bilbies is on Kanyana’s books at any time, and we were privileged to see the current crop the following evening inside a large, netted enclosure with spacious enclosures either side of the central isle – in one, mother with two cute little offspring in tow. Cameras lowered into the burrows have revealed many new secrets of the lives of bilbies when underground. For instance, during peak daylight hours Bilbies shut their systems down – body temperatures and breathing drop considerably, leaving them in a torpor thus conserving considerable energy. A full moon signals a lay night with no venturing out – too visible to predators? Mating takes place underground and is a rather drawn out process … up to 18 hours at a time! So drawn out that the record of one such engagement shows the larger male going to sleep on the job and toppling sideways! Energy saving again maybe?

In another first, June waited many years to record the actual birth of a Bobtail – that phone call at the crucial moment or some other distraction at the crucial moment – but then success! The quite large youngster had a battle for a start but mum raised her rear end a little and the baby, once its front feet touched the ground, helped itself the rest of the way. Then there was a tussle of who would feast on the after birth. Baby won!

It was great to hear the story of Kanyana, see the film shots of bilbies (even giving birth) and then having the privilege of seeing the institution itself and some of its inhabitants first hand. A remarkable achievement for June and her numerous team. We look forward to the next stage, hopefully mid 2012 – the new Education Centre. Thank you June and staff.

Kevin Griffiths

Dr Kayley Usher, from the CSIRO, was our guest speaker for the October meeting and presented a talk entitled ‘How marvellous microbes made our world’.

We were introduced into the world of the microscopic and sub-microscopic through a series of images and were presented with some interesting aspects of microbial life and its activities.

A group term for a range of ultra-small life forms is microbes and includes: Archaea, Eucarya, Fungi and bacteria. Some important characteristics between these domains were explained, some of the extreme conditions in which they can exist and a few examples of specialised forms of bacteria were introduced. Not all microbes are single cells but they can function as complex pro organelles with specialised existences. An interesting example is magnetosomes that contain magnetic crystals and have flagella that enable them to source their food magnetically.

We were reminded of the great antiquity of bacterial activities and that thrombolites and stromatolites were developing about 3.5 billion years ago. These fossilised layered accumulations of calcareous sediment were formed by the activities of colonies of bacteria and resulted in the first life forms on Earth. Micro-organisms were to remain the only life forms in the Archean history of the Earth.

The study of micro-organisms requires different types of microscope and high tech equipment; these include microscopes with fluorescence attachments using light sources, the transmitting electron microscope (TEM) and the scanning electron microscope (SEM). The energy sources used in both TEM and SEM are electron beams and this enables details to single wave length dimensions to be examined. Both TEM and SEM equipment is based at the Centre for Microscopy and Microanalysis at UWA, and are used by researchers from many Institutions on an hourly basis.

The images used for the talk were largely those produced by TEM and SEM microscopy and we were shown a fascinating selection illustrating the varied forms of several bacteria including coccoid, spiral, flagellated and rod-like forms as well as examples that were attached to one another and to the substrate via a series of microfilaments. Electricity is conducted through this nano wiring system allowing the bacterial colony to communicate. Microbes tend to live in communities, acting together symbiotically. They co-operate through biofilms where they attach to the surfaces, grow and then detach to recolonise. Bacteria also communicate as colonies using chemical sensing, termed quorum sensing. Bacteria can also sense smells and head for food!

Microbial environments are everywhere. As examples, extremophiles dwell in environments that are; highly saline, high temperature, extreme pH, with toxic metals, at depths of 1.6 km in sediments and they do not require organic carbon to exist. The first mass extinction was likely caused by the activities of cyanobacteria in the Archean when large amounts of free oxygen was being produced as a by-product of iron precipitation. The importance and significance of microbial life become apparent when considering such examples as mycorrhiza activity (symbiotic relationship between a fungus and a plant) that benefits plants by an increase the water and mineral take up capacity and nitrogen-fixing bacteria that improve soil fertility. As humans the abundance of micro-organisms is considerable when we learn that our cells are 99% comprised of microbial life. Microbes manufacture the vitamin K in our bodies and aid digestion processes. Cell mitochondria are a specialised form of bacteria.

Kayley’s particular area of research includes interactions between natural metal ores and bacteria. Her work has shown that elemental metal can be released from mineral ores by bacterial chemical processes such as isolating copper from copper sulphide ore. Element mapping using TEM showed the distribution of certain elements within the bacteria as chemical changes progressed.

We were introduced to the mechanisms of rusting on metals with an explanation about rusticles and their development. Images of the wreck of the Titanic over a number of years show how rusticles (pendulous growths of rusting iron) have enlarged as corrosion has advanced. Eventually all materials, including concrete, wood, metals and plastics, become degraded by microbial action.

There are many positive ways that microbes can be utilised including the cleaning up of toxic waste and degradation of contaminants such as oil spills. In outlining a few of the important aspects of microbial activity Kayley made us aware of some important research work and its potential applications.

Susan Stocklmayer

Some 20 intrepid DRB members and visitors travelled to Twink Smurthwaite’s ‘Topsy’ garden in Boya on Sunday September 18th – ‘intrepid’ because the day promised to be truly equinoxal. About half of those people continued to inspect rehabilitation work by the Helena River Catchment Group (HRCG) along the Scott Street/Pumpback Dam section of the river. The following account draws heavily from written material provided by Twink and Craig Wansbrough, Deputy Chair of the HRCG.

DRB members in Twink’s garden. Twink 3rd from right. Photo by Andre du Plessis

Twink’s garden

The group was impressed with the variety of plants in the garden, which has become established over 45 years. Twink said that the garden had been hit hard by the previous exceptionally dry winter and hot summer, although virtually all plants were showing renewed growth after the welcome rains this winter. Unfortunately weeds have also thrived.

Twink noted that when she settled there in 1963 the garden contained some non-native plants, including a Fiddlewood tree (retained for its shade), Hibiscus, Bougainvillea, Cotoneasters (mostly gone), an Olive tree (also removed, but seedlings reappear from time to time), Irish Strawberry trees and a Lemon-scented gum.

Naturally-occurring natives include Allocasuarina huegelliana, Wandoo, Eucalyptus rudis, Hakea prostrata, H. petiolaris, Xanthorrea, Marri (happy in one part of the garden but will not survive in another) and Zamias (one with a very large base and two grown from seed).

Plants which have appeared voluntarily over time include Phyllanthus calycinus, Stypandra grandiflora, Daviesia horrida, Trymalium floribunda, Thomasia foliosa, Orthrosanthus laxus, Acacia pulchella, Rulingia cygnorum, Grevillea pilulifera, Haemodorum Orchids and several grasses, including Kangaroo grass, Wallaby grass, Spear grass, Astrostipa elegantissima, Neurachne alopecuroides and Microlaena stipoides. Seeds have washed down from upslope, including Hibbertia serrata, Darwiniia citriodora, Verticordia plumosa and Melaleuca radula.

Trees planted include E. Kruseana, Allocasuarina, Melaleuca and Corymbia species.

Birds thrive in this inspirational garden, which strongly reflects the character of its owner and carer.

Helena valley

The second part of the excursion took in an inspection of the restoration work being carried out by the HRCG along the lower Helena river. Funds were obtained from Swan Alcoa Landcare Program grants and an Australian Government Natural Heritage Trust Envirofund grant. Craig Wansbrough led the group to the four sections of the project. The ten-year project was initiated in 2005 and is aimed principally at weed control followed by revegetation, on both banks of the river from Scott Street to the Pumpback Dam. Following the disastrous 2010 winter, the group was encouraged by the strong flow of the Helena.

Section 1 of the project extends from the Scott Street bridge to Fyfe Street. No work has been done here as yet. The objective was to show the group the nature of the extensive weed infestation, primarily Blackberries, Watsonia, Giant Reed, Figs and Buckthorn, prior to their removal.

Craig Wansbrough showing Helena rehabilitation. Photo John Abbott

Section 2 comprises the Fyfe Street Flats and also illustrates the fuse break/habitat island concept. Twelve landholders and the Shire of Mundaring were involved in the work. The Flats had been excavated for alluvium (sold as ‘garden soil’ in the landholder’s garden centre) between 1940 and the 1960s, with some 2 m of alluvium being removed. As a result it is now very susceptible to flooding. After two years (2005-2007) of weed control, planting of Juncus subsecundus was undertaken, but there are still problems. Craig also demonstrated the fuse break/habitat island concept, where clumps or islands of shrubs are replanted as fauna habitat, leaving some areas with relatively bare understorey to act as ‘fuse breaks’ to help in fire fighting. He noted that fires (usually lit by arsonists) are a major problem in this area, and that the river vegetation can act as a wick, carrying the fire rapidly through the valley.

Along Helena Valley Road Craig pointed out the effectiveness of four-year-old direct seeding by the Water Corporation on the upslope side. Weed control works were achieved in 2007- 2010.

Section 3, Victor Road revegetation, has had two years of weed control and was planted by community members and 13 landholders in July 2010, using the same species as in the Fyfe Street section.

Section 4 includes the picnic ground at the end of Helena Valley Road and continues towards the Pumpback Dam. There are many problems in this area, including some very steep slopes (abseiling had to be used to access some of the Watsonias) and the widespread occurrence of annual weed species. Adjacent to the picnic ground the DRB viewed the Western Power Offset Project, which includes weed control and revegetation. Water Corporation weed control was completed on the eastern side of the river from 2006/2007. On the western side Watsonia control was completed from 2008 to 2010.

Members of the group were most impressed by what they saw and were highly appreciative of Craig’s explanation of the project – which won the 2010 WA Environment Award (Bush, Land and Waterways category). Nevertheless, controlling annual weeds, which have proliferated following the removal of the perennial weeds and the wet winter, will prove challenging; and ongoing maintenance will be required.

Arthur Conacher

Eric McCrum, past President and active member of the Darling Range Branch, presented a talk on grasshoppers entitled ‘The bizarre world of grasshoppers’.

Eric’s talk was well illustrated from his extensive collection of slides, a selection of which showed the wide morphology and colourful varieties of grasshoppers from WA.

Eric began with a summary of the essential general body form of grasshoppers and explained that they are a primitive insect group. Their eggs hatch into miniature grasshoppers (nymphs) in contrast to some other insects that have developmental stages involving metamorphoses prior to maturity. Young grasshoppers shed their skins a number of times and initially lack wings (when they are called hoppers); however their essential body form is recognizable throughout their life cycle. The number of moults varies between species. Grasshoppers, crickets and katydids are all members of the Order Orthoptera and it was emphasised that they are many unnamed species in WA.

Grasshoppers live only for a year, dying in winter; the action of ‘flying’ and general physical activities involved in living and feeding eventually damage the wings, making the adults vulnerable to predation. However, the eggs survive through the cold season to a new generation.

General characteristics of grasshoppers are very variable but certain features can be indicative of lifestyle, such as short antennae – an indication that the insect feeds on grasses in the daytime. Many long-horned grasshoppers tend to be more omnivorous. Most grasshoppers are vegetarians, although some are scavengers and others predate, with caterpillars and cockroaches being among the victims. Grasshoppers themselves are victims to many other insects such as wasps as well as birds and animals.

The major groups of grasshoppers are designated by several body characteristics such as the number of segments in the antennae, differences in the structure of the feet, wing structure and veining in the wings. Eric introduced us to eight of the thirteen families and briefly explained some of the major characteristics of each. Examples include ‘ridgebacks’ or gumleaf eaters of the Gonidaea species that shed their skins four times and are themselves often wasp-food. A fine example of a pink coloured Casedicia sp. showed the variation from the usual green and brown colours: this species feeds on cockroaches. Species of Acrididae with an unusual conical head are an example of more bizarre body forms. Also illustrated were a selection showing: colourful crested yellow and green species from the Pilbara and Murchison areas; Monistria sp., a spotted form with vestigial wings from Two Peoples Bay; and sandgropers – an odd form (family Cylindrachetidae) related to grasshoppers, with its front parts formed as shovels. These insects live a subterranean existence feeding on the roots of plants at depths up to 1.5m. Five of the seven of this species are found in W.A., with the only other two species being found in widely separate places; Papua New Guinea and Patagonia.

A common attitude seen in several slides was the attention the grasshoppers give to cleaning their antennae with their feet, and a noticeable number of female grasshoppers displaying conspicuous ovipositors.

The variety of grasshoppers shown through the presentation clearly demonstrated that ‘not all grasshoppers are green’ and that their size, shape, colour, and general body morphology are widely varied. Colour and camouflage are especially well adapted to varied environments, with several photographs showing how difficult it can be to spot a well-camouflaged grasshopper on bark, lichen or in leaf litter, or when cryptically imitating both green leaves and stalks of certain plants. The translucency of some body parts assists this effect.

Eric’s slides represent many years of patient insect watching and the talk was well received by a well-attended meeting. A lively question time followed.

Susan Stöcklmayer