SEASONAL BEST WISHES

There have been many memories of bird surveys and walks, excursions, etc. during 2023. Here’s just a few that come to mind...

Blue-banded bee at Jindivick (thanks A&P for all those visits)

Copperhead at Longwarry. Encountered in mid-winter!

 

Fairy Aprons: a fascinating bladderwort at Bunyip SP

Imagine the weathering! Cave Rock on Mt Cannibal

Mueller's Snow Gentian on Mt Baw Baw

Eastern Bronze Caladenia at Corinella. In decline.

There was the odd bird or two also...

At Thornell's Reserve: the extraordinary songster - Rufous Whistler

Rose Robin at Neerim East - always a delight.

Normally shy Striated Foeldwren - Bass Landing

Thanks for looking in from time to time. Don't we live in a great corner of the planet? Please keep up the good fight. Your support is greatly appreciated.

May 2024 be all that you want it to be.

Death by a falling tree - the risk is low

Climate change is with us. According to Victoria Government’s Natural Environment Climate Change Adaptation Action Plan 2022-2026, “Victoria's climate has changed in recent decades, becoming warmer and drier. These changes are expected to continue in the future.”

Extreme weather events are expected to increase, including bush fires, floods and wind storms. Trees are susceptible to wild weather and the reports of trees blowing down due to windthrow during wet and windy conditions are likely to rise.

Trees though are very resilient – they are biologically engineered to adjust to their situations. They are naturally designed to sway in the wind. Root systems will develop in a direction to take account of prevailing wind directions. Often it is recommended that new trees not be staked for long periods in order for the tree to develop natural resistance to existing wind directions. In March 2022, New Scientist reported that “Trees that grow close together are better at withstanding storms”.

Although extreme storms are a concern, we should remember that trees provide many environmental, economical and health benefits – lowering ambient temperatures, increasing property values, cleaning the air we breathe - are examples.

Information on deaths in Australia due to a falling tree is scarce. In 2007, A Brookes produced a paper Outdoor education fatalities in Australia for the Australian Journal of Outdoor Education in which, for the first time, a list of deaths from tree failure in Australia was published. Details of seventeen fatalities over a forty-year period were given.

In 2019, M Hartley and J Chalk produced A review of deaths in Australia from accidental tree failure for the Arborist Network. In their report, Hartley and Chalk quote “Our results have shown that injuries attributed to accidental tree failures make up a very small proportion of the total trauma admissions to our Level-1 Trauma Centre.”  The report also indicates that not all deaths from a falling tree occurred during a storm. Other circumstances included work related incidents such as timber harvesting processes, cleaning up after a storm and controlling or mopping up after bushfires.

Hartley and Chalk pointed out that, “Most people are comfortable being exposed to risks many times greater than the risk posed by tree failure” and that the risk of being killed by a falling tree is markedly lower than the risk from some other common causes of mortality such as:

Melanoma – 1 in 13,500

Driving a vehicle – 1 in 20,000

Asthma attack – 1 in 60,000

Murder, 1 in 100,000

Falling from a bed – 1 in 420,000

Accidental tree failure – 1 in 5,000,000

Accidental tree failure while inside a house – 1 in 189,000,000

 

Further references:

The epidemiology of injuries related to falling trees and tree branches – Way and Balough – Royal Australasian College of Surgeons (“We demonstrated that the likelihood of being injured by falling trees is very low. This information should be taken into account when planning future developments or considering the removal of existing trees in the interest of public safety.”)

 

 

Fairy Aprons

On the recent FoDT Buttongrass Walk in Bunyip State Forest, we were fortunate to find some colonies of Fairy Aprons, Utricularia dichotoma (utriculus  = small leather bag, dichotoma  = two flowerheads which many of the plants have).

Utricularia dichotoma is a perennial herb with numerous underground trailing stems with bladders 1.5–2 mm diameter. It is a widespread species found in Australia, New Zealand and New Caledonia. All bladderworts are highly specialized plants.

Bladderworts such as Fairy Aprons capture small organisms by means of bladder-like traps. Terrestrial species tend to have tiny traps that feed on minute prey such as protozoa and rotifers swimming in water-saturated soil.

Despite their small size, the traps are extremely sophisticated. Prey brush against trigger hairs connected to the trapdoor. The bladder, when "set", is under negative pressure in relation to its environment so that when the trapdoor is mechanically triggered, the prey, along with the water surrounding it, is sucked into the bladder. Once the bladder is full of water, the door closes again, the whole process taking only ten to fifteen milliseconds.

Diagram credit: Wikipedia

Once inside, the prey is dissolved by digestive secretions. This generally occurs within a few hours but the bladder can be ready for its next capture within 15-30 minutes.

Now you can’t tell me that Nature ain’t grand!

Biophilia – a desire to connect with nature

Biophilia is the term used to describe the tendency for humans to seek connections with nature and other living forms (bio = life, philia = love). The term was first used by the psychoanalyst Eric Fromm in 1973 when he used it to describe a psychological tendency to being attracted to all living forms. Later, in1984, Edward O Wilson a biologist used the term biophilia to propose that the tendency for humans to be attracted to nature was partly genetic. 

Nangara Reserve Jindivick

In Japan in 1980, ‘karoshi’, Japanese for ‘worked to death’, was a widespread phenomenon causing ill health often resulting in heart attacks, strokes and even death. Some government-sponsored research determined that time spent in nature would benefit overworked people and a form of therapy called Shinrin-yoku, or forest bathing, was developed. Today there are nature therapy associations with millions of followers around the world. Nature therapy is about slowing down, feeling the breeze, smelling the bush, hearing the birds, etc. - immersing yourself in the natural environment. 

Alex Goudie Park

As a race, we humans have diverged somewhat from nature with our advances in technology in the last 100 years or so. We have become isolated from nature. We now spend most of our time at work, in our homes, our cars, etc. surrounded by technology to a degree sometimes that some of us even fear nature – biophobia. Various studies around the world now suggest that the decline in our interactions with the natural world is resulting in environmental degradation. 

Arachnophobia is very common but very few people die from a spider bite

Our urban lifestyle has resulted in less frequent contacts with nature. We are at risk of losing our connection with nature and of developing negative perceptions about our natural environment. 

Given that the physiological and cognitive benefits derived from connecting with nature are widely recognized, it is increasingly important that we create urban environments that will stimulate our connections with nature as much as possible. Our future depends on it.

It's snake time!

The season is noticeably warming and anecdotally, copperheads and tigers are emerging from their winter quiescence. Both species are mostly diurnal and usually found near a water body. They both eat insects, frogs, lizards, other snakes and sometimes birds – Tiger Snakes in particular will readily climb trees.

Tiger Snake - Drouin

Australia is home to the most number of species of venomous snakes in the world and yet we rank very low on the number of deaths due to snake bite per capita. In Australia, about 0.13 people per million per year die from snake bite. In South America the figure is about 10 deaths per million people per year, In India about 13 people per million die from snake bite each year and in Sri Lanka, the figure is around 50 people per million population per year.

By and large, Australian snakes have an undeserved reputation for being deadly. None of Australia’s snakes are normally aggressive unless they are cornered or being attacked. Our snakes would find a human too large as a food item and usually, if you just stand still or quietly retire from its presence, a snake will just continue on its way or eventually seek cover and simply disappear from sight.

Along with the Brown Snake and the Taipan, the Tiger Snake is one of the top 3 most venomous snakes in Australia. Both the Tiger Snake and the Copperhead are largely diurnal but it is not unusual to encounter either on a warm night.

Copperhead - Longwarry

Copperheads are venomous too and a bite could be fatal without medical assistance. Copperheads appear to be adjusting to urbanization and are generally happy to be living amongst us. Butcherbirds, Kookaburras, Kites and Goshawks are known predators of both Tiger Snakes and Copperheads.

PS:

Everyone has a snake anecdote. Here’s two I found particularly interesting recently:

A high proportion of Tiger Snakes on Carnac Island off the West Australian coast near Perth, were found to be blind in one or both eyes from attacks by nesting gulls.

A ‘micro-chipped’ tiger in the Botanic Gardens at Cranbourne is periodically relocated several kilometres away and invariably reappears back at its original location within a few days

Where have the insects gone?

When was the last time you experienced an invasion of Christmas beetles, or had a headache from listening to cicadas ‘sing’ all day long?

World wide, the insects are in trouble. In 2019, a review of global research undertaken by the University of Sydney,  found that 40% of the world’s insect species were ‘catastrophically threatened’ and that the principal reasons were habitat loss, chemical pollutants, invasive species and climate change. The research found that in some countries over 75% of all insects had vanished. 

Even annoying or ‘pest’ insects such as march flies and mosquitoes, play a useful role within their ecosystem – as food for other animals if nothing else. More broadly speaking, insects perform a variety of essential functions.

Plant natives to attract beneficial insects to a garden

Many beetle species are decomposers, returning nutrients to the soil as they go about feasting on dead plants, animals and animal feces. Insects that live in the soil contribute to healthy soil biota by digging tunnels that allow air and water to enter the soil.

Ichneumon wasps and hover flies are beneficial insects to the plants in our gardens

Species of butterflies, bees, wasps, ants, flies and others, help pollinate thousands of species of plants. Many insects help keep other pest insect populations in check – hover flies for example are not just great pollinators, their larvae consume aphids and scale. The beautiful dragonfly and damselfly are voracious feeders on mosquitoes and are not harmful to plants in any way. 

A block of wood with some different sized holes erected in a warm, dry part of the garden makes a simple insect hotel which is quickly inhabited by beneficial native insects

Beneficial insects can be attracted to the backyard garden by planting natives, building (or buying) an insect hotel and stop spraying insecticides.

Urban trees can get hot too

Urban trees give us welcome shade

With the Bureau of Meteorology declaring that the El Niño weather pattern is active over the Pacific Ocean and that a positive Indian Ocean Dipole has developed, the chances are we are in for a hot and dry summer. July this year was the Earth’s hottest month on record.

Some researchers are concerned that many species of native and exotic urban trees are not particularly heat tolerant.

Just like us when we sweat, trees lose water in order to remain cool. If a tree is unable to source enough water during hot weather, it becomes susceptible to dieback, insect infestation and pathogens.

During the 2019-2020 Sydney heatwave, researchers discovered that some urban tree species such as Red Maple, Tulip Poplar and Coast Banksia showed low tolerance of elevated temperatures and many actually died or became so debilitated they had to be removed.

Chinese Elm, Chinese Ash, Weeping Bottlebrush and Kurrajong on the other hand, all seemed able to avoid excessive dieback and death.

Trees control their water loss by opening and closing pores in their foliage. In dry times, they close their pores to conserve moisture but this means the leaves become susceptible to high temperatures. The leaves can become scorched and shriveled, placing the tree itself in a dire situation.

Eucalyptus stomata. Credit - Eye of Science photo library

Trees with thin leaves are generally more susceptible. Trees that lose foliage due to heat stress can take many years to fully recover.

Many of our native trees and shrubs are often more tolerant of hot, dry conditions. They have adapted to it over millennia. But they are not immune, and during hot weather most will appreciate a deep but less frequent watering.

Kurrajongs are ideal street trees that can tolerate drought

Mulching the root zones helps retain moisture. Regional and State authourities could install passive irrigation systems for street and parkland trees – runoff from buildings and roadsides is directed to the surface or sub-service - via a recharge pit – where soil moisture is retained at a depth where the tree roots can access it.

At a personal level, don’t forget to give that tree or shrub on the nature strip a good drink on a hot day.

References:

We Need Urban Trees More Than Ever - The Conversation

Summer of Severe Heat Predicted - ABC News

 

 

 

Spring bird surveys

The FoDT bird survey team has begun this season’s surveys. We are sticking to our standard arrangement – seven core sites twice each and a couple of supplementary sites if time and weather patterns permit.

The surveys are done each Tuesday and Thursday morning from around 830am for a couple of hours.

Fantailed Cuckoos have begun arriving. They're on the lookout for live nests in which to lay their eggs

The core sites are: Gum Scrub Creek wetland between Hopeton Rd and Buln Buln Rd, The Drouin Waste Water Treatment ponds as arranged with Gippsland Water, riparian strip and Swamp Gum bush block in Amberly Estate, Golden Whistler Reserve in McGlone’s Rd, Thornell’s Reserve at Picnic Point, Bellbird Park wetland in Settlement Rd and McNeilly Park wetland in Jackson’s Dr.

Supplementary sites include: Alex Goudie Park, Roberts Ct bush, Crystal Waters estate including John Lardner Reserve and possibly others. The autumn survey earlier this year yielded 83 species.

Birds are great bio-indicators. They can give an indication of the health of an ecosystem. Drouin’s parks, gardens, wetlands and corridors are vital habitat for urban birds and other wildlife. Development however is placing great pressure on urban bird populations. It is hopeful that over time, our survey results will provide some measure of success, or otherwise, of attempts to save and enhance Drouin’s wonderful tree canopy.

The reed beds around wetlands are beginning to resound with the loud territorial calls of the Reed Warbler - a true harbinger of spring.

Our survey team are mostly experienced bird-o-philes and often rely on their ears as much as their eyes. If one hears a familiar call, it is always confirmed, or not, with others in the team before it is added to the list.

The results are uploaded each year to the Victorian Biodiversity Atlas and a summary appears on our own website – bawbawbiodiversity.com

 

The effect of climate change on health

Heatwaves kill more Australians than all other extreme weather events such as floods, bushfires, cyclones and storms combined – LINK 1, and year on year, Australia is getting hotter and drier – LINK 2. Ambulance call outs, hospitalizations and deaths all peak during extreme heat events – LINK 3.

Ambulance ramping NSW Credit: ABC News

During heatwaves, people can die directly from the heat – heat exhaustion, dehydration, etc. Vulnerable people with heart, lung or kidney diseases will often experience increased morbidity during extreme heat events when their condition is exacerbated by the rise in temperature.

Indisputably, our planet is warming. Average temperatures are increasing everywhere but especially in urban areas where buildings, roads and footpaths absorb more heat compared to regions of natural environment. This phenomenon is known as the urban heat island effect and is well documented – LINK 4. Some urban spaces can be more than 10°C hotter than surrounding areas.

Shady oaks in Porter Pl Drouin

Many jurisdictions are developing strategies to counter the urban heat island effect by reducing greenhouse gas emissions, increasing tree cover and green spaces, providing shade structures, outdoor misting systems and increased drinking stations and using reflective surfaces on infrastructure.

Climate change is already impacting our health. The World Health Organization suggests that globally, between 2030 and 2050, there will be approximately 250,000 extra deaths per year directly and indirectly due to the warming of our planet – LINK 5.

 

 

 

The birds are nesting

Always a harbinger of seasonal change, birds going about their nesting procedures means that spring is only just around the corner – be welcome won’t it?

The little Brown Thornbill builds a dome-shaped nest, generally low down in a thicket of understory. The rather untidy nest is built with grasses, strips of bark, fern fronds and cobweb. It is lined with fur and feathers. The female Brown Thornbill incubates the eggs which hatch after about 2-3 weeks. The young fledge about a fortnight later.

A Brown Thornbill at Garfield collecting animal fur to line its nest

Ravens build a rough bowl-shaped nest of twigs and sticks. They line the nest with soft grasses, wool and fur. Australian Ravens – ‘aah-aah-aah-aaaahhhhh’ – usually select a site high in the canopy. The more common Little Raven – ‘ah-ah-ah-ah’ – often builds its nest lower down, even on the ground in some places.

A Raven in Cranbourne collecting nesting material

The ubiquitous Grey Fantail Builds a beautiful little cup-shaped ‘wine glass’ nest of fine shreds of bark and grasses interwoven with cobweb. It is nearly always placed low down in the fork of a thin branch (to deter approaching heavy predators?). Fantail nests are built with coloured materials that blend them into their surroundings for camouflage.

Grey Fantail on its nest at Longwarry North

 

 

Another way to save trees …

… use eco-friendly toilet paper.

Apparently, someone has done the research and the average Australian uses 675km of toilet paper per year. The average Brit: 950km. The average American: a whopping 1020km. It is estimated that it takes more than 31 million trees to supply the USA with one year’s worth of toilet rolls.

‘Experts’ say that one tree can provide 1,500 toilet rolls. In Australia, we use 2.24 billion rolls of toilet paper per year to wipe … That is equivalent to about one and half million trees.

So, if you haven’t already, switching to eco-friendly toilet paper will help to save some trees. And anyway, the medical profession states that it is much healthier to use just WATER!

If you have ever wondered how toilet paper is made, take 10 minutes to watch this video LINK.

From pits to paradise?

The Great Latrobe Park is a voluntary community movement that envisages repurposing the Latrobe Valley open cut coal mines into a linked parkland of forests, parks, wetlands, grasslands and gardens that would become a valuable environmental and community asset.

The Great Latrobe Park group point out the many benefits of rehabilitating industrial wastelands and that there are many precedents worldwide.

A Google Earth capture of the three open cut mines 230713

The group’s website has links to four articles that cover: the geology of the Latrobe Valley, the impacts from mining, stable conditions after mining ceases and the limitations for solving the complex problems of rehabilitation.

The Hazelwood coal mine at Morwell closed in 2017. Yallourn and Loy Yang mines are due to close in 2032 and 2048 respectively.

Readers might like to explore further …

Great Latrobe Park website LINK

Great Latrobe Park Facebook LINK  

Monday's meander

A hardy bunch of seven braved a pretty bad forecast to enjoy a two hour walk in Mt Worth State Park – what else would you do on a cold and wet day but visit a rainforest? Actually, we timed it just right for the walk and got through to ‘brunch’ back at the shelter just before the hailstorm!

Still smilin'

After donning the rain gear – to protect us from the drips from the trees – we set off on the Giants Circuit accompanied by the glorious serenade of several Lyrebirds. Great start to the day.

We paused several times to get a few shots of the beautiful Kangaroo Fern with their sori packs on the under-leaf and some sturdy shelf-bracket Ganodermas.

Kangaroo Fern – a common rainforest epiphyte in our district. Ganoderma – there’s about 80 species of this wood-decaying fungi. The extract from some Ganoderma species are used for medicinal purposes.

Apart from the Lyrebirds, the avifauna was remarkably quiet, probably due to the conditions. We think we saw a pair of Brown Gerygones but being so wet there were not very many binoculars between us.

Once we got into the patch of Soft Tree Ferns, we found some epiphytic Fieldia and fortunately we even found a couple of flowerheads.

Fieldia – a small, native epiphytic plant that can sometimes be locally common in rainforest gullies.

Some nice examples Strap Water Fern was next.

Strap Waterfern – a Blechnum species that likes to inhabit more fertile and wetter locations in the rainforest.

We passed under some leaves of the Blanket Leaf tree (Bushman’s D…y Paper) and came across a nice colony of Split Gill on the end of a log.

Split Gill – a cosmopolitan mushroom identifiable by the way the gills are longitudinally divided.

Just before getting back to the car park, we encountered the whistling call of the Olive Whistler – a great rainforest species. As usual, this fairly shy bird didn’t show itself. Also found a couple of tree trunks nicely decorated with some Whitewash Lichen.

Whitewash Lichen – A crustose lichen (or is it a fungus or ‘lichenised fungus’?) that looks like spilled paint.

A couple of us decided to engage in a ‘smoking ceremony’ in a vain attempt to get a fire going while we had lunch. Ultimately we could only warm up with our ‘cuppas’.

"Cough, cough".

Still, ‘brunch’ became entertaining when a Bassian Thrush came out into the open to seek its own tasty morsel – or perhaps it was smoke from our failed attempt to start a fire that enticed the bird to approach us. Either way, always nice to see one.

Bassian Thrush - a secretive. cryptic bird that inhabits the leaf litter in damp, densely forested areas

Despite the weather, I think the consensus was it was an enjoyable day – it was nice though to get into the cars and switch the heaters on for the run back home.

 

 

It's fungi time!

Noticed a few fungi in the parks and gardens lately? Fungi tend to wait for the dry and heat of summer to be over before they spread their spores for reproduction (fungi do not have seeds like plants). Autumn and early winter rain is usually the signal for the fungi to produce their fruiting bodies containing the spore.

Armillaria sp - Uralla Trafalgar

The array of size, shape and colours of fungi never ceases to amaze. It is almost certain that in any patch of bushland the number of species of fungi is far greater than the number of plant species. It’s worth remembering too that probably 90% of plants rely on fungi for their survival.

Clavaria sp - Rokeby

Because fungi do not use photosynthesis for making nutrients, they don’t rely on sunshine for their growth. As a result, fungi are often found growing in dark places such as under shrubs and logs.

Tremella sp - Nangara Jindivick

In our district, we have some great nearby locations for seeing these remarkable organisms – Thornell’s Reserve Longwarry Nth, Labertouche Bushland Reserve, Nangara Reserve Jindivick, Rokeby-Crossover Rail Trail, Mount Worth State Park, etc. Some interesting fungi can often be found just on roadsides. Horse-dung Fungi, Pisolithus arhizus, is often found in the middle of walking tracks and bush roads.

Pisolithus sp - Labertouche

Fungi are essential for a healthy environment. We should appreciate and conserve the presence of fungi in the environment just as we do the plants and animals.

 

Winter-flowering natives

One of the nicest things about living in our corner of the planet is the change in seasons. While we might bemoan the sudden chill in the air at this time of year, many native trees and shrubs welcome the lower temperatures and have adapted to survive and even bloom during the colder months.

There are many forms of the beautiful Correa.

Indeed, many of our natives actually come into flower at this time of year – correas, epacris, hakeas, lechenaultias, various eucalypts, acacias, banksias, grevilleas and others, can all put on a great floral display during autumn and winter. Who doesn’t enjoy the wonderful sight of the beautiful scarlet, pink or white Common Heath (epacris), in our forests at this time of year?

Common Heath is Victoria's floral emblem

Many native insects, mammals and birds benefit from a nectar and protein source during winter and many plants and animals have evolved to be mutually beneficial to one another at this time of year – the animals have a food source and the plants are pollinated.

Tetratheca or Pink Bells is often seen flowering on roadsides in the bush in winter

Winter flowering plants will often form seed earlier than plants that flower later in the year. In this way, the winter-flowerers get a head start on the others when it comes to germination as the temperature rises and any young seedlings have less competition as they grow.

Many of our Hakea species are happy to bloom profusely at this time of year

Winter flowering eucalypts are vital for the survival of one of Australia’s rarest birds, the critically endangered Swift Parrot. Swift Parrots breed in Tasmania in spring and in late summer they fly to Victoria and parts of SA and NSW to spend winter feeding on blossom, nectar and insects in our flowering eucs.

'Swifties' rely on winter-flowering eucs for their survival

There’s a lot going on in our bush at this time of year.