Endangered Emu-wrens and the South Australian rocket launching site

“Southern Launch has previously assured the general public that there would be minimal disturbance to birdlife beyond a “startled response”, where birds left the area during launch noises but returned soon afterwards.”

https://www.abc.net.au/news/2024-10-29/eyre-peninsula-rocket-launch-gets-tanya-plibersek-approval/104503048

This style of minimising the harm is typical of an impact assessment, where proponents make the case for development. In reality these sensitive, shy birds will most likely leave their nests and not find their way back in time to keep their eggs viable.

During nesting season at night when the endangered emu-wrens are sleeping, if they leave their nests and eggs, what is the likelihood of them flying back in the dark?

Page 111 of the Assessment report explains how frequently these terrifying launch noises may occur.

Rocket launches can occur every 24 hours during nesting season at night while the birds are sleeping.

The proposal has the potential to disturb fauna, nearby residents and visitors to the locality through the creation of noise and vibration impacts during construction and operation. In particular, each rocket launch event would produce a moderate level of operational noise over several weeks and a high level of noise for a very brief period during the launch itself. Noise impacts from rocket testing would also occur over a brief period. Vibration effects during a launch would be confined to within the launch pad. At the maximum operating scenario, the proposed facility will host in the vicinity of 36 yearly launches (one every 2-3 weeks on average), with a rocket launched at any time over a 24-hour period.

https://plan.sa.gov.au/__data/assets/pdf_file/0007/1423357/Assessment-Report-Whalers-Way-Orbital-Launch-Complex.pdf

The same article mentioned above by the ABC claims:

“Conservationists are concerned the launches will endanger 12 bird species, including the endangered southern emu wren, whose population stands at fewer than 750. “

https://www.abc.net.au/news/2024-10-29/eyre-peninsula-rocket-launch-gets-tanya-plibersek-approval/104503048

My question for Tanya Plibersek, the federal environment minister who approved this project, have you ever observed birds startle at night? And do you sincerely believe these birds would find their way to their safe perches and nests every time?

Sydney basin and the broad-headed snake

Hoplocephalus bungaroides

Woronora hill in Heathcote National Park at 282m above sea level is the highest natural point in metropolitan Sydney. The Blue Mountains to the west are most imposing but equal elevation occurs on the gently rising Woronora Plateau in the south that lead to the Southern Highlands and 1000 square kilometres of untouched bushland, including the Special Areas set aside for water collection. The city of 5.3 million people sits inside a larger geological basin and this basin contains enough unique biodiversity to have been defined as the Sydney basin bioregion.

One species that is found only in the rocky bushland slopes of Sydney is the critically endangered broad-headed snake, an animal exquisitely adapted to the particular niche it inhabits. This snake is found on the relatively wet west facing slopes of the basin where solar radiation stores heat to assist nocturnal hunting and hatching of eggs. The snake lives on the geckos and other creatures also thriving on the particular conditions of the west facing slopes.

Contour map of Sydney basin

Geology of Sydney Basin

The Sydney Basin is a sedimentary basin with an area of approximately 44,000 square kilometres. It is defined by the great diving range in the west and the ocean escarpment in the east. The defining geology extends to the Hunter Valley in the north and south to Batemans Bay.

Around 5,000 metres (16,000 ft) thick, the Sydney Basin consists of Permian and Triassic sedimentary rocks… and contains economically significant reserves of coal.

Wikipedia page Sydney Basin

During Gondawana times, about 250 million years ago the sandstone in Sydney Basin was deposited by monolithic rivers flowing from the south west to the east.

50 million years later (200 mya) the Lapstone fault (running north south at the foot hills of the blue mountains) caused a lift in the sandstone in the east defining Sydney’s sandstone coastline, the flattened Cumberland plains and lifted the great diving range – including the Blue Mountains.

Three Sisters at Katoomba in the Blue Mountains

Fast forward another 100 million years (100 mya) and the first snake fossils appear in tropical Asia .

Fast forward another 40 million years (60 mya) and Gondawana breaks up, Australia becomes a continent and the Sydney basin is then shaped …

into a landscape that was defined by bedrock valleys exposed into a raised plateau. Sydney’s largest rivers, such as the HawkesburyParramattaGeorges and Hacking Rivers eroded the region’s deepest valleys. In this period, the Ashfield Shale got weathered to create a flatter landform with low, undulating topography and reasonably fertile soils, which heavily contrasted the plateaus, cliffs and gorges on the sandstone areas in the Sydney Region. The Botany Bay Basin was also developed at that time, which is infilled with sand.

Wikipedia page Sydney Basin

Rainfall on the eastern rim of Sydney basin

Elapid snakes come to Australia

At the same time Sydney Basin is forming (60 mya) the first fossil records of elapid snakes emerge in tropical Asia. Around 24 mya elapids made the journey to Australia. Elapid snakes are in the cobra snake family and have permanently erect fangs, which may also deliver venom. Many species can deliver a bite potentially deadly to humans (and dogs), but most are effectively harmless given the availability of anti-venom. Recorded snakebites exceed deaths by a hundredfold. There are 1 to 4 snakebite deaths per year in Australia, most are from handling or cornering the snakes.

There are around 80 species of Australian elapid snakes, including: death adder, red-bellied black snake, tiger snake, duggite, mulga snake, brown snake, yellow-faced whip snake, copperhead, golden -crowned snake, and mustard-bellied snake.

Broad-headed snake

Photo of Broad-headed snake on a tree in Heathcote National Park 2021 Tom Kristensen

The critically endangered Hoplocephalus bungaroides, broad-headed snake is a venomous snake from the elapidae family. Broad-headed snakes are possibly Australia’s most endangered snake given their dependence on the unique geology of specific sites in the sydney basin. Once relatively common, the BHS is now locally extinct in metropolitan Sydney and only found in a few of the National parks and state forests within the Sydney basin.

Unlike most elapids the BHS are at home in the trees. When the rocky outcrops become too hot in the summer the snakes will disperse into gullies where they seek refuge in hollow tree limbs. Being nocturnal ambush predators, they pick up geckos on the rocks and a wider array of prey found in the forest and leaf litter on the forest floor. Seasonal behaviour patterns over a long life span find the BHS returning to the same outcrops and hiding holes year on year.

Besides the favourable western-tilted geology the Sydney basin has produced a network of upland hanging swamps. These impermeable depression on sandstone benches offer a place for the development of peat swamps supporting dense low vegetation with ponding water. These swamps store and release water through dry periods providing an oasis to a wide range of animals, including frogs, another staple food for BHS. These biodiversity gems are destroyed by the longwall coal mining that fractures the entire geology overlying the coal seams. Unfortunately the location of the swamps within the protected Special Areas has meant that their destruction has gone largely unnoticed.

Technical Report 2: Upland swamp development and erosion on the Woronora Plateau during the Holocene
Kerrie M. Tomkins and Geoff S. Humphreys
Macquarie University

Slow to mature, slow to reproduce, and confined to western slopes living under the flat sandstone rocks prized by landscapers, BHS are not able to adapt to human impacts on their environment. Being a small snake under a metre in length, and very attractively marked the BHS are poached from reserves and sold to collectors. Basking snakes are also commonly squashed on the proliferating mountain bike trails as national parks are increasingly managed as a recreational resource.

BHS give birth to live young unlike other elapid snakes that lay eggs. Presumably there is an advantage for baby BH snakes to be able to hide in rocks as soon as they are born.

If you come across a pretty yellow and black patterned snake in Sydney it’s most likely to be a carpet diamond python – the southern most and highest altitude occuring carpet python. While from an entirely different snake family to elapids, diamond pythons and broad-headed snakes look very similar to the untrained eye.

Golden-crowned snake, a small Australian elapid snake on the road at dusk, just missed by the car.

Sources

https://australian.museum/learn/animals/reptiles/broad-headed-snake/

https://en.wikipedia.org/wiki/Broad-headed_snake

https://en.wikipedia.org/wiki/Snake#Evolution

https://en.wikipedia.org/wiki/Sydney_Basin

https://en.wikipedia.org/wiki/Elapidae

https://www.livescience.com/animals/snakes/cobras-and-their-relatives-evolved-in-asia#

https://www.ozanimals.com/wildlife/reptile/elapid-snakes.html

http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=1182

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Frog offsets: too good to be true

Green and golden bell frog, Ranoidea aurea NSW status, Endangered. Commonwealth status, Vulnerable.

Eats insects, worms and small vertebrates. Sunbakes to aid digestion.

Tadpoles take 3-11 months to mature.

Classification

A ground dwelling frog in the tree frog family, one of Australia’s largest frogs the adults are between 4.5-11cm in size.

Very similar to other frogs in the Ranoidea genus, the green and golden bell frog is able to hybridise and is often found together with the closely related growling grass frog (R. castanea) and yellow spotted bell frog (R. raniformis).

“The species is now classified within the Ranoidea aurea complex, a closely related group of frogs in the genus Ranoidea.[4] This complex is scattered throughout Australia: three species occur in south-east Australia, one in northern Australia, and two in Southwest Australia.”

Ranoidea aurea is equally and most closely related to R. castanea and R. raniformis. A microcomplement fixation technique using serum albumins has indicated the species closest to R. aurea is R. ranifomis. Albumin immunological distance data suggest no differentiation between the two, and the green and golden bell frog evolutionally separated from the other two species about 1.1 million years ago.”

From the Wikipedia entry on the green and golden bell frog (GGBF)

Offsets

The GGBF faces steep population declines in the remaining habitat, and is listed as endangered in NSW, where threats to biodiversity are largely managed with an “offset” mechanism. The Biodiversity Offset Market puts a monetary value onto threatened species and their habitat, this can be used to draw up compensation deals. These values are known as “species credits” and given that the market has been established by government to facilitate development in environmentally sensitive areas, outcomes favour developers. The cost of offsets is never a deterrent to a major development because the rules will be altered in such cases. There’s been no recorded improvement in environmental outcomes using an offset scheme, for frogs or any other species, anywhere, ever.

The market price on endangered frogs fluctuates depending on supply and demand for sites to be destroyed versus sites that might potentially be saved. We could speculate that the price should also reflect frog population health and numbers, but it’s unlikely that populations are monitored sufficiently to establish if offsets are effective. When it rains do the prices go down as more frogs reproduce? When it’s dry do prices go up as frogs perish? As frogs head to extinction does the price reflect the intrinsic value of another lost species. Does any of this economic activity increase the extent of frog habitat? Probably not, but it provides job opportunities for biologists who might otherwise raise concerns about development threats.

According to wikipedia, only 40 sites remain where GGBFs can be found. However species credit market prices dealing in habitat loss continue to fluctuate. How is it that the habitat market offset price can rise and fall while habitat loss continues in one direction?

On the 11th Nov 2022 species credit price for the green and golden bell frog was $22,348. The most recent sale of GGBF species credits on 28th Oct 2024 was $1,651, a 93% fall in value, yet the underlying conservation concerns are as dire as ever, chytrid fungus and habitat destruction remain as major threats.

No one can properly explain the species market, but green and golden bell frogs remain endangered and have vanished entirely from 90% of its previous recorded range. Meanwhile several government enquires at state and federal level have established that the biodiversity offset market is a failed concept.

Wetlands

The key to conservation is protecting habitat. Wetlands provide habitat for frogs but are just as crucial for birds, and frogs provide protein for birds. It’s entirely possible for an endangered bird to eat an endangered frog, such are the complications of conservation and over reliance on a diminishing area of suitable habitat.

Kooragang Island is one of three East Australian Islands where GGBF are found, and also major industrial hub. In 1983 a Kooragang wetlands rehabilitation and nature reserve were formed. 1984 it was declared a Ramsar site of 2926 hectares.

“The Hunter Estuary Wetlands Ramsar site is extremely important as both a feeding and roosting site for a large seasonal population of shorebirds and as a waylay site for transient migrants. Over 250 species of birds have been recorded within the Ramsar site, including 45 species listed under international migratory conservation agreements. In addition, the Ramsar site provides habitat for the nationally threatened Green and Golden Bell Frog, Estuary Stingray and Australasian Bittern.” Aust Gov DCCEEW 2019

Sources

https://www.dcceew.gov.au/environment/biodiversity/threatened/publications/factsheet-frogs-australia#:~:text=Australia’s%20frogs%20vary%20in%20size,is%20only%2014%20millimetres%20long.

https://en.wikipedia.org/wiki/Green_and_golden_bell_frog

https://australian.museum/learn/animals/frogs/green-and-golden-bell-frog/

https://www.environment.gov.au/cgi-bin/wetlands/ramsardetails.pl?refcode=24

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