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Threatened Species Thursday Series 2020

Every year on September 7, National Threatened Species Day is commemorated across Australia to raise awareness of plants and animals at risk of extinction.

There are currently 429 species of fauna and a whopping 1336 species of flora listed as threatened under Australia’s Environment and Biodiversity Conservation Act 1999 (EPBC Act). Of these, we often hear a whole lot more about the larger and more typically endearing ones – think koalas, sea turtles and the blue whale. Such species are known as charismatic megafauna and often scoop a disproportionate share of media attention, research effort, conservation funding, threatened species listings and policy protection. This makes it difficult to identify when the “less popular” species become threatened or extinct, or to recognise the impacts of their loss on global ecosystems.

The number of species listed on Australia’s threatened catalogue means that a single day is just not enough to do them justice. So, each week between National Threatened Species Day and the end of November we featured one of Australia’s less-well-known threatened species on ESA social media. These are the posts…

Living in rainforests and wet sclerophyll forests of south-east Queensland and north-east NSW, this endangered species is usually found hiding in leaf litter near permanent, fast-flowing streams. Numbers have declined in recent decades, likely due to pollution or sedimentation of water sources, habitat disturbance, predation by feral pigs, changes in water flow patterns, weed invasion, competition with and predation from cane toads, and the impacts of the fungus chytridiomycosis. In addition, populations are often fragmented and low in density, making them vulnerable to changes in their environment.

A range of programs to conserve Fleay’s frog have been initiated in recent years including long-term population monitoring and assessments, a captive husbandry project and habitat restoration. After initially severe declines in population numbers, monitoring surveys suggest that numbers are now stabilising. 👏

📷: Stewart MacDonald

Once feared to be extinct, populations of this shy species are now known in central Australia around the Finke and MacDonnell Ranges. They predominantly inhabit eucalypt and mulga woodlands, floodplains and riverine environments where they dig burrows with multiple entrances underneath shrubs, grasses and small trees.⁠ However, the spread of buffel grass in the same region may be causing the numbers of Slater’s skinks to decline. It is thought that the height and density of buffel grass may impede the wide field of view that Slater’s skinks rely on for their foraging strategies.

Several groups, including indigenous owners and ranger groups, are actively working to manage this weed. 💪🏾⁠ ⁠ The ESA awarded the 2018 Jill Landsberg Trust Fund Scholarship to Charles Darwin University PhD student Ellen Ryan-Colton for her project “Does Buffel Grass (Cenchrus ciliaris) invasion impact plant-animal interactions in an arid system?” We look forward to hearing her results and how they may help protect native species like the Slater’s skink.⁠ ⁠

📷: Claire Treilibs⁠

With over 50 described species spread along the eastern mainland from far north Queensland to South Australia, these freshwater crustaceans are widespread! However, most have restricted or fragmented distributions, making them vulnerable to changes in their environment. For example, the critically endangered Fitzroy Falls Spiny Crayfish (Euastacus dharawalus) is only found in an 8.3km stretch of creek in the southern highlands of NSW.

Predation from, competition with, and being misidentified for the common yabby (Cherax destructor) pose a significant threat to this species. Additional threats of habitat degradation, pollution, illegal collection for the aquarium trade, and other introduced species such as trout, cane toads and feral pigs adversely impact Euastacus’s chances of survival. This is exacerbated by the slow-growing, long-lived, low-fecundity life history pattern of the species.

Sixteen Euastacus species have been recognised on the IUCN Redlist as critically endangered. However, only three have been listed under Australia’s EPBC Act. For actions to improve the survival of these crayfish (such as targeted research, habitat restoration and pest control) to be effective, formal recognition is needed to help drive and support them.

What can you do?

  • Make sure you know the difference between a yabby and a spiny crayfish.
  • Call for the protection of vital habitat.
  • Report sightings to relevant authorities, like the NSW DPI 'Report a Threatened Species’ site.
  • Support research into these endemic species.

📷: Alex Pike (@alexjpike). This image of E. hirsutus won the 2019 ESA 'Ecology in Action' Photography Competition.

This endangered bird is an expert at camouflaging amongst reeds and rushes near the freshwater wetlands that they call home. ⁠Found in coastal areas around south-eastern and south-western mainland Australia as well as along the east coast of Tasmania, they forage at night for small animals including small birds and mammals, fish, frogs, snails, spiders and other insects.⁠

Over the last few decades the Australasian Bittern has declined in number due to threats like drainage of wetlands; drought; predation by foxes and cats; grazing and burning near wetlands; and changes in precipitation and seasonality due to climate change.⁠⁠

Several actions can help protect this species. These include:

  • Restoring wetland habitat and identified breeding sites, ⁠
  • Managing introduced predators like foxes, ⁠
  • Increasing targeted research and monitoring of populations, and ⁠
  • Looking for novel ways to create habitat as done by the Bitterns in Rice project. ⁠ ⁠

📷: Peter Menkhorst⁠

Australia is home to 41 mangrove species covering 11,500 square kilometres of coast and accounting for approximately 7% of the world’s mangrove forests. This includes the critically endangered Haines' Orange Mangrove (Bruguiera hainesii). Australian mangroves are thought to be declining by about 0.7% per year, predominantly due to the impacts of climate change (storms, heatwaves and rising sea levels), coastal development and sedimentation. Scientists and indigenous custodians in the Gulf of Carpentaria reported a 400km stretch of dead and damaged mangroves in 2015, considered to be the worst mass dieback ever recorded in the world, and likely due to the effects of extreme weather.

 

Why is this a problem?

Mangroves play an essential role in coastal ecosystems. They are amazing sequesters of atmospheric carbon, storing about five times more carbon than terrestrial forests. This translates to about 20 million tonnes of carbon dioxide a year being absorbed by Australia’s mangrove forests, locked it away in their soils and in the plants themselves. Degradation of mangrove ecosystems releases the carbon stored in their biomass and soils, exacerbating climate impacts which are already affecting their health. They protect coastlines from erosion and storm damage; filter runoff from the land; provide habitat, breeding grounds and food for fish, migratory birds and crustaceans; and serve as a nutrient source for other inshore marine habitats. They also support a wide range of threatened species that rely on mangroves for all or part of their life cycles, such as the vulnerable Illidge’s Ant Blue Butterfly (Acrodipsas illidgei) found only in mangroves along the east coast of Australia. 

📷: Alex Pike (@alexjpike)

With only a handful of confirmed sightings in the previous two decades, in 2017 it was considered likely to be the next Australian bird to go extinct. Despite this title, it has no recovery plan in place and enjoys less public attention than larger, more colourful species like the swift and orange-bellied parrots.⁠ This prompted ANU’s aptly-named Difficult Birds Research Group to undertake the first, and largest, systematic surveys of the species. They found an estimated 30-50 thornbills at 20 sites across the island, including on private land several kilometres outside of its known range in the Pegarah state forest.⁠ ⁠

While this is positive news, the survival of the species remains uncertain. They are threatened by habitat loss and fire, with these risks expected to increase due to pressures of agricultural land clearing and climate change. Our lack of insight into the status and requirements of the species also makes tailoring effective recovery strategies difficult. This lack of information may also explain why a bird with so few numbers in the wild has not been promoted to the ‘critically endangered’ list and why it attracts so little conservation funding. ⁠ ⁠ Regardless, the species is starting to be given the attention it needs. A 2017 article in The Guardian highlighted the challenges faced by 'little brown birds' like the King Island brown thornbill compared to their colourful, more charismatic cousins. In the article, Birdlife Australia's head of conservation, Samantha Vine is quoted as saying “It really is up to those sort of committed champions to raise the alarm and lobby for resources...You would be surprised how many times a species has been saved from extinction by a handful of people.”⁠ ⁠ So, if you want to save a little brown bird from extinction, be one of those people. Be a champion, raise the alarm, lobby for resources. We’re starting here. ⁠ ⁠

📷: @bazzabaker⁠ ⁠

We often hear about the cute and cuddly species that are under threat, but did you know that there are almost three times more plant species than fauna that are threatened under Australia's EPBC Act? One of these is the endangered Maroon Leek-orchid (Prasophyllum frenchii).

Historically, the MaroonLeek-orchid was endemic to south-eastern Australia but declines in both range and abundance mean that it is now only found in seven populations across southern Victoria and south-eastern South Australia. ⁠This decline is predominantly due to destruction of habitat for agriculture, grazing by native and introduced herbivores, and invasion of weed species. With remaining populations mostly small and highly fragmented, their pollination needs may also be adversely affected. Further, its preferred damp-to-wet habitats are also likely to be impacted by the predicted drying patterns of climate change.⁠ ⁠

To combat these threats, a number of initiatives have been started, including collection of seed capsules for storage at the Royal Botanic Gardens in Melbourne, and a collaboration between the South East Natural Resources Management Board, Natural Resources South East and Nature Glenelg Trust to grow, plant and monitor the species at nine sites. 👏⁠ ⁠

📷: Oisín Sweeney. Orchid dupe wasps (Lissopimpla excelsa) are well known pollinators of Australian orchids. This one has obviously visited several flowers on this maroon leek-orchid judging from the number of pollinia on its head: playing its part in conservation by helping increase population size of an endangered species!⁠

There are 41 frogs listed under Australia's EPBC Act, almost half of which are critically endangered or already extinct. The green and golden bell frog (Litoria aurea) was once common throughout south-eastern Australia but numbers have declined by more than 30% in the past decade and the species is now listed as endangered in NSW, vulnerable under the national EPBC Act and endangered in the National Frog Action Plan. ⁠ ⁠

The decline in numbers is thought to be due to the raft of threats they face, including:⁠

 

  • Habitat destruction and degradation (e.g. increased siltation, pollution and erosion, elevated light and noise, changes to vegetation, altered fire regimes)⁠
  • Habitat fragmentation⁠
  • Disease (particularly the fungal infection chytridiomycosis)⁠
  • Predation from introduced species (e.g. mosquito fish Gambusia spp, cats, foxes)⁠
  • Alteration of drainage and flooding patterns⁠
  • Road mortality and the impact of four-wheel drives on habitat⁠
  • Drying and warming effects of climate change on habitat and the animals themselves⁠ ⁠

A large portion of the remaining population inhabits private lands, which makes conservation efforts more difficult. Nonetheless, efforts are underway to protect the green and golden bell frog. A captive breeding program was established at Taronga Zoo in 1998 and the NSW Government includes a strategy for the species under the ‘Saving our Species’ program. Measures to reduce the impact of the introduced mosquitofish are underway and Greening Australia is working in the Gippsland Lakes area to improve species habitat. ⁠ ⁠

And what can YOU do? Get involved in the Australian Museum’s FrogID week! Download the app and start counting calls – every recording contributes to an ‘audioshot’ of Australian frogs and helps to measure the health of our frogs and the environment. ⁠

⁠📷: Angus McNab⁠

Insects (including bees, butterflies, moths, flies, and beetles) are well known as excellent pollinators, however wild insect numbers have declined drastically in recent decades, mainly from habitat loss, climate change, pesticides and pathogens. ⁠In Australia, a lack of information on the state of invertebrate populations makes it difficult to measure and manage changes in their numbers and diversity. Citizen science projects like those associated with Australian Pollinator Week are essential to addressing this knowledge gap. You can find out more (including how to get involved) at www.australianpollinatorweek.org.au.⁠⁠

Much of our news is dominated by species losses but occasionally, one reappears. This happened with one of Australia’s rarest bees, an endemic plasterer bee known as the Rottnest bee or Douglas’s broad-headed bee (Hesperocolletes douglasi). Officially listed as ‘presumed extinct’ under the Western Australian Wildlife Conservation Act, a single female specimen was found in 2015 in banksia woodland at Pinjar, in Perth’s northern suburbs. Subsequent efforts to find another specimen were unsuccessful, suggesting that the species is extremely rare, inhabits an as-yet-undiscovered ecological niche, or is easily misidentified for other native bee species. While historically rare anyway, H. douglasi has not been helped by land clearing and more frequent fire events. Managing these threats would improve the conservation outlook not just for H. douglasi, but for other rare and threatened species that inhabit similar niches. ⁠  ⁠ ⁠

📷: Nikolai Tatarnic from Western Australian Museum

For the past three years, hundreds of Tasmanian ’Nature Trackers' of all ages have scattered widely across the state to survey for the endangered wedge-tailed eagle in Bookend Trust's annual ‘Where? Where? Wedgie!’ survey.⁠

⁠Are conservation efforts working? “With population monitoring, it tends to be a long game to detect any changes," says Bookend Trust citizen science coordinator Dr Clare Hawkins, “but we’ve demonstrated that our method is effective, and that there hasn’t been an extreme change in population size during the monitoring period." ⁠

⁠Guided by the project’s social science research, the focus now is to retain and increase volunteer numbers, to help get informative results as swiftly as possible. Clare is currently running a crowd-funder, and inviting more nature-lovers to take part in next May’s ‘Where? Where? Wedgie!’ survey by signing up to naturetrackers.com.au⁠

⁠For more on 'Where? Where? Wedgie!' visit www.youtube.com/watch?v=F72iuGXsPwo&feature=youtu.be⁠

📷: Elizabeth Latham

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