As Australian cities and suburbs continue to expand, new developments exert pressure on the species and habitats that exist on their margins. But do smaller
species stand a chance against big developers? Researchers are looking for ways to level the playing field.
Golden sun-moths live on and above small patches of remnant native grassland, on the outskirts of north-western Melbourne and eastern Canberra. They derive their common name from the bright golden colours decorating the wings of the females, and they live up to it by being one of the few diurnal (day-time) moths found in Australia.
“The golden sun-moth is listed as critically endangered under Australian legislation,” says Luis Mata, an insect ecology research fellow from RMIT University working with the NESP Clean Air and Urban Landscape Hub (CAUL Hub), who has teamed up with Threatened Species Recovery Hub researcher (TSR Hub) and RMIT Associate Professor Sarah Bekessy to assess the viability of the species under different management scenarios.
“It’s an exceptional and charismatic species – beautiful colours and daytime activity make it a familiar sight for many Melbournians. But the golden sun-moth’s habitat is under pressure from the city’s expanding suburbs.
“It’s not always a favourite with developers because it’s presence has prevented some projects from gaining approval in the past.”
Golden sun-moth populations are closely bound to native grasslands, which are now believed to have been reduced to less than 1% of their original extent.
“Their distribution and native grasslands are a close match – where the grassland remains, the moths can sometimes hold on.”
The interactions between human communities and threatened species is a specialty subject for Associate Professor Bekessy, who leads the TSR Hub’s Methods for better communication and community buy-in to threatened species conservation (Project 6.3).
“This presented a really good opportunity to investigate the interface between the viability of a threatened species and urban design principles. Does the golden sun-moth have a future in the context of urban development?” asks Sarah.
The researchers made use of a Bayesian Belief Network – a conceptual tool that considers the possible actions people can take on the urban fringe and their likely influence on moth populations – to assess the viability of moth populations under different combinations of actions. The tool was informed by a full review of the existing scientific literature on the moth and identified 13 variables likely to affect populations.
“When people build homes by the grasslands, they inadvertently provide perching structures for birds at the same time, increasing the likelihood of predation,” says Luis. “They also risk introducing weeds and contaminants that disrupt the natural environment by blanketing the bare ground required by larvae and competing with native grasses.”
Fences and architectural designs that discourage birds are just a few of the options explored that could make life easier for threatened sun-moths.
“We need to understand and account for the viability of not just the golden sun-moth, but a range of threatened species in our urban landscapes, and make these considerations a feature of our urban design,” says Sarah.
“People derive all kinds of health benefits from their interactions with wildlife, which range from encouraging childhood cognitive development to lowering blood pressure. We should recognise that what’s good for nature is usually good for people.”
Photo: The endangered Golden Sun Moth (Synemon plana) – a rare site in Melbourne’s critically endangered basalt plains grasslands community. Image supplied by Eviator Bach.
We are offering an honours project looking at feral cats in two national parks. The student will analyse spatial data to quantify and compare home range, habitat use, and activity times of feral cats at both sites, and interpret these data in terms of risks to threatened species at the sites (bridled nailtail wallabies, bilbies, and others), and ecology and control of invasive predators.
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Mouse-sized carnivorous marsupial the Endangered Kangaroo Island dunnart has only rarely been seen in the past 20 years. TSR Hub researcher Rosemary Hohnen is on the job working with local partners to develop better monitoring methods for the elusive species, and to evaluate the impact of feral cats on its persistence. Here she gives us a taste of the action, and despite the tiny size of the mammal there is a lot of heavy lifting…
Monitoring the nests of endangered species of cockatoos has not always been practical using traditional methods. However, new bioacoustic methods are now being applied to the monitoring of two endangered sub-species of cockatoo in southern Australia, the south-eastern red-tailed black-cockatoo and the Kangaroo Island glossy black-cockatoo. Daniella Teixeira, PhD candidate at The University of Queensland, takes up the story.
Threatened Species Recovery Hub researcher profile.