Caring for the Rare

by Dr Catriona Nguyen-Robertson

This article follows a panel discussion during National Science Week 2022 with John Arnott, Manager of Horticulture at Royal Botanic Gardens Victoria; Dr Megan Hirst, Post-Doctoral Fellow at Royal Botanic Gardens Victoria; Dr Joanna Sumner, Manager of Genetic Resources at Museums Victoria; Dr Marissa Parrott, Reproductive Biologist at Zoos Victoria; and Darren Grover, General Manager of Threatened Species, Zoos Victoria.

Why should we “care for the rare”? After more than 40-50 million years of independent evolution after Australia became an isolated continent, approximately 600,000-700,000 species now call Australia home. Of this, so much of our flora and fauna is endemic to this land – only found here and nowhere else in the world. It is therefore our responsibility to protect it.

Biodiversity is the collection of all the different types of life found in an area. It is the trees and grass that grow, the animals that call them home and even the microorganisms, like bacteria, that live on the plants and animals and in the soil. Biodiversity is all these things living together to create an ecosystem, which allows life to thrive. And every part of it is essential.

But ‘there are only pockets of good habitat left,’ according to Dr Joanna Sumner. We need to look after them or else we will lose our biodiversity. And once a species is gone, it is gone. It is wiped off the planet for good.

Sadly, Australia has a terrible reputation when it comes to extinction. Since European invasion, at least 100 of Australia’s unique flora and fauna species have been lost. Australia’s biodiversity is still in rapid decline with more than 1,700 species and entire ecological communities known to be threatened and at risk of extinction.

When populations decline, they lose diversity and their ability to adapt to changing environments. This means that once a species is threatened, it becomes harder and harder for them to bounce back.

As Darren Grover puts it: ‘we’ve mucked things up’.

During National Science Week, we heard from our state’s leading botanists, zoologists and collection managers who are caring for the rare in the face of mounting challenges.

Protecting Plants

About 27,500 introduced plant species have made their way into the country, and they now outnumber Australian natives. Many introduced species have become established in the wild and are regarded as invasive. Exotic species that were imported to decorate gardens can sometimes jump the fence and invade the countryside and bush. Invasive plants outcompete and choke native plants, depleting the soil (and nutrients) and becoming a devastating problem. Once invasive weeds spread, they are hard to control.

Conservation horticulturalist John Arnott cultivates rare and threatened species for their future survival as part of the Care for the Rare project. He works with regional botanic gardens to grow their local flora – plants that are indigenous to the specific region. While the display gardens that visitors can enjoy feature several rare species, the real magic is happens behind the scenes.

The heart of the Royal Botanic Gardens’ conservation efforts is the Victorian Conservation Seedbank. It houses seeds and spores of native Victorian plants, especially endemic and at-risk species. Researchers like Dr Megan Hirst collect seed in the wild and determine how best to store them long-term so that these native plant species – some of which are on the brink of extinction – can be grown again in the future. The facility currently holds over 2,160 collections and many of these plants have never been propagated before. It is a learning process of trial and error but propagating the plants directly in the field – like in gardens across Victoria – seems to yield the best results.

Meg and her colleagues also deliver public programs to motivate people to become involved in plant conservation. Raising Rarity, for example, aims to increase public awareness of rare plants and ecosystems in Victoria, and provides resources from the Seedbank for home gardeners to grow threatened native plants at home.

Another major threat to flora is the changing climate. Botanists at the Royal Botanic Gardens Victoria adapt the living collections to adapt in response to increasing temperatures and sustainability imperatives, such as reduced water use. This way, they can ensure that plants grown in the Royal Botanic Gardens are well-suited to Melbourne’s future climate.

The combination of future planning and saving what plants we already have will ensure that plants will thrive and survive in the future.

Saving Dwindling Animal Populations

Zoos Victoria has a mission to fight extinction: no animal species will go extinct in Victoria on their watch. Their Fighting Extinction program is dedicated to the recovery of 27 threatened native species that are on the brink of extinction due to a range of threats including predation, disease, and loss of habitat.

While we often lament at the state of our declining biodiversity, the Eastern Barred Bandicoot Recovery provides a story of hope. These small nocturnal marsupials were once widespread across the grasslands and woodlands of western Victoria and South Australia, but by 1989, there were fewer than 150 left. Those that remained were collected for a captive breeding program and the species was declared Extinct in the Wild on mainland Australia.

In 1991, Zoos Victoria bred enough for release back into the wild. But for continued survival, the bandicoots relied heavily on fox control. Fences are costly to maintain and the releases on mainland failed. The best chance of survival was on fox-free islands.

The Eastern Barred Bandicoot Recovery Team, including reproductive biologist Dr Marissa Parrott, first did a trial release of 20 bandicoots on Churchill Island and the population quickly grew to over 100. The team has since established populations on Phillip Island and French Island, and works with private landowners who have fenced reserves on mainland Australia to keep bandicoots safe on their lands. After a 30-year captive breeding and insurance program, populations of Eastern Barred Bandicoots now persist in several safe havens across the state. Their conservation status has been reclassified from Extinct in the Wild to Endangered – the first time a species has ever gone backwards on the extinction trajectory.

But what happens once a population is gone? Thanks to the work of Dr Joanna Sumner, who manages the Ian Potter Australian Wildlife BioBank at Museums Victoria, it might not be too late.

The BioBank preserves tissue samples and DNA from Australian animals as a resource for conservation biologists in the field an opportunity to reintroduce genetic diversity to small populations at threat of extinction. Freezing tissues samples ensures that a snapshot of all the genetic information from threatened fauna is preserved. If their cells are kept safe, then scientists can retrieve their DNA.

Genetic diversity provides the building blocks of evolution. Without diversity, populations are vulnerable to change because if threatened animals become so genetically similar, they can all be wiped out with one threat. Both Zoos Victoria and Museums Victoria have projects that add genetic diversity back into vulnerable populations to give them a better shot. The goal of storing living tissue and DNA is not to revive species, but rather, to ensure that genetic information is not lost and can be used to restore genetic diversity. For example, there were once 12 Victorian populations of New Holland Mouse but now only five. Conservation biologists can use DNA from frozen tissue samples from extinct populations to add to the gene pool of the surviving populations, keeping them genetically healthy.

The Eastern Barred Bandicoot highlights the success of captive breeding programs and the reintroduction of animals back into the wild. However, if we want rare and endangered animals to survive, we need to deal with the threats to them. Just as the bandicoots cannot exist where there are foxes, there is no future for native animals if the threats to their populations are not managed. This is why it is important that we are all on board with conservation efforts.

What Can We All Do to Help? The Power of people

All panellists agreed that we can all pitch in to make a difference. Help monitor animals with citizen science apps – all it takes is to upload photos of wildlife or recordings of their calls. Plant native flora in your garden to support pollinators and a provide refuge for other fauna. Try to be sustainable in your everyday life and share stories like those in this article.

Zoos Victoria understands the power of people in protecting animals. They have run multiple campaigns to spread awareness of harmful human activities and encourage change.

Balloons are the deadliest form of litter when ingested by seabirds. Zoos Victoria and Phillip Island Nature Parks developed the campaign “When Balloons Fly, Seabirds Die,” encouraging people to blow bubbles rather than releasing balloons outdoors to avoid accumulating deadly litter in oceans or waterways. The campaign was so successful that releasing balloons into the environment is now illegal in Victoria.

Another campaign is “lights off for the moths”, as light pollution was derailing the yearly nocturnal migration of Bogong Moths to the Victorian Alps. There, they are an important food source for many animals including the Mountain Pygmy-possum, one of Australia’s mammals most at risk of extinction. Several years ago, the Bogong Moths stopped showing up to the alpine region, and when hungry pygmy possums woke from their winter hibernation, they had very little to eat. Marissa encourages us to minimise outdoor light and help track Bogong Moth migration with a citizen science app. With unnecessary outdoor lights switched off and citizen scientists looking out for Bogong Moths, there is still hope for the Mountain Pygmy-possums.

‘Small things done on mass make a big difference,’ says Marissa.

All of us can help protect Victoria’s biodiversity.  The botanists, zoologists and collection managers leading this important work are nurturing threatened species back to population health, but their endeavours will only be successful so long as we all help.

The STEM and Society series of panel discussions highlights the game-changing work undertaken by Victorian scientists, researchers and other holders of specialised knowledge. In 2022, the series had a particular focus on biodiversity conservation and recovery, with Bill Bainbridge facilitating discussions with leaders in this area to share their perspectives on protecting Victoria’s biodiversity. Presented as a partnership between the Parliament of Victoria, the Royal Society of Victoria, and the Victorian Parliamentarians for STEM as a part of the Inspiring Victoria program, discussions were held in the chambers at Parliament House, where Victorian era grandeur added gravitas to conversations. Proceedings were broadcast to a live audience; the recording is provided below.

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