5. Tasmanian Midlands - To The Rescue/Help At Hand
Scientists
Five Phd students from the University of Tasmania were part of an ‘animals centric’ research program to find out more about the native animals in the Midlands and their connections to the landscape. They had questions such as, How many are there? Where do they live? How far are they roaming? What do they eat? What are their threats? The aim was to help Greening Australia plan their planting programs to support native animals. This research was part of a collaboration between the University of Tasmania, Greening Australia, Bush Heritage, the Tasmanian Land Conservancy, the Tasmanian Government and committed landholders.
Rowena and the Carnivores
Rowena Hamer walked through the supermarket with a trolley full of cheap cat food. Not a ‘ a crazy cat lady,’ but a scientist investigating carnivores in the Midlands by trapping and tracking them. She focussed on four carnivores, the spotted tailed quolls, eastern quolls, Tasmanian devils and feral cats. Rowena wanted to know all about these animals. How far do they travel? Do they all use the same parts of their habitat (the middle of the woodland, or its edge)? Do they prefer to live in remnant vegetation, replanted woodlands, native grasslands or pastures?
To answer these questions, she put out traps in four sites through the Midlands. She lured quolls and feral cats into the traps using the cat food. Tasmanian Devils aren’t so fond of cat food, so she baited their traps with lamb chops. Each morning, she checked the traps for animals.
On one cold, drizzly morning Rowena checked and re-baited her traps. She found five traps: empty, empty, empty, empty and…empty. The next trap? A closed door, brown fur and a tail…with white spots. A spotted-tailed quoll!
Before she released the endangered marsupial, Rowena fitted it with a GPS collar. The light-weight collar would collect locations for one month. Rowena tracked the movements of 20 animals of each species – spotted-tailed quolls, eastern Quolls, Tasmanian devils and feral cats – across four Midland sites to understand how different carnivores use the landscape.
Rowena found that feral cats are a huge threat to Midlands native wildlife. Evidence from wildlife cameras and found that the most common animal that was photographed was the feral cat. Rowena found that cats had consistently higher population densities than quolls. ”The average densities of cats in the Midlands (0.9 cats per square km are higher than the national average of 0.27 cats per square km. These results are bad news for small native mammals living with feral cats.
Rowena found evidence that their hunting is less successful in areas of high biodiversity with lots of understorey plants. It is very difficult to control cats so building habitat may be the best way to manage them.
Rowena’s research looked at further ways to limit the impacts of feral cats on wildlife in the Midlands. She is now experimenting with feral cat control using a Felixer. The Felixer is a robotic trap for feral cats. It uses laser beams to recognise a cat’s shape, triggering a poison onto the cat’s fur. Rowena is testing if the Felixer is safe for cat-shaped animals, like the vulnerable Spotted-tailed Quoll.
Kirsten Proft: Bettongs and Quolls
Eastern Bettongs are curious creatures. They use their prehensile (grasping) tails to carry grass to their nests. They are small, but they can hop one metre into the air. And they like fine food – a favourite delicacy in their diet is truffles!
Kirstin Proft loves bettongs. When she moved to Tasmania to do her research she didn’t know much about bettongs, also known as ‘rat kangaroos’. Three years later, after many long nights trapping these marsupials, she describes them as ‘weird and wonderful… charismatic little animals, each with their own personality’.
Kirstin focussed on the eastern bettongs and the spotted-tailed quoll to find out how they have been affected by habitat clearing.
Eastern Bettongs are important ‘ecosystem engineers’: they are good diggers and turn over topsoil in woodlands. This creates healthy soil, helping plant and fungi species to grow. Eastern bettongs were once found across eastern Australia. They are the second-largest native mammalian carnivore in Tasmania (after the Tasmanian devil). They used to be on the mainland, but because of land clearing and the introduction of the feral cat and fox, the mainland population became extinct in the 1920s. The species is still found throughout Tasmania. They are now listed nationally as Endangered.
Both quolls and bettongs need vegetation cover to move from place to place. But now the Midlands landscape has small ‘islands’ of native woodland and grasslands, surrounded by sheep paddocks and cultivated fields. In the last few years, an increase in pivot irrigation is making these gaps even greater. Kirstin wanted to know, ‘How big do these gaps have to be before animals no longer ‘cross the paddock’?
Kirstin describes herself as ‘the mad genetics person in the group’. She gathered tissue samples from bettongs across the Midlands. She set traps in woodland patches and took small biopsies from the ear of captured animals. She took these samples back to the lab for analysis. By sequencing the DNA in the samples, she made a unique genetic fingerprint (or “genotype”) for each animal. From this, she could see how closely related different animals are, and how the species has evolved. Basically, Kirstin is constructing family trees of bettongs and quolls in the Midlands!
Importantly, Kirstin’s work highlighted where patches are so disconnected that bettongs and quolls can no longer travel between them. This helps groups like Greening Australia and Bush Heritage know where to protect and replant habitat. Together, we’re working towards a landscape where our native bettongs can find the tastiest truffles and a safe home!
Glen Bain: Bushland Birds
Do you know your 'kar-week-week-kar' from your 'chur-ock-churock’? Do you know which animal sings ‘zit zit zit whooorl’? Unless you are a bird-loving Tasmanian, you may not recognise the Black Currawong, the Yellow-Throated Honey-eater and the Tasmanian Thornbill.
When Glen Bain moved to Hobart to start his PhD, he quickly learned the calls of the 12 bird species endemic to (only found in) Tasmania, like the Green Rosella and the Yellow-throated Honeyeater. Many other Tasmanian bird species are migratory – flying across Bass Strait to the mainland over winter.
But why would someone need to know bird calls by heart?
Little is known about the woodland birds that live in this fragmented region. Less is known about the kind of habitat that these birds need to survive.
Armed with binoculars, data sheets and a keen sense of hearing, Glen surveyed the Midlands for birds. On a cold Midlands mornings, Glen carried out his woodland bird surveys on 75 study sites. Glen recorded birds seen and heard along the 800 metre transects. He followed every flutter in the trees and every movement in the bracken fern. Glen’s ability to differentiate bird calls is remarkable.
Glen visited each site 6 times, and added to his list with audio recordings. These acoustic recordings picked up species that Glen didn’t see or hear on his morning surveys – masked owls, nightjars, and even the critically endangered swift parrot. He then compared his bird list with those recorded in the 1990s by scientist Michael McDonald. He also compared the sites to each other: how many species are found in the woodland sites compared to the grasslands, pastures, weed-infested shrub lands and sites revegetated by Greening Australia?
When Glen was not recording bird song, he was trying to understand:
what was eating the eggs and nestlings of woodland birds in the Midlands? He set up cameras on 27 nests, to see which animals are nest-raiders. He caught cats, snakes and other birds in the act!
If birds had more concealed nests (hidden by dense foliage, for instance) were they less likely to have their nests raided by predators? How should we restore areas so that birds can hide their nests?
What kinds of habitats do the birds regard as ‘safe’ and which ones are risky for them? This was measured using survey techniques such as ‘flight initiation distances’, measuring how close the birds will let the researcher approach before flying away, and ‘giving up densities’, which looks at how birds balance the need to find food against the risk of being eaten.
Glen found that the small patches of bushland are a problem for smaller birds, like wrens and thornbills. They avoid flying too far into the open for fear of being eaten.
Glen is helping to inform restoration projects, so that replanted areas support all types of birds, from robins to raptors.
Tanya Bailey: Restoration Ecologist
Tanya has become the leading authority on Midlands restoration.
I love trees. I get very emotional when I see trees being cut for highway development. Ongoing tree decline and degradation of native vegetation in the Midlands, and wanting to do something about it has inspired my PhD research. I studied how eucalypt seedlings grow in ‘microsites’ and developed best techniques to restore degraded native remnants on healthy farms.
For the past ten yearsI have been been a scientist in the School of Biological Sciences at the University of Tasmania. My research focused on Greening Australia’s large scale restoration plantings in the Midlands especially with the effects of climate change. This involved coordinating the seed collection, growing and planting nearly 750,000 native plants. Around 10% of these were eucalypt trees that were planted to test whether local seed or seed from warmer drier climates grows better in the altered landscape of the Midlands, with climate change.
I am keen to share my story with you…
With the help of people from across the community there have been over 800,000 trees planted in restoration efforts in the Midlands. Farmers in the Midlands have played a big role in the restoration of the Midlands. By encouraging research and tree planting to take place on their property farmers have shown that they care for the land.
Acknowledgements
We would like to acknowledge the original owners, the Palawa people and the use and crossing of the Midlands where we meet with our partners to share, learn and raise awareness about the land:
Paredarerme nation people, Laremairremener and Poredareme tribes, Luggermairrerpairrer tribe and the Tyrrernotepanner tribe
