Otways Threatened Species Forum 2019 – Abstracts

Geelong City Library, Friday 9 August 2019

Platypus CSI: genetic fingerprints reveal platypus distribution in the upper Barwon.

Josh Griffiths – EviroDnA

The conservation status of the platypus was recently upgraded to “Near Threatened” in recognition of mounting evidence of population declines and localised extinctions throughout its range. Platypus populations in Victoria are considered under the greatest stress. The waterways of the upper Barwon region have been significantly modified due to widespread land clearing for agriculture, invasive species (e.g. willows), changed flow regimes, and reduced water quality. All of these factors can be expected to have impacts on platypus populations, but little empirical data exists on their current distribution or abundance.

The Upper Barwon Landcare Network and EnviroDNA worked with local citizen scientists and used environmental DNA to investigate the current distribution of platypuses throughout the region and provide a comprehensive baseline for future monitoring. Citizen scientists were trained to correctly collect water samples and undertake habitat assessments at 48 sites across 26 upper Barwon waterways. Sixteen sites (36%) returned positive results for platypus DNA. Limited historical data exists to quantify declines but platypuses were not detected at several sites between Winchelsea and Birregurra where they had previously been recorded. Site occupancy of platypuses was correlated with habitat quality assessed by citizen scientists as well as with Index of Stream Condition data.

The possible decline and fragmentation of platypus populations raises some concerns over the long-term persistence of the species in the area in the face in climate change and human population growth. These data can be used to direct rehabilitation works to improve habitat quality and reconnect populations to improve their resilience. Involving citizens scientists in this project was a great way to connect the community with their local waterways and raise awareness of river health issues.

Using modern genetic methods to inform conservation of threatened species.

Michael Amor – Royal Botanic Gardens Victoria – La Trobe University- Museum Victoria

Increasing temperature and pressure from human activities has a substantial impact on species distributions, and potentially, their vulnerability to extinction. Some species have shown the capacity to shift their distribution to relieve the impact of climate change. However, many species are unable to expand their range and extensive habitat loss has resulted in a decline in abundance and population sizes. Molecular studies are a powerful tool for investigating levels of genetic diversity and connectivity among populations of threatened species. Traditionally, these studies have been based on few genetic markers, however, modern methods have enabled a more complete genome-wide view of species boundaries, genetic diversity and gene flow. Here, I will show examples of how conservation genomics can be applied to distinct scenarios; (i) species-level diversity of a high-value fisheries target species, Octopus vulgaris, (ii) genetic diversity among sky-island populations of an endangered alpine skink, Lipholis guthega and (iii) the extent of clonality within a rare leafless plant, Bossiaea vombata. Finally, I will show some preliminary results from a collaborative project among the Conservation Ecology Centre, Foundation for Australia’s Most Endangered Species, Melbourne University and the Royal Botanic Gardens Victoria. This research investigates the Tall Astelia (Astelia australiana), a threatened herb endemic to temperate rainforests and riparian thickets from the Central Highlands and Otway Ranges.

Conserving mammals in the face of fire and predation: assessment of supplementary refuges in post-fire environments in the eastern Otways.

Watchorn, D., Doherty, T., Wilson B. A., Driscoll, D. and M.J. Garkaklis, School of Life and Environmental Sciences, Deakin University, Victoria, 3125.

There is strong evidence that the impacts of introduced foxes and feral cats are amplified following fire, thus increasing extinction risk for native mammals.  Managing invasive predators and fire together is a formidable challenge, but the provision of supplementary refuges in post-fire environments is a new approach that could reduce predation rates and increase population persistence post-fire. The overall objective of this project is to assess how ground-dwelling mammals respond to the provision of supplementary refuges (wire tunnels) in post-fire environments.  A suitable burn area was identified for the first landscape study in the eastern Otway’s in consultation with Department of Land, Water and Planning and Parks Victoria. The activity of invasive predators within the landscape has been monitored using camera traps prior to (October 2018, February 2019), and following (June 2019) the burn, which occurred in May 2019. To assess the population responses of small mammals to the supplementary refuges, pre-fire trapping was conducted at 12 sites, separated by a minimum distance of 500 metres and spanning both gullies and mid-slopes. Trapping resulted in the capture of three small mammal species: agile antechinus: 0-7, bush rat: 0-8 and swamp rat: 0-7 animals per site per survey. The burn resulted in patchy coverage across the landscape and we subsequently established five tunnel refuges at each of two burnt sites, which are being compared to other burnt and unburnt sites. To determine: (i) which species utilise the supplementary refuges, (ii) the daily temporal activity trends of supplementary refuge use, and (iii) how these change with time since fire, we are monitoring the use of the supplementary refuges with camera traps. We have also deployed cameras 10 metres adjacent to the supplementary refuges to act as a control. Species recorded inside the tunnels (within just a few days of establishment) include bush rats, agile antechinus, fairy wrens, grey shrike-thrush, brown thornbills and scarlet robins. Monitoring will continue over the next 12 months to track the long-term population and behavioural responses of fauna.

Mammal Community Responses to Fire Regimes in the Otway Ranges

Annalie Dorph – The University of Melbourne

Fire is a major driver of spatial patterns within landscapes and is commonly used as a management tool to promote biodiversity. However, fire is not the only factor affecting biodiversity, with spatial patterns also created by topography, climate, vegetation and habitat structure acting at different scales. There is poor understanding of how spatial patterns in these environmental factors affect species diversity, especially at spatial scales relevant to land management. We investigated how changes in spatial patterns caused by fire and other environmental variables affected mammal species richness. We also tested whether these relationships varied with spatial scale. We sampled ground-dwelling mammals at 187 sites spanning a range of fire histories within the Otway Ranges, Victoria. We modelled species richness responses to assess the influence of topography, climate, time since fire, vegetation and habitat structure on mammal communities at multiple spatial scales. At a landscape scale, mammal richness was most strongly influenced by the configuration of time since fire, increasing in areas with both more fire edges and greater contrast in adjacent fire ages. Configuration of elevation and aridity in the landscape had the next greatest effect on species richness. Generally, the observed effects on species richness did not vary greatly with changing scales, although the models indicated the interactions between these variables does change with scale.  These results suggest land managers should aim to use prescribed burning to create areas with high age contrasts and this can be effective at multiple spatial scales.

The Geelong Bird Report 2013-2016

Craig Morley –  Editor of the Geelong Bird Report

The purpose of this report is to document the distribution and movements of all bird species observed in the Geelong region over the period 2013 ̵ 2016. This report highlights all breeding records as well as records of interesting and unusual behaviour including feeding and vocal mimicry, arrival and departure dates of migrants, and spatial and temporal changes in breeding and non-breeding distribution.

The Geelong Bird Report (GBR) continues to grow and evolve. A key function of previous editions of the Geelong Bird Report was to document bird records from the Geelong region. This function is now performed by public databases such as eBird and Birdata. As a result, this report no longer contains a list of records. Instead we summarise the records by presenting charts and maps showing the seasonal distribution and frequency of the vast majority of bird species recorded in the Geelong region over this four-year period.

A link to download a PDF of this 550 page report which is based on more than 306 000 individual records

of 318 bird species across the Geelong region, contributed by over 630 observers, is available on request at info@gfnc.org.au

Impacts of Phytophthora ‘dieback’ on biodiversity in the Otways.

Wilson B. A.¹ and M.J. Garkaklis², .¹School of Life and Environmental Sciences, Deakin University, Victoria, 3125, ² State of the Environment Pty Ltd. Aireys Inlet, Victoria, 3231

The plant pathogen Phytophthora cinnamomi is one of the world’s top 100 worst invasive alien species (IUCN SSC). The soil-borne organism attacks the roots of susceptible plants leading to deaths. The epidemic of P. cinnamomi ‘dieback’ in Australia is listed as a Key Threatening Process (EPBC Act 1999). It causes severe declines in plant species, loss of susceptible flora, degradation of fauna habitat, fauna declines and ecosystem deterioration. Areas degraded by the pathogen do not regenerate. Research on the impacts of the pathogen and its management have been undertaken in the eastern Otways since the 1970s.  The disease has spread significantly and has been recorded in heathy open forest and woodland and riparian open forest.   Studies of disease impacts in heathy woodland (1989-2015) found an 83% decline in uninfected area; significant declines in total number of plant species, susceptible species, cover abundance of X. australis grass trees; and an increase in disease resistant species.  Substantial impacts on small mammals included; the mean number of species and mammal captures were significantly lower in post-disease areas and captures of species (e.g. Antechinus agilis) were less frequent in diseased vegetation. Radiotracking of marsupials to X. australis showed their significance as providing cover and nest sites.   As there are no methods to eradicate P. cinnamomi management options focus on preventing spread into uninfected areas and reducing the impact at infected sites. Treatment with phosphite can protect plants and backpack and aerial spraying have been found to be effective in the eastern Otways.   While site-specific assessments of P. cinnamomi distribution and impacts in the area have been undertaken there is an urgent need for the identification of significant non-infected refuge areas. These should be managed as a priority with phosphite application, hygiene quarantine and track closures.  Remote sensing has been employed to provide accurate measurement of disease extent and progress and promises to be a cost effective tool for such landscape management.

Otway Ark

Claire Miller – Parks Victoria

Otway Ark is a landscape scale predator control program that aims to maintain and improve the diverse ground-dwelling mammal assemblage of the Otway landscapes.

The predator control program consists of 400 bait sites across the Otways, baited on a 4 week check and replace regimen. To measure effectiveness of the predator control program, an extensive, expanded camera monitoring program has been implemented across 380 monitoring sites across the Otways.

The data from the monitoring program has recently been analysed for the first 3 years of monitoring. The results provide insight into the success of the baiting program in creating conditions which allow small to medium size mammals to persist, and inform recommendations to move forward with the program.

Expanding the Otway Ark – A Cross Tenure fox control program

Emma Birnbaum – Conservation Ecology Centre

The Otway Ark is a large scale fox-baiting and monitoring program that stretches across some 85,000 ha of Great Otway National Park. However, the National Park is thin and long, bordered by large areas of Forest Park and private property, making it vulnerable to re-invasion by foxes. Better outcomes for biodiversity, within our National Reserve system, can be achieved if the management of these systems is not isolated from the management of adjacent land use types and land tenure.

With funding from the Victorian Government’s Biodiversity Response Planning program, we have expanded the Otway Ark to incorporate nearby areas of Otway Forest Park, private forestry and a large, highly diverse, block of private properties.

This presentation will summarise the fox-baiting expansion program and the collaboration that has led to a cross-tenure fox control program that seeks to address the isolated nature of the current Otway Ark.

Managing foxes and fire to conserve biodiversity in the Otway Ranges

Bronwyn Hradsky – the University of Melbourne

Predation by invasive foxes and feral cats and inappropriate fire regimes pose some of the greatest threats to Australia’s native mammals. But working out how to best manage them is no simple business.  The University of Melbourne has developed a suite of projects with the Conservation Ecology Centre, Parks Victoria and the Department of Environment, Land, Water and Planning to measure the effects of landscape-scale fox control and prescribed burns on fox, feral cat and native mammal populations in south-western Victoria.  I’ll provide an update on the progress of our field studies, and how we’re integrating our findings into a simulation model to help land managers make identify effective and efficient management approaches.

Non-invasive genetic sampling to evaluate the impact of baiting upon fox populations in the Otways

Mark Le Pla – Conservation Ecology Centre

Australia spends more than $16 million annually on red fox control to mitigate their impact on our native fauna and reduce stock predation events. Despite this considerable investment, the effect of fox control on fox densities remains poorly understood, largely due to the relationship between traditional index-based measures of fox density (e.g. bait take rates, occurrence on motion-sensing cameras) and true fox density being complex and non-linear. Therefore, in order to produce robust estimates of fox density we need to develop new monitoring tools. Non-invasive genetic sampling offers a powerful alternative to traditional approaches and can produce robust estimates of fox density from scat analysis.

The “Otway Ark”, a landscape scale fox control program, was established by Parks Victoria in late 2017. To evaluate the efficacy of baiting, we surveyed transects for fox scat before and after baiting commenced – one in a baited region, and the other in a region remaining unbaited. Scats were genotyped using microsatellites to identify individual foxes and this data was used to generate fox density estimates at several key moments throughout the control program. Despite significant declines in the relative abundance of fox’s post baiting (mean scats/km2), our results suggest a relatively muted impact of baiting upon fox density thus far. Additionally, individual identification of scats allowed for insight into individual persistence post-baiting and movement of foxes, parameters of key interest to land managers undertaking fox control. Our study demonstrates the power of genetic sampling approaches when evaluating the efficacy of predator control.

Tales from the Ranges: a selection of short stories from 3 years of field work in the Western Otway Ranges.

Matt Rees – The University of Melbourne

You learn a lot from deploying 525 cameras deep in Western Otway Ranges.  From uncovering the strange habits of animals when they think no one is watching, to developing the perfect eye for knowing whether a rotting log will or will not support your body weight. My PhD research is focused on the secret lives of the feral cats, and how they interact with foxes and threatened native mammals. In this presentation I will touch on some of the surprising things that we have found so far, including an abundance of cats, foxes which have acquired the taste of platypus and the strange dance of the echidna.

New Holland Mouse (Pseudomys novaehollandiae) in the Western Otways?

Phoebe Burns

Following decades with no sightings, two endangered rodent species native to the Otway region are considered locally extinct – the New Holland Mouse (Pseudomys novaehollandiae) and the Smoky Mouse (P. fumeus). Recently, a Conservation Ecology Centre and University of Melbourne project detected a potential New Holland Mouse hair in a fox scat in the Otways, 70 km south-west of any prior Victorian record, and over 200 km from current known populations.

The CEC, DELWP, Parks Victoria and Zoos Victoria initiated a collaborative project to confirm the occurrence of New Holland Mice in the area. Camera trapping surveys were conducted at 50 sites in the most plausible New Holland Mouse habitat around the scat detection site and at 50 sites in the most plausible habitat in the broader landscape – Carlisle Heath.

No New Holland Mice were detected during the surveys. On-site vegetation assessment around the scat detection site and the distance to suitable habitat suggest that it is unlikely the hair belonged to a New Holland Mouse. The uncertainty inherent in hair analysis for rare and poorly sampled species means that it is possible the hair belonged to a Smoky Mouse, however, the species was also not detected during the surveys.

Although the source of the suspect hair sample remains uncertain, the surveys revealed an abundance of other threatened species: Eastern Pygmy Possum, Long-nosed Potoroo, Southern Brown Bandicoot, White-footed Dunnart, and Swamp Antechinus. In particular, high detection rates of threatened mammals in the Carlisle Heath area highlight the heath’s exceptionally high conservation value and the need for us to better understand why species are doing so well there before we accidentally upset the balance.

Meanwhile, the hunt for endangered mice in the Otways continues.

Distribution of the Southern Toadlet in the Otways

Emma O’Dwyer Hall – Deakin University

Climate change has resulted in habitat displacement, rising air temperatures and water levels and increased ultraviolet radiation, all which are been linked as major factors to Amphibian decline. Due to their high level of endemism, Australian frogs are particularly sensitive to environmental changes. Bush fires in Australia have increased exponentially in the last 20 years and anecdotal evidence links it as a huge factor in habitat lost for many Native Australian species. Amphibians are particularly sensitive to this environmental change due to their complex lifestyles and permeable skin.

Pseuodophryne semimarmorata is a ground dwelling Anuran which was once common throughout South-West Victoria. Anecdotal evidence suggests a decline in their population, but as there has been near to no published research since the 1990’s, this cannot be confirmed.

Due to the large fuel load and the high biodiversity in The Otway’s National Park, the risk of fires are huge and heavily managed. Thus, for proper fire management to be implemented, study on the impact on native frogs, in particular the P. semimarmorata, is paramount.
This project aims to solve the following objectives:

To find out if fire history impacts the occurrence of Autumn Calling frogs

To find out if Fire History impacts the occurrence of the Southern Toadlet

To generate an updated idea of where the Toadlet is found within the park

To find out how other covariates such as road density, site disturbance, vegetation structure, temperature, wind speed and rainfall impact the occurrence of the Southern Toadlet and other Autumn calling frogs

Optimal habitats were deduced in ArcMap 10.1.3 using historical sightings corresponded with their Ecological Vegetation Class. This habitat was then crossed with Fire History data and sites chosen in relation to their proximity to roads and watercourses. From these, 75 sites were chosen, 50 sites using call play back analysis and 25 using soundboxes to increases time efficiency in the West of the study area.  P. semimarmorata was more prominent in the East end of The Otway’s than the West, with Victoria geocrinia and Litoria ewingii also being prominent.

Can the Yaugher potoroos survive?

Trevor Pescott – Geelong Field Naturalists Club

Yaugher lies about 2km north of Forrest, on the north side of the West Barwon River flood plain. Once considered a site for a township, it did not develop once the rail and roads were built across the flats to Forrest.

There is a section of public land west of the Tiger Rail Trail and south of Seven Bridges Road. To the west and south of the area is cleared farmland. Several small freehold blocks exist along the Forrest-Birregurra Road that runs close to, and parallel with the rail trail.

There is a small pine plantation on the north edge of the block which is approximately 180 ha in area, and all public land is now designated part of the Otway Forest Park – its function to provide recreational opportunities not permitted in the adjacent Great Otway National Park.

At present there is a series of mountain bike tracks through the area, some firewood harvesting is permitted in designated areas, and the area is subjected to “planned burns” presumably as a measure to protect Forrest township.

Two sections of the area were burnt in the 2009-10 and 2014-15 seasons and a third is planned for a burn in 2019-20.

“Camera trapping,” and some Elliott trapping over the last 10 years, has shown that there is a population of Long-nosed Potoroos in the area, but its survival on the long-term depends on appropriate management.

The surveys are intended to follow the return-time of the potoroos to areas that have been burnt under the “planned burn” program.

The Southern Right Whales (Eubalaena australis) of south-eastern Australia and their Paparazzi

Mandy Watson – Department of Environment, Land, Water and Planning 78 Henna Street, Warrnambool, Victoria Email: mandy.watson@delwp.vic.gov.au

Southern right whales in Australian waters were hunted to the brink of extinction at the turn of the last century. Approximately 19,000 southern right whales were harvested from south-east Australia alone. Historically, much of the western Victorian, eastern Tasmanian and southern New South Wales (NSW) coastline were considered high-use areas for the species. It is thought that local extirpation has led to a loss of cultural memory of calving sites contributing to the limited recovery of the south-eastern Australian population and knowledge of population demographics of the south-eastern Australian southern right whale population is lacking. Photo-identification is a non-invasive method that can be used to investigate the distribution, movement and population trends of cetaceans. Southern right whales have unique callosity patterns (patches of thickened, keratinised tissue) around the head that allow the easy photo-identification of individuals. The Department of Environment, land, Water and Planning (DELWP) has been conducting photo-identification research on southern right whales since 2002. In recent years citizen scientists have been becoming an increasingly important source of data for DELWP’s Southern Right Whale photo-identification research program. A group of south west Victorian photographers contributed two thirds of the photo-ID data collated by DELWP in 2017 and 2018.

The Next Big Threat – Tackling the Feral Pig Problem

Emma Birnbaum – Conservation Ecology Centre

Feral animals plague the Otways. Countless dollars have already been spent trying to lessen the damage caused by deer, foxes, cats and rabbits. But despite best management efforts, we can only hope to curb these populations with eradication long since out of reach. Sadly, unless we act quickly, pigs are set to become another name on that list.

The Conservation Ecology Centre has spent the last year, together with Parks Victoria, gaining an understanding of the scale of this looming feral threat.  I’ll summarise what we know so far, methods in feral pig control and end with a call to arms to all land practitioners and landowners in the region.

One thing is certain; we need to act quickly, work together, and address the feral pig problem while eradication is still within our reach.