UDIA Industry Briefing Biodiversity Conservation Strategy - 3 June 2013
Aerial Survey Techniques for Brolga Population Estimates
1. Aaron Organ – Director / Principal Ecologist
Melbourne, Geelong, Brisbane
Ph (03) 9377 0100, Mob. 0425 873 159
2. Presentation Outline
Relevant Research
Background
Case Study - South West Victoria
Key considerations for Industry (Proponents,
Ecological Consultants, Government)
Conclusion
4. Relevant Research
1. Caughley 1977 – Considered methods of aerial survey –
both practically and statistical efficiency. Transect sampling
is preferred
2. Morton et al. 1993 – Distribution and abundance of Brolgas
and Black-necked Storks in the Alligator Rivers Region, NT
3. Dolbeer et al. 1997 – Aerial photography techniques to
estimate populations of Laughing Gull nests at Jamaica Bay,
New York
4. Kingsford 1999 - Aerial survey of waterbirds on wetlands as
a measure of river and floodplain health
5. Harding, C. 2002 - The use of remote sensing and
geographic information systems to predict suitable
breeding habitat for the Brolga in SW Victoria
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5. Brolga Grus rubicunda
Vulnerable in Victoria, New South Wales and South Australia,
listed under relevant State legislation
Listed as ‘migratory’ under the Environment Protection and
Biodiversity Conservation Act 1999
Action Statement and Recovery Plans in place
Subject to a range of threatening processes (largely wetland
drainage, fox predation)
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6. Distribution and Population
Abundant and widespread occurring across
northern and south-eastern Australia
In Victoria, the species occurs in the western part
of the state and on the Northern Plains adjacent to
Murray River
Australian population estimated to be 20,000 to
100,000
Victorian population
◦ 1980s and 1990s - 600 to 650 individuals
◦ 2007 - 465-576 individuals
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10. South West Victoria – Case Study
Survey objectives
Spatial distribution of Brolga nests
Extent of available habitat
Importance of study area
Information used to inform turbine and
infrastructure layout
Risk and impact under relevant legislation and
policy
Measures to avoid, minimise and offset the impacts
to Brolga
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11. Case Study - South West Victoria
Methods
Surveys undertaken in accordance with survey
guidelines developed by DSE and other experts
Cessna 172, four-seat, high-wing, fixed wing aircraft
Flight height of 500 feet
Flight speed of 60-70 knots
Two observers observing 250 metres to the north and
the south of the transects
Observers scanned the landscape and all wetlands,
dams, creeks and drainage lines with binoculars
Each observer had an aerial map showing wetlands and
numbered transects
Each observer had a GPS and data sheets
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20. Key Considerations
The Proponent
Reliable survey method accepted by DSE
Cost effective
Major time reductions (important for quicker
decisions regarding site layout)
Early determination of the magnitude of
constraints across the wind farm site
Information on the relative importance of
habitat (avoid, minimise and offset)
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21. Key Considerations
The Consultant
Ensure survey techniques remain consistent and
repeatable for analysis over time
Surveys obviously need to coincide with when the
species is nesting
Be prepared (take tablets and a paper bag)
Understand your role during the flight
Bad lighting conditions, turbulence, using naked
eye rather than binoculars and motion sickness is
likely to reduce detectability of brolgas
Communication is important
Collect data consistently
Augment with other intensive survey methods
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22. Key Considerations
The Government
Further refinement to the survey guidelines and
policies (detection probabilities, turbine buffer
distances)
DSE should improve spatial data on important
Brolga breeding habitat across the SW and make it
publicly available (exclusion areas for
development?)
The Government continues to receive data, and our
understanding of the species’ distribution and
relative importance of areas for breeding
Assists all levels of Government in ensuring
accurate and consistent planning decisions
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23. Conclusion
A proven survey technique that shouldn’t be used
in isolation
Spatial understanding of habitat
High detection rates
Allows areas which have access restrictions to be
surveyed
Determine any potential impacts associated with a
proposed wind farm facility on the species
Inform avoidance and minimisation strategies
Reduced time and costs
Can determine where wetland restoration actions
should be directed
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