Monitoring Flying-Fox Populations

Interactive Flying-fox Web Viewer

An interactive Flying-fox web viewer has been developed to visually present the camp census data collected via the National Flying-fox Monitoring Program. The viewer shows the camp occurrence of the Grey-headed and Spectacled Flying-fox. Within the eastern coastal belt, the viewer also shows Black Flying-fox and Little Red Flying-fox camps. The Grey-headed and Spectacled Flying-fox are listed threatened under the Environment Protection and Biodiversity Conservation Act 1999. See the ‘Environment Law’ tab above for more information on Australia’s Flying-foxes and their legal status.

The viewer allows users to explore Flying-fox camps and the numbers of each species counted over time. This information spans the data gathered from November 2012 to present.

If you are aware of Flying-fox camps that contain either Grey-headed or Spectacled Flying-foxes, but are not shown on this interactive web tool then you can notify the Department by emailing details of the camp to speciespolicy@environment.gov.au.

National Monitoring Methodology

The CSIRO has developed a scientifically rigorous monitoring methodology to gather updated information about the status of the national Grey-headed Flying-fox population and population trends (see below). The Commonwealth and state governments are working together to implement a multi-year monitoring program, based on the CSIRO's methodology (see below).

A monitoring method for the grey-headed flying-fox, Pteropus poliocephalus (PDF - 1,127 KB) | (Word - 4,209 KB)

National Flying-Fox Monitoring Program

On 29 July 2011, the Australian Government announced a new commitment of $6 million for Hendra virus research, including $1 million from the Department of the Environment. Australian Government Hendra funding will complement contributions of $3 million each from the NSW and Queensland Governments. The National Hendra Virus Research Programme has allocated $9 million to a number of Hendra virus, human health and Flying-fox related research projects which will continue until 2015. The National Health and Medical Research Council has also allocated $3 million to research projects to better understand and fight Hendra virus.

Six new research projects totaling just over $2 million were announced on 31 May 2012, including $794,717 to CSIRO Ecosystem Sciences (Dr David Westcott) for the project 'Implementing a National Flying-fox Monitoring program' (NFFMP). The Minister approved an additional $700,000 towards the NFFMP under the 'Emerging Priorities' of the National Environment Research Programme (NERP). This funding will be used to estimate the accuracy of Flying-fox counts made through the NFFMP.

The NFFMP will be focused primarily on monitoring national Grey-headed and Spectacled Flying-fox populations, however within the range of these two species, counts of Black and Little Red Flying-foxes will also be undertaken. The monitoring program will include four censuses per year for the first three years. The NFFMP is being coordinated by CSIRO and the Department, with additional resources and support from relevant state governments. CSIRO is also contributing resources into the radio tracking component of the program and working on and funding separately the development of a new generation of energy-efficient technologies that can continuously track the position of Flying-foxes.

Frequently asked questions

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Why monitor?

Monitoring is the process of collecting data on the abundance of a species and its distribution. It is a critical activity in biodiversity conservation because it provides insight into the status of a species and over time provides an indication into population trends and other ecological factors. This information is necessary to assess the kind of management required and to measure the effectiveness of management.

Monitoring of flying-foxes is even more important because two species, the grey-headed flying-fox and the spectacled flying-fox, are listed as threatened under the Commonwealth Environmental Protection and Biodiversity Conservation Act 1999 (EPBC Act) and relevant state legislation. The results of the program will also help inform responses to public concerns about the impact of flying-foxes on industry, agriculture and public health, including any potential Hendra outbreaks.

How is the monitoring being conducted?

The monitoring of any species must be specifically designed according to the species' ecology and behaviour. It must also be designed to match the resources available. The large size of flying-fox aggregations (or camps) and their extreme mobility mean that flying-fox monitoring is not a straightforward task.

The National Flying-fox Monitoring Program (NFFMP) is designed to collect data on the abundance and distribution of flying-foxes in eastern Australia. Counts will be conducted at all known camps in the range of the grey-headed flying-fox - which stretches from Adelaide through to Bundaberg - and the spectacled flying-fox - which is between Ingham and Cooktown in far north Queensland. Counts will also be carried out at as many little-red and black flying-fox camps in these regions as resources allow. The method employed has been chosen as it is:

appropriate for the spatial ecology and behaviour of flying-foxes, and
allows estimation of the errors associated with counting animals.

This last point is critical. All monitoring methods have errors and without quantifying these, it is impossible to determine the degree of confidence that can be placed in any population estimate.

At small camps, usually 1000 individuals or fewer, flying-foxes are counted directly. At larger camps it isn't possible to count every flying-fox and it becomes necessary to use a sampling method. The method being used is point-based distance sampling. Essentially, this method estimates flying-fox density and can be used to estimate of the number of animals in a camp based on the area of that camp. On-the-ground counters move through a camp or around a camp's perimeter and at random points they count every flying-fox they can see and the distance of each flying-fox or cluster of flying-foxes from where they are standing. This distance is subsequently used to estimate the probability of detecting a flying-fox. This probability, otherwise known as detection error, is an important contributor to monitoring error and its quantification is critical to estimating the reliability of monitoring results.

Why is monitoring being conducted this way?

This method has been chosen because it provides a scientifically robust estimate that is underpinned by well-researched statistical analysis. Critically, this analysis includes estimation of the reliability of the estimates produced. Research by several groups here in Australia has shown that when this method is applied to flying-foxes, it performs better than alternatives, including the traditional fly-out counts, and it is simpler to implement.

Who is doing the counting?

The NFFMP is a collaboration between the Australian Government, South Australian, Victorian, New South Wales, Australian Capital Territory and Queensland governments, the CSIRO, and local governments and volunteers.

The participating state and territory environment departments coordinate counts in their jurisdiction by identifying camps, maintaining a database of their locations, and assigning counters for those camps. The state coordinators also collect data sheets and forward these on to CSIRO for data management and analysis.

Counts are performed by agency staff in South Australia, Victoria and the Australian Capital Territory. In New South Wales and Queensland, counts are performed by agency staff, local government staff and volunteers.

Can this data be used to change listing of the species?

Decisions about the status of a species - that is, which threat category it is listed under - are based on a range of criteria. These include the size of a species' population, changes in the population size over time, the extent of its distribution, changes in distribution, the number of populations, and current and future threats to the species and its habitat.

For the listing of a species under the Commonwealth EPBC Act, advice is provided to the Minister by a selected group of scientists - the Threatened Species Scientific Committee (TSSC). The TSSC undertakes a rigorous assessment of all available information against the criteria when providing advice on the threat status of a species. The data being collected through the NFFMP, abundance and distribution, could contribute to a re-assessment of the threat status of flying-foxes as would other relevant information. It will be some years before populations and trends can be estimated reliably enough through the NFFMP to inform such an assessment.

Is it possible to count all flying-fox camps?

There are always going to be camps and flying-foxes that are missed. This is a common problem in ecological monitoring. In the NFFMP this could be because the camps are not known to anyone, because the camps are not known to the monitoring program or because, despite being known, it is not practical or feasible to count the camps.

All possible efforts will be made to include and count all known camps, but this may not always be possible. For example, camps in remote locations may be difficult to access. As a consequence, research that complements the monitoring program will estimate the effect of missing camps on the reliability of the population estimate.

Can the counts be compared with the counts conducted prior to 2006?

The counts conducted prior to 2006 were conducted at different times of the year, using different methods and were conducted over different areas. These differences make direct comparisons between the numbers produced by the two sets of counts difficult. Research under the NFFMP will investigate how reliable comparisons between the NFFMP and these previous counts are.

How can I get involved?

If you know of additional camps or have questions about the counts, please contact Dr David Westcott (david.westcott@csiro.au) or Mr Adam McKeown (adam.mckeown@csiro.au) from the CSIRO.

If you would like to participate in the counts in New South Wales or Queensland, please contact:
New South Wales - ff.census@environment.nsw.gov.au
Queensland - Wildlife.Management@des.qld.gov.au

Reports of the National Flying-fox Monitoring Program

Disclaimer:
The views and opinions expressed in these publications are those of the authors and do not necessarily reflect those of the Australian Government or the Minister for the Environment and Energy. While reasonable efforts have been made to ensure that the contents of this publication are factually correct, the Commonwealth does not accept responsibility for the accuracy or completeness of the contents, and shall not be liable for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the contents of this publication.