Ian Shannon

Combining a map-based public survey with an estimation of site occupancy to determine the recent and changing distribution of the koala in New South Wales

The present study demonstrates one solution to a problem faced by managers of species of conservation concern – how to develop broad-scale maps of populations, within known general distribution limits, for the purpose of targeted management action. We aimed to map the current populations of the koala, Phascolarctos cinereus, in New South Wales, Australia. This cryptic animal is widespread, although patchily distributed. It principally occurs on private property, and it can be hard to detect. We combined a map-based mail survey of rural and outer-urban New South Wales with recent developments in estimating site occupancy and species-detection parameters to determine the current (2006) distribution of the koala throughout New South Wales. We were able to define the distribution of koalas in New South Wales at a level commensurate with previous community and field surveys. Comparison with a 1986 survey provided an indication of changes in relative koala density across the state. The 2006 distribution map allows for local and state plans, including the 2008 New South Wales Koala Recovery Plan, to be more effectively implemented. The application of this combined technique can now be extended to a suite of other iconic species or species that are easily recognised by the public.

The contribution of community wisdom to conservation ecology

Scientists have traditionally collected data on whether a population is increasing, decreasing, or staying the same, but such studies are often limited by geographic scale and time frame. This means that for many species, understanding of trends comes from only part of their ranges at particular periods. Working with citizen scientists has the potential to overcome these limits. Citizen science has the added benefit of exposing citizens to the scientific process and engaging them in management outcomes. We examined a different way of using citizen scientists (instead of data collection). We asked community members to answer a question directly and thus examined whether community wisdom can inform conservation. We reviewed the results of 3 mail-in surveys that asked community members to say whether they thought koala populations were increasing, decreasing, or staying the same. We then compared the survey results with population trends derived from more traditional research. Population trends identified through community wisdom were similar to the trends identified by traditional research. The community wisdom surveys, however, allowed the question to be addressed at much broader geographical scales and time frames. Studies that apply community wisdom have the benefit of engaging a broad section of the community in conservation research and education and therefore in the political process of conserving species.

Interpreting patterns of population change in koalas from long-term datasets in Coffs Harbour on the north coast of New South Wales

We examined a long-term, repeat dataset for the koala population within Coffs Harbour Local Government Area. Analyses of these data have led to the conclusion that, following a perceived population decline in the 1980s, the koala population of Coffs Harbour has endured between 1990 and 2011 and showed no evidence of a precipitous decline during this period. Rather, the population change is best characterised as stable to slowly declining. This conclusion appears to contradict a common view of recent koala population declines on the north coast of New South Wales. There are four possible explanations for the population’s apparent stability: that conservation efforts and planning regulations have been effective; that surviving adults are persisting in existing home ranges in remnant habitat; that the broader Coffs Harbour population is operating as a ‘source and sink’ metapopulation; and/or that the standard survey methods employed are not sufficiently sensitive to detect small population changes. These findings do not mean there is no need for future conservation efforts aimed at koalas in Coffs Harbour; however, such efforts will need to better understand and account for a koala population that can be considered to be stable to slowly declining.

Using repeat citizen science surveys of koalas to assess their population trend in the north-west of New South Wales: scale matters

Scale matters when assessing population trends. Whereas traditional field-based ecological surveys are generally restricted to small temporal and spatial scales, community (citizen science) surveys allow wider consideration of population trends. We used repeat community surveys (completed in 2006 and 2015) to assess population change in koalas (Phascolarctos cinereus) across an area of 36 900 km2 in the north-west of New South Wales. In both community surveys we asked respondents to record the location of their koala sightings as well as those of eight other common species. We further asked respondents about their perceptions of population change. Through three different measures (likelihood of koala occurrence, number of koalas observed per respondent, and the perception of population change), we found that koala numbers were declining across the region during the study period. The timing and broad and consistent geographic spread of the decline suggests that broad-scale environmental factors, such as weather, are important drivers of this change. This information will allow managers to place conservation efforts into an appropriate spatial context. While such information sourced from the community can provide critical information on threatened species, including the koala, this study highlights the limits of such information.

Mapping the likelihood of koalas across New South Wales for use in Private Native Forestry: developing a simple, species distribution model that deals with opportunistic data

In Private Native Forestry in New South Wales, species-specific provisions in the code of practice are triggered by the presence of koalas (Phascolarctos cinereus), based on existing database records in the Atlas of NSW Wildlife. Whereas Species Distribution Modelling allows questions to be posed regarding the distribution of a species, and how it relates to environmental variables and threats, the key question, in many management situations, is whether or not a species is, or has been, present at a particular location, rather than the overall predicted distribution of the species. This is particularly the case for such a high-profile species as the koala. In this project, we developed a simple distribution model for the koala in New South Wales based on the proportion of koala records from within a suite of mammal records in 10 km × 10 km cells. This provides a measure of the likelihood of koalas being present. At the same time it allows deficiencies in the data to be highlighted, and recommendations made for further survey. This model and map will allow the potential for more robust and transparent decisions to be made regarding koala protection in areas proposed for private native forestry.

The remaining koalas (Phascolarctos cinereus) of the Pilliga forests, north-west New South Wales: Refugial persistence or a population on the road to extinction?

In the 1990s, the Pilliga forests were carrying the largest population of koalas west of the Great Dividing Range in New South Wales (NSW). Whereas the NSW koala population in its entirety was thought to be in decline, the Pilliga population stood out as potentially increasing. By 2007, anecdotal evidence suggested that the population was in decline. We undertook surveys of koalas in the Pilliga forests that repeated surveys undertaken between 1991 and 2011. We found that koalas had declined and were found in only 21% of sites in which they were observed in the initial surveys – by any measure, a 5-fold drop in occupancy in less than two decades is severe. Declines occurred evenly across the Pilliga, with persistence at a site seemingly related to a high initial density of koalas rather than to a slower rate of decline. Sites where koalas persisted were characterised as having higher temperatures and lower rainfall relative to other sites, being close to drainage lines with deeper soils and having a lower occurrence of fire. This pattern fits with the observation in the recent surveys that koalas were next to drainage lines in the western half of the Pilliga and fits with the suggestion that koalas show refugial persistence. Recovery from this point is not assured and will depend on how we manage the landscape, particularly with the threat of climate change. This will likely require active management within an adaptive management framework, such as restoration of refuges, and not simply habitat reservation.

Protect our protected areas!: the value of protected areas for fauna research and conservation, a case study of New South Wales

Our aim in this study is to provide the first ever quantitative, historical and map-based information of what fauna has been studied and recorded both outside and inside the protected areas of New South Wales (NSW), which are principally National Parks and Nature Reserves. Our objective was to consider the value of National Parks and Nature Reserves for fauna research and biodiversity conservation, and gauge the extent and limits of our knowledge of the fauna of NSW. We compared the increase in the area of parks and reserves in NSW with the expansion of the fauna records in the Office of Environment and Heritage (OEH) Atlas of NSW Wildlife, and analysed the use of Scientific Licences issued by OEH for fauna research for 3.5 years to mid-2014. We found that the distribution and the number of Scientific Licences within protected areas show a heavy bias to the eastern strip of the State, with a greater clustering for the area around Sydney and the north coast, but it is evident that researchers make considerable use of protected areas. The 6, 070, 769 Atlas fauna records were divided by tenure type: National Parks held 1, 118, 204 records (21.4 records/km2), while Nature Reserves held 386, 755 records (40.6 records/km2). The off-park records total was 4, 407, 486 representing 72.6% of all records, with a density of 6.0 records per km2. Of the grand total of all the fauna records, 7% were of threatened species. Birds and mammals comprise 81% of all fauna records in the Atlas. The greatest number of records are of birds (n = 4, 913, 511), followed by mammals (n = 832, 361, of which 321, 721, or 39%, were from WildCount). Given the success of the growth of the number, area and distribution of parks and reserves in NSW, the idea that they can carry the heavy load of the aspiration to conserve the biodiversity of NSW now seems feasible, even desirable, especially given the increasing intensity of land use from never-ending population growth and its impacts, such as land clearing, roading, logging, water use, alien invasive species and climate change. However, this study has also revealed that we have a very poor understanding of some faunal groups, in particular invertebrates, reptiles and amphibians. Fauna accumulation curves of both records and of species match closely the growth in the area of parks and reserves since the formation of the NSW National Parks and Wildlife Service in 1967. Thus, the greater the area of parks and reserves, the greater the number of fauna records and of species. We took the historical view so that research is encouraged and the trajectory of the acquisition of new protected areas can be maintained. This study shows the ever-increasing value of protected areas to fauna conservation, and that it is vital to uphold the protected areas concept as a principal way to conserve our fauna. It should also be a guide to help recognise the importance of sustaining the effort to study our native fauna.