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AIM 3: MANAGE IMPACTS OF KANGAROOS ON LAND CONDITIONWidespread changes to the environment since European settlement have changed the natural balance of species. Many species have declined in number, and some are now threatened. Other species have been able to adapt to the changes and can exploit the opportunities provided by altered habitats. These species – including kangaroos – are now present in larger numbers, or more widespread distributions, than before. Kangaroos can be in conflict with various land uses and the objectives for which land is being managed. When this conflict occurs, kangaroos can cause detrimental impacts that may be environmental, economic or social in nature. This plan adopts the ethic that the mitigation of environmental, economic and social impacts of kangaroos should be allowed, provided it takes place in a manner that is humane and does not pose a risk to the long-term conservation of kangaroos. The NPW Act provides for the destruction of kangaroos for the purposes of mitigating or preventing damage. This process is managed outside of the commercial harvest through the permit to destroy wildlife system, whereby a landholder can apply for a permit to destroy a specified number of kangaroos when kangaroos are causing, or are likely to cause, detrimental impacts. ACTION 9: DEWNR will issue permits to landholders for the destruction of kangaroos for damage mitigation purposes. Key objectives of the permit to destroy wildlife framework are to:
Performance indicators: 9.1 Issue Permits to Destroy Wildlife to landholders to mitigate detrimental impacts of kangaroos. 9.2 Any landholder of an appropriate property size seeking a destruction permit for more than 25 animals within a current commercial quota allocation is offered a commercial harvesting permit in the first instance. Permits to Destroy Wildlife (non-commercially) are only offered after a commercial harvest permit has been declined. 9.3 DEWNR will investigate the introduction of formal training requirements (similar to those undertaken by Kangaroo Filed Processors) for landholders requesting non-commercial Permits to Destroy Wildlife. 9.4 DEWNR will develop decision making tools, informed by current survey, climatic and other data, to assist regional staff in permit issue. 9.5 DEWNR will develop a mapping facility to allow landowners to determine whether they fall within the commercial harvest regions. AIM 4: MONITOR KANGAROO POPULATIONS AND SET QUOTASMonitoring commercially harvested kangaroo populations, both directly and indirectly, is essential to effectively maintaining viable populations of kangaroos throughout their ranges. The three currently commercially utilised kangaroo species – Macropus rufus, M. fuliginosus and M. robustus – are widespread and abundant in South Australia. The 2011 population estimate for these kangaroo species in Commercial Harvest Management Regions (CHMRs - Figure 1) totalled approximately 2.3 million. A great deal is known about the biology of kangaroos including their habitats, distribution, diet and reproduction (Appendix 1), and this knowledge is continually improving. In particular, the reproductive biology of kangaroos has been researched extensively. While there are variations between the kangaroo species (e.g. gestation period, lactation period and interval between young), these are relatively well understood and accounted for in the various quotas set for each species. In addition, there is abundant information from direct and indirect monitoring of kangaroos. Results of aerial surveys since the mid-1970s show that kangaroo populations fluctuate primarily in response to rainfall and other seasonal conditions. A wide range of literature relating to kangaroos and their management is currently available. Of particular interest is a comprehensive review prepared for the Commonwealth Government entitled Commercial Harvesting of Kangaroos in Australia. This review is available on the Commonwealth Government website (www.environment.gov.au/biodiversity/trade-use/wild-harvest/kangaroo/harvesting/index.html) and encompasses topics including the biology of the harvested kangaroo species, the effects of harvesting on kangaroo populations, animal welfare issues and the conservation status of the harvested kangaroo species. A review of recent scientific literature relevant to the commercial harvest was prepared by Herbert & Elzer for the New South Wales Commercial Kangaroo Harvest Management Plan 2012-2016, and is available on the New South Wales Kangaroo Management Program’s webpage.
Kangaroo population estimates obtained from surveys (direct monitoring) will be used as the basis of setting commercial quotas following the procedures set out in this management plan. There are two standard survey techniques that may be employed for direct monitoring of kangaroo populations. 1. Broad-scale aerial surveys using fixed-wing aircraft (fixed strip-width transect survey methodologies). 2. Small-scale surveys conducted on foot (line transect survey methodology). This technique is employed due to the dangers associated with low level flying in steep terrain, but has high associated costs. Fixed-wing aircraft are used across SA to annually survey kangaroo populations. Survey lines have been established at regular intervals across this region and the same lines are surveyed at the same time every year to allow comparison of results between years. Some terrain is too steep to be safely surveyed using fixed-wing aircraft so walking surveys are used instead. During the life of this plan, methodology of walking surveys will be reviewed, and more efficient survey methods may be trialled and implemented, all the while ensuring continuity of data comparison. For the three species currently harvested commercially – M. rufus, M. fuliginosus, and M. robustus – the quota will be adjusted based on the most recent population estimate and will therefore account for all kangaroo mortalities, including those unrelated to commercial use. Performance indicators: 10.1 Kangaroo population estimates are obtained at required time intervals using standard survey methodology throughout the life of this plan. 10.2 DEWNR will continue to investigate development of an optimal monitoring strategy for kangaroo management.
The commercial quota for a species is the maximum number that can be utilised commercially in a calendar year. Quotas will be set for each commercially harvested kangaroo species for which current population estimates are available in specific Commercial Harvest Management Regions (CHMR). The Commonwealth Government will be advised of the quotas prior to implementation. Based on kangaroo population dynamics, quotas set at 15 to 20 percent are considered sustainable in the long-term (Caughley 1987, Hacker et al. 2004). Kangaroo populations are expected to continue to fluctuate primarily in response to seasonal conditions, and the quota does not seek to achieve a specific density of kangaroos (unless undertaken as part of an approved adaptive management experiment (see Action 23). regional quotas are set at a maximum of 20% of estimated population size for red kangaroo, and 15% of estimated population size for western grey kangaroo and euro. More conservative quotas are set for regions that are not monitored annually. There are currently four defined CHMRs in South Australia: Western Pastoral, Eastern Pastoral, Western Agricultural, and Eastern Agricultural. Within each of these defined harvest management regions lie a number of sub-regions (shown as internal boundaries on Figure 1). These management sub-regions are based on the old administrative boundaries of Soil Conservation Board districts. Population estimates and commercial quotas are currently derived and set at the level of each management sub-region (i.e. old Soil Conservation Board boundaries). However, for the purposes of providing flexibility to manage quotas in response to spatial and temporal changes in kangaroo distribution, sub-region quotas can be moved between other sub-regions within the same CHMR. Quotas cannot be moved between any of the four defined harvest regions. Quota is distributed across these sub-regions as per the surveyed densities of animals. Quotas may be shifted between sub-regions within the same CHMR only for approved damage mitigation reasons, and only where available quota in a sub-region has been fully utilised. Once all of the available quota for a species has been reached in a CHMR, no additional quota will be issued for that species in that CHMR until the following year (with the possible exception of Special Land Management Quota – see action 14). The boundaries of these regions will be updated during the life of this plan to align with the more commonly used and widely recognised Natural Resource Management Board and Group boundaries (or another suitable boundary). However, within the life of this plan new commercial kangaroo harvesting sub-regions may be opened, on the basis of population surveys, in areas of South Australia where commercial harvesting of kangaroos is not currently occurring. Performance indicators: 11.1 All commercial kangaroo harvest quotas are set in accordance with the provisions of the South Australian Kangaroo Management Plan 2013 – 2017 throughout the life of the plan. 11.2 The Commonwealth Government is advised of commercial harvest quotas for the following calendar year by 30 November. The Quota Report will contain the following information:
11.3 If Commonwealth approval is required for quotas set above the rates specified in the plan as part of an adaptive management experiment, such approval is obtained before the additional quota is implemented. 11.4 The Quota Report is made available to the public via the Kangaroo Management Program web page. ACTION 12: If kangaroo populations decline to specific trigger points, the commercial harvest of particular species in particular sub-regions will be reduced or suspended. This management plan aims to accommodate fluctuations in kangaroo populations to change according to seasonal conditions. Calculating trigger points based on long-term average populations or densities, and standard deviations, recognises these environmental differences. ‘Standard deviation’ is a statistical measure of how much the population changes relative to its average – in erratic environments, the population changes much more and the standard deviation is larger than in environments that are more stable. This means that the ‘standard deviation’ is different for each species in each sub-region. The standard deviations will be recalculated after each survey to ensure all available information is utilised. Appendix 3 provides additional information on the use of population thresholds in harvest management. If survey results indicate a population has fallen below the long term average density for that species in that harvest region, the commercial quota will be reduced or suspended for the following calendar year. The suspension will remain in place until surveys indicate populations have increased. Reduction in quota – when populations are below the long-term average by between 1.5 and two standard deviations.
For Commercial Harvest sub-regions that are surveyed triennially (i.e., those that have average annual harvest of less than 50% of the maximum quota), quota is already set at a reduced level. In these sub-regions, for any survey that indicates a population that has fallen to between 1.5 and 2 standard deviations of the average, quota will be set at the usual reduced level. Even if future surveys show an increase in population, this reduced quota will remain in place until such time that the average quota uptake is greater than 50%, and surveys occur annually. If the triennial surveys indicate that the population has fallen more than two standard deviations below the long term average, quota will be suspended, and an additional survey will be undertaken in that sub-region in the following year. If commercial quotas are reduced or suspended due to low population estimates, issuing of non-commercial permits to destroy wildlife may also be reduced or suspended. Performance indicators: 12.1 Commercial harvest quotas are reduced if population estimates fall below 1.5 standard deviations of the long-term average density, or suspended if population estimates fall below two standard deviations of the long-term average. ACTION 13: Special Land Management Quotas will be set in accordance with the provisions of the South Australian Kangaroo Management Plan 2013 – 2017. A Special Land Management Quota (SLMQ) for commercial CHMRs will be set annually at a maximum of 1.5 percent of the population of each species across all CHMRs. SLMQ is a reserve pool of tags allocated within a CHMR for use when all commercial quota has been exhausted in the CHMR to mitigate extenuating damage. SLMQ will only be issued if warranted by climatic trends, destocking orders, kangaroo population trends, or other extenuating circumstances. SLMQ will provide for commercial utilisation of kangaroos that would be shot and left in the field under the normal non-commercial licensing system. Performance indicator: 13.1 Any issue of Special Land Management Quota and the reasons for its issue are recorded and reported through annual reporting.
Indirect data on kangaroo populations will be obtained continuously throughout the life of this plan from commercial kangaroo industry returns. Permit holder returns detail the number of each species taken and data on average carcass weights, sex and location of take, depending on the type of permit. Monitoring of permit returns by DEWNR could identify significant changes in harvest per effort, which may provide an indication of population sizes and accessibility. Performance indicators: 14.1 A system will be developed to automatically analyse industry returns for unusual changes in information. 14.2 Sudden, sustained or acute changes in information provided through permit returns will be investigated to determine where practicable the cause of the change. 14.3 Collation of non commercial destruction permits and associated numbers will occur, to support data gathered from industry returns.
Eastern Pastoral Western Agricultural Eastern Agricultural Figure 1: Current South Australian Kangaroo Commercial Harvest Management Regions (CHMR) |
