Australian Rangeland Society

Greg Brennan, Grazing Innovation, Geraldton WA.  Email: greg@grazinginnovation.com

 

Introduction

With the two Kangaroo Symposia held in Canberra and Launceston in September and November 2019, information from many sources came together to enable development of action plans to make positive progress in the management of Australia’s kangaroo populations.  It was disappointing that at the Canberra Symposium, land managers appeared to be alone in expressing any sense of urgency to address the challenge of enabling land managers to cost-effectively control kangaroo populations on pastoral lands.  One pastoralist stated that the high kangaroo population on his land in the Western Division of NSW may have brought drought conditions forward by at least six months.

The southern rangelands of Australia (SRA) face increasing challenges as a result of climate change, increasing threats from wild dog predation and uncontrolled grazing pressures.  Maintaining sustainable and profitable livestock enterprises in these regions will require rapid uptake of technologies, many of which currently exist (Foran et al. 2019).  Management of total grazing pressure is a fundamental tenet of a sustainable livestock enterprise and there is a need for legislative recognition of the need for landholders to undertake control of kangaroo populations in a timely, effective and humane manner (Waters 2018).  It can be argued that current regulations for kangaroo population control do not meet these criteria.  It is no coincidence that most regions across the SRA have in recent decades had major government interventions attempting to address the economic, environmental and social dysfunctions that afflict these areas.  Could it be that the apparent lack of success of these interventions is due to a failure to effectively address the core issue of total grazing pressure control?

The populations of Red, Eastern Grey and Western Grey kangaroo species have increased markedly since European colonisation (Pople and Grigg 1999), mostly as a result of the proliferation of stock water points and the containment of wild dog populations.  Pastoralists claim that the existing regulations for kangaroo control do not enable them to cost-effectively control kangaroo grazing pressure, particularly when populations expand rapidly during above average seasons (Waters et al. 2018).  It can be argued that across the breadth of the SRA, the regulations that preserve kangaroo populations for conservation purposes have for decades resulted in serious threats to landscape function, biodiversity and livestock productivity.  In aggregate, these factors contribute significantly to the loss in resilience of regional economies across the SRA.  A harvest rate of 20% of the assessed kangaroo population (with males comprising 70 percent) was recommended for the Murray-Darling basin (Hacker et al. 2004) but under current harvest regulations, no more than 10% is normally harvested.  More cost-effective harvest methods need to be developed as it’s clearly uneconomic for commercial harvesters to harvest beyond 10% of the population.  There is also a need to establish the benefits to landscape function, soil carbon stocks, biodiversity and livestock productivity when kangaroo populations are controlled to predetermined levels, proportional to the fluctuating numbers of livestock that can be sustainably and profitably carried across the range of widely variable seasonal conditions.

This natural resource management dilemma meets all the criteria of a wicked problem (Australian Public Service Commission 2007).  Achieving enduring solutions will require full accommodation of the principles and processes known to be necessary when addressing problems of this ‘wicked’ nature.

Many highly regarded scientists have worked tirelessly on this issue of kangaroo management without significant rewards for their efforts.  With the current urgency to face the challenges of reduced rainfall in the future and the need to revegetate vast areas of drought affected districts of the SRA, I believe that kangaroo authorities must be more open to investigating the development of more cost-effective methods of controlling kangaroo numbers.  Below I argue the case for systemic changes to address two important issues: first, enabling land managers to cost-effectively manage the grazing pressure of kangaroos; and second, improving kangaroo meat products from the current variable quality, commodity product to the status of a quality assured, premium eating quality meat with a low carbon footprint.

 

Developing a high eating quality kangaroo meat product

One eminent speaker at the Canberra Symposium said that he will not risk serving kangaroo meat to his house guests because it is not possible to buy kangaroo meat with a guaranteed eating quality.  This statement highlights the urgent need to develop improvements to the harvesting, processing and marketing of kangaroo meat.  The shift in community attitudes towards eating a low animal fat diet with a low carbon footprint suggests that high eating quality kangaroo meat products may provide an attractive alternative to the growing number of health and climate conscious consumers (Choice 2015).  It is feasible that high eating quality beef can be reliably produced across the SRA when total grazing pressure is rigorously managed and pasture resting regimes are introduced (Materne et al. 2017).  It is highly likely that this opportunity is also available for sheep meat production.  By implementing a similar management regime, it is also feasible to concurrently and reliably produce high eating quality kangaroo meat products.  However, if such a development is to be realised, the internationally recognised principle of conservation through sustainable use must be acknowledged and employed (Ampt and Baumber 2006).  This principle holds that if a native animal is to be reliably conserved on privately held land, the landholder must be able to profit financially from the exercise.  The opportunity to capture a larger portion of the red meat market may require two major changes to the current management of the kangaroo industry and kangaroo populations:

  1. Development of more cost-effective, quality-assured and socially acceptable kangaroo harvest methods; and
  2. Development of a kangaroo meat supply chain that can supply the premium red meat market with a quality-assured, high eating quality, grass-fed product.

Australia has some of the best meat scientists in the world.  They have been responsible for the development and on-going refinement of the world-renowned Meat Standards Australia (MSA) quality assurance system for beef and sheep meat.  The MSA system is designed to provide the consumer with a meat product that has a guaranteed eating quality.  Given adequate funding, these scientists are well equipped to develop a system equivalent to MSA for kangaroo meat.

 

Enabling land managers to control total grazing pressure

The ability to control total grazing pressure is the most fundamental tenet of good land management. The Commonwealth government is currently directing funds towards drought mitigation.  In this context, developing more cost-effective methods for harvesting and managing the kangaroo numbers in the SRA must be a stand-out priority for government investment.  Meat and Livestock Australia (MLA) commissioned the development of an investment strategy addressing forage supply and demand through total grazing pressure (TGP) management in the extensive livestock industries of Australia (Waters 2018).  The resultant report made the following recommendation:

“…… a fourth investment priority has a policy focus and is required to ensure legislative requirements to control wildlife recognise the need for pastoralists to undertake control of kangaroo populations in a timely, effective and humane manner.

4. The legal capacity for industry to manage all herbivores

4.1 National task force to co-ordinate and develop TGP management policy”

If land managers are to ‘undertake control of kangaroo populations in a timely, effective and humane manner’, such an outcome will require that kangaroo management authorities negotiate with landholders to determine:

  1. how many kangaroos a landholder(s) should be obliged to carry in a management unit, relative to the number of livestock that can be carried sustainably and profitably in that season; and
  2. the development of methods to cost-effectively harvest the excess number of kangaroos in a way that a) meets the highest animal welfare standards, and b) meets the community requirements for granting the social licence to operate.

Long term grazing trials at Old Man Plains (OMP) research station, Alice Springs, have shown that over a ten year period, by rigorous determination of appropriate annual stocking rates and with the introduction of pasture resting, rangeland condition was improved and rainfall use efficiency improved by a factor of 2.5 in terms of kg dry matter/ha/yr/mm rainfall.  These improvements came largely from regenerating populations of native perennial grasses (C. Materne  pers comm, 4 November 2019).  This scale of improvement in perennial grass cover and rainfall use efficiency would also result in significant improvements to biodiversity and alleviate soil erosion processes.  The management regime employed at OMP has enabled steers of mixed breeds to be turned off at 575 to 600 kg at 30 months of age, meeting MSA standards for fat cover (Materne et al. 2017).  C. Materne (pers comm, 4 November 2019) claims that the research program at OMP shows that this same management regime can reliably produce similar livestock performances across a wide range of seasonal conditions.  Management regimes similar to those employed at OMP have achieved similar results across many arid Mediterranean regions around the world, where rainfall use efficiencies of degraded rangelands have been improved by factors of 3 to 6 across similar time scales (Le Houerou 2006).  Such attractive and important improvements across the SRA will continue to be denied landholders until they are provided with cost effective methods to control the grazing pressure of kangaroos.

With the increasing demand for grass fed beef, the OMP results augur well for major improvements in the sustainable productivity of livestock enterprises across similar systems in the SRA, but only where kangaroo grazing pressure can be controlled.  C. Materne (pers comm, 4 November 2019) explained that at OMP, kangaroos are predominantly reds and their population is relatively stable despite the variable climate; they do not impact significantly on grazing pressures, nor the results of the OMP long term grazing management research.

At OMP, wild dogs are heavily baited only adjacent to neighbouring areas with high wild dog populations.  It can be assumed that the wild dog population is enough on the remainder of OMP to prevent large increases in the kangaroo population in good seasons.  Where wild dogs are not yet prevalent or controlled with rigour across other parts of the SRA, managed herbivores sometimes represent only half of the dry sheep equivalents carried (Waters 2018).  Under these circumstances, rigorous control of total grazing pressure is unattainable, as are the significant benefits enjoyed under the management regime at OMP.  Without dog predation, kangaroo populations can increase relatively unhindered during successive good seasons (Prowse et al. 2014), even when commercial harvesting is being employed.  Commercial harvests are small in relation to the population and are unrelated to the population fluctuations.  Frequently only 50% or less of the quota that is normally set at 15%-20% of the estimated population is harvested (Edwards and Wilson 2008).  These harvest percentages are insufficient to contain the expanding populations during favourable seasons.  With the inevitable arrival of successive dry seasons, the high population of kangaroos contributes to a denuding of ground cover vegetation; and if it stays dry for long enough, kangaroos die in large numbers.

Adult Merino sheep and cattle can survive on the low digestibility and high protein content of shrub vegetation in the SRA, but in successive dry seasons they contribute to the denuding of the intershrub vegetation.  When rains return, rain drops on bare soil render fine soil particles air borne and the consequent sheet and gully erosion accelerates the land desiccation processes (Pringle and Tinley 2003).  Additionally, the rapid build-up of the rangeland goat populations over the past decades has exacerbated these dehydration processes since goats can thrive on shrub vegetation and reproduction is relatively unaffected by seasonal conditions (Fletcher 1991).  Furthermore the expansion in numbers of sheep meat breeds such as the Damara and Dorper also exacerbates the denudation during extended dry seasons as these breeds have digestive systems that enable them to thrive on the relatively low-quality forage of shrub vegetation (Wilkes et al. 2012).   Another issue is that these breeds are also renowned for their ability to pass through traditional Merino fences.  In the absence of predator proof fences in the SRA, when pastoralists cannot control kangaroo numbers cost-effectively there is also no incentive to control domestic livestock numbers, or rangeland goats.  Landholders who rigorously control TGP will inevitably have more forage than neighbours.  When the season turns dry, neighbouring non-domestic grazers, as well as domestics such as Damaras and Dorpers, will easily cross the traditional Merino plain wire fences to harvest the superior forage.  While the rapid increase in areas protected by wild dog proof boundaries significantly alleviates this problem, there remains no cost-effective method to control kangaroo populations inside these enclosures.

It can be argued that since the beginning of pastoralism in the SRA, this dehydration cycle of the removal of vegetative ground cover, has been repeated with increasing intensity, every time there is a run of successive dry seasons.  It is ironic, but more accurately tragic, that this dehydration cycle is facilitated by the year-round supply of high protein shrub vegetation which should provide the foundation of a highly productive, highly resilient livestock production system; but only when total grazing pressure is managed rigorously.  The ‘tragedy’ is that during extended dry seasons, with abundant shrub protein available, the digestible intershrub vegetation is consumed by herbivores until it has all gone, leaving vast areas of bare ground.  Kangaroos’ dietary preference is grass (Dawson 2012) and pastoralists describe how in dry times, they dig up grass roots and even invade rubbish tips to eat cardboard, and likely perish in large numbers.

With rigorous control of total grazing pressure, grazing the perennial grasses below 10-15cm in height can be prevented, reducing the risk that some of these species will die in extended dry seasons (Hacker et al 2006); and it will improve the probability that they will proliferate during good seasons.  This phenomenon has been ably demonstrated in the grazing trials at Old Man Plains (Materne et al. 2017) and by some high performing pastoralists throughout the SRA who commit to controlling TGP, often at significant personal cost in the early years (see pictures of the regeneration by the Clinch family at Nallan, Cue, WA).  It is these perennial grasses and other perennial and facultative perennial plants that grow between shrubs and on flood and wash plains, that provide valuable sources of digestible energy that complement the high protein shrub vegetation.  This mix of plants provides a diet balanced in protein and energy that can be highly productive for livestock as well playing important roles as drivers of both rainfall use efficiency and the alleviation of soil erosion processes.

Photo 1: Hard won regeneration of Swamp grass Eriachne flaccida after 10 years commitment to TGP by the Clinch family of Nallan Station, Cue, Western Australia.

 

Photo 2: Michael Clinch of Nallan Station showing  Eriachne flaccida regeneration after 16 years of family commitment to TGP.

 

Native perennial grasses and kangaroo populations

A substantial body of research evidence describes the importance of the native perennial grasses across the SRA for both livestock productivity and for maintaining landscape function.  For example, Freudenberger et al. (1998) showed at Lake Mere, Louth, NSW, the importance of the native perennial grasses for livestock productivity.  These authors recommended that research be conducted to develop grazing management practices that optimise the survival of these perennial grasses.  Twenty years later, and other than the work conducted at Alice Springs (Materne et al. 2017), this work remains largely neglected in the SRA, possibly because of the futility of controlling total grazing pressures over much of the area, particularly that of kangaroos.  At the same research site at Louth, NSW, Anderson and Hodgkinson (1997) showed the importance of the perennial grasses for maintaining landscape function, by regulating both rainfall infiltration and over-land water flow.  Hacker et al. (2006) showed how summer death of the valuable C3 perennial grass Thyridolepis mitchelliana increased rapidly when foliar height fell below 10cm.  Ludwig et al. (2005) explained the importance of perennial grasses for maintaining landscape ‘patchiness’ for regulating runoff-erosion processes at a landscape scale.

While Dawson (2012) stated that the dietary preference of kangaroos is grass, there is substantial research evidence describing the negative impact that kangaroo grazing pressure has on the viability of native perennial grasses.  For example, Gardner (1986) in WA’s southern rangelands showed that kangaroo grazing compromised the viability of a valuable native perennial grass, Eragrostis xerophila.  Norbury and Norbury (1993) showed that in the Gascoyne region of the WA southern rangelands, after the removal of sheep from a paddock, the red kangaroo population increased significantly over a 15-month period.  This preference of kangaroos for de-stocked land stands in the way of the pasture resting practices required by regenerative management regimes.

These examples, and many others in peer reviewed publications, support the need for cost-effective control of total grazing pressures, including kangaroos, for managing the risk of on-going desertification processes across the SRA.

Is now an appropriate time for action?

Vast areas of Australian rangelands have suffered under heavy grazing pressures during recent drought years.  Satisfactory recovery of these depleted pasture systems will require careful management of total grazing pressure in the years following the break of the drought.  Currently it is likely that relatively low populations of kangaroos exist across much of the droughted lands of the continent.  This situation may provide ideal circumstances to begin pilot research projects to identify the cost of effective control of kangaroo populations under the existing regulations; and the associated regenerative impacts on perennial grasses and landscape function when total grazing pressure is rigorously controlled.  Where authorities are cooperative, socially acceptable and more cost-effective, kangaroo harvest methods could be investigated.  A concurrent research process could focus on redesigning the production, processing and marketing systems for a high eating quality kangaroo meat.  Such a project could run in parallel with a project, possibly on the same land, duplicating the management system at Old Man Plains to reliably produce high quality, MSA graded grass-fed beef and sheep meat.

The investment program developed for MLA (Waters et al. 2018) includes the development of tools to identify and predict imbalances in feed supply and herbivore demand, identify grazing pressure damage thresholds; develop an ‘industry verified tool for TGP management’; and conduct on-farm benchmarking to determine the environmental value of TGP management.  Such an all-encompassing, industry wide recommendation involving NSW, SA and Queensland, may be necessary to satisfy a national body such as Meat & Livestock Australia.

To accelerate progress towards achieving control of TGP across Australia’s southern rangelands, a cost-effective and timely approach might be to identify pastoral businesses that are already well advanced in the implementation of regenerative management practices and who will benefit most from more effective management of TGP and in particular, the management of kangaroo grazing pressure.  These businesses might meet the following criteria:

  1. located inside an existing or planned predator proof boundary;
  2. already participate in economic benchmarking for the previous three years;
  3. management can demonstrate well developed expertise in assessing seasonal forage supplies and matching domestic stock numbers accordingly; and
  4. willingness to participate in a co-researching exercise where adaptive and regenerative grazing management practices are implemented and the results monitored.

These businesses would provide ideal co-researching sites where outside support can be provided to first, assess accurately the number of non-domestic grazers and second, to reduce them to pre-determined levels relative to domestic stock numbers.  Outside assistance could be provided where required to monitor the responses to landscape function, ground cover, plant species diversity as well as livestock productivity and financial returns.  Remote sensing can be employed to objectively monitor forage supplies and ground cover.  Community engagement can also be achieved by giving the regional producer groups the authority to oversee the selection of co-researching managers and trial properties through an agreed Expression of Interest process.  Regular field days would inform the community of progress and provide a forum for local landholders to contribute ideas and share experiences.

Financial remuneration for participation will be necessary to attract participants.  These rewards can be determined according to the principles established with a previous ground-cover-based incentive scheme (Hacker et al. 2010).  A commitment to be involved for ten to fifteen years may be required.  Responses to significant changes in land management to improve range condition, landscape function and soil conditions may take ten years to manifest in arid and semi-arid rangelands (Le Houerou 2006, C. Materne pers comm 4 November 2019) and changes in soil carbon and soil biology may take up to fifteen years in these environments (Teague and Barnes 2017, Lei Deng et al. 2016).

The control of TGP must be considered the priority in order to enable the vast expanse of the southern rangelands systems of Australia to regenerate vegetatively and become capable of reliably producing a high eating quality, grass fed red meat.  To break through into a paradigm of conserving kangaroos through sustainable use (Ampt and Baumber 2006) it will be important to address this opportunity to develop quality assured production, harvest and processing systems to reliably produce high eating quality kangaroo meat products.

 

Photo 3: Michael Clinch of Nallan Station, Cue, WA  showing regeneration of Soft Wanderrie Grass (Thyridolepis multiculmis) in 2016.  Photo is taken on sandy country within 70m of stock water.

 

References

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