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MMFS Manual

Chapter 12.6 Manage vertebrate pests

 

Chapter 12.6 Manage vertebrate pests

Background information

This chapter outlines what you need to know about the more prevalent vertebrate pest animal species and how to use this information to effect control of the pests which are relevant to your business.

This chapter contains links to the most up to date information on managing vertebrate pest species to ensure you get the most effective control for investment of your time in controlling these animals. Use the links to further your level of knowledge and understanding of the pest species you are targeting.

Without a basic understanding of the key times for strategic baiting and other control agents, and the positive impacts that working in a coordinated fashion can have on decreasing populations, your time may be not spent effectively.

At a glance

  • Effective vertebrate pest species management requires careful planning to optimise control of animals.
  • Target times of the year to effectively manage one or more species in a single program.
  • Aim to work in a coordinated fashion in a regional context for enhanced control of predator species.

There are three must-dos in this chapter:

  • Develop a vertebrate pest animal management plan.
  • Control predator animals.
  • Control competing grazing species.

Develop a Vertebrate Pest Management Plan

Pest animal control is just one part of an integrated approach to the management of grazing system production and natural resource systems. The approach taken to manage vertebrate pests should be carefully planned and coordinated to ensure that maximum benefit is achieved from the effort and cost of implementing the control program.

The planning process:

  • Identify the vertebrate pests that are present on your property – including methods of identifying and quantifying pest animal activity.
  • Identify if there are any pest animals active nearby that may become a problem in the future.
  • Identify and cost the damage the pest species causes to your property, animals, and environment.
  • List times when activity is highest.
  • List times when activity is lowest.
  • Seek advice and support from local authorities on management techniques available and any regulations pertaining to their use.
  • Identify when the main breeding season (s) are.
  • Research when the recommended times are for optimum control of each pest species.
  • Write down which control agents are effective and are an option for your business in terms of time, cost, effectiveness, availability and non-target risks.
  • Record your planned activity and methods of control that you will use on your property.
  • Review your activities for effectiveness, and ways that might improve control in the next campaign.
  • Find out if there are any seasonal, local or regional group-based campaigns coordinated towards your target species, and join the group(s) if you are able.

Individual efforts

Individually, you can maintain constant pressure on the pest animal species by employing control agents in times of peak activity, other important times (such as lambing), as well as in between times.

This could be as simple as having bait stations located along tracks which you use when running waters, that can be replenished and monitored routinely, for the in between times, with a targeted campaign in the lead up to and over lambing time. Feral animals are heavily reliant on water in pastoral areas and are a great focal point for management activities.

Sustained pressure can help keep populations at lower levels throughout the year. It is also very useful to track and control the influx of new animals after a major campaign.

Coordinated efforts

Depending on the species present, your individual efforts may not be rewarded if there is a high population, and no coordination in controlling the species across the region or neighbouring properties.

Predator control is usually more effective when coordinated around a group or district approach with neighbouring properties undertaking the control program at specific times. Make all attempts to work closely with neighbouring properties to control feral animals where possible.

Community pest management groups deliver integrated management programs for wild dogs, foxes, rabbits and feral pigs in some cases. These coordinated approaches may also be eligible for assistance from industry bodies, natural resource management organisations or government departments. These groups also offer a mechanism to engage individuals who are new to managing pest species in a non-threatening way.

Multiple target species

In areas where foxes and wild dogs both occur it is advantageous to conduct regular wild dog baiting programs to manage both species. Foxes are natural scavengers and will readily take and be killed by wild dog-strength baits or canid pest ejectors (using 1080 or PAPP) targeted for wild dogs. Wild dogs however require a higher dose rate of 1080 and PAPP than is used for foxes and are less likely to be killed by fox bait if eaten.

If fox numbers are high they can also have adverse effects on wild dog baiting programs by taking the baits targeted for the wild dogs. A replacement baiting program using wild dog strength baits will manage this non-target uptake and provide increased control for both species.

There is also a need for follow up monitoring and ongoing control efforts to ensure that predator populations are maintained at low levels with a minimum impact on the grazing management system.
Be sure to know and adhere to regulations regarding use of control agents for pest species, as different jurisdictions (states) have different rules. Your local pest management officer with the relevant statutory authority or government agency will assist you with this.

Understand the interactions which may occur that can have negative or positive impacts on control of particular pest animal species. Investing in this knowledge can optimise results and prevent failed campaigns.

Control predator animals

The main predator animals found in the pastoral areas of Australia are wild dogs, foxes and feral pigs. Many control techniques for these pest species are effective across more than one pest species, which is a bonus for control programs, especially where foxes and wild dogs are concerned.

Make it a priority to understand a little about the biology of each pest species present and when is the best time in their life cycle to target them for optimum control.

Wild dogs and foxes can cause significant impacts on grazing businesses. Wild dogs are a primary predator on young or weak stock and a significant predator in sheep country. Foxes are most often a secondary predator, preying on animals that are injured, mismothered, sick or similar. Importantly, both of these species require control agents to keep populations down.

Feral pigs require much larger doses of 1080 to be killed and therefore can consume a number of wild dog or fox baits before being affected by the toxin. Large numbers of feral pigs can have detrimental effects on wild dog management programmes as they will consume meat baits targeted at wild dogs.

Pig numbers should be controlled leading up to wild dog control programmes with a targeted program using the appropriate control measures (e.g., traps, baits, shooting, etc.), in order to ensure effective wild dog control. In many pastoral regions where grain growing is uncommon, feral pigs will often require “free feeding” to become accustomed to and more readily take grain-based baits.

Feral pigs can cause significant levels of damage to grazing businesses through:

  • Reducing lambing percentages by preying on newborn lambs;
  • Damaging fences;
  • Damaging water points and contamination of surface catchments;
  • Having the potential to spread exotic diseases;
  • Competing for and reducing the palatability of feed; and
  • Harbouring diseases that may impact on humans and other animals.

There are five key messages which apply to controlling predator animals:

1. Predator management is most effective when it’s coordinated and applied at a landscape scale

  • Community management programs have proven to be effective in pastoral regions of Australia for the management of wild dogs and foxes.
  • Effective predator management programs are those that involve all stakeholders, including private and public land managers.
  • Programs need to integrate as many forms of control as possible (e.g., ground baiting (manufactured, prepared meat or canid pest ejectors), aerial baiting, trapping, targeted shooting with thermal equipment, exclusion fencing, etc.), in order take out a greater proportion of the predator population. There are a range of strategies and methods to integrate these tools to achieve the best outcome (e.g. replacement baiting at the same locations until the baits stop being taken).
  • Large scale coordinated baiting programs are an effective means of reducing populations across a region but targeted on farm replacement baiting programs may be required to reduce annual impacts.
  • Developing community-based predator management plans will assist in providing information on the movements and habitat of predators and allow for better targeting and communication of the control program.
  • If wild dogs and foxes are present in the region or on the property, undertake baiting programs for wild dogs with the additional benefit of fox control at the same time.
  • If feral pigs are present when targeting wild dogs/foxes, ensure control activities for pigs are undertaken before targeting wild dogs as pigs are known to collect a lot of dog-strength baits which only give them a sub-lethal dose and stop them being taken up by wild dogs and foxes.
  • If you’re experiencing difficulty in engaging with local stakeholders to undertake a coordinated approach, this shouldn’t stop you starting your own control program.

2. Control needs to be targeted

  • Less is better when targeted.
  • Be proactive instead of reactive.
  • Build proactive control programs into daily or weekly property management activities, such as water runs, etc.
  • Become familiar with the signs of wild dog, fox, and feral pig activity.
  • In addition to obvious signs such as tracks, scats and howling, the presence of wild dogs on the property could be suspected if stock are agitated and restless, kangaroos and wallabies have cleared out of paddocks where they are usually found or working dogs are unusually focused on scent marking and marking tussocks or trees out in the paddock.
  • Actively look for the presence of wild dogs and implement control before they have an impact rather than implementing control in response to attacks.
  • Wild dogs, and to a lesser extent foxes, are creatures of habit and will use the same travel routes and corridors within the landscape regardless of where they have come from.
  • Target control in areas such as travel ways and landscape features such as roadways, creek lines, ridges, stock pads, tree plantations, etc.

3. Baiting programs (using 1080/PAPP) can be conducted while minimising risk to working dogs

  • Following the best practice guidelines for baiting will limit the risk to working dogs.
  • The retrieval and destruction of baits at the conclusion of a program, where feasible, reduces the risk to working dogs.
  • Tying baits with wire to known locations and/or burying them will allow effective retrieval of baits giving the producer confidence that the bait has either been eaten or collected prior to mustering.
  • Tying and burying baits prevents them being removed by non-target species, improving effectiveness by ensuring the baits remain available to wild dogs.
  • Use of canid pest ejectors (CPE) in documented locations can limit the risk to working dogs because they cannot be shifted, and you can disarm them or cover them (e.g. drop a plough disc over the top of them before mustering) if you need to work in their vicinity to reduce the risk of working dogs accessing the bait.
  • More is not necessarily better, a few strategically-placed baits in areas of known wild dog activity often delivers far more effective control than broad scale distribution of baits in areas the dogs don’t use.
  • Avoid risks to working dogs by leaving them at home when checking baits or travelling to areas of the property where control is being undertaken, and use muzzles when using working dogs if a baiting program is underway.

4. Integrate as many control techniques as possible on farm

  • Utilise trapping and shooting in conjunction with baiting to achieve better control. No one technique on its own will deliver 100% effective control.
  • Additional techniques such as fencing and guardian animals may be used in conjunction with traditional control, but shouldn’t be used in isolation of conventional control tools.
  • Seek professional advice to increase your understanding of the relevant techniques and their integration.

5. Wild dog management should be about reducing impacts rather than counting dead dogs

  • Manage dogs to reduce impacts as eradication is unlikely in many areas.

Case study

The benefit of coordinated community wild dog control

An AWI-funded vertebrate pest control program has contributed to control programs being conducted across 1.3 million square kilometres of country in every mainland state of Australia through 116 wild dog control groups.

Survey results of 331 participants indicated:

  • 29% intend to reintroduce sheep
  • 58% noticed an increase in native animals
  • 4% intend to increase sheep numbers
  • 85% reported better wellbeing as a result of participating.

The AWI-funded wild dog coordinators used a ‘nil-tenure landscape level’ approach with local communities that highlights the benefit of focusing on the ‘common problem’ rather than attributing ownership of the wild dog problem to individual land managers. This approach encourages good working relationships between private and public land managers. More importantly, it can have a positive impact on the emotional wellbeing of farmers in the area who now feel that something positive is being done to address the constant financial and emotional impact of wild dogs.

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Control competing grazing species

Non-domestic grazing species are a cost to pastoral areas through the direct competition that they place on the available plants utilised by grazing operations. Not only do the competing grazing species consume pasture that could be utilised by domestic species, they are often responsible for environmental and infrastructure damage.

Competing grazing species are generally thought of as the wild species which exist in the pastoral areas, such as:

  • Rangeland goats;
  • Rabbits;
  • Camels; and
  • Donkeys.

It is also important to consider the native species which can, during certain conditions, place significant pressure on the environment and plant material present.

A key challenge for the pastoral manager is to minimise the numbers and impact of both the native and feral species on their grazing operation.

This chapter covers only introduced feral pest species. The role and impact of native species on total grazing pressure is covered in chapter 12.5.

Goats

Goats arrived in Australia with the first European settlers. Historically, unmanaged rangeland goats were considered a significant pest species but in recent times, an industry focusing on the harvest of goats in rangeland areas has developed. Nowadays, the Australian goat meat export industry is a significant industry and many pastoralists now consider the capture and sale of unmanaged rangeland goats to be an important part of their business. The added benefit of this harvest comes from improved control over grazing management with harvesting of rangeland goats also providing valuable enterprise cash flow.

The rangeland goat industry is becoming increasingly professional, with many producers developing production systems that allow improved husbandry, management and increasing control over grazing pressure – managing their goat population in a similar way to their other livestock enterprises.

Chris Ferguson_Loading Goats at Dawn.jpg
Figure 12.5 Loading goats at dawn.
Source: Chris Ferguson from the ‘Life and Light in the Western Region Photo Competition’

Maintaining pastoral land condition and avoiding issues such as soil erosion and feed degradation relies on having control over total grazing pressure (TGP). As unmanaged goat populations contribute to total grazing pressure, their inclusion in either a management program or control program is required to minimise the risk of overgrazing on the property.

Controlling populations also presents the opportunity to capitalise on unmanaged populations moving through the landscape. Goats also have different grazing patterns to sheep, with a preference for browsing shrubs and trees, and therefore at appropriate stocking densities will increase the utilisation of available feed resources.

Legislation on the management of rangeland goats varies from state to state and you should adhere to regulations specific to your jurisdiction.

Rabbits

The rabbit is Australia’s most widespread pest species which has a significant impact on grazing lands across Australia. First arriving in Australia with the First Fleet, then deliberately released for hunting in the 1800s, the rate of spread of the rabbit in Australia was the fastest of any colonising mammal anywhere in the world. They are now found in all states and territories, including several offshore islands, with lower prevalence in the more northern parts of Australia.

Rabbits graze on native and introduced vegetation, crops and pastures. Rabbit grazing can prevent seedlings from regenerating and reduce crop yields, as well as increase competition for feed with livestock. Rabbits damage native plants and directly compete with native wildlife for food and shelter. Their digging and browsing leads to a loss of vegetation cover, which in turn can result in slope instability and soil erosion.

Rabbits generally eat around 15% of their body weight per day – approximately 250 g. This compares dramatically with the averages for stock – adult sheep and cattle eat around 3% of their body weight per day. Further comparisons are given in table 12.2, with consumption rates expressed in rabbit equivalents.

Table 12.2 Dry sheep equivalent (DSE) comparison table.
Source: Queensland Department of Primary Industries and Fisheries 2008, adapted by AWI and MLA

Animal Mean body weight (kg) Approx. daily feed intake (kg) Dry sheep equivalent (DSE) Rabbit equivalents (DSE)
Rabbit    1.5 0.25 0.11  1
Wether 50 1.5 1.00 9
Ewe and lamb 50 1.5 1.40 13
Ram 60 1.8 1.50 14
Steer (1-2 years) 400 12 10.80 98
Steer (2+ years) 500 15 13.50 123
Steer (2+ years) 600 18 16.20 147
Cow and unweaned calf 500 15 16.10 146
Bull 800 24 18.00 163
Horse 600 12 11.00 100
Kangaroo 35 1.05 0.70 7

 

The rabbit is such a successful pest species because of its high reproductive rate, allowing them to produce five or more litters per year, depending on available food supply.

Control measures, as with other pest species, are best implemented through an integrated approach which targets the species at key times with key practices to offer maximum impact at that time.

Options include:

  • Poison;
  • Biological control;
  • Ripping warrens; and
  • Shooting and trapping.

Camels

Australia is home to approximately 1 million camels, which is believed to be one of the largest, if not the largest, population of wild camels in the world. They are found across most of Australia’s desert country including the Great Sandy, Gibson, Great Victoria and Simpson deserts, as well as much of the semi-desert lands (figure 12.6).

211130 FeralScan_camel.png
Figure 12.6 Sightings of feral camels reported via the FeralScan app.
Source: FeralScan

What makes them effective pests is their ability to forage over very large areas, up to and exceeding 70 kilometres per day. Camels breed every second year, so their fecundity is not what makes them effective pest species. Camels are an effective pest species due to the fact that they can cover large distances, are well acclimatised and have no predators, aside from culling operations.

Camels are selective feeders with a preference for shrubs and trees browse, rather than grasses. They can go for long periods without needing to drink, but during the heat of summer they will drink every day if water is available. Camels compete for available feed and water, and may cause extensive damage to fences, watering points important cultural sites and other farm infrastructure. They are also a potential carrier of exotic disease.

Camels are mainly controlled through:

  • Trapping at water points;
  • Mustering;
  • Shooting; and
  • Slaughter or live export.

Donkeys

The first donkeys were brought to Australia in 1866 and were used widely as pack and draught animals until the early 1900s when they were superseded by motorised transport. As transport improved donkeys were liberated and large populations built up. In the 1920s and 1930s large numbers of feral donkey populations were reported and by 1949 the donkey was sufficiently numerous to be declared a pest in Western Australia. Although absolute numbers are difficult to estimate, there are thought to be between 2 and 5 million feral donkeys in Australia.

The feral donkey is well-adapted to arid regions and is most abundant in the Kimberley pastoral district of Western Australia and the Victoria River area of the Northern Territory. Lower densities are found in the semi-arid regions and deserts of central and western Australia.

Feral donkeys are both grazers and browsers and feed during the day on a wide variety of plants. They can subsist on coarse vegetation and in the Kimberley region are attracted to perennial tussock grasslands.

Feral donkeys can damage native vegetation, contribute to soil erosion and compete with stock for pasture and water.

Control methods include:

  • Ground shooting;
  • Shooting from a helicopter; and
  • Exclusion fencing.

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