Feral goats

Introduction

The aim of this National Code of Practice is to provide information and guidance to vertebrate pest managers responsible for the control of feral goats. Control programs aim to reduce the negative impacts of feral goats using the most humane, target specific, cost effective and efficacious techniques available.

This National Code of Practice (CoP) is adopted nationally. Jurisdictions can apply more stringent requirements as long as they retain the principles set out in these codes. The CoP should only be used subject to the applicable legal requirements (including OH&S) operating in the relevant jurisdiction.

Background

There is an expectation that animal suffering associated with pest management be minimised. The most humane methods that will achieve the control program’s aims must be used. Consideration of animal suffering should occur regardless of the status given to a particular pest species or the extent of the damage or impact created by that pest. While the ecological and economic rationales for the control of pests such as the feral goat are frequently documented, little attention has been paid to the development of an ethical framework in which these pests are controlled. An ethical approach to pest control includes the recognition of and attention to the welfare of all animals affected directly or indirectly by control programs. Ensuring such approaches are uniformly applied as management practices requires the development of agreed National Standard Operating Procedures (NATSOPs) for pest animal control. These NATSOPs are written in a way that describes the procedures involved for each control technique as applied to each of the major pest animal species. While NATSOPs address animal welfare issues applicable to each technique, a National Code of Practice (CoP) is also required that bring together these procedures into a document which also specifies humane control strategies and their implementation. CoPs encompass all aspects of controlling a pest animal species. This includes aspects of best practice principles, relevant biological information, guidance on choosing the most humane and appropriate control technique and how to most effectively implement management programs.

This Code is based on current knowledge and experience in the area of feral goat control and will be revised as required to take into account advances in knowledge and development of new control techniques and strategies.

Definitions and terms

Pest animal – native or introduced, wild or feral, non-human species of animal that is currently troublesome locally, or over a wide area, to one or more persons, either by being a health hazard, a general nuisance, or by destroying food, fibre, or natural resources (Koehler, 1964).

Welfare – an animals’ state as regards its attempts to cope with its environment (Broom, 1999). Welfare includes the extent of any difficulty in coping or any failure to cope; it is a characteristic of an individual at a particular time and can range from very good to very poor. Pain and suffering are important aspects of poor welfare, whereas good welfare is present when the nutritional, environmental, health, behavioural and mental needs of animals are met. When welfare is good, suffering is absent (Littin et al., 2004).

Humane Vertebrate Pest Animal Control – the development and selection of feasible control programs and techniques that avoid or minimise pain, suffering and distress to target and non-target animals (RSPCA, 2004).

Best Practice Management – a structured and consistent approach to the management of vertebrate pests in an attempt to achieve enduring and cost-effective outcomes. ‘Best practice’ is defined as the best practice agreed at a particular time following consideration of scientific information and accumulated experience (Braysher, 1993).

Best practice pest management

From an animal welfare perspective, it is highly desirable that pest control programs affect a minimum number of individuals and that effort is sustained so that pest densities always remain at a low level. Over the last decade, the approach to managing pest animals has changed. Rather than focussing on killing as many pests as possible, it is now realised that like most other aspects of agriculture or nature conservation, pest management needs to be carefully planned and coordinated. Pest animal control is just one aspect of an integrated approach to the management of production and natural resource systems. Most pests are highly mobile and can readily replace those that are killed in control programs. Unless actions are well planned and coordinated across an area, individual control programs are unlikely to have a lasting effect. When planning pest management, there are some important steps that should be considered (after Braysher & Saunders, 2002).

1. What is the trigger to undertake pest animal management? Is there a community or political pressure for action on pests and an expectation that pest animals should be controlled? Pest control is unlikely to be effective unless there is strong local or political will to take action and commit the necessary resources.
2. Who is the key group to take responsibility for bringing together those individuals and groups that have a key interest in dealing with the pest issue?
3. What is the problem? In the past the pest was usually seen as the problem. Hence the solution was to kill as many pests as possible. We now know that the situation is more complex. First, determine what the problem is. For example, it may be soil degradation, grazing competition or damage to native vegetation. Several factors impact on each of these problems and control of pests are often only part of the solution. The following questions then help define the problem:

• • Who has the problem?
  • Where is the problem?
  • How severe is the problem?
  • Will the problem change with time?

4. Identify and describe the area of concern. Sometimes it helps to remove agency and property boundaries so that the problem can be viewed without the tendency to point blame at individuals; groups or agencies. Property and agency boundaries can be added later once agreement is reached on the best approach.
5. Trying to deal with the complexity of a very large area can be daunting so it often helps to break the area into smaller management units for planning. These smaller units may be determined by water bodies, mountain ranges, fences, vegetation that is unsuitable for a particular pest or other suitable boundaries that managers can work to. While it is best to work to boundaries that restrict the movement of pests, this may not be practicable and jurisdictional boundaries, for example, the border of a Landcare group, may have to be used in combination with physical boundaries. Once the management units are identified:

• Identify as best you can, the pest animal distribution and abundance in each management unit.
• Estimate as far as is practicable, the damage caused by the pest or pests to production and to conservation.

6. Gather and assess other relevant planning documents such as Catchment Management Plans, Recovery Plans for threatened species and Property Management Plans. Identify any key constraints that may prevent the plan being put into operation and identify all the key stakeholders.
7. Develop the most appropriate pest management plans for each of the management units.

Implementing effective and humane pest control programs requires a basic understanding of the ecology and biology of the targeted pest species and in some cases those species affected directly (non-targets) or indirectly (prey species) by a control program. It is also essential to understand the impact created by the pest i.e. what is the problem? Managers should take the time to make themselves aware of such information by reading the recommended texts at the end of this code of practice. A brief summary follows. This information is extracted from the publication Managing Vertebrate Pests: Feral Goats by Parkes et al. (1996) and also from a fact sheet titled “The Feral Goat (Capra hircus)” by the Natural Heritage Trust, Department of Environment and Heritage (2004).

Feral goat facts

Goats arrived in Australia with the First Fleet in 1788. As they were small and hardy, ate a range of plants and provided milk and meat, they were convenient livestock for early European settlers. During the 19th century, sailors released goats onto islands and some areas of the mainland for emergency food. Certain breeds were imported for their hair. More recently, goats have been used to keep plantation forests and inland pastoral land free of weeds. Feral herds developed as these domestic goats escaped, were abandoned or were deliberately released.

Feral goats now occur in all Australian states and on many offshore islands, but are most common in the rocky or hilly semi-arid areas of western New South Wales, South Australia, Western Australia and Queensland. In 1996, there were an estimated 2.6 million feral goats in Australia.

Where dingos and wild dogs are present, feral goats generally do poorly. However, they are often found in sheep-grazing areas, where dingoes and wild dogs have been removed or heavily controlled by pastoralists.

Feral goats live in herds, and although males and females live separately for much of the year they share a home range of about one square kilometre under good conditions, but a larger area when food or water is scarce. The two groups only mix together during the breeding season in autumn and winter, with females becoming sexually mature in their first year. Feral goats can breed twice a year, with twins and triplets being common.

Feral goats are generalist herbivores and have a varied diet – leaves, twigs, bark, flowers, fruit and roots. They will eat most plant types in pastoral regions and often consume vegetation that is avoided by sheep or cattle.

Feral goat impact

Feral goats have a major effect on native vegetation through soil damage and overgrazing of native herbs, grasses, shrubs and trees, which can cause erosion and prevent regeneration. Particularly in the rangelands, they compete with domestic livestock for food. Such competition can become severe when food is limited during drought. They foul waterholes, and can spread weeds through seeds carried in their dung.

Feral goats can also compete with native animals for food, water and shelter. For example, they may threaten some yellow-footed rock wallaby populations by competing for rock shelters and food, leaving the wallabies exposed to a greater risk of predation by foxes and wedge-tailed eagles.

Feral goats carry footrot, and it is difficult to cure sheep of this disease when there is reinfection through contact with feral goat populations. They could also carry exotic diseases such as foot-and-mouth disease, should there be an outbreak in Australia.

Feral goat control strategies

Control of feral goats is a complex issue. While they are a major environmental and agricultural pest, they are seen by some to have commercial value, and are also used as a game species by recreational hunters. Feral goat populations tend to recover well from culling and, except on islands, eradication is usually impossible. To protect the environment, control is best focused on areas that contain threatened native plants, animals and communities.

Managers have five options in relation to feral goat damage:

• Local eradication. The permanent removal of all pests from a defined area in a set time.
• Strategic management. This is necessary where local eradication is not an achievable option, but where it is clear that pest damage will require continuing management. Strategic management is indicated where it is decided to reduce and sustain pest density, and pest damage, to a low level.
• Commercial management. A significant but highly variable proportion of goats can be mustered and removed for sale. The strategic outcome of mustering depends on whether it is seen as a commercial end in itself or as a first step in the strategic management of feral goats as pests.
• Crisis management. All too often managers undertake feral goat control only when populations are large enough to be causing obvious economic or environmental damage. There is no clear objective and feral goat numbers rapidly increase to pre-control levels due to immigration and natural increase, with considerable waste of resources and little lasting benefit.
• No management. The consequences of not harvesting or managing feral goats for most habitats are assumed to be harmful, given the perception that present densities in harvested populations still damage production or environmental resources.

There are many ways of managing goats, but the challenge is to combine them in an integrated strategy to achieve the desired resource impact outcome. Ideally, strategies should be based on reliable, quantitative information about the damage caused by goats, the cost of control and the effect of implementing control on damage levels.

There are three essential requirements for a pest control technique – necessity, effectiveness and humaneness. The best strategy is to develop a plan which maximizes the effect of control operations and reduces the need to cull large numbers of animals on a regular basis.

Developing a feral goat management plan

This involves:

• Defining management objectives. Objectives are a statement of what is to be achieved, defined in terms of desired outcomes, usually conservation or economic benefits. Objectives should state what will be achieved (reduced impact) where, by when and by whom.
• Selecting management options. The management option is selected that will most effectively and efficiently meet the management objectives. The options include: eradication, containment, sustained management, targeted management, one-off action and taking no action.
• Set the management strategy. This defines the actions that will be undertaken: who will do what, when, how and where. It describes how the selected pest management options and techniques will be integrated and implemented to achieve the management objectives.
• Monitoring the success of the program against the stated objectives. Monitoring has two components, operational monitoring – what was done when and at what cost: this determines the efficiency of the program, and performance monitoring: were the objectives of the plan achieved and if not why not, that is the effectiveness of the program.

Choosing control techniques

Feral goat control techniques have the potential to cause animals to suffer. To minimise this suffering the most humane techniques that will achieve the control program’s aims must be used. This will be the technique that causes the least amount of pain and suffering to the target animal with the least harm or risk to non-target animals, people and the environment. The technique should also be effective in the situation where it will be used (e.g. ground shooting will have little effect in a rangeland setting). It is also important to remember that the humaneness of a technique is highly dependant on whether or not it is correctly employed. In selecting techniques it is therefore important to consider whether sufficient resources are available to fully implement that technique.

Cooperative control

Cooperative action is recognised as essential in pest management for many reasons. As with many other animal pests, feral goats can be mobile with large home ranges in arid areas. Group schemes allow better management of pests that easily cross tenure boundaries by providing for broad-scale, synchronised actions to minimise reinfestation problems. Economies of scale are inherent if joint action is taken by landowners, and groups also facilitate peer pressure on those unconvinced of the need for management.

Feral goat control techniques

The most commonly used feral goat control techniques are mustering, trapping at water, aerial shooting, ground shooting and exclusion fencing. ‘Judas’ goats fitted with radio collars are sometimes used to help locate difficult to find groups of goats during control or eradication programs. Other measures such as poisoning with 1080 have been trialed but are not registered for use in Australia due to a number of reasons including the significant risk of poisoning non-target species.

Mustering and trapping are used in cases where goats are intended for commercial slaughter. But mustering and trapping become uneconomic once populations are reduced to densities of about one goat per square kilometre. Management of these low density herds, those in rough or densely vegetated areas, or of remnant or colonising herds, relies on lethal techniques such as aerial or ground shooting, or trapping and on-site slaughter. The use of Judas goats can improve the efficiency of some of these latter control techniques.

Cost-effectiveness, humaneness and efficacy for each control technique are useful in deciding the most appropriate strategy. A brief evaluation of the humaneness of control techniques follows:

Humaneness of control techniques

Exclusion fencing

The use of exclusion fencing is generally regarded as a humane, non-lethal alternative to lethal control methods. However, fencing of large areas is expensive to construct and maintain and is eventually breached by feral goats. Fences can be of limited use in feral goat control by restricting access to sensitive areas, and excluding goats from some water points to concentrate them at others where they can be trapped. They have also been used to break up large areas into manageable blocks during eradication programs. Fences should be constructed using material that minimises the risk of goats getting entangled (especially their head). Exclusion fencing can have negative effects on non-target species by restricting access to natural watering points, altering dispersion and foraging patterns, and causing entanglement and electrocution. It can also create a significant hazard to wildlife in the event of a bushfire.

Use of Judas goats

Capture, handling and restraint of goats for use as Judas animals can cause anxiety and sometimes pain or injury if they struggle to escape. Repeatedly being isolated and having to find other goats may cause fear and anxiety as goats are highly social animals. Tracking and the nearby shooting of cohorts may also be another source of distress.

The lightest collar/transmitter available should always be used (< 5% of the body weight of the animal). The collar must be properly fitted for the comfort and safety of the animal. It should fit snugly enough to prevent it from coming off or chafing the neck, but it must also be sufficiently loose as to be comfortable and not interfere with swallowing or panting. Efforts should be made to reduce the possibility of the collar getting caught up in vegetation.

Shooting

Ground shooting

Shooting can be a humane method of destroying feral goats when it is carried out by experienced, skilled and responsible shooters; the animal can be clearly seen and is within range; and with the use of correct firearm, ammunition and shot placement.

Wounded animals must be located and killed as quickly and humanely as possible. If lactating females are shot, reasonable efforts should be made to find dependent kids and kill them quickly and humanely.

Aerial shooting

Aerial shooting of feral goats from a helicopter can be a humane control method when it is carried out by highly skilled and experienced shooters and pilots; the correct firearm, ammunition and shot placement is used; and wounded animals are promptly located and killed. Shooting from a moving platform can significantly detract from the shooter’s accuracy therefore helicopter shooting operations do not always result in a clean kill for all animals. Follow-up procedures are essential to ensure that all wounded animals are killed.

With aerial shooting, chest shots are preferred as the heart and lungs are the largest vital area and an accurate shot is more achievable particularly within the range of unusual angles encountered when shooting from above. Although death from a chest shot may be more certain, compared to an accurate head shot, a shot to the chest does not render the animal instantaneously insensible and time to death is slower.

Trapping at water

To minimise the possibility of starvation and stress, all traps must be inspected at least once daily. Goats must be provided with water at all times and appropriate feed should be made available if captured goats with kids at foot are to be held for more than 24 hours. Feed should be provided for non-breeding goats if held for more than 48 hours. More frequent checking may be necessary during extreme weather conditions. Traps should be constructed to provide goats with shade and shelter and should be large enough to avoid overcrowding.

Capture and handling should be avoided when females are kidding or have young at foot. Kids that do not accompany their mother into the trap may be separated and die of starvation or if trapped can get trampled underfoot.

Goat traps can have a significant negative impact on native non-target species (especially macropods) by inadvertently trapping them and also by excluding them from water sources.

Mustering

To avoid heat stress, mustering should be carried out when conditions are cool or mild. Feral goats should be handled quietly without force to avoid panic and trampling.

The tail end of the mob should set the pace rather than being forced to keep up with the leaders. Distances that the goats have to be mustered should be kept to a minimum e.g. by using portable yards.

Management of captured or mustered goats

Mustering, capture and handling increase stress in feral goats as they are not used to confinement or close contact with humans. Consequently, these procedures can result in mismothering, feeding disruption, social disruption, heat stress and also abortion in heavily pregnant females. Metabolic, nutritional and parasitic diseases and also changes in environmental conditions are common causes of mortality and morbidity in confined feral goats, especially when confined for long periods.

The removal of trapped feral goats off-property for either sale to abattoirs, live export, or for domestication, involves additional stress to animals.

Table 1: Humaneness, Efficacy, Cost-effectiveness and Target Specificity of Feral Goat Control Methods

* Acceptable methods are those that are humane when used correctly.

* Conditionally acceptable methods are those that, by the nature of the technique, may not be consistently humane. There may be a period of poor welfare before death.

* Methods that are not acceptable are considered to be inhumane. The welfare of the animal is very poor before death, often for a prolonged period.

National Standard Operating Procedures

For regional variations on control techniques refer to local legislation and regulations. For additional examples refer to the Humane Pest Animal Control National Standard Operating Procedures (NATSOPs).

NATSOPs are currently available for the following feral goat control methods are listed below

• NATSOP-GOA001 National Standard Operating Procedure: Ground shooting of feral goats
• NATSOP-GOA002 National Standard Operating Procedure: Aerial shooting of feral goats
• NATSOP-GOA003 National Standard Operating Procedure: Mustering of feral goats
• NATSOP-GOA004 National Standard Operating Procedure: Trapping of feral goats
• NATSOP-GOA005 National Standard Operating Procedure: Use of Judas goats

Legislation

All those involved in pest animal control should familiarise themselves with relevant aspects of the appropriate federal and state or territory legislation. The table below gives examples of some of the relevant legislation. This list is by no means exhaustive and is current at September 2012.

Note: copies of the above legislation and relevant regulations may be obtained from federal, state and territory publishing services.

References

1. Anon. (2004). The feral goat (Capra hircus). Natural Heritage Trust, Department of the Environment and Heritage, Canberra.
2. Braysher, M. (1993). Managing Vertebrate Pests: Principals and Strategies. Bureau of Resource Sciences, Canberra.
3. Braysher, M. and Saunders, G. (2002). Best practice pest animal management. NSW Department of Agriculture Advisory Note DAI 279
4. Broom, D.M. (1999). The welfare of vertebrate pests in relation to their management. In: Cowand DP & Feare CJ (eds.). Advances in vertebrate pest management. Filander Verlag, Fürth. pp 309–329.
5. Environment Australia (1999). Threat Abatement Plan for Competition and Land Degradation by Feral Goats. Biodiversity Group, Environment Australia, Canberra.
6. RSPCA (2004). A national approach towards humane vertebrate pest control. Discussion paper arising from the proceedings of an RSPCA Australia/AWC/VPC joint workshop, August 4–5, Melbourne. RSPCA Australia, Canberra.
7. Koehler, J. W. (1964). Opening remarks. Proceedings of the 2nd Vertebrate Pest Control Conference. March 4 and 5, 1964, Anaheim, California.
8. Litten, K. E., Mellor, D. J., Warburton, B., and Eason, C. T (2004). Animal welfare and ethical issues relevant to the humane control of vertebrate pests. New Zealand Veterinary Journal. 52, 1–10.
9. NCCAW (2004). The Australian Animal Welfare Strategy. National Consultative Committee on Animal Welfare, Primary Industries Ministerial Council. Document available electronically from the Australian Government Department of Agriculture, Fisheries and Forestry website: http://www.affa.gov.au/content/output.cfm?ObjectID=3C9C4ACE-B85B-465C-9C508C771F08C87E
10. Parkes, J., Henzell, R. and Pickles, G. (1996) Managing Vertebrate Pests: Feral Goats. Bureau of Resource Sciences and Australian Nature Conservation Agency. Australian Government Publishing Service, Canberra.