Feral deer

Endorsed by the Environment and Invasives Committee 31 January 2023. Updated 31 July 2024.

This document outlines best practice guidelines for the effective and humane management of feral and wild deer in Australia.

The National Code of Practice (COP) outlines humane control strategies and their implementation while National Standard Operating Procedures (NATSOPs) describe control techniques, their application, and strategies to minimise any harmful impacts.

The National CoP and NATSOPs comprise model guidelines that set minimum animal welfare standards. They do not override CoPs and SOPs in jurisdictions where these documents have been developed, prior to or after the endorsement of these documents, to address specific management issues or to comply with relevant legislation. For example, the national-level CoP and NATSOP for the management of feral and wild deer are not relevant in New South Wales, which currently has both state-level COP and SOPs in place (Sharp et al. 2022).

This CoP along with associated NATSOPs will be reviewed by the Terrestrial Vertebrate Working Group (TVWG) within 12 months of when they were endorsed, to manage any potential risks to operations throughout the country.

Jurisdictions conducting operations for feral and wild deer control are encouraged to submit reports to the TVWG secretariat for discussion at either the 12 monthly review, or sooner if there are urgent matters that need to be raised. The reports should include:

• whether the national CoP and NATSOPs were implemented in their jurisdiction
• whether the national CoP and NATSOPs were effective
• apparent mistakes or oversights in the national CoP and NATSOPs
• unintended consequences or adverse events that occurred when implementing the national CoP and NATSOPs
• new techniques or modifications to existing techniques as a result of research or registration

These reports will form the basis of reviews by the TVWG.

This document is based on the original work by Sharp, Cope and Saunders titled ‘NSW Code of Practice and Standard Operating Procedures for the Effective and Humane Management of Feral Deer’ published in 2022. Some of the text is a direct reproduction of the original source, with minor edits to adapt it for a national audience. The national document was then developed with guidance, input, and reviews by the multi-jurisdictional membership of the Terrestrial Vertebrate Working Group and the Environment and Invasives Committee. The document was further improved by feedback from Animal Welfare Organisations, veterinary surgeons, contractors, and operational and policy government staff.

Preface

The Code of Practice (CoP) provides information and guidance to government agencies, land managers, and pest animal controllers who are managing feral and wild deer (hereafter ‘feral deer’) in Australia. The aim is for pest control programs to be conducted in a way that reduces feral deer impacts using the most humane, target-specific, and effective means as practicable.

Previously published CoP and associated NATSOPs for feral deer management are available via the PestSmart website. This revision of the CoP for feral deer management builds on the extensive work conducted by NSW over several years (see Sharp et al. 2022), which provided the springboard for expansion to a national approach. This national CoP and associated NATSOPs provide the most relevant and up-to-date information to support best practice approach to feral deer management for all regions.

This CoP and associated NATSOPs also cover the activities of recreational or sporting shooters in some jurisdictions, but not in others, as specified by jurisdictional legislation. This CoP also recognises that differences exist among jurisdictions in their approaches to managing feral deer. For example, access to suppressors for firearms varies among jurisdictions. Variations and modifications to pest control techniques among jurisdictions will be reflected in jurisdiction-specific CoP and NATSOPs, which take precedence over the national versions.

Introduction

Pest animal management activities aim to minimise animal suffering while optimising the population impact of a pest control program. Minimising animal suffering is a priority regardless of the status given to a particular pest species or the extent of the damage or impact they create.

A Code of Practice (CoP) provides overarching context for the management of feral and wild deer in Australia. The CoP encompasses all aspects of controlling a pest animal species as determined by best practice principles, relevant biological information, guidance on choosing the most humane and appropriate pest control technique, and how to effectively implement management programs. This CoP provides guidelines for feral deer management and is based on current knowledge and experience of feral deer control programs. Importantly, it includes information on relatively new control methods, based on current knowledge.

The National Standard Operating Procedures (NATSOPs) associated with this CoP will provide procedural details for pest animal control and ensures a humane approach (including the recognition of, and attention to, the welfare of animals directly or indirectly affected by pest control programs) is applied. NATSOPs are written for each pest control technique in a way that describes the procedures involved for specific control methods, as applied to a nominated pest animal species, and the relevant animal welfare issues. They provide a guide to support and improve pest control programs.

Definitions and Terms

Best practice management – structured, consistent, and adaptive approach to the humane management of pest animals aimed at achieving enduring and cost-effective outcomes. ‘Best practice’ is defined as the principles and techniques based on both scientific information and experience (e.g. Braysher 2017).

Euthanasia – meaning ‘good death’ when used in pest animal control terms; it refers to how the animal is killed rather than the reason for killing it (Morton 2010; American Veterinary Medical Association 2020).

Humane – The ‘humaneness’ of a pest animal control method refers to the overall welfare impact that the method has on an individual animal. A relatively more humane method will have less impact than a relatively less humane method (see PestSmart 2021).

Pest animal – native or introduced, wild or feral, non-human species of animal that is 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.

Welfare – the physical and emotional state of an animal; pain and suffering are important aspects of poor welfare outcomes; assessing welfare of animals will consider their nutritional, environmental, health, behavioural, and mental needs (e.g., Broom 1999; Littin et al. 2004).

Best practice in pest animal management

From an animal welfare and management perspective it is desirable that pest control programs are efficient, effective, and coordinated. These attributes are required to reduce or eradicate pest populations and avoid the need for repeated large-scale killing for pest control. The approach to managing pest animals continues to evolve as lessons are learned and new tools and information become available. The emerging best-practice approach aims to reduce or eradicate pests based on measurable economic and environmental cues.

Pest animal control is one aspect of an integrated approach to the management of production and natural resource systems; management of other factors may be required to achieve a desired result. For example, lamb production may be affected by weed control and nutrition in addition to predators. When planning pest animal management, important steps to consider include identifying:

1. Triggers for undertaking pest animal management. Are there community or political pressures to act or not act on pests, an expectation that pest animals should or should not be controlled? Pest control is unlikely to be effective unless strong local or broader will exists for action, including committing the necessary resources.
2. The lead agency to take responsibility for bringing together and engaging with all stakeholders including other relevant government departments, animal welfare regulators, relevant community groups, landholders, shooting associations.
3. The problem. Pest management is complex and understanding the nature of the problem is important for planning purposes. For example, the problem could be impacts on native plants or animals, agricultural productivity, or aesthetic impacts (e.g., landscaping). Many factors, in addition to pest control, will intersect with the problem.
4. The area of concern. It can help to remove agency and property boundaries (nil tenure) so that the problem is viewed at the landscape-level, rather than at the level of individuals, groups, or agencies. Landscape-scale assessment is also required because pest animals move large distances and can cross jurisdictions. Property and agency boundaries can be addressed when agreement is reached on the approach.
5. Management units for planning and prioritising efforts. Units will be determined by water bodies, mountain ranges, fences, habitat preferences, vegetation, resources, urban density, and other landscape features. While it is preferable to work in units that will restrict the movement of pests, it may not be practicable.

Implementing effective and humane pest animal control programs requires a basic understanding of the ecology and biology of the targeted pest, other species that may be affected directly (non-target animals), or indirectly (e.g., prey species of pest carcasses) by a pest control program. Managers should make themselves aware of such information (see references at the end of this document for recommended reading). Pest animal control programs are usually not implemented until the impacts of the pest animal are no longer tolerated. However, pest animal control programs that are implemented prior to this point, when the population of the target pest are low, have a greater opportunity to be successful in eradication from that area. Proactively targeting pests with low population densities also reduces the overall number of animals controlled, compared to reactive controls, which is an important animal welfare consideration.

Animal welfare and humaneness

The humaneness of a pest control technique is influenced by the experience and skills of the pest controller. Attention to detail is necessary for delivering effective programs with humane outcomes. Details should be followed for the timing and coordination of the pest control, bait delivery methods, lethal dose rates, and type or calibre of firearm and ammunition used in pest control programs. This CoP and the associated NATSOPs provide a guide to the application of pest control methods, which will minimise and prevent the risk of negative welfare impacts for target and non-target animals.

Sharp and Saunders (2008; 2011) and PestSmart (2021) provide resources for assessing the relative humaneness of each pest animal control method. The assessment can be applied to any pest control technique. A ‘humaneness assessment’ can also be conducted to evaluate the impact of a pest control technique on individual animals; the humaneness assessment is based on:

1. Nutrition – water or food deprivation, malnutrition.
2. Environmental – exposure to excessive heat or cold.
3. Health – disease or physical injury.
4. Behaviour – spatial or interactive restriction.
5. Psychological – includes impacts from the first four domains (e.g., thirst, hunger, anxiety, fear, nausea, pain, boredom, depression, frustration, loneliness, distress) and any other cognitive awareness of external factors.

Compromise in one or all the physical indicators (i.e., nutrition, environment, health, behaviour) is used to infer potential negative psychological impacts. The assessment can be applied to different methods and the outcomes used to inform management.

Another important animal welfare consideration when conducting pest control pest programs is to target the pest populations when they are small. This approach will reduce the overall number of animals destroyed in the pest control, compared to enacting programs only after the impacts become problematic. Most people consider the management of pest animals to be acceptable if the activities are humane and justified (e.g., Mellor & Littin 2004). Pest controllers also need to continuously improve their approach to pest control, including trialling and updating techniques with new, increasingly humane, and cost-effective approaches as they emerge.

Management of feral deer

Background

Australia has wild populations of six deer species: fallow deer (Dama dama); red deer (Cervus elaphus); sambar deer (C. unicolor); rusa deer (C. timorensis); chital deer (Axis axis); hog deer (A. porcinus). These species differ in their habitat preferences, reproductive biology, population growth rates, group size, and movements (Forsyth et al. 2017). Different species, and assemblages of species, occur among the states and territories. Evidence of population growth exists for multiple species in many regions; for example, increases in distribution and abundance are reported for NSW, QLD, VIC, TAS, and SA. It is estimated that feral deer populations in Australia increased from a total of 200,000 in 2000 to 2 million in 2021.

Impacts from feral deer include damage to native plants, competition with native animals, economic losses to primary industries (crops, pastures, horticulture, plantations), and human safety risks from vehicle collisions. Further, feral deer are potential reservoirs and vectors of exotic animal diseases, such as foot-and-mouth disease.

The National Code of Practice provides information and guidance to government agencies, land managers, and pest animal controllers who are managing feral and wild deer in Australia. The aim is for pest control programs to be conducted in a way that reduces feral deer impacts using the most humane, target-specific, and effective means as practicable.

Further information:

• PestSmart: https://pestsmart.org.au/resources/
• Invasive Species Council: https://invasives.org.au/our-work/feral-animals/feral-deer/

Primary and supplementary control techniques

Primary techniques are those used to achieve rapid population knockdowns over large areas in a cost-effective manner. Supplementary techniques help to suppress the population in the longer term.

Aerial shooting of feral deer is a primary technique as it removes many animals quickly over large areas. Ground shooting of feral deer can also be a primary control technique when it is conducted as part of a coordinated and intensive program. Supplementary techniques include trapping and opportunistic shooting.

Spatial scale is important and will influence pest control planning and technique selection. To achieve cost efficiencies the area of pest control will usually comprise many adjoining land managers. This network is particularly important for highly mobile pests, such as feral deer.

Poorly executed pest control programs can become on-going operations that are ineffective, do little to achieve long-term beneficial outcomes, and require more animals to be killed. Common reasons for poorly executed programs include an insufficient intensity of the pest control activities using primary techniques and programs being conducted on small spatial scales of controls, leaving safe havens from which pests can breed and reinvade the control zones.

A rotation of primary and supplementary techniques may also be important. Pest animals can become familiar with particular technique (e.g., spotlight aversion), which may require use of another method (e.g., aerial shooting). Another factor to consider is the timing of pest controls; operations should exploit biological weaknesses of pest animals (e.g., a period of food and water stress, or before young are born to remove a generation). Controls may also align with the need for primary production assets to be protected when it is most vulnerable (e.g. targeting controls to minimise impacts at harvest time).

Humaneness of control techniques

Shooting

Ground shooting

Shooting is a humane pest control method when it is carried out by competent and responsible shooters. The correct combination of firearm, ammunition, and shot placement are necessary. The target animal must be within range and seen clearly – thermal and night-vision scopes can improve visibility. Wounded animals must be promptly located and euthanised. Head shots are preferred for shot placement, when conditions allow (e.g., stillness of target; DeNicola et al. 2019).

Dependent young should be euthanised quickly if the mother is shot. To avoid poor welfare outcomes, the intensity of shooting programs may increase before fawns are born or occur after they are weaned. This approach is not possible in all cases, particularly for species of deer without synchronised, seasonal breeding.

Rifles are the most common firearm used in ground shooting because they allow for an accurate shot over a greater distance compared to other firearm types. However, shotguns are also used in some circumstances (e.g., for feral deer caught in a trap).

In urban and peri urban areas, tranquilising darts with satellite tracking capacity can be used to sedate and locate the animal for effective removal. Sedation must only be used under the guidance of veterinarian. Hampton et al. (2019) has conducted a review of chemical restraints and dosage amounts for deer species in Australia. When a feral deer is anesthetised, a captive bolt may be used in urban areas where firearm restrictions apply. Carcasses of feral deer tranquilised prior to being shot are disposed of, through burial or incineration, to eliminate the risk of secondary impacts to non-target animals.

Aerial shooting

All aerial shooting programs must adhere to jurisdictional requirements, including agency SOPs and the requirements of the Civil Aviation Safety Authority (CASA 2020). Pilots and shooters undertaking aerial programs must be assessed as competent by an appropriate accreditation process relevant to the jurisdiction.

Aerial shooting of feral deer from a helicopter is a humane pest control method when:

• it is conducted by highly skilled and experienced shooters and pilots for the aerial shooting operation being undertaken
• pursuit times are minimised
• the correct firearm, ammunition, and shot placement are used
• wounded animals are promptly located and euthanised
• correct procedures are applied such as implementing a ‘flyback’ to confirm kill
• a minimum 2 shots per animal policy with the aim of ensuring a quick death.

Aerial shooting programs allow for the delivery of multiple shots in quick succession to ensure a rapid death. Hampton et al. (2021) found that operations that mandate multiple shots per target, as well as fly-back procedures, will maximise welfare outcomes. Shots to the head can be difficult and so chest shots are typically used as well. Head shots may be taken when conditions are ideal. Aiming for other parts of the body must not be undertaken.

Rifles and shotguns are both used in aerial shooting operations, for feral deer, in Australia (PIRSA 2022; Hampton et al. 2021) and New Zealand (Forsyth et al. 2013). Both types of firearms bring different capabilities to an aerial shooting operation. Recent experience in aerial shooting programs, for feral deer, indicates that the ability to safely carry a rifle and a shotgun, allowing the shooter(s) to change guns based on the terrain and conditions, can be beneficial (PIRSA 2022).

Aerial shooting programs can use thermal equipment to enhance the detectability of feral deer and reduce risks to non-target animals (Cox et al. in preparation). Thermal equipment also improves the visibility of shot deer, including under vegetated canopies, enabling delivery of rapid follow-up shots as part of a minimum two shot policy and fly back procedures. The use of thermal equipment also provides immediate and detailed motion and heat signals to confirm death. Thermal equipment can be used by the shooter and/or a dedicated thermal operator.

A minimum of two shots per animal, one being a chest (heart-lung) shot, is required for aerial shooting programs. In some programs, two people are required to verbally confirm the death of each animal before moving to the next target. A confirmation of death is based on seeing no visible signs of life, such as attempting to lift head, any coordinated body movement, and eye blinking or breathing.

Trapping

Traps can be important for controlling deer in urban areas, where firearms may not be permitted or safe, and in rural areas. Clover traps can be used for trapping individual feral deer, and larger traps (corral and paddock) can be used for trapping groups of deer. Deer caught in a trap may injure themselves if they make frantic attempts to escape. Non-target animals that are caught in traps can be released unharmed; however, some animals, such as kangaroos, may suffer from capture myopathy.

Clover traps are small (around 2 m × 1 m and 1.5 m in height) and are constructed with a metal or wooden box frame with nylon netting sides and a door that slides closed when triggered. Corral and paddock traps are large (area of 0.04-4.00 ha or 400-40,000 m2) and can be permanent or portable with hessian or shade cloth sides. The door is triggered either by remote device or trip wire; a one-way entrance can also be used. Drop net traps comprise a large square of nylon netting (about 10 cm mesh) suspended on poles by pulleys, which release the net when triggered.

Trapped animals can suffer from exposure, thirst, starvation, shock, capture myopathy, and predation; to avoid these impacts, traps should be protected from weather and inspected daily. Trapped animals must have access to water and feed when in corral and paddock traps for more than 24 hours. Traps should be established away from the view of people to prevent deer being spooked from people and their pets (e.g. dogs) that may approach the trap. Trapped animals should be approached quietly to minimise panic, stress, and risk of injury. Trapped deer should be culled as quickly and humanely as possible with a shot to the brain from a suitable firearm or by a captive bolt if firearm restrictions apply. If there are multiple animals in a trap tranquilising darts can be used to sedate the animals prior to culling under the direction of a veterinarian. Other options to reduce stress, if multiple animals are within a trap can be found in the associated SOP. If lactating females are caught in a trap dependent fawns should be killed quickly and humanely. Non-target animals should be released at the trap site unless they are injured, in which case veterinary treatment may be required. Severely injured non-target animals should be destroyed quickly and humanely.

The animal welfare outcomes of trapped deer are still poorly understood; ongoing reporting and review is required to continue to hone a best-practice approach (e.g. Hampton et al. 2019).

Exclusion fencing

Exclusion fencing is typically a humane, non-lethal alternative to lethal pest control. The high costs of establishing and maintaining deer-proof fences limits this technique to areas that have a significant and persistent deer problem or for the protection of small, valuable conservation or primary production assets. Exclusion fencing is an effective barrier to deer, but it can impact non-target animals by altering movement and foraging patterns and causing entanglement and electrocution. It can also create a hazard to native animals in the event of a bushfire (e.g., Long & Robley 2004).

Lethal baiting

In some jurisdictions, pesticide control trials for feral deer are underway. Pesticides are currently only approved for use on feral deer under Minor Use and Research Permits from the Australian Pesticides and Veterinary Medicines Authority. Research in New Zealand and Australia has identified several potential pesticides, which may have future application for feral deer management. Prior to any widespread baiting, pesticides will be required to be both target specific and produce consistent and humane results.

Summary

The key attributes of each pest control technique are summarised in Table 1.

Table 1: Humaneness, efficacy, cost effectiveness, and target specificity of pest control methods (Sharp et al. 2022)

1. Assessments conducted using a model to assess the relative humaneness of pest animal control methods (Sharp and Saunders 2011). Humaneness score (AB) consists of Part A – welfare impact prior to death, scale of 1 – 8, less suffering to more suffering and Part B – mode of death, scale of A – H, less suffering to more suffering. For assessment worksheets and matrix of relative humaneness scores see: Feral / wild deer control methods humaneness matrix – PestSmart

Relevant legislation

Vertebrate pest controllers should familiarise themselves with relevant Commonwealth, State, or Territory legislation (Table 2).

Table 2: The most relevant legislation for each jurisdiction and strategic plans for the management of feral deer.

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 Standard Operating Procedures (SOPs).

References

1. American Veterinary Medical Association (2020) AVMA Guidelines for the euthanasia of animals. AVMA, available: https://www.avma.org/sites/default/files/2020-01/2020-Euthanasia-Final-1-17-20.pdf
2. Braysher M (2017) Managing Australia’s Pest Animals: A Guide to Strategic Planning and Effective Management. CSIRO Publishing, Melbourne.
3. Broom D (1999) The welfare of vertebrate pests in relation to their management. In ‘Advances in Vertebrate Pest Management’ (P Cowan and C Feare ,Eds) pp 309-329.  Filander Verlag, Fürth.
4. CASA (2020) Part 138 (Aerial Work Operations) Manual of Standards 2020. Australian Government, Canberra.
5. Cox T, Matthews R, Paine D, O’Dwyer-Hall E, Blumson T, Florence B, Fielder K, Tarran M, Korcz M, Wiebkin A, Hamnett PW, Bradshaw CJ and Page B (2022) Thermal-assisted aerial culling (TAAC) for the improved control of vertebrate pest animal populations. Unpublished.
6. DeNicola AJ, Miller DS, DeNicola VL, Meyer RE and Gambino JM (2019) Assessment of humaneness using gunshot targeting the brain and cervical spine for cervid depopulation under field conditions. PloS One 14: e0213200.
7. Forsyth DM, Ramsey DSL, Veltman CJ, Allen RB, Allen WJ, Barker RJ, Jacobson CL, Nicol SJ, Richardson SJ and Todd CR (2013) When deer must die: large uncertainty surrounds changes in deer abundance achieved by helicopter- and ground-based hunting in New Zealand forests. Wildlife Research 40: 447-458
8. Forsyth D, Pople T, Page B, Moriarty A, Ramsey D, Parkes J, Wiebkin A and Lane C (2017) National Wild Deer Management Workshop Proceedings, Adelaide. Invasive Animals CRC, Canberra.
9. Hampton JO, Bengsen AJ, Pople A, Brennan M, Leeson M and Forsyth DM (2021) Animal welfare outcomes of helicopter-based shooting of deer in Australia. Wildlife Research 49, 264-273.
10. Hampton JO, Finch NA, Watter K, Amos M, Pople T, Moriarty A, Jacotine A, Panther D., McGhie C, Davies C, Mitchell J and Forsyth DM (2019) A review of methods used to capture and restrain introduced wild deer in Australia. Australian Mammalogy 41.
11. Littin K, Mellor D, Warburton B and Eason C (2004) Animal welfare and ethical issues relevant to the humane control of vertebrate pests. New Zealand Veterinary Journal 52: 1-10.
12. Long K and Robley A (2004) Cost effective feral animal exclusion fencing for areas of high conservation value in Australia. Department of the Environment and Heritage, Australian Government, Canberra.
13. Mellor D and Littin K (2004) Using science to support ethical decisions promoting humane livestock slaughter and vertebrate pest control. Animal Welfare 13: 127-132.
14. Morton DB (2010) Euthanasia. In ‘The Encyclopedia of Applied Animal Behaviour and Welfare’ (DS Mills and JN Marchant-Forde, Eds). CABI, Wallingford, UK.
15. PestSmart (2021) Feral/wild deer control methods humaneness matrix. Centre for Invasive Species Solutions. Available: https://pestsmart.org.au/toolkit-resource/feral-deer-control-methods-humaneness-matrix/
16. PIRSA (2022) Trialling the use of a shotgun to cull feral deer from a helicopter. PIRSA (Department of Primary Industries and Regions), Government of South Australia, Adelaide.
17. Sharp T and Saunders G (2008) A model for assessing the relative humaneness of pest animal control methods. Department of Agriculture, Fisheries and Forestry, Canberra.
18. Sharp T and Saunders G (2011) A model for assessing the relative humaneness of pest animal control methods. Department of Agriculture, Fisheries and Forestry, Canberra, ACT.
19. Sharp TM, Cope H and Saunders G (2022) New South Wales Code of Practice and Standard Operating Procedures for the Effective and Humane Management of Feral Deer. NSW Department of Primary Industries, Orange, NSW.

This 2023 National Code of Practice and associated National Standard Operating Procedures provide the most relevant and up-to-date information to support best practice approach to feral deer management for all regions.

Associated National Standard Operating Procedures

• NATSOP-DEER001 National Standard Operating Procedure: Aerial shooting for feral and wild deer
• NATSOP-DEER002 National Standard Operating Procedure: Ground shooting for feral and wild deer
• NATSOP-DEER003 National Standard Operating Procedure: Trapping for feral and wild deer

The Centre for Invasive Species Solutions manages these documents on behalf of the Environment and Invasives Committee. The authors of these documents have taken care to validate the accuracy of the information at the time of writing. This information has been prepared with care but it is provided “as is”, without warranty of any kind, to the extent permitted by law.