Standard Operating Procedure – PIG002
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Feral pigs (Sus scrofa) have a significant impact on the environment and agricultural production and are a potential reservoir and vector of exotic diseases. Control methods include poisoning, trapping, exclusion fencing, ground shooting and aerial shooting.
Aerial shooting of feral pigs from a helicopter is used in extensive or otherwise inaccessible areas where the density of pigs is high. It is an effective and relatively cost-efficient method of quickly reducing feral pig populations. Teams involved in shooting from a helicopter include a shooter and a pilot. The pilot also acts as a spotter/counter who locates the pigs and records the number of pigs shot.
Aerial shooting can be a humane method of destroying feral pigs when it is carried out by experienced and skilled shooters and pilots; the animal can be clearly seen and is within range; the correct firearm, ammunition and shot placement is used; and wounded animals are promptly located and killed.
This standard operating procedure (SOP) is a guide only; it does not replace or override the legislation that applies in the relevant state or territory jurisdiction. The SOP should only be used subject to the applicable legal requirements (including OH&S) operating in the relevant jurisdiction.
- Shooting should only be used in a strategic manner as part of a coordinated program designed to achieve sustained effective control.
- Aerial shooting is a cost-effective method where pig density is high. Costs increase greatly as pig numbers decrease.
- Aerial shooting is best suited to areas where pigs are living and feeding in extensive or inaccessible areas (e.g. swamps, marshes, rough terrain or broadacre crops) where vehicle access is impossible or impractical and/or pre-feeding will not successfully attract enough pigs for trapping or baiting.
- In areas of heavy cover (e.g. heavily vegetated creek lines, woodlands and dense forest), effectiveness is limited since pigs may be concealed and difficult to locate from the air.
- The optimal period for aerial shooting is when pigs are away from cover e.g. during dry seasons or droughts when pigs are forced to congregate in areas with limited access to water and feed.
- For safety reasons, shooting from a helicopter cannot be undertaken in adverse weather conditions (e.g. strong wind, rain, low cloud).
- Shooting of feral pigs should only be performed by competent, trained personnel who have been tested and accredited for suitability to the task and marksmanship and who hold the appropriate licences (eg NSW Feral Animal Aerial Shooter Training [FAAST] course; NT Parks and Wildlife Advanced Firearms course; Qld Biosecurity Aerial Platform Marksmanship Course).
- Helicopter pilots must hold the appropriate licences and permits and be skilled and experienced in aerial shooting operations.
- Helicopter operators must have approval from the Civil Aviation Safety Authority to undertake aerial shooting operations.
- Aerial shooting should comply with all relevant federal and state/territory legislation, policy and guidelines.
- Storage, use and transportation of firearms and ammunition must comply with relevant legislative requirements.
Aerial shoot-pig. Image by Mal Leeson
Animal welfare considerations
Impact on target animals
- The humaneness of aerial shooting as a control technique depends on the skill and judgement of both the shooter and the pilot. If properly done, it can be a humane method of destroying feral pigs. On the other hand, if done inexpertly, shooting can result in wounding which may cause considerable pain and suffering.
- Aerial shooting should not be carried out if the nature of the terrain reduces accuracy resulting in too many wounding shots and prevents the humane and prompt despatch of wounded animals.
- Shooting must be conducted in a manner which maximises its effect thus causing rapid death. This requires the use of appropriate firearms and ammunition.
- Only head (brain) or chest (heart-lung) shots must be used. Shooting at other parts of the body is unacceptable.
- Since it is very difficult to assess if an animal is dead from a distance, it is essential that a deliberate policy of ‘overkill’ be followed, where a minimum of two shots are used per animal. That is, after an initial head or chest shot, another shots/s must be fired into the chest or head to ensure death. If the initial shot is to the head, it must be correctly placed to achieve instantaneous loss of consciousness and loss of brain function. A follow-up chest shot (or shots) will ensure death if the initial head shot is not lethal.
- Correctly placed head shots cause brain function to cease and insensibility will be immediate. Death from a shot to the chest is due to massive tissue damage and haemorrhage from major blood vessels. Insensibility will occur sometime after, from a few seconds to a minute or more. If a shot stops the heart functioning, the animal will lose consciousness very rapidly.
- Wounded pigs must be located and killed as quickly and humanely as possible with further shot(s) directed at the chest or head. If left, wounded animals can suffer from pain and the disabling effects of the injury (including sickness due to infection).
- A ‘fly-back’ procedure must be followed, in which the shooter is flown back over the shot animals so that follow-up shots to the vital areas can be applied. The cost of ammunition and extra flying time must not deter operators from applying this flyback procedure. In areas that are accessible, a ground crew of several individuals walking or on all-terrain vehicles can be used to locate and humanely kill any wounded animals.
- To minimise the animal welfare implications of leaving dependent piglets to die a slow death from starvation it is preferable not to undertake aerial shooting programs when sows have recently farrowed. This will vary with season and area. Peaks in mating often occur in response to the flush of green vegetation that follows heavy rain or flooding with farrowing occurring 112—114 days later. For example, in southern NSW, most births occur in summer and autumn whilst in the monsoonal lowlands of Northern Territory there is a peak in births in the early dry season.
- Weaning age of piglets varies from 2—3 months. At times of farrowing, sows tend to move over less distances and are usually more cryptic which may reduce the effectiveness of any pig control conducted at this time.
- If lactating sows are shot, efforts should be made to find dependent piglets and kill them quickly and humanely. Piglets older than 5 weeks of age will tend to fall in to line behind the sow. Any piglets that escape after a sow has been shot will usually return to the area over the following few hours.
Impact on non-target animals
- Shooting is relatively target specific and does not usually impact on other species. However, there is always a risk of injuring or killing non-target animals, including livestock, if shots are taken before an animal has been positively identified.
- Sensitive livestock such as horses, deer and ostriches are easily frightened by gunshots, helicopter rotor noise, wind etc. and may injure themselves by running into fences and other obstacles. Avoid shooting in areas where these livestock occur or organise the removal of them from the area prior to the shooting program.
Health and safety considerations
- The potentially hazardous nature of aerial shooting requires that safety protocols be strictly followed. Each team member must be aware of and trained in all aspects of helicopter and firearm safety.
- The helicopter pilot must perform a thorough pre-flight briefing with all personnel to establish communication protocols between the shooter and the pilot including pre-shot manoeuvre, commands for firing and emergency procedures.
- Shooting from a helicopter can be hazardous, particularly in areas of rugged topography. The combination of low-level flight, close proximity to obstacles (trees, rocks, wires) and the use of firearms make this task extremely hazardous.
- It is essential that ejected firearm shells do not interfere with the safe operations of the helicopter. It might be necessary to fit a deflector plate to the firearm to ensure shells are ejected safely.
- Firearm users must strictly observe all relevant safety guidelines relating to firearm ownership, possession and use.
When not in use, firearms must be securely stored in a compartment that meets state/territory legal requirements. Ammunition must be stored in
a locked container separate from firearms.
- Adequate hearing protection should be worn by the shooter and others in the immediate vicinity of the shooter. Repeated exposure to firearm noise can cause irreversible hearing damage.
- Safety glasses are recommended to protect the eyes from gases, metal fragments and other particles.
Firearms and ammunition
- Self-loading rifles (SLR) with large magazine capacity such as the M14, M1A, L1A1 or Heckler and Koch M19 in .308 calibre are suitable. They should be fitted with a spot on/aim-point/ red dot scope. 150 or 160 grain soft- or hollow-point ammunition is appropriate for feral pigs.
- 12 gauge pump action shotguns with 70-75 cm barrels set on ¾ to full choke with SSG or SG ammunition are also used (usually for smaller animals). SSG or AAA shot is recommended for piglets.
- To provide a backup in case of firearm/ammunition malfunction, at least two firearms should be carried by shooters at all times.
The accuracy and precision of firearms should be tested against inanimate targets before any shooting operation.
- Aircraft used for aerial shooting should be manoeuvrable, fast and responsive to allow quick follow-up of any wounded animals. They should also allow for a good shooting position for the shooter. Operating conditions and performance characteristics of the aircraft will determine the most suitable for the job. Robinson 44 or equivalent or turbine-powered helicopters such as the Bell 206 Jet Ranger are recommended.
- GPS (global positioning systems) and computer mapping equipment such as GIS (geographic information systems) should be used to assist in the accurate recording of information (eg where animals are shot) and to eliminate the risk of shooting in off-target areas.
- flight helmet (with intercom)
- fire-resistant flight suit
- safety harness
- other personal protective equipment including lace-up boots, gloves and appropriate eye and hearing protection
survival kit (including a first aid kit)
- emergency locating beacon
- lockable firearm box
- lockable ammunition box.
- The best time to shoot feral pigs is when they are most active and away from cover; that is, in the early morning, late afternoon and evening. During winter months and on cooler, overcast days pigs will be more active during daylight hours.
- Target pigs should be mustered away from watercourses and areas of dense vegetation before being shot, as wounded animals will be difficult to locate if they go down in these locations.
- Once a target is sighted and has been positively identified, the pilot should position the helicopter as close as is safe to the target animal to permit the shooter the best opportunity for a humane kill.
- The pilot should aim to provide a shooting platform that is as stable as possible. Shooting from a moving platform can significantly detract from the shooter’s accuracy.
- A feral pig should only be shot at when:
- it can be clearly seen and recognised
- it is within the effective range of the firearm and ammunition being used
- a humane kill is probable.
- If in doubt, do NOT shoot.
- Piglets are harder to hit with a single projectile so a pump action shotgun may be more effective at achieving a humane kill. The recommended range is 20—30 m. An SLR should only be used on piglets when conditions are good (minimal wind and turbulence) and the pilot can position the helicopter to within 20 m of the target animal.
- When shooting feral pigs, all animals must receive multiple shots to vital areas to ensure a rapid death. This is because animals can appear to be dead but might only be temporarily unconscious after a single shot.
- For aerial shooting, the initial shot to the head is preferred since it is easier to achieve with a moving animal. However, the judgement of the shooter is paramount in determining the optimum first shot placement for each target animal. In some situations (ie when conditions are ideal) an initial head shot will achieve a quick humane death. In other situations, an initial chest shot will be more appropriate.
- Immediately after delivering the first shot, the shooter must perform a second chest shot to ensure a humane death.
- In a line of running animals, shoot the animals at the tail end first and then move forward until all animals in the line have been shot.
Any wounded animals must be destroyed immediately before returning to the remainder of the herd.
- The fly-back procedure must then be undertaken to ensure death and apply follow-up shots to vital areas if necessary. Any wounded animal in a group should be killed immediately before any further groups are targeted and shot. Records should be kept of number, type and location of animals killed, hours flown, ammunition used and details of established fly-back procedures.
- Aiming points for head and chest shots are as follows (see Diagram):
- The firearm is aimed at the centre of a line encircling the minimum girth of the animal’s chest, immediately behind the forelegs (see Diagram). The shot should be taken slightly to the rear of the shoulder blade (scapula). This angle is taken because the scapula and humerus provide partial protection of the heart from a direct side-on shot.
Poll position (rear view)
- When aerial shooting, most head shots will be taken at this position as animals are running away from the helicopter.
The firearm should be aimed at the back of the
head at a point between the base of the ears and directed towards the mouth.
Temporal position (side view)
- This shot is occasionally used where a second shot needs to be delivered to an injured animal that is lying on its side.
The pig is shot from the side so that the bullet enters the skull at a point midway between the eye and the base of the ear.
Frontal position (front view)
- This position is occasionally used when an animal faces the shooter (see Diagram 3). It should not be used for larger adult pigs due to the heavier bone structure of the front of the skull. The shot is directed at a point of intersection of lines taken from the base of each ear to the opposite eye.
- American Veterinary Medical Association (2007). AVMA Guidelines on Euthanasia (formerly The Report of the AVMA Panel on Euthanasia).
Senate Select Committee on Animal Welfare (1991). Culling of large feral animals in the Northern Territory: A report by the Senate Select Committee on Animal Welfare. Senate Printing, Unit Canberra.
- Department of Natural Resources and Mines (2001). NRM facts. Control of feral pigs. Department of Natural Resources and Mines, Queensland.
- Caley P (1999). Feral Pig: Biology and control in the Northeren Territory. Agnote No. J52. Agdex No. 440/91. Department of Business, Industry and Resource Development, Northern Territory.
- Choquenot D, McIlroy J and Korn T (1996). Managing vertebrate pests: feral pigs. Australian Government Publishing Service, Canberra.
- Gregory N (2003). Assessing the humaneness of pest control methods. In: Solutions for Achieving Humane Vertebrate Pest Control. Proceedings of the 2003 RSPCA Australia Scientific Seminar held at the Telstra Theatre, Australian War Memorial, Canberra 25 February, 2003. Royal Society for the Prevention of Cruelty to Animals Australia, Canberra. Pp 65-84.
- Korn T and Fosdick M (1992). Shooting from helicopters. Guidelines for the use of helicopters in New South Wales for the control of feral pigs. New South Wales Agriculture, Agdex 440/678.
- Longair JA, Finley GG, Laniel MA, MacKay C, Mould K, Olfert ED, Roswell H and Preston A (1991). Guidelines for euthanasia of domestic animals by firearms. Canadian Veterinary Journal 32:724-726.
- Mawson P (1991). Ethics, Animal Welfare and Operational Guidelines for the Humane Shooting of Pest Animals. Agriculture Protection Board of Western Australia Infonote 8/91 Agdex 670.
- NSW Agriculture, NSW National Parks and Wildlife Service, Rural Lands Protection Boards, NSW Police (2003). Feral Animal Aerial Shooting Team (FAAST) Management and Training System.
- Smith G (1999). A guide to hunting and shooting in Australia. Regency Publishing, South Australia.
- Standing Committee on Agriculture, Animal Health Committee (1991). Model Code of Practice for the Welfare of Animals: Feral Livestock animals – Destruction or Capture, Handling and Marketing. CSIRO, Australia.
- Universities Federation for Animal Welfare (UFAW) (1976). Humane Destruction of Unwanted Animals. UFAW, Potters Bar, England.
The Centre for Invasive Species Solutions manages these documents on behalf of the Environment and Invasives Committee (EIC). 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.
Connect with government
It is important to contact the relevant federal, state or territory government agency before undertaking feral pig control to ensure you have the right permits in place.
Aerial shooting from helicopters is useful for rapid population reduction in large, inaccessible areas. Where pig densities are high, aerial shooting can kill many pigs at a time, quickly knocking down pig numbers in the short term. Aerial shooting is also useful when pigs show avoidance behaviour to baits, traps, vehicles and/or people on foot. Pigs can modify their behaviour if aerial shooting exercises are extended, making their detection harder.
Aerial shooting works best in open terrain or remote/ inaccessible areas, such as swamps, marshes or seasonally inundated areas. Such areas tend to have reasonable numbers of pigs and are open enough for the operator to see pigs from the air. Aerial shooting can be the only viable option in some areas where vehicle access is limited, or environmental conditions, such as widespread rainfall, severely limit the effectiveness of other ground-based control methods.
Aerial shooting is best carried out when pigs are most active (in the early morning or late afternoon, even during daylight hours in winter on cooler, overcast days) and when they are away from cover (during dry seasons or droughts). To maximise the effectiveness, timing for shooting should be balanced between winter (when pigs are more active than usual in daylight) and summer (when pigs concentrate around water points and light cover) although this will depend on local conditions.
Successful aerial shooting requires proficient marksmen, spotters and pilots. There are inherent safety risks associated with operating any aircraft at low attitudes above ground level. In some States (eg NSW) a qualified, trained marksman is required to be on board even when operating above private properties. In this case, it is important to consult with the landholders before the operation to confirm their property boundaries and hotspots to target. Hotspots can be identified by the landholders one or two days before the operation by looking for fresh pig tracks or diggings. Using aerial images of the property can be an effective way to discuss the hotspots. As a regulatory requirement, helicopter operators must have approval from the Civil Aviation Safety Authority and shooters need to be accredited for competency. In NSW, they must complete the Feral Animal Aerial Shooter Training (FAAST) course.
To maximise kill rates, pigs should always be shot from the tail end of the mob first and move forward until the line has been shot. The most suitable weapons in aerial shooting include automatic shotguns or semi- automatic large calibre (.308) rifles. ‘Judas’ pigs may be useful in locating groups of pigs although previous results have been highly variable. Judas pigs are radio- collared individuals released to associate and reveal the location of pigs in an area that are difficult to find by other methods. They are used mostly for removing remaining pigs in the last stages of eradication campaigns. It is not effective to use Judas pigs when pig densities are high.