Lethal Bird Control
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OverviewAs a method of bird control, lethal control falls roughly into two categories; agricultural bird control (including landfill sites and airport sites) and the control of pigeons in urban areas. Although lethal control is used to control many other species of birds and waterfowl, it is pigeons that are the most commonly controlled using lethal means. For the purpose of this review we will concentrate on the use of lethal control to control feral pigeon populations in urban areas.
The lethal control of birds is prohibited under the The Wildlife and Countryside Act 1981 unless the species concerned is listed under the relevant section of the Act. Although specific licences are required for some methods of lethal control, such as the use of stupefying baits, the most commonly controlled species of pest birds (such as the feral pigeon) are allowed to be killed under a General Licence. This means that providing an ‘authorised person’ undertakes the culling and providing that the culling is undertaken in accordance with the guidelines laid down by the General Licence, a specific application to kill is not required. All licences are issued and overseen by The Department for Environment, Food and Rural Affairs (DEFRA) including the General Licence. The General Licence states the following:
“This licence can only be relied on in circumstances where the authorised person is satisfied that appropriate non-lethal methods of control such as scaring are either ineffective or impracticable.”
This condition of the General Licence suggests that lethal control can only be used by an “authorised person” and only where non-lethal methods of control have first been tried and have failed or where they are impractical. Where a vast majority of lethal pest control operations are concerned, however, no attempt is made to employ non-lethal methods of control prior to providing lethal control operations. Similarly, it is extremely rare to find a building where it is “impractical” to install anti-perching devices. Subsequently, a majority of lethal bird control operations that are undertaken in the UK are carried out in direct contravention of the The Wildlife and Countryside Act 1981, yet prosecutions are rarely if ever brought.
Lethal control has been used as a ‘quick-fix’ means of reducing pigeon numbers for as long as there has been a need to control the species. The pest control industry has historically recommended lethal controls alongside the provision of anti-perching and bird exclusion products in an effort to maximise relief for those experiencing pigeon-related problems. Although the installation of anti-perching products (and some bird exclusion products) will resolve a vast majority of pigeon-related problems without the need for additional controls, many pest control companies still recommend lethal control either as a complementary service or as a stand-alone control.
In recent years a great deal of research, both scientific and non-scientific, has been undertaken to assess the effectiveness of lethal controls and the provision of alternatives to lethal control. In the scientific world, research* undertaken by Daniel Haag-Wackernagel of Basel University has confirmed what the pest control industry has always suspected, that lethal control of pigeons, far from reducing flock size, can actually have the effect of increasing flock size in the medium/long-term. Years of non-scientific research undertaken by the Pigeon Control Advisory Service has lead to the same conclusion. The most significant reason that lethal control cannot be used to reduce pigeon flock size, whatever method of lethal control is chosen, is the fact that pigeon flock size is dictated, almost exclusively, by the extent of available food. If available food increases, so does the incidence of breeding within the flock. If available food reduces, pigeons will breed less or not at all. Therefore, the only means of permanently reducing flock size is to reduce the availability of food.
Although flock size can be reduced by restricting available food, reducing the number of individual pigeons perching or roosting on a specific building can only be achieved by protecting the building with anti-roosting products or bird exclusion products. It is in these circumstances that contractors will commonly recommend a culling operation in tandem with the provision of deterrents. The contractor will be selling two revenue-rich services to the client rather than just one. Most clients will simply accept the contractor’s recommendation that a cull needs to be undertaken with the contractor justifying the cull on the grounds that bird pressure is too high for deterrents to be effective in their own right. The contractor will then undertake a cull followed by the installation of deterrents and the property owner will experience an immediate reduction in both pigeon activity and a cessation of perching and roosting-related problems (assuming that the deterrents have been installed as per manufacturer’s recommendations).
Within a matter of weeks following a culling operation, however, pigeon numbers will have risen back up to the pre-cull level and in many cases will have exceeded it. This is because culling has the effect of rejuvenating the flock by removing older non-breeding birds and leaving the prolifically breeding juvenile birds in place. Lost members of the flock will be replaced rapidly due to the fact that although some birds have been physically removed, the food source still remains in situ and it is the food source that dictates the extent of breeding and as a result, flock size. As there will be fewer birds exploiting the food supply following a cull, there will be increased availability of food for the remainder of the flock. Increased food supply means increased breeding activity resulting in a mini population explosion. If the property upon which the cull has taken place has been adequately protected by anti-roosting products the problem should not re-manifest itself for the property owner. If, however, the property owner was sold a cull without the installation of deterrents, the problem will return within weeks rendering the cull worthless. This begs the question, why was a cull needed in the first place?
As a result of the fact that the feral pigeon is one of the few species of bird that breeds all-year round, there will never be a safe period to undertake a cull when adult birds are guaranteed to have no young. Assuming that there is an abundance of available food, pigeons will even breed in mid-winter, and therefore it is highly likely that culled adult pigeons will have dependent young in nests. Even if the humanitarian implications of allowing flightless birds to starve to death are put aside, there are more worrying implications for the property owner with pigeon nests in a roof void or any other internal area of a property. Pigeon squabs (chicks) will live up to 6 days when denied food from their parents but when they die, their carcass will become maggot-infested within a matter of days, particularly in the summer months. This can cause significant health and safety issues for residents or workers in the building concerned, to say nothing of the extremely unpleasant smells that accompany decomposing carcasses.
Based on the evidence that culled birds are replaced within a matter of weeks following a cull, culling cannot be used, under any circumstances, to reduce flock size in anything other than the short-term. If a property owner is expected to undertake a cull every few weeks in order to protect his/her property, the cost of the service would be prohibitive. Even in light of these facts, culling is still widely recommended and used by the pest control industry as a method of control. The following methods are commonly used to cull pigeons:
Cage trapping and killing
This method of lethal control involves the use of a baited cage trap to catch pigeons and then remove and kill the trapped birds, normally by breaking their necks with a special pair of pliers or by gassing.
A suitable area is identified in which to site the trap that is easy to access for the pest control contractor and which is considered to be in an area of high pigeon activity. Other criteria, such as finding a site that is not overlooked, is equally important as the general public find the sight of trapped birds extremely distressing. The cage trap is then baited with pigeon corn for approximately 7 days, allowing pigeons’ free access to enter the trap, feed and then exit the trap. This process is designed to make the birds feel safe whilst feeding within the trap so that after 7 days when the trap is set, the maximum number of birds will be caught. The trap has a two-way door which, when set, allows the pigeon to enter the trap but not to exit it. The trap is then visited once a day and any birds within the trap are removed and either killed on the site or removed live, normally in a sack and taken away to be gassed.
Many pest control contractors will offer what they perceive as being more sensitive clients the option of having pigeons trapped on their property and then removed to be released elsewhere rather than having them killed. Anyone that is offered this service should be aware that it would be highly unlikely for pest control contractors to release trapped birds. This is because pigeons have an extremely strong homing instinct and irrespective of how far away from their roosting or feeding area they are released, even if the release site is several hundred miles away, the pigeons will return. The only beneficiary of a cage trapping and release operation is the contractor offering the service, as the contractor will inevitably need to be re-employed to remove the same pigeons a second time!
Of all the methods of lethal control, cage trapping is the least effective and subsequently the most expensive. Although varying numbers of pigeons will be caught in the trap for the first week or two of operation, after the initial 2-week period very few if any pigeons will enter the trap as the flock will have become aware that the trap is a danger zone. Pigeons are highly intelligent birds and will not blindly enter a cage trap indefinitely when they have seen other pigeons enter the trap and fail to escape. Even in light of this reduced effectiveness, many contractors recommend on-going cage trapping operations to clients, in some cases for years not just months. Clearly, in these circumstances the client is not getting value for money nor indeed any type of real service.
Cage trapping is also highly labour intensive, resulting in higher costs to the client due to the fact that the law states that as a minimum, cage traps must be inspected once every 24 hours. Although the law is quite clear on this point, not all contractors comply with this legislation and empty their traps every 24 hours. If the contractor fails to inspect and empty their traps every 24 hours they run the risk of prosecution, as does the client upon whose site the traps are located. There is also a legal requirement to provide food and water in cage traps but again, not all contractors comply with this aspect of the legislation. The Wildlife and Countryside Act, produced and overseen by DEFRA, is used to determine procedure and to ensure that no suffering is experienced by the target species. The 1911 Protection of Animals Act may also be used to prosecute any company or individual that causes suffering, either intentionally or otherwise, to the target species.
Shooting as a method of lethal control is one of the most commonly used methods of killing pigeons and other birds. In the agricultural sector, shooting is used almost exclusively as a means of killing wood pigeons and other birds that feed on crops. In an urban application shooting is commonly used to control pigeons and in some cases other smaller birds such as sparrows and starlings, but is rarely used to control larger birds such as roof nesting gulls. This is because air weapons used to shoot pigeons are not considered to be powerful enough to kill an adult gull and therefore a gun like a .22 rifle must be used and for this, the user must have specific permission from the Police. The Police are extremely unlikely to grant permission for a .22 rifle, or any other weapon of this type, to be discharged in an urban area. The Police must also be informed when using a conventional air weapon to shoot pigeons as part of a pest control operation.
Shooting operations are normally undertaken at night with daytime shoots only being used in agricultural applications or for specialised urban applications. In urban applications, pigeons are usually shot at night and in their roosting sites because the birds are unable to fly away when the shooting starts, as they would if shoots were undertaken in daylight hours. The major problem inherent with shooting operations is the inability of the shooter to recover and dispatch injured birds. It is virtually impossible to kill a pigeon outright with an air weapon and therefore a majority of birds are simply shot and injured. Because pigeons normally roost at height and because when shot, a pigeon will be pushed backwards with the impact of the pellet entering the body, very few injured pigeons actually fall to the ground. This means that injured birds cannot be dispatched humanely, as is required by law, to prevent suffering taking place, rendering this method of lethal control inhumane. A pigeon can survive for weeks with a pellet lodged in its body and will suffer a slow and lingering death as a result. Also, in situations where a majority of the seriously injured birds cannot be humanely dispatched, the property owner upon who’s site the shooting has taken place will inevitably experience unpleasant smells and maggot infestations as birds die in their roosting places.
Although shooting as a method of lethal pigeon control requires the use of high-powered and highly specialised .22 air weapons, there is no legal requirement for operators to undergo any sort of training prior to offering their services to the general public. As a result, many of those tasked with shooting pigeons in control operations are a potential hazard to both the public and to the fabric of the buildings upon which they are shooting. A good example of this is London Victoria Railway Station in which a national pest control company, instructed by Railtrack, was shooting roosting pigeons in the main concourse area of the station. Railtrack was made aware that pest control operatives had been damaging irreplaceable glass panels in the roof of the station when trying to shoot pigeons. As the entire station is a Listed building, including the glass in the roof, Railtrack was instructed by English Heritage to stop any shooting operations that have the potential to damage the fabric of the building.
The Wildlife and Countryside Act 1981, little appears to be done to oversee rough shoots to ensure that they comply with current legislation.In the agricultural sector, shooting is used extensively to control pest species of birds but in most cases shooting is undertaken for pleasure and for profit, not for the purposes of control. This is because shooting is a wasted effort when attempting to control vast flocks of wood pigeon and other agricultural pests in rural applications. Rough shooting is becoming an increasingly popular sport and one that is highly profitable for farmers and landowners who sell the right to shoot on their land. Organised shoots not only kill large numbers of ‘game’ birds, the intended targets, but also kill vast numbers of non-target species, including many protected species as well as pest species. Although lethal control used for these purposes would be in direct contravention of the
The use of stupefying bait as a method of lethal control requires a specific licence from DEFRA. This method of lethal control was used extensively on pigeons in the 1960’s and the 1970’s but is rarely used now since the licensing system has been tightened up to reduce suffering experienced by the target species when controlled using this method. DEFRA now provide few licences for the use of stupefying bait, certainly relative to the volume of licences granted in previous years and will only grant a licence when it is completely satisfied that suffering will not occur as a result of its use.
Stupefying bait (Alphachloralose) is fed to the target species in the form of treated grain which, when ingested is designed to induce stupor in the bird so that it can be humanely dispatched. A site is identified where the bait will be fed to the target species, normally a secluded area away from the general public and ideally close to where pigeons roost or feed. For 7 days untreated grain will be fed to the target species in an effort to encourage the maximum number of birds to visit the site each day. On the 8th day the untreated grain will be replaced with treated grain. The principle of this control option is for the birds to feed and when they become drowsy with the effects of the stupefying drug, the pest control operatives will simply pick the birds up, without any resistance, and humanely dispatch them. The reality of this control option, however, is very different.
When pigeons are fed stupefying bait they quickly eat their fill, (which only takes a few minutes as pigeons have relatively small crops) and then fly away. Alternatively the birds may be feeding when they hear a loud bang and fly away. Either way, the chance of a pigeon waiting long enough for the drug to take effect after it has eaten its fill is extremely low. As a result, many stupefying operations go horribly wrong with drugged pigeons crashing into cars, shops and even people as the drug takes effect. In the city of Perth, Australia exactly this happened with the city centre becoming a scene of devastation with pigeons falling out of the sky, crashing into buildings and flopping about on pavements. In the city of Melbourne, Australia, another operation using stupefying bait to control pigeons went terribly wrong. The city’s treasured family of peregrine falcons (the main predator of the pigeon) clearly took one or more drugged pigeons as prey and as a result the entire family of peregrines died. This confirms that stupefying bait is indiscriminate and cannot be used without the drug affecting other species of bird, either through ingestion of treated grain or through predation. Even in light of this, licences are still issued by DEFRA for use of alphachloralose in the UK.
Flying a raptor
Flying a raptor as a method of bird control is an increasingly common control option which is marketed as being humane and non-lethal by virtually all the companies and individuals offering the service. It must be understood that although this method of control is sold to the client as a non-lethal scaring operation and not a culling operation, handlers have little or no control over the birds that they fly and it is common for raptors to kill whilst ‘working’ as a bird scarer. This method of control must be considered to be a form of lethal control as a result. When a raptor makes a kill, the bird will often bring the prey to the ground to devour and this can be a very public, gory and distressing spectacle, particularly when it takes place on or immediately outside of the customer site. It can also be the source of extremely damaging publicity for the client.
This method of control is discussed, in detail, in a separate ‘Birds of Prey’ product review.
The Department of the Environment, Food and Rural Affairs (DEFRA) is the UK’s Government body that oversees the Wildlife and Countryside Act and produces legislation to which the pest control industry must adhere.The following information is taken from a document provided on DEFRA website entitled: ‘Review of international research regarding the effectiveness of auditory bird scaring techniques and potential alternatives’. By J Bishop, H McKay, D Parrott and J Allan.
“The principle mechanism for the legislative protection of wildlife in Great Britain is the Wildlife and Countryside Act (1981). Section 1 of the Act prohibits the intentional killing, injuring or taking of any wild bird and the taking, damaging or destroying of the nest or eggs. However, under section 16 of the Act, General Licences are issued which provide a mechanism for permitting actions that would otherwise be unlawful. A General Licence allows the killing of the following 13 agricultural pest species: carrion crow, collared dove, great blacked-back gull, lesser blacked-back gull, herring gull, jackdaw, jay, magpie, feral pigeon, rook, house sparrow, starling and woodpigeon. It permits the killing or taking of birds for the purposes of: ‘preventing serious damage to livestock, crops, vegetables, fruit, growing timber, fisheries or inland waters’ or for ‘protecting any collection of wild birds’ or for ‘preserving public health or public air safety’. ‘Killing or taking’ includes taking, damaging or destruction of their nests or the taking or destruction of their eggs, where there is no other satisfactory solution. Unless otherwise stated the licence permits authorised persons to carry out the licensable act. An ‘authorised person’ is defined as the owner/occupier or any person authorised by the local authority or by listed officials. Further licences can be issued for the control of other bird species, for example, cormorants at fisheries. Control methods permitted are by shooting, a cage trap or net (hand-propelled). Defra policy is that shooting should be conducted in conjunction with non-lethal measures as part of an overall control strategy. The principle of shooting is to enhance non-lethal methods of deterrence and not as a deliberate means of population reduction. Some further alternative lethal techniques are permissible under Special Licence, such as the use of mist nets and stupefying baits.
"Shooting may be deployed as an avian deterrent using two different approaches: shooting to kill and shooting to scare.
Firstly, shooting may directly reduce numbers of pest birds through killing. The shooting of over 50,000 gulls at John F. Kennedy International Airport between 1991 and 1997, successfully reduced airstrikes by 76-89% (Dolbeer 1998; Dolbeer et al.1993, Dolbeer and Bucknall 1997, cited in Harris and Davis 1998). The birds were shot as they crossed the airfield on route to feeding areas, and the technique was successful at reducing the local nesting population of gulls but had no impact on the regional or national population (Dolbeer and Barras 2000). However shooting such large numbers of birds is not something that would normally be allowed or accepted.
In many circumstances, shooting may fail to reduce overall bird pest numbers as mortality is unlikely to exceed the recruitment rate from immigration and breeding (National Goose Forum 1998; Feare 1984). In addition, shooting may just remove the surplus birds that would have died of natural causes such as starvation or disease, without any reduction in the overall population size or associated problems (Murton, Westwood and Isaacson 1964, cited in Murton 1968). However, if bird problems are caused by small localized populations such as small groups of feral pigeons in buildings, shooting may be reasonably effective and long-lasting.
Alternatively, shooting may be used as a scaring strategy only, whereby birds are frightened away without attempts to kill; although a small number of birds may be killed with a view to enhance the scaring effect. Baxter (pers. comm.) investigated lethal shooting in combination with other techniques such as pyrotechnics as a means of reducing birds at landfill sites in England. They concluded that shooting a small percentage of the birds present was very effective in deterring birds from sites. In the UK, certain species may be shot under licence. Licensed shooting, however, should be part of a wider bird scaring programme; it is not intended as a means of population control.
It is generally accepted in bird control manuals that killing enhances the scaring effect of shooting (e.g. Transport Canada 1994, Civil Aviation Authority 2002). However, scientific evidence to substantiate this view is equivocal. Although increased wariness and dispersal by waterbirds in response to wildfowling have been well documented (Bell & Owen 1990; Madsen & Fox, 1995) no attempts have been made to differentiate between the disturbance effects of human activity and hunting mortality. Frederick et al. (1987) produced a multifactorial simulation model which attempted to describe the effects of alternative management schemes on the use of refuges by autumn-migrating snow geese Anser c. caerulescens. The main conclusion was that disturbance associated with hunting was more important in reducing population size, through early migration, than the direct effects of hunting mortality. The increased disturbance during shooting, caused by the retrieval of kills and injured birds may cause as much disturbance as the shot itself (Townshend and O’Conner 1993). This extra level of disturbance (rather than mortality itself) may deter birds from using a site. In a controlled, replicated field experiment shooting, both lethal and non-lethal, significantly reduced cormorant numbers by over 50% at fisheries, though it could not be shown whether killing enhanced the scaring effect of shooting (McKay et al. 1999).
The effectiveness of shooting depends on a number of factors: the target species, the site characteristics and the shooting regime. Sensitivity to shooting varies between species and between individuals within species (Bell & Owen 1990, Madsen 1998). For waterbirds, shooting has been shown to be more effective at smaller sites than large sites (Hughes 1996; McKay et al. 1999). The number of consecutive days shooting (Townshend & O’Connor 1993) and the number of shooting parties (Madsen 1993a,b) has also been shown to affect the magnitude of reduction in bird numbers.
In summary, shooting to kill under licence may have short-term advantages but its efficacy may be exaggerated through the immediate self-gratification to the shooter, who feels he is taking a positive action towards solving a bird problem (Kevan 1992). The success of the technique depends on the sensitivity of the target species, the physical characteristics of the site, the shooting strategy and the availability of alternative sites for the birds to move to, and these in turn affect the cost-effectiveness of shooting."
The cost of lethal control services vary according to the contractor chosen, the species of bird concerned and the extent of the problem being experienced.
A spokesperson for the Pigeon Control Advisory Service International (PiCAS International), an organisation that deals exclusively with non-lethal controls for birds, said the following of lethal controls:
“PiCAS International is contacted for independent advice on all aspects of bird management and in particular for advice on alternatives to lethal controls. A vast majority of those that come to us for advice have been sold lethal control services, in some cases for many years, without experiencing any relief as a result. The most common complaint that we receive is that the client experiences a reduction in bird-related problems for 4-6 weeks following a cull but thereafter the problem appears to return to its original proportion. The response from their contractor is that another cull will be required and this continues indefinitely until such a time as the client looks elsewhere for advice.
Most clients quickly realise that lethal controls are completely ineffective other than in the short-term and that the installation of anti-perching products is a much more effective and cost effective means of managing the problem. Anti-perching products are relatively inexpensive to install, particularly if the client installs the product themselves and the results are instant and permanent if a product such as the anti-roosting spike is used. Lethal controls are at best a short-term option and when taking into consideration the negative publicity that is often associated with their use, they are a complete waste of time and money.”
The following is an excerpt from an article that appeared in the New York Times, July 3rd 2007, entitled “Pigeons on the pill bring cleaner Byrant Park”. The piece discussed how the management of Bryant Park had fought a running battle with pigeons for many years and eventually turned to contraceptive controls after their experiences with stupefying bait:
“Actually, Bryant Park succeeded in discouraging pigeons two years ago, after the park reopened with extensive renovation. But it gave up on the drug that zapped them, Avitrol, because it did awful things to the birds that took it, and shook up people who watched them, including Mr. Manshel.
"It looks like delirium tremens," he said. "They shake. Apparently it affects the nervous system."
Then they die.
"I was taken aback," said Mr. Manshel, explaining that the exterminator had told him the drug would not harm the birds. It works chiefly by frightening off other pigeons after they see what happens to those that ingested the stuff.”
The Pigeon Control Resource Centre is an organisation specialising in promoting non-lethal bird controls based on the overwhelming amount of evidence confirming that lethal controls have little or no effect where the management of bird populations is concerned. In this product/service review we have outlined the various methods of lethal bird control that are commonly used in the UK and provided the reader with a brief overview of this controversial control option. Lethal controls are no longer appropriate as a method of bird control in the 21st century when evidence that they are cruel and ineffective is confirmed and re-confirmed by experts and scientists worldwide.
There is, however, an extensive industry that has built up around the use of lethal control, particularly in the USA and the UK, where the lethal control of bird populations is still commonly recommended by contractors as an effective and preferred control option. In mainland Europe the picture is very different, however, with countries like Germany and Holland leading the way where non-lethal and effective bird management systems are concerned. It seems that mainland Europe has not aligned itself with the USA and the UK where pest control is a rich and powerful industry pumping out huge volumes of propaganda each year designed to scare the public into buying lethal pest control services.
Although the use of lethal control is still common in the UK, the pest control industry is undergoing an inevitable change and starting to wake up to the fact that the public does not want invasive and inhumane controls to be used when there are much more effective non-lethal options available. The days of “if it moves, kill it’ are gone forever with cultural and social changes forcing those that offer pest control services to re-assess the services that they offer and the way they provide those services. If lethal controls had any validity as an effective control option their continued use could be justified, even if the methods used were unpalatable for many, but with the advent of the internet and the wealth of information available to us all, the average person is able to make an informed decision rather than blindly taking advice from a company with a vested interest.
There are a vast number of extremely effective non-lethal bird control options available to resolve virtually any bird-related problem. Anti-roosting products like the anti-roosting spike are considered to be 100% effective when installed according to the manufacturers instructions. Market leaders will normally provide the purchaser with a free installation DVD providing full details of how and where to install the product empowering the home user and DIY installer alike with more than enough information to protect their property.
Lethal bird control is inhumane and ineffective and its use cannot be recommended or justified irrespective of the scale of the problem. There is always an alternative to the use of lethal control and this website has been designed to offer a source of wholly independent advice to anyone experiencing a bird-related problem. This section of the PCRC website provides the user with a detailed breakdown and review of all the most commonly used pest control products, outlining the advantages and disadvantages of each product without commercial bias. We are always happy to provide more detailed advice on any product or bird-related problem if the product concerned, or solution to a specific problem, is not discussed on this website.
PDF on DEFRA website entitled: ‘Review of international research regarding
the effectiveness of auditory bird scaring techniques and potential alternatives’
By J Bishop, H McKay, D Parrott and J Allan.
Wildlife and Countryside Act 1981.
Protection of Animals Act 1911.
Pigeon Control Advisory Service (International).
*’Regulation of Street Pigeons in Basel’ by Daniel Haag-Wackernagel.
Also commonly known as:
Culling, killing, pigeon culling, pigeon killing, shooting, cage trapping, narcotising, stupefying, stupefying bait, poisoning, trapping and killing, bird shooting, pigeon trapping, pigeon poisoning, bird killing, bird culling, pigeon shooting, bird of prey, flying a hawk
Relevance to pigeon control:
Lethal control is commonly used as a method of pigeon control