The case for the humane control of pigeons

 

There are many places world-wide where attempts have been made to control pigeons by culling. Culling methods have included poisoning, shooting with air rifles and trapping. However, modern scientific research (1) shows that culling is completely ineffective, as bird numbers can increase above pre-cull levels within weeks of the cull being carried out.

Why is culling promoted?

Pest control companies are fully aware that culling is ineffective but they continue to recommend this option because it ensures that they will be offered a lucrative long-term contract.

Why is culling ineffective?

In areas where culling is carried out, there will be an initial reduction in pigeon numbers. However, this effect is very short term as the population will almost certainly have returned to or even exceeded the previous level within a few weeks. This is because pigeons control their own numbers according to the food source available.

Approximately 90% of pigeons die in their first year and the main cause of death is starvation. The mortality rate of adult pigeons is very low, typically around 11% (2). Therefore when culling is carried out on a pigeon population, the vacancies left by the dead birds are quickly filled by young birds.

This means that killing adult pigeons in a flock discriminates in favour of young birds who would otherwise have perished. It has no long-term effect on the level of population, as it merely rejuvenates the flock.

A culling programme was carried out in Basel, Switzerland; a city which had a population of approximately 20,000 pigeons. From 1961-85, 100,000 pigeons were culled by shooting and trapping. Despite this, the population remained stable.

In 1988 a group called Pigeon Action was founded to establish an ecological and long term solution to the city’s pigeon issue. They began a programme of public education campaigns which warned against feeding pigeons and installed pigeon lofts from which eggs were removed. As a result, the population was halved within four years.

Other arguments against culling

Culling is an extremely expensive option, as a long-term contract with pest controllers will have to be entered into because regular repeat culls will be necessary. Culling by poison puts other species at risk because it is both indiscriminate and because poisoned birds will affect other animals in the food chain. Cats and birds of prey may consume poisoned pigeons with fatal results.

Narcotics have been used to stupefy pigeons and make them easier to catch. However, this culling method can have disastrous consequences, with drugged birds disrupting traffic and smashing into buildings. This happened in Perth, Australia in 1999. Narcotics and poison are both very inhumane as the pigeons taking the bait will die slowly and may suffer dehydration and hypothermia.

Shooting is a widely-used culling method which also results in suffering as the majority of birds shot are wounded, rather than killed. There have been many reports of injured birds being thrown into bin bags or stamped upon by pest control operatives. Young chicks are also left to slowly perish.

Trapping of pigeons is also widespread. Apart from the risk that trapped birds are sometimes left to die from exposure, this culling method is also very time-consuming and expensive.

What are the alternatives?

There are three approaches to pigeon control which do not involve culling. They are the use of deterrents, the installation of artificial nesting sites and public education campaigns.

Deterrents

Deterrents such as spikes, holograms of owls’ eyes and wire systems can be very effective at preventing pigeons from roosting on buildings.

Netting is often used on buildings, but it can result in young flightless birds being trapped behind it and flying birds can become tangled and injured. The RSPCA and wildlife groups receive thousands of reports every year of pigeons and other birds trapped by netting.

Trained raptors (birds of prey) have been used in some areas to drive away pigeons. These birds are trained to chase, but not kill pigeons and can successfully drive a flock elsewhere. In some enclosed sites, such as railway stations, the use of raptors can be extremely effective. However, this method is expensive and will only work on a specific site, so is unsuitable for large areas.

The use of falconry to control pigeons involves pigeons being caught and killed. Nottingham City Council tried this method in 1999 but the sight of pigeons being attacked by the bird resulted in public distress, lots of negative publicity and cost thousands of pounds, whilst having no overall effect on pigeon numbers.

The problem with all deterrent methods is that the pigeons driven away from one site will simply re-locate to another, equally unsuitable site. Therefore, this form of control has limited use unless employed in conjunction with other methods.

Artificial Nesting Sites

Dovecotes or nesting boxes can be constructed and installed for a low, one-off cost. Once the pigeons have been encouraged to roost in these sites, their eggs can be collected regularly and destroyed. This is a simple, fast and very effective way to reduce pigeon numbers. It is also humane, as no killing is involved. Another advantage of dovecotes or nesting boxes is that they provide a way to move pigeon flocks away from sites where they are considered a nuisance to sites where they will pose no problems. Designated feeding areas can then be set up for public use.

Public Education Campaigns

The only effective long-term method of reducing pigeon populations is to manipulate their environment in such a way that they can no longer eat or roost easily. Each breeding pair can produce up to ten chicks per year if they have an abundant food supply, but if available food is reduced, their breeding rate slows down and can even stop altogether.

Large numbers of people regularly feed pigeons in the belief that they are caring for the birds. Litter also provides an abundant food supply to pigeons in towns and cities. As the mortality rate of adult pigeons is so low, there is strong competition for food and breeding sites.

Pigeon overpopulation is caused by large quantities of food being provided by the public. Therefore, it is essential to educate people to either stop feeding pigeons or to do so in designated areas near artificial nesting sites.

In Basel, Pigeon Action embarked on a campaign to convince the public that feeding pigeons harms them, as it causes overpopulation. They produced leaflets and posters and distributed them widely. These featured pictures of baby pigeons infected by diseases and pushed the point that overcrowding is bad for pigeons as well as people.

A successful publicity campaign will result in a large reduction in people feeding pigeons and will impose a very effective limit to their population size. Sheffield City Council produced colour leaflets which explained clearly to people why they should stop feeding pigeons. Leaflets such as these, together with signs in the relevant places should ensure that the message gets through.

Case studies

Nottingham City Hospital

Following a visit from Guy Merchant of PICAS in May 2000, the hospital suspended lethal culling of pigeons.

An on-site pest controller was employed, who proofed many sensitive areas and installed nest boxes on several large flat roofs which were heavily populated by pigeons. These were made from recycled staff lockers. The pigeons were then provided with food, water and nesting materials near the boxes in order to encourage the birds to roost there. The pest-controller visited these roosting sites daily in order to remove eggs. Hatchlings were left alone.

The result: “The impact on the trust has been dramatic. In less than a year, the bird population has reduced by an estimated 50%. The cost of cleaning fouling has also reduced significantly.” Statement made in March 2001 by Clive Young, Environmental Services Manager at Nottingham City Hospital NHS Trust.

Barking and Dagenham District Council

As a result of public pressure, this Council decided to explore alternatives to culling pigeons. A colour leaflet was produced which urged the public not to feed pigeons and to dispose of food litter properly.

Council properties, including high-rise flats were proofed in order to reduce the potential breeding sites available to the pigeons. In July 2000 a dovecote was opened in the park which had been identified as the main public feeding site. This generated a lot of very positive publicity.

This Council took some very positive action to reduce pigeon numbers, but their dovecote was designed with aesthetic appearance as the priority, rather than its attractiveness to pigeons and many nearby buildings were not proofed.

Railtrack

Railtrack abandoned culling at London mainline stations in 1999 and began to employ the services of a trained raptor and handler, as advised by PICAS. This proved extremely successful and other train operators are now exploring this option.

Summary

Lethal control of pigeons by culling has been consistently shown to have no long-term effect on population levels. It is also expensive, inhumane and can result in very negative publicity. Extensive research and recent case studies have shown that the use of artificial breeding sites, combined with egg removal, proofing of buildings and public education campaigns can result in a long term reduction of pigeon populations by as much as 50% within months. These control methods are humane, cost-efficient and will generate positive publicity.

For more information:

Pigeon Control Advisory Service (PICAS)
www.picasuk.com.

Further information about pigeons

The feral pigeon is descended from the rock dove whose natural habitat is cliffs and caves. Large buildings and statues offer pigeons roosting sites which closely resemble these. This, combined with their resourcefulness, tendency to scavenge and lack of territorial aggression has led to large flocks of pigeons living in close proximity with people.

Although it is widely believed that pigeons carry and spread diseases to people, there is very little evidence that pigeons jeopardise human health. (3) Pigeon lung disease is an allergic reaction which affects some people who have prolonged contact with pigeons in confined places. It is easily treated if diagnosed early and can be avoided by wearing a mask if in contact with pigeons in a dusty environment.

“It is absolute nonsense … to suggest that pigeons present a health hazard and presumably need eliminating for the well-being of the nation’s health.” David A Palmer, BVSc, MRCVS

“There is no evidence to show that they spread disease.” Mike Everett, RSPB

References

1. Regulation of the Street Pigeon in Basel by Daniel Haag-Wackernagel. Article published in Wildlife Society Bulletin, 1995.
2. From an article by D. Haag published in Swiss journal, Ornithol Beobachter. No. 87, pg 147-151.
3. Pigeon Lung Disease Fatality and Health by David A Palmer B. V. Sc. MRCVS.