Pigeon prevention instead of shooting

In many cities, pigeons are still used as a projection screen for everything that bothers people about the urban fauna.

And as is so often the case when animals are in the way, authorities reflexively resort to hunting methods: trapping, poisoning, shooting. What is justified in the open countryside with deer, foxes, or wild boar is repeated in urban areas with pigeons on a smaller scale.

At the same time, surprisingly precise data is now available showing that there is another way. Belgium, Spain, and Italy have quietly developed a counter-model over the years: birth control with nicarbazine granules instead of bloodstains on the pavement.

Belgium: 40 percent fewer pigeons – and then the politicians turn off the tap.

In the Brussels municipality of Ixelles, automatic feeders dispensing contraceptive pellets were installed starting in 2021. The aim was to reduce the pigeon population without killing any animals. After three years, the number of pigeons was down by around 40 percent.

The municipality itself acknowledges the program's "positive effects" but nevertheless ended it in 2025, officially for cost reasons. However, local animal welfare organizations report a significant increase in the pigeon population and growing problems just a few months after the program's termination, as the previously achieved benefits are being completely negated.

While Ixelles is phasing out the pigeons, the city of Brussels is expanding its contraception machines and publicly promoting the project as a humane alternative: at designated locations, the pigeons receive a defined amount of corn kernels treated with nicarbazine daily to limit reproduction, instead of periodically killing the animals.

Even more interesting is a look at Zaventem, a municipality near Brussels. There, a pigeon control program was launched in April 2024. After just seven months, the municipality reported a 10 percent reduction in the pigeon population and describes it as a "consciously humane and animal-friendly solution."

These figures are highly inconvenient for hunting logic. They show, in fact:

• Shotgun cartridges are not needed to measurably reduce pigeon populations.
• What matters is continuity, not violence.
• Short-sighted political decisions can destroy successful animal welfare projects within a few months.

Eight years of data from Catalonia: Fewer pigeons, halved costs

Perhaps the most important new work comes from Catalonia. A 2024 study evaluated up to eight years of use of nicarbazine feed in 24 cities and municipalities.

The key findings:

• On average, the pigeon population declined by around 12 percent per year.
• In 68 percent of the municipalities, the total annual costs were halved after three years because fewer pigeons also mean less food and less effort.
• Non-target species were rarely observed feeding and in such small quantities that no relevant impact on reproduction was detected.

The authors conclude that nicarbazine is an "effective and selective method in terms of animal welfare" for reducing pigeon populations without trapping, without killing and without the usual side effects of hunting-based "problem solving".

This brings us full circle: Previous studies from Genoa (eight years of Ovistop use) and Barcelona (three years of a contraception program in conflict-prone pigeon colonies) already showed significant reductions and improved public acceptance when reproduction is limited rather than killing.

Is Ovistop dangerous for pigeons?

Critics often refer to Ovistop as "poisoning" pigeons. However, a review of the scientific literature largely contradicts this claim. Ovistop contains nicarbazine in a dosage that specifically targets the reproductive system: the drug temporarily disrupts the formation of a stable eggshell, thus reducing the hatching rate. It does not kill the birds; it renders them infertile for a limited period.

The crucial point is:

• The effect only occurs if pigeons eat the intended amount for several consecutive days. Individual grains are practically ineffective.
• Once treatment is stopped, reproduction returns to normal, so the effects are reversible.
• The large-scale evaluations from Spain and Italy did not describe any systematic health problems in the animals: The pigeons are not being "treated to be sick", but are simply reproducing less successfully.

Toxicological assessments also classify nicarbazine as practically non-toxic in birds and mammals; the relevant effects occur at the level of reproduction, not as classic poisoning with organ damage or death.

Those who describe Ovistop as "dangerous" for pigeons are deliberately conflating two issues: Yes, the drug interferes with reproduction; that is precisely its purpose. But it does so without the massive suffering caused by trapping, neck breaking, or shotgunning. From an animal welfare perspective, it is difficult to justify why the targeted prevention of chicks should be considered more cruel than the routine killing of adult birds.

The Barcelona Controversy: How to Poorly Calculate a Method

Opponents of the method often cite a 2020 study from Barcelona that concluded nicarbazine had "no effect" on the pigeon population. This study is still cited in hunting circles to this day to portray birth control as naive or ineffective.

What is almost always omitted in the public debate:

• The study essentially only considered one year of treatment. However, population biology operates over multiple reproductive cycles.
• At the same time, the pigeon density increased by about 10 percent in the control areas, while it stagnated in the treatment area.
• More recent, significantly larger studies from Barcelona and across Catalonia clearly show declines over several years when the system is consistently implemented.

The supposed "refutation" of the contraceptive method thus turns out to be a classic sham debate, as is known from hunting arguments: An unfavorably designed or too short period is invoked to discredit an unwelcome alternative that does not fit into the worldview of the necessary cull.

Safety: Minimal risk to other species and birds of prey

A frequently raised objection is that nicarbazine could endanger other bird species or even birds of prey that eat pigeons. Here, too, the data has become more conclusive.

A 2023 review on the safety of nicarbazine in birds of prey concludes that secondary exposure through the consumption of treated pigeons is not expected to pose any acute or chronic risks. Nicarbazine is classified as "practically non-toxic" to birds and mammals; the only conceivable effect in non-target birds would be a temporary reduction in egg hatching rates with persistently high intake.

Furthermore, nicarbazine rapidly breaks down in the body into two compounds that, when separated, no longer have a contraceptive effect. Experts therefore consider it highly unlikely that birds of prey, which occasionally eat a treated pigeon, would receive a relevant dose.

Practical experience with several hundred pigeon colonies in Europe now shows the same picture:

• no documented cases of poisoning in birds of prey,
• no significant side effects in mammals,
• The effect on pigeons is completely reversible as soon as the feed is discontinued.

To speak of "poison", as is done in some hunting-related campaigns, is simply scientifically wrong.

Hunting logic under stress: What happens when you stop shooting?

Perhaps the most important question from an animal welfare perspective is: What does all this say about the basic assumptions of recreational hunting, which are also readily adopted in urban contexts?

The classic hunting story goes like this:

1. There are too many animals.
2. The only effective solution is to shoot them down.
3. All other methods are, at best, a supplement, and at worst, ideology.

In practice, birth control in pigeons shows the exact opposite:

• Populations can be reduced measurably and predictably without killing a single animal.
• Animals suffer less because they are not born in the first place, instead of dying after a mutilating shotgun blast.
• Costs will decrease in the medium term, instead of exploding in an endless spiral of capture and killing operations.

What the pigeon demonstrates in urban areas can be directly applied to other wildlife issues: Where politically desired, alternatives to shooting suddenly become possible, be it through birth control, habitat management or consistent adaptation of human behavior.

The real constant is not "too much game", but a system that profits from hunting and ideologically charges it.

What cities in Switzerland and the German-speaking world could learn from this

While Brussels, Zaventem, Barcelona, and Genoa work with concrete figures, many Swiss and German municipalities still resort to buzzwords. They speak of "exploding pigeon populations," "hygiene weapons," and "rats of the air." And the corresponding services are offered by culling squads and pest control companies.

International experience with nicarbazine-based feed suggests a different strategy:

• First count, don't make claims. Thorough assessments are the basis of any action.
• Then address the root cause: regulate people's feeding habits, improve waste management, defuse breeding grounds and additionally implement birth control.
• Creating transparency: The population has a right to know whether their community systematically kills animals even though there are demonstrably more animal-friendly alternatives.

The example of Ixelles shows that the method can fail politically: success is no guarantee of continuation if short-term budget debates or ideological reservations are given more importance than animal welfare and long-term effectiveness.

That is precisely why a critical public is needed to ask probing questions when authorities reflexively resort to firearms or when hunting-related circles stir up sentiment against non-lethal methods with supposedly "scientific" counterarguments.

The new data from Belgium, Catalonia, and Italy confirm what animal rights activists have been demanding for years: We don't have to kill animals to defuse conflicts. We must be willing to change how we treat them.

Pigeon control is not a romantic urban ecology project, but a soberly calculated alternative to the logic of hunting. It reduces populations, saves money, protects animals, and gradually undermines the narrative of supposedly unavoidable culling.

The question, therefore, is not whether such methods work. The question is how long politicians and the hunting lobby will continue to try to ignore them.