Belgium: Contraceptive Grains to Control Pigeon Population

This method has already led to a 40% reduction in the number of pigeons in Ixelles within three years and is inspiring other cities across Europe.

On an autumn morning in Ixelles, a dispenser for contraceptive grains is being filled at the Place de la Croix-Rouge. The pigeons hiding in the trees initially remain calm. Fifteen minutes later, at 7:45 a.m., the food distribution works better and nearly 200 pigeons descend on the grains.

«We wanted to find a solution that reduces the pigeon population while also respecting animal welfare,» says Yves Rouyet, municipal councillor of Ixelles.

Instead of killing pigeons — an approach criticised by animal welfare advocates — the municipality has been using contraceptive grains since 2021. This has enabled a reduction of approximately 40% in the pigeon population in Ixelles.

The municipality received numerous complaints about the large number of pigeons. «The sheer numbers and the droppings of the pigeons are damaging buildings,» explains Rouyet.

The dispensers are located at six sites within the municipality and are refilled twice each morning. This measure costs the municipality 10,000 euros per dispenser annually.

The pigeon is a gregarious animal, and within a colony there is a clear hierarchy, particularly when it comes to feeding. The dominant animals make up 15% of the flock, receive the most food and reproduce rapidly. It is this group that Vets For City Pigeons targets. By focusing on this group, the entire population is indirectly reached. By feeding Ovistop during the breeding season, the dominant group automatically ingests the correct dose of the active product. The result: fewer offspring.

Pigeons are very site-loyal. That is why the managed dovecote model (Augsburg model) does not work everywhere, also because no suitable location can be found, such as at train stations. Therefore, contraception can be an additional piece of the puzzle in pigeon management.

Pigeons may notice, after multiple breeding cycles and egg removal, that something is not right and begin seeking new or former nesting sites away from the managed dovecote.

«It is better to involve feeders»

The municipality has also included people who feed pigeons in the program and has stopped imposing fines. «It is better to integrate them into the system,» says Rouyet, speaking to euronews.

Volunteers, mostly women, are allowed to distribute grain at specific locations and times in order to guide the pigeons.

Stéphanie De Jonghe, who has been feeding pigeons for ten years and has now been working within the program for four years, explains: «I fed them every day, because they need food.»

De Jonghe emphasizes that the pigeons must be fed to prevent them from becoming malnourished. She believes it would be animal cruelty to give them only the contraceptive, as this would lead to a rapid reduction.

The activist points out that pigeons are highly dependent on humans, as they were originally bred and then came to cities without receiving what they need.

Other European cities such as Brussels, Strasbourg, Barcelona and many more have also introduced systems using contraceptive grain (OvoControl) and are likewise supported by animal welfare organizations, on the basis of specialist literature and case studies.

Alternative Facts

There are also critical voices regarding OvoControl, with some making rather adventurous claims.

The fact that it is mostly veterinarians and animal welfare advocates who distribute OvoControl — or rather the active ingredient nicarbazin — on the ground (in Belgium alone at over 100 locations), and who apparently report no negative experiences or observations regarding the critics' prejudices, speaks for itself.

Ovistop has been in use for decades and there are no empirical studies on harmful effects in pigeons at low doses. Not from ETH Zurich either. According to studies, pigeons can experience neither acute nor chronic intoxication from the medication. The results of the studies clearly show that the administration of nicarbazin can lead to a reduction in the number of colony-forming pigeons without causing lethal effects or notable side effects.

Studies:

• Botstiber Institute for Wildlife Fertility Control
• Wikipedia
• Arxius de Miscel·lània Zoològica
• Efficacy of nicarbazin (Ovistop®) in the containment and reduction of the populations of feral pigeons (Columba livia var. domestica) in the city of Genoa, Italy: a retrospective evaluation
• PAZ
• Controlling urban pigeons populations humanely
• Use of Fertility Control (Nicarbazin) in Barcelona: An Effective yet Respectful Method towards Animal Welfare for the Management of Conflictive Feral Pigeon Colonies
• Pigeons in Urban Landscapes
• On the use of pharmacological sterilisation to control feral pigeon populations
• Cities Are Testing Birth Control to Solve Pigeon Problems

Were this not the case, there would hardly be an EU-wide approval. Ovistop is used in pigeons not only in several European countries — Italy (since 1996), Spain, Hungary, France, Malta, Belgium, Austria, and Germany since spring 2023 — but worldwide.

Those who advocate for Ovistop in German-speaking countries face massive pressure from aggressive egg thieves. Interestingly, it is precisely these circles that demand animal testing to justify their claims about something that has already been tried and tested for decades.

The medication seems to us to be a suitable means of countering the oversized pigeon population with all its side effects. What we have done so far — feeding the pigeons and replacing the eggs — was ultimately not that successful. Martin Adamski, Head of Environmental Affairs, Bielefeld

The Austrian city of Linz states that the population has declined by more than half since the start of the Ovistop project in 2001. 

Medications in human and veterinary medicine can always affect others as well — antibiotic resistance being one example. Every medication, whether of plant-based or synthetic origin, can have side effects.

Those who also do not generally opt for organic food or plant-based nutrition distribute disease-causing toxins such as traces of antibiotics, hormones, genetically modified feed, pesticides, sprays, herbicides, etc., which are demonstrably harmful to health and damage the soil, the environment, drinking water, and living beings.

Under Art. 5 Para. 3 of the Federal Act on Hunting and the Protection of Wild Mammals and Birds (Hunting Act, JSG, SR 992.0), urban pigeons are considered feral domestic pigeons that may be hunted throughout the year, which according to IG Wild beim Wild does not constitute a recommendable pigeon management approach.