Plaza pigeons in Bogotá: a matter of public health and animal welfare

Anyone who has ever walked through the center of Bogotá will remember seeing a large number of pigeons fluttering in the Plaza de Bolívar and on the roofs and cornices of the buildings. The collective imagination that exists around these birds is that they are “dirty and annoying.” In fact, you often hear some citizens refer to them in a derogatory way: they call them “flying rats.” On the other hand, there are those who feel sympathy, feed them corn and take photos with them.

Although the market pigeon (Columba livia) is quite typical in the city, its uncontrolled reproduction and growth represent a serious risk to public health, as it can transmit a variety of diseases to humans through contact or prolonged exposure to its feces and feathers. In addition, having too many pigeons in an urban environment like Bogotá affects their health and living conditions. Many of them suffer from serious illnesses, such as tumors or the loss of their legs.

“When there is a large concentration of pigeons, there is also a large concentration of faeces and waste. This means that the infectious agents they carry (fungi, bacteria or viruses) can be transmitted more easily to humans. Pigeons’ feet are in constant contact with their faeces, especially in their nests. When they move through crowded spaces, such as squares, there is a greater risk of transmission to people, through direct contact or through the respiratory tract,” explains María Ángela Echeverry, a doctor in ecology and evolutionary biology.

According to the expert, the high density of pigeons can also be a risk for domestic animals and even wildlife, although this has not been studied in depth. What has been proven is that contact with pigeon droppings poses a risk for humans of contracting histoplasmosis, cryptococcosis and psittacosis.

What is the District doing to control pigeon overpopulation?

Since 2018, the Ministry of the Environment, through the District Institute for Animal Protection and Welfare (IDPYBA), created the Sinantropics program, which works for the population management of pigeons in the city. According to Mauricio Cano, leader of the area, to carry out this work, different strategies have been implemented such as clinical care, non-bloody perching barriers, and the discarding of nests with eggs, among others.

Within the clinical part, one of the most important measures is the sterilization of pigeons using the minimally invasive laparoscopy technique. According to Cano, this procedure guarantees a quick recovery and lasts less than 15 minutes with local anesthesia. “The Institute has been doing this pilot process with very good results. Males are sterilized, not females. “It is done like a vasectomy and it is a population management method.”

However, currently there are doubts and reservations regarding these surgical procedures. Biologist and researcher María Echeverry explains that sterilizations are a questionable measure in terms of effectiveness and usefulness, especially because there seems to be an imbalance between the cost and the final benefit: “Each of these surgeries have quite high costs. The results are not so satisfactory if we take into account the pigeons that already exist. They reproduce less, yes, but they will continue to affect. That does not help us control public health problems. Furthermore, this budget that is invested could be used in a much more efficient and relevant way in other conservation, adaptation and education processes.”

Although there is no updated data on the costs of these procedures, in 2022, the leader of the Sinantrópicos program informed W Radio that, during the pilot plan, the operation of each specimen cost $80,000. Likewise, he assured that public resources were not being allocated to the project, but that the research was funded by the Antonio Nariño University.

For Echeverry, measures such as non-invasive anti-perching barriers (sloping glass or acrylic surfaces that prevent birds from perching on buildings) and the disposal of nests with eggs can be more effective and are a good first step. However, he clarifies that it is necessary to implement several alternatives at the same time to successfully control the population of this species.

It should be noted that over the years, different cities around the world have implemented several of these methods. A study carried out in Slovenia concluded that egg removal has great potential to reduce the size of pigeon populations, but requires synergy with other strategies such as community education.

In other places such as Barcelona, ​​Spain, contraceptive methods have been implemented. This measure basically consists of the addition of a chemical substance or controlled contraceptive to the food consumed by pigeons in the wild on a permanent basis to prevent the eggs from becoming fertile and being discarded, thus controlling the population.

The strategy has raised doubts among some experts and has been the subject of study in several places. Although in some cases a reduction in the size of the population and an improvement in the health of the pigeons have been reported, specialists say that there is no long-term evidence. “In other parts of the world, especially in Europe, this technique was being carried out. However, municipalities such as those in France and Spain realised that it was not as effective in the long term,” explains biologist Oswaldo Cortes.

Other measures

The IDPYBA has the first Pigeon Care Center (CAP), the only one of its kind in Colombia. There, the sickest specimens receive all the necessary medical treatment and once they recover, they are released into their natural environment, that is, green areas of cities such as parks.

“We are proud to be a reference in a clinic that treats pigeons in a high state of illness and vulnerability. We provide them with care, we deworm them, we remove flea marks, we smooth their beaks and file their claws. In general, this strategy has been very well received and successful; we have treated more than 2,500 pigeons,” Cano reports.

The Sinantrópicos program also has a very important social axis that is responsible for developing awareness campaigns through talks and workshops. Its purpose is for residents and visitors of the city to know how to properly interact with these birds. To do this, they have a system of attention and listening to citizens. “We have made 1,600 requests since we started, 95% of which are focused on the management of birds. We make visits and there we explain to citizens how to properly manage pigeon populations,” says Cano.

The program leader is emphatic in saying that all the strategies implemented by the District to control the pigeon population in Bogotá are governed by the parameters of animal welfare and protection. This guarantees respect for the species: “The last thing we want is for people to poison or kill them. We take a comprehensive approach, that is, not only from a clinical perspective, but also from a social and cultural perspective. Pigeons should not be mistreated, they should be treated with respect. We consider the risks of overpopulation of this species, so the solution is management and control with respect.”

According to IDPYBA, the measures implemented so far have shown positive results. The entity’s data indicate that in 2018 the Plaza de Bolívar had 1,862 pigeons. At this time, the censuses report a population between 450 and 500. “In Lourdes there were up to 600 pigeons. Right now there are 200. In Plaza España we started with an average of 1,100. We are already at 300,” adds Cano. The District’s purpose is not to eliminate these birds, but to control their population and ensure the good condition of those that already live in the city.

How should we relate to pigeons?

Pigeons tend to concentrate in places such as squares, squares and cement parks. They go to these spaces for the food that people provide them, mainly yellow corn. However, this practice can be quite harmful for several reasons, both for birds and for citizens.

According to biologist Oswaldo Cortes, this type of pigeons do not eat processed or cooked foods. They only eat raw seeds. They cannot be given yellow corn because it causes nutritional deficiencies. But the biggest problem of all is that this behavior encourages their uncontrolled reproduction in the city.

In Bogotá, according to IDPYBA, the overpopulation of pigeons is due to the oversupply of food provided by citizens, tourists and visitors. These actions not only affect the health and well-being of pigeons, but also alter their natural behavior, generating dependence on humans.

María Echeverry agrees with this: “Our relationship with pigeons should really be distant. We should not be in so much contact with them or generate mechanisms so that they continue to reproduce without control. Do not feed them in any way. It is not a question of giving them the right food or not, but rather this species must face the same difficulties and situations that all the others face. The pigeons are not going to die of hunger because we do not feed them, they know how to look for their own food.”

The District also invites citizens to respect and care for pigeons without resorting to “mascotism”, that is, the retention of the species in homes as if they were pets.

Although it is not advisable to have contact with them, you should not cause them harm either. The IDPYBA has recorded cases of people mistreating them by throwing objects at them, putting poison at them, installing electric fences or chemical barriers to keep them away. These birds in controlled populations are harmless and there is no reason to threaten their well-being. Likewise, avoid contact with excreta, feathers and other waste.

Finally, the authorities encourage citizens to learn about the species and know how to relate to it. If these birds are causing any type of problem, non-invasive barriers can be used, always under the advice of IDPYBA.