For more than two years, the Institute of Forest and Wildlife Protection at Mendel University’s Faculty of Forestry and Wood Science (LFS), in cooperation with Masaryk University, has been carrying out research into Brno’s wildlife, focusing on the common pigeon and in particular its abundance, distribution in the city, feeding behaviour, and centres of occurrence. Experts are also studying the health condition of pigeons, including the impact of these birds on human life.
The first step in researching wild pigeons in Brno was to determine their numbers. However, only a fraction of the pigeons can be seen in the city centre. They mainly live on the roofs of tall buildings, making them difficult to count.
“First we went around the city and found out which corridors the pigeons use to fly from the city to the fields, and we set up counters in the most frequented places,” explained Miloslav Homolka, a zoologist at the Czech Academy of Sciences who is working on the research with colleagues from the LDF. “From morning to noon, we counted the pigeons flying out of the city to find food, about 10,000 a day. This gave us an idea of the minimum number of pigeons in the city.”
Homolka said that they also used a traditional ornithological approach. They divided an area of the city into sectors with similar characteristics, such as prefabricated housing estates and central areas with tall old buildings. A standard observational census was then carried out by walking through each area and counting the pigeons visible. This method provided an additional estimate of the minimum pigeon population in the model area, while also revealing differences in pigeon numbers in different environments. In total, over 3,000 pigeons were counted in a 13-square-kilometre area, representing only a fraction of the actual population.
The total number of pigeons in Brno is estimated at at least 15-20,000 individuals. The proportion of migratory pigeons varies from 10% to 90%, with an average of 60% of individuals flying into fields. At least 10,000 pigeons fly to the surrounding fields every day, while the rest feed in the city.
The researchers recorded the highest number of pigeons in the centre of the city, bounded by an inner circle, where they counted more than 1,000 birds; on the contrary, they found that pigeons did not occur in the peripheral areas of the city with low-rise buildings. Each suitable environment is inhabited by a flock of pigeons that has its home district there. This prevents mixing and conflicts between flocks.
The research also focuses on the feeding behaviour of the pigeons. It has been shown that flocks that have enough food around their nesting area do not fly out of the city. The food analysis, which included 4,000 samples, showed that flocks that settled in Zelný trh, near the former Tesco store on Dornych, or on Mendlovo náměstí did not fly to the fields.
However, sites with sufficient food are in the minority in Brno. The majority are places where pigeons have enough nesting places but not enough food. These pigeons have to go to the fields to find food. “There can be more than 1,000 birds in a field. Large flocks are an advantage for the pigeons, as they provide greater safety from predators,” said Homolka.
The researchers also obtained interesting results by analysing the pigeons’ droppings. “By analysing fifty samples from one flock on one day, we found that the flock consisted of five groups that differed in the composition of their food. This suggests that birds in a flock do not fly together to feed, but rather in smaller groups, which allows them to use different food sources more efficiently,” Homolka explained.
Sampling the movement of pigeons and their habits is important for researchers to gain an idea of the behaviour and life of pigeons. The conclusions, including recommendations on the issue of human-pigeon coexistence in the city and the need for a possible reduction in the number of wild pigeons, will then be submitted to the Czech Technology Agency and state administration officials.
However, the experts already admit that the situation has no clear solution. “Brno has a stable number of pigeons and the population has a certain structure. If we prevent pigeons from nesting on buildings where they have optimal conditions, they will no longer have much space to move to, or they will move to unsuitable conditions, and the result will be a decrease in their density,” said Jiří Kamler from the Institute of Forest Protection and Hunting.
Given the diversity of conditions in the city, Kamler believes that there is no single solution to reducing the number of wild pigeons, and that responsibility for reducing their numbers should lie primarily with the owners of the properties where they nest.
The project, which focuses on urban wildlife, both terrestrial and aquatic, will be completed in December 2025.
