The urban pigeon population (Columba livia) in Pisa has declined by around 60% over the past twenty years. The finding comes from a University of Pisa study published in the journal Urban Ecosystems, which analysed changes in the pigeon population in the city between 2004 and 2024. During this period, the estimated number of pigeons fell from around 13,000 to fewer than 5,000. The decline was particularly marked in the historic city centre, where the population dropped by more than 65%, from approximately 6,000 to fewer than 1,000 birds.
“Having data covering such a long period is quite exceptional and has allowed us to observe changes that would normally escape short-term studies,” explains Dimitri Giunchi, Professor of Ethology in the Department of Biology at the University of Pisa.
According to the study, the decline cannot be attributed to a single cause. Rather, it appears to result from the combined effect of several factors that have altered the urban environment and reduced the resources available to pigeons. Among these, the new waste management system appears to have played a significant role. The introduction of door-to-door waste collection and underground waste containers is likely to have reduced pigeons’ access to easily available food sources. Other contributing factors may include the effects of the COVID-19 pandemic and lockdown on the presence of people in the historic city centre.
“The urban pigeon population in Pisa has declined dramatically over the course of twenty years without any specific pigeon control programmes being implemented in the city,” says Giunchi. “The evidence suggests that the reduction is mainly linked to the reduced availability of resources rather than to culling carried out in surrounding agricultural areas. Given pigeons’ very high reproductive capacity, culling alone often fails to produce significant or lasting results.”
“This study demonstrates how long-term monitoring of urban wildlife populations, combined with careful management of the urban environment, can provide an effective model for coexistence with wildlife in cities,” Giunchi concludes. “In the case of pigeons, the most important measure remains reducing access to food sources associated with human activities by addressing the factors that favour their presence rather than targeting the birds themselves.”
The study, entitled Ecology Matters: A Long-Term Study on Population Trend of Feral Pigeons (Columba livia) in Pisa (Italy), was authored by Luca Marinoni, the study’s first author, together with Lorenzo Vanni, Giulia Cerritelli, Sara Cioccarelli, Anno Gagliardo, Resi Mencacci, Enrica Pollonara and Dimitri Giunchi, all from the University of Pisa.
