Practical use of GPS-localization of Feral Pigeons Columba livia in the urban environment

Feral Pigeons Columba livia live in almost every city in the world and are often a problem because of their large numbers. Knowledge of the spatial use of the city by Pigeons is important for population control management. Previous studies have given contradictory results concerning the urban area used by Pigeons and their feeding strategies. We used the global positioning system (GPS) to investigate the spatial use of urban habitats by Feral Pigeons in Basel, Switzerland. The total ranges of the subpopulations varied between 32.9 and 306.3 ha and overlapped partially. The total ranges of individual Feral Pigeons varied between 2.9 and 150.6 ha. Pigeons from a single loft had one or two main feeding places and up to 33 other places that they used for occasional feeding or for resting. Individual Pigeons visited up to ten different locations. Our study shows that Feral Pigeons have individual feeding strategies and are flexible enough to adapt to different urban environments. Therefore, we must contradict the view that Feral Pigeons are dependent on intentional feeding by humans and are unable to fly more than a few hundred metres. Our results are important for Pigeon control management, biomonitoring projects using Feral Pigeons as indicators of pollution and the study of disease transmission. Pigeon control management based on killing has only a local and temporary effect, because Pigeon subpopulations are interconnected. Pigeons from other areas will replace removed individuals. Biomonitoring projects usually assume that Pigeons show a limited mobility. Our study reveals that this is not a generally valid assumption. Because Pigeon subpopulations are connected, diseases can be spread over an entire urban area. This is of human concern, as seven infectious diseases have been shown to be transmitted from Feral Pigeons to humans.