Wild boar in urban space

Wild boar have already established stable populations in many European cities. Effective and efficient population management is needed to avoid human-wildlife conflicts. For its implementation, it has to be clarified whether these urban populations are self-sustaining or require a constant influx of animals from surrounding areas (source-sink dynamics). We are investigating this in two European cities, namely Berlin and with our collaborative partner Wildlife Ecology & Health in Barcelona.

^{Outskirts of Barcelona: Anesthetization of a wild boar to attach a GPS transmitter collar. The anesthetic is administered by means of a blowpipe dart.
(© Foto: WE&H – Wildlife Ecology & Health)}

Project details

Duration:	2018 - indefinite (long-term planned)
Third-party funded:	Third-party co-financed
Involved Department(s):	Dept. of Evolutionary Genetics, Dept. of Ecological Dynamics
Leibniz-IZW Project Leader(s):	Jörns Fickel, Stephanie Kramer-Schadt
Leibniz-IZW Project Team:	Anke Schmidt (Dept. of Evolutionary Genetics), Jörns Fickel (Dept. of Evolutionary Genetics), Justus Hagemann (former Dept. of Evolutionary Genetics, now University Potsdam), Stephanie Kramer-Schadt (Dept. of Ecological Dynamics)
Consortium Partner(s):	Jorge Ramón Lopez Olvera (Universidad Autónoma de Barcelona, WE&H – Wildlife Ecology & Health)
Current Funding Organisation:	none
Research Foci:	Determination of the structure of populations in Berlin and Barcelona, determination of migration routes, hybridizations Understanding traits and evolutionary adaptations

Urban sprawl has also resulted in the permanent presence of large mammal species in urban areas, causing an increased frequency of human–wildlife conflicts. Among the first of these large mammal species was also wild boar (Sus scrofa), a species that successfully established permanent populations in many cities in Europe. Surprisingly, little is known of colonization processes, dispersal patterns or connectivity among urban populations and among urban and rural populations, hampering the development of effective and efficient management plans.

To gain these lacking insights, we are working in an international collaborative project to genetically study urban wild boar populations in Berlin and Barcelona, which will be compared with simultaneously studied populations living in surrounding rural areas. The comparison will be done via genotyping of wild boars at genetic markers, with ~400 wild boars being studied in each of the two cities. Using genetic clustering algorithms, we analyse these wild boar populations for the presence of a genetic structure that would allow us to draw conclusions about the colonization history of both cities by wild boars (looking for city-specific and/or general aspects in the colonization processes).

Results obtained so far indicate that there are many similarities in the processes by which wild boars have colonized Berlin and Barcelona. Whether these can be generalized for all larger cities remains to be seen. In both cities urban wild boars form a genotypic cluster, clearly distinguishable from the genotypic cluster formed by rural conspecifics. Such a structured metapopulation allows the assignment of animals of unknown origin to either one of the two clusters, necessary to determine dispersal directions. It also allows to measure strength and direction of gene-flow between rural and urban populations via the detection and the number of admixed individuals.

Our results should have immediate implications for management strategies for urban wild boar populations in Berlin and Barcelona, as they show that there is not only a pronounced genetic differentiation between urban and rural wild boar populations, but also persistent source-sink-dynamics between urban and surrounding areas (more pronounced in Berlin, somewhat weaker in Barcelona). Therefore, it is important that cities and neighbouring municipalities develop joint management plans to effectively and efficiently control the wild boar population and reduce and avoid conflicts in urban areas in the long term.

^{After the animal is under anesthesia, the GPS transmitter collar is attached (© Photo: Department "Ecological Dynamics")}

Selected Publications

Stillfried M, Fickel J, Börner K, Wittstatt U, Heddergott M, Ortmann S, Kramer-Schadt S, Frantz AC (2017). Do cities represent sources, sinks or isolated islands for urban wild boar population structure? Journal of Applied Ecology 54: 272-281.

Hagemann J, Conejero C, Stillfried M, Mentaberre G, Castillo-Contreras R, Fickel J, López-Olvera JR (2022). Genetic population structure defines wild boar as an urban exploiter species in Barcelona, Spain. Science of the Total Environment 833: 155126.