How do foxes, martens and raccoons get along in the big city? How do they adapt their behavior to the dense presence of people and also their pets? A citizen science project in Berlin investigated this. The scientists were also able to observe how the lockdowns affected the behavior of the wild animals. At the same time, they got an insight into how the predatory wild animals and domestic animals interact with each other in the city.
Avoid or compete, eat or be eaten, exploit or work together – animal and plant species communities are shaped by the diverse interactions of their species. In cities, these rules of the game for coexistence are also fundamentally influenced by the presence of people and their pets.
Photo traps in Berlin gardens
Scientists from the Leibniz Institute for Zoo and Wildlife Research (Leibniz -IZW) in the last few years with a Citizen Science project. Garden owners all over Berlin set up a wildlife camera in their garden that recorded animal sightings as soon as their motion sensor detected movement.
“We humans exert strong selection pressures on wild animal species and thereby change their behavior and their way of life,” explains Stephanie Kramer-Schadt from Leibniz-IZW. The 10,000 photos from Berlin gardens created in the five field phases should help to research these influences more closely. The team chose private gardens as study areas because they represent an important food source for wild animals with compost, vegetable patches, fruit trees or pet food. At the same time, they are places where there is a high probability of unwanted encounters with people or pets.
Unexpected but welcome, the research team saw a special feature from spring 2020: the corona pandemic and the associated restrictions on public life for human city dwellers. “The lockdowns were lucky for research because they gave us the opportunity to investigate how our wild neighbors behave when people suddenly disappear from urban areas,” says Kramer-Schadt.
Wild animals in a time lag
The evaluations showed: During the lockdowns there were changes in the behavior of the wild animals: The presence of foxes, martens and raccoons in gardens increased overall during the curfews, which is probably due to the generally lower activity of people in urban areas. But because more people also used their gardens during the day, the wild animals avoided the night more than before.
Regardless of the lockdowns, all wildlife species studied tolerated the presence of humans to some extent but avoided real encounters with them. Fox, martens and raccoons therefore mostly concentrated their activity in the gardens outside of lockdowns on the night and thus on the time when people are least active. At the same time, there were also clear signs of avoidance behavior between the various wild animal species: the frequency and presence of the three wild animal species followed a similar spatial pattern. In terms of time, however, the scientists discovered a systematic offset: the species avoided each other and used the same areas separately.
Domestic cats were an exception: they showed no avoidance pattern over time compared to the other species. According to scientists, suggests a hierarchy of animal species. The cat, which is closely related to humans, is apparently the dominant species – although it is physically inferior to wild animals. As the researchers explain, urban humans play the role of a “super key species” and their domestic animals dominate local wildlife – even species that can cope relatively well with human presence. “Our study provides new insights into the rules that underlie the interactions in a community of medium-sized predators in an urban environment,” says first author Julie Louvrier from Leibniz-IZW.
Source: Leibniz Institute for Zoo and Wildlife Research (IZW) in the Forschungsverbund Berlin eV; Technical article: Journal of Animal Ecology, doi: 10.1111 / 1365-2656.13635