Tkestrels and blackbirds, foxes and hedgehogs are wild animals that have also become at home in cities. In some places, the wild boar is also one of them. The massive bristly animals sometimes seem to feel completely at home in parks and gardens on the outskirts of town. Not only nutritious waste like discarded leftovers are a found food for them there. Wild boar also like to rummage in the ground for worms, snails and other delicacies. Plowing up manicured lawns and flower beds with their muscular trunks makes them unpopular. But what annoys garden owners and park visitors can have positive consequences for nature conservation. This is what scientists working with Valentin Cabon and Miriam Bùi from the Technical University of Berlin found out. In the urban area of Berlin, the researchers studied the influence of busily rooting wild boars on flora and fauna.
With the largest population in Germany, Berlin is also the capital of the urban wild boar, so to speak. 22 Dry grasslands on sandy soil served as research objects. On these barren meadows, all located near the forest or in forest clearings, Cabon and his colleagues always came across more or less extensive burial tracks of wild boar. For the most part, however, the raised soil was already populated by plants. At this stage, the areas disturbed by burrowing pig snouts apparently had little effect on the flora: there was no connection either with the total number of plant species or with the number and frequency of plant species that are on the Red List of Threatened Species.
The sand lizard knows how to use sparse vegetation
The situation is different with some animal species. Grasshoppers, for example, who cavort on the dry, sandy grassland, do not react so indifferently. As Cabon’s researchers report in the “Scientific Reports”, soil freshly turned over by pig snouts has a negative effect on the diversity of grasshopper species. However, if the wild boar tracks were again covered by new growth, the Berlin biologists observed the opposite effect: the species diversity of the locusts increased significantly.
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wildlife in the city
Three species included in the Red List of Threatened Species also clearly benefited from older burial tracks. The Italian Grasshopper (Calliptamus italicus) was even thought to be extinct in Berlin until recently. Contrary to what its name suggests, this grasshopper, which shows its red colored lower legs and hind wings when flying away, is quite native to Germany. But only on particularly warm and dry terrain.
Also the sand lizard (Lacerta agilis) benefits from wild boar churned up and freshly overgrown soil. Finally, this vulnerable lizard, whose males stand out with bright green side stripes during mating season, needs areas with sparse vegetation. Not only to warm up there with a sunbath if necessary. Sand lizards also bury their eggs in such places to let the sun hatch them.
Cabon and his colleagues conclude that where wild boar are part of the native fauna, their burrowing work is not necessarily harmful from an ecological perspective. The fact that the bristly animals are often busy plowing the ground can be seen as a natural disturbance that can even be beneficial for biodiversity and Red List species.
