Cities harbor a surprisingly high diversity of species. Zurich, for example, is home to numerous mammals, from native beavers to introduced raccoons.

However, we have data on only a few of these species.  These shy "wild neighbors" are mostly nocturnal, which makes it difficult to estimate their numbers and distribution. As cities become denser and the habitats shrink, the animals come under increasing pressure.

Efficient monitoring is therefore key to better protecting nature and enabling sustainable coexistence with wildlife.

We compared several methods: wildlife cameras with and without camouflage boxes, sightings by the population, and eDNA from Zurich streams.