Otter tunnels

Otter tunnel and its direct environment (aerial image Dop20, LVermA Geo SH 2011)
photo from a wildlife camera

The Brandsau culvert under the busy highway between Kiebitzholm and Daldorf is a vital link between valuable wildlife habitats in Schleswig-Holstein. It forms a corridor for watermeadow species making their way between habitats divided by a major highway.

In particular it is hoped it will encourage the recolonisation of waterways and banks by the Eurasian river otter. While today’s wildlife culverts are built to a larger scale, the Brandsau culvert was constructed to a size suitable only for the use of waterlife, amphibians and smaller mammals. Larger creatures like otter and deer are reluctant to enter its confined space so are much less likely to use it to cross between habitats either side of the highway.

The natural wariness of the culvert exhibited by larger animals is compounded by its frequent use by people, both on foot and on bicycle. Rocks and blocks can create physical obstacles to deter human use, but these cannot be so big as to prevent larger animals (otter and deer) passing through. A more effective solution would be an awareness campaign to help people understand that their use of the culvert prevents endangered wildlife using it as a passage between habitats.

In addition, creating greater areas of watermeadow habitat on either side of the culvert would be beneficial. If the conditions are right for wildlife on the approaches to the culvert, it is likely that watermeadow species will establish a presence there in greater numbers. Increased populations will heighten the likelihood of some individuals passing through the culvert itself to find similar habitat on the other side of the highway.