Bureau Waardenburg
Varkensmarkt 9
4101 CK Culemborg
the Netherlands
T: +31 (0) 345 512710
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Monitoring faunapassages
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Monitoring wildlife crossings

Wildlife crossings come is a variety of forms and sizes. There are ecoducts, badger tunnels, small animal tunnels, amphibian tunnels and extended banks or walkways above the waterline in pipes that pass under roads. Whether a specific crossing is of benefit to the target species has to be investigated by a field study. Fort this a number of techniques can be used.

At Bureau Waardenburg, we carry out research into the use of wildlife crossings through a number of methods that aim to reveal the species and numbers of animals using the crossing.

Tracks and signs

The first step almost always involves investigations into the tracks and signs that can be found. At ecoducts, larger tunnels and extended backs on underpasses, this is commonly carried out with the help of sand traps. These traps consist of a layer of fine sand, which is fine enough in which to detect the tracks of mice, amphibians, reptiles and even beetles.

On smaller bridges and tunnels ink traps can be used. These traps consist of an ink pad and a sheet of paper. As an animal walks over the trap it's track is left on the paper. The ink used is made from paraffin oil and carbon (both environmentally friendly products). At Bureau Waardenburg, we have built up a reference collection of tracks made during ink trapping. This includes relatively rare species such as the water shrew and sand lizard.

Research with infrared cameras

Besides tracks and signs, we also make use of infrared cameras and in particular on ecoducts. These cameras are automatically triggered whenever an animal comes into view. The presence of an animal is detected by a passive infrared (recording temperature differences) or motion detector. In this way the cameras work as a trap, taking images of the animals that pass by.

The advantage of monitoring wildlife crossings with the use of a camera traps over looking at tracks and signs is that additional information, such as behaviour, numbers and possible ages of animals can be collected. Camera traps can also continue working in heavy rain and wind, when tracks in sand traps are likely to be lost.