GPR badger survey

Badger setts are often located in areas of woodland, or under clumps of bushes, hedges, or brambles. GPR needs to be in direct contact with the ground to work efficiently and therefor these obstructions can prevent the radar being used directly over the sett. In many cases we have scanned the ground around the obstructions covering a known set to look for spurious tunnels, whilst being unable to scan the sett itself.

For the areas which are surveyed, they should first have vegetation cropped down to ground level, with no protruding stumps, grass ideally will be cut.

Badger tunnels take indirect paths through the ground, this makes data interpretation much more difficult than for something more uniform, like a pipe.

In the end GPR is rarely able to fully ‘map’ a badger sett, but it is often possible to determine the extents of a sett, to determine the areas with the main activity, to verify where tunnels are not present, and to map which elements which can be seen. This information will help an ecologist or planning officer to make informed decisions about a proposed developments potential impact on the badgers, in compliance with the law.

A GPR survey can be used to map the extents of a badger sett, and potentially map some of the tunnels and chambers within the sett. This information can be used to inform planning and to ensure that developments do not encroach unduly onto a badger sett and can instead be planned around them or inform a decision (backed by an ecologist) to close a sett and relocate the badgers.

It can be necessary to map spurious tunnels and see where they lead, or on other occasions, a GPR survey can be used to confirm that badger tunnels are not present in an area and allow building works to commence or continue, for example, in an area with known badger activity nearby.

In summary GPR can be used to:

-detect badger tunnels and chambers

-map the extents of badger sets

-confirm that badgers’ setts or tunnels are not present in a given area.

Surveyors will attend site and collect GPR data for the area of interest.

Depending on the type of survey, it is likely that the data will be collected in an orthogonal grid with relatively close spacing, or using a GPR array, and the data will be saved for office-based post processing and interpretation.

The data would then be processed, viewed and interpreted from the office to locate any evidence of the badger tunnels and compile them together into a drawing.

In the case of surveys with an onsite interpretation element, lines of data may be collected and interpreted directly on site, with the locations of any tunnels marked directly onto the ground using temporary paint.

The locations of those lines would then be recorded for the report / drawing if appropriate.

Typically, office based offsite processing is more appropriate for badger surveys.

In the UK, Badgers are protected under the Protection of Badgers Act 1992. It is illegal to hunt, kill, injure, or otherwise disturb a badger, or to damage, destroy, allow a dog to enter, or to block access to their setts.

Badgers have become relatively successful mammals and are widespread throughout the UK (and other countries), as a result of this, and the wide extents of their setts, it is easy to fall foul of the law if adequate measures are not taken to protect them.