image of Withcall & South Willingham Tunnels

Withcall & South Willingham SSSI Bat Hibernation Surveys

Withcall & South Willingham Tunnels lie on the old Barney to Louth railway line. Work on tunnels started in January 1852 and were completed in 1876. The last train passed through on 17th September 1956 and the line was closed following the Government report by Dr Beeching.

Members of Lincolnshire Bat Group first inspected the tunnels for signs of use by bats in the mid-1980’s, but it wasn’t until 1996 that LBG member Garry Steele began recording the results in a systematic way. On 9 July 2002, English Nature (now Natural England) designated the tunnels as a Site of Special Scientific Interest SSSI for their nationally important assemblage of hibernating bats. In 2007, Garry passed the baton to Dave Hughes who co-ordinates the surveys today
image of frosted mnatThe data we collect from these very important sites are entered into the Bat Conservation Trust (BCT) National Bat Monitoring Programme which includes data collected from hibernation sites across the UK. BCT’s annual report is available online at

Over the years, the annual tunnel surveys have been a become a mainstay of the LBG survey programme and are extremely popular, attracting bat enthusiasts from far and wide. In a good year, we get to see over 300 bats of six species in hibernation.

How to get Involved

The surveys are carried out in January and February. If you want to take part, just join the Lincolnshire Bat Group (a rather modest £5 per year) and contact Dave once the dates are published in the Autumn newsletter. Be quick though – places are very limited in order to minimise disturbance to the bats, and they book up fast!