Study to Monitor Temperature and Humidity in Bat Hibernacula

 

SUSSEX BAT GROUP

TEMPERATURE AND RELATIVE HUMIDITY MONITORING IN BAT HIBERNACULA OVER EXTENDED PERIODS

Background

Little information is available for the conditions that exist within the West Sussex bat hibernacula, either during the winter hibernation period or during the summer when bats may still use these tunnels for roosting. This sort of data will be particularly pertinent during the autumn when bats will be deciding if conditions in the hibernacula are right to start hibernation.

There are four tunnels in West Sussex that are regularly used by bats as hibernacula. These four tunnels are now gated to prevent disturbance to the bats. This is crucially important during the winter hibernation period. We do not have any consistent data regarding the differences in conditions between these tunnels during the winter or at any other time of year. Understanding these differences may have a bearing on the observed wide variation in use indicated by the winter bat counts.

Proposed Study

To locate data loggers within the tunnels, to record Temperature and Humidity through a full year with the potential to continue the recording over a number of years.

It is proposed to install two data loggers in each tunnel. One near to the tunnel entrance and one close to the centre of each tunnel. The data loggers will be installed at approximately head height to facilitate access for downloading data.

The data loggers will each be capable of recording approximately 8000 readings. This will allow the data loggers to be left unattended for long periods collecting the data. Thereby minimising the disturbance to any roosting or hibernating bats.

Data would be downloaded on a two monthly basis allowing for some monitoring of bat use during the summer and on each of the ‘normal' bat counting visits during the winter.

The personnel involved in the summer data collection / bat counts   would be strictly limited to a maximum of say two or three persons, including at least one appropriately licensed person, to minimise disturbance but ensure personnel safety.

Data collection personnel will be drawn from Sussex Bat Group members or hibernacula owners personnel only.

Data will be downloaded from the data loggers to a laptop PC or similar equipment.

Use of Collected Data

All collected data would be made available to the owners/controllers of the sites monitored and those organisations that provide the funding for the project and in addition, Sussex Bat Group, Natural England and The Sussex Biological Record Centre (if not included in any of the above interested parties). Provided that the data was not used for financial gain or published without the consent of the Sussex Bat Group.

These data should help with decisions regarding the future management of the hibernacula particularly and to inform decisions regarding any proposed changes to the hibernacula that may alter the conditions. i.e. changes to ‘improve' hibernacula that appear to have a low use by bats.

Contributors

SUSSEX BAT GROUP would like to extend their thanks to the following organisations that have generously contributed to making this study possible.

Sussex Biological Record Centre
Natural England
Sussex Bat Group
The National Trust
The Edward James Foundation, West Dean Estates
Low Weald Countryside Unit, WSCC

Martin Love

14 th April 2005