Berwick Wildlife Group Promoting wildlife within the Berwick area.

This page contains - A report to Spittal Improvement Trust by Berwick Wildlife Group - August 2006

General: Following a request from Spittal Improvement Trust for advice on the provision of batboxes at the Spa Well site, Berwick Wildlife Group conducted a bat survey on Thursday, 17th August, 2006. Present: Assisting with the survey were Fiona Aungier, Leslie Cook, David Johnston, Priscilla Simpson, Ann Thompson, Enid Turnbull and Margaret Williams from Berwick Wildlife Group. Also present were Mike Greener and Gillian Hunter from Spittal Improvement Trust. Conditions: The sky was overcast, with the threat of rain, during the period of the survey, which commenced at 21.00 hrs and was terminated at 21.40 hrs. Survey Method: The survey equipment used were two Batbox III bat detectors, each placed with a group, the one to survey the section of Main Street, opposite the Spa Well site and Spa Well Road, where there was reputed to be a house roost, the other to survey the site, and the adjacent Spa Well Terrace. Survey Results: Initially, a batcall was detected on Main Street, immediately opposite the Spa Well site, followed by a batcall, and bat sighting, in garden ground on the east side of the site. Further batcalls were identified along the Main Street house frontage, in the vicinity of Spa Well Road, on the seaward side of the street. The house roost was not confirmed. The group surveying the Spa Well site detected ‘long-range’ batcalls suggesting activity at the southern end of the site. These were verified by a series of strong batcalls, registered by the bat detector, between the two deciduous trees and the retaining wall on the southern boundary. Analysis: No connection was detected between the two areas where batcalls were registered. It seems reasonable to suggest that there may be two discrete colonies, the one using the Main Street frontage of houses on the seaward side of the street, where there are many trees of medium height in medium sized gardens; the other frequenting a feeding territory on the higher ground above the Spa Well, and houses set well back on the south side of Main Street, where there are numbers of small trees and large bushes. Species: The calls registered by the bat detectors, set at 45 kHz, indicated that they were made by the common pipistrelle (Pipistrellus pipistrellus) – most calls being the " 'typical' (which) sounds like clapping with cupped hands” (Briggs and King, 1998). Conclusion: The success of boxes as bat roosts depends largely upon location. They are most successful in coniferous woodland, where few alternative roosting places exist. (Richardson, 1985). Given the pressure on householders for energy conservation, involving insulation of roofs, and sealing of gaps, bats may use boxes in gardens if nearby roosting places have been recently lost. If it is decided to proceed with the erection of batboxes, they should be erected as high as possible on one of the deciduous trees, with the entry unobstructed by branches. The boxes should be grouped together, preferably three, facing between south and west to enable bats to select the most suitable conditions. It should be recognised that it may be many years before a batbox is used, and even then, possibly for only a short period of time, as bats often move between roosts. Page 2

References. Briggs, B. and King, D., 1998. The Bat Detective, A Field Guide for Bat Detection. BATBOX Ltd. Richardson, P., 1985. Bats. Whittet Books. Page 3

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©Berwick Wildlife Group. This page was last updated on Oct 10th 2006.