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Volume 712: debated on Monday 5 October 2009


Asked by

To ask Her Majesty's Government in respect of the two bridges for bats constructed on the Dobwalls bypass in Cornwall, (a) what was the purpose of the bridges; (b) how much they cost to build; (c) how many bats have been monitored using the bridges; (d) how many bats used the route of those bridges before they were built; (e) how many bats cross the bypass without using the bridges; and (f) how many bats have hit cars using the bypass since the bridges were built. [HL5321]

(a) The bridges provide a linear feature over the bypass that is used by the bats to guide them along their flight lines. Previously they used the hedgerows but these were removed by the scheme.

(b) The bridges cost £300,000 to construct.

(c) Sample monitoring during 2008 and 2009 has identified that on the day of the survey on average there were between 11 and 17 bats using the bridges to cross the bypass.

(d) In 2004, prior to construction of the scheme, on the day of the survey, some 30 to 40 bat movements were recorded at the bridge locations.

(e) The monitoring exercise concentrated on bat movement at the bridge. There are consequently no specific data about how many bats cross the bypass without using the bridge.

(f) There have been no recorded incidents of bats hitting cars since the bridges were built.