Bat bridge
Road construction to aid the navigation of bats From Wikipedia, the free encyclopedia
A bat bridge is a structure of varying construction crossing a new or altered road to aid the navigation of bats following the destruction of a hedgerow, and to cause the bats to cross the roadway at a sufficient height to avoid traffic. Bats are thought to follow the lines of hedgerows and woods, and removing these may confuse the bats.
 | This article needs to be updated. (February 2023) |
The theory is that these "bridges" will be seen by the bats' sonar as linear features sufficiently similar to the old hedgerows as to provide an adequate substitute.[1] The English Highways Agency is performing a study of those on the Dobwalls bypass to determine if this assumption is justified.[when?][citation needed]
Usage
Summarize
Perspective
France
The first bridge to be installed in France is on the A65 motorway between junctions for Roquefort and Caloy in the Landes department.[2]
Two additional bat bridges were completed in November 2012 near Balbigny, on the A89 motorway.[3][4]
Germany
Two metal bridges were built in 2013 to protect the Mouse-eared Bat at Biberach an der Riss, Baden-Wuerttemberg. The structures cost £375,000 (400,000 €).[5]
United Kingdom
 | This section needs additional citations for verification. (February 2023) |
Bat bridges have been implemented in the United Kingdom by various agencies, including the Highways Agency, with support of the Bat Conservation Trust.[6]
At A38 Dobwalls Bypass, the bridges are more elaborate and sophisticated than the earlier Welsh structures, which consisted of cables strung from poles.[7][8]
| Name | Road | Opened | Approx. length | Single or dual carriageway | Placement | Approx. cost | Other details | Ref. |
|---|---|---|---|---|---|---|---|---|
| Stainburn and Great Clifton Bypass | A66 | December 2002 | Gantry | Single (three-lane carriageway) | ||||
| High and Low Newton | A590 | April 2008 | 33 m | Dual | In cutting | £45,000 | ||
| Dobwalls (2 Structures) | A38 | June 2008 | Structure 1: 59.47 m, Structure 2: 70 m | Dual | At Grade/In Cutting | £300,000 | One structure consists of three steel towers with cables suspended between them carrying mesh panels. The other consists of a single span of cables and mesh panels between concrete and steel anchors either side of a cutting. In the Dobwalls scheme, a third bat-crossing consisted of a raised parapet modification to a new road bridge, Havett Road. | [7][8] |
| Parton to Lillyhall | A595 | Dec 2008 | 34 m | Dual | On embankment | £34,133 | ||
| Haydon Bridge | A69 | April 2009 | 19.5 | Single | In cutting | £60,000 | ||
| Pwllheli and Criccieth | A497 | 2006 | Single | At Grade | A bat bridge was installed following the upgrade of the A497 to help the six species of bats in the area to cross the road. | [9] | ||
| Elveden | A11 | 2014 | Dual | Various | £350,000 | Six bat bridges. | [6][10] | |
| Gilwern to Abergavenny | A465 | 2007 | Dual | Embankment | Two bat bridges were constructed during road upgrade in locations where full bridges previously stood. | [11] | ||
| Groeslon | A487 | 2010 | Single | The road runs through the Glynllifon Special Area of Conservation which is home to a lesser horseshoe bat colony. | [12] | |||
| Norwich | A1270 | 2017 | Dual | £1,000,000 | Seven bat bridges on the Norwich Northern Distributor Road. | [13][14] |
Criticism
The overall cost of bat bridges was criticised by Lord Marlesford in the House of Lords in 2011, for being funded "at a time when we're having to cut a lot of public spending".[15]
A team from the University of Leeds examined the effectiveness of bat bridges, gantries and underpasses. They found that one underpass, placed on a commuting route, was used by 96% of bats, but few bats used the other underpasses and gantries, preferring routes which put them in the path of traffic.[16][17]
See also
References
External links
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