This article needs to be updated.(February 2023) |
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.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/8/8c/Batbridge.jpg/220px-Batbridge.jpg)
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
editFrance
editThe 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
editTwo 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
editThis 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
editThe 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
editReferences
edit- ^ "New bypass going 'batty' to help the environment". Western Morning News, The Plymouth (UK). April 5, 2008. Retrieved 2009-09-12.
- ^ Un couloir à chauves-souris, Sud-Ouest, février 2012
- ^ Reportage de France 3
- ^ Photographies de l'installation des ouvrages
- ^ "Warum fliegen die nicht einfach drüber?" (Print version). Kölner Stadt-Anzeiger. 2013-11-02. Archived from the original on 2013-11-06. Retrieved 2 April 2015.
Rund 400 000 Euro wurden dafür ausgegeben
[Around 400,000 euros were spent on it] - ^ a b "A11 Elveden bypass to be shut for bat bridges". BBC News. 2014-08-04. Retrieved 2015-04-02.
- ^ a b "New Bat bridge for bypass : Marishal Thompson Group - Tree Subsidence, Arboriculture, Ecology and Landscape Architecture throughout the UK". Marishalthompson.co.uk. Archived from the original on 2009-11-07. Retrieved 2009-09-12.
- ^ a b "House of Lords Written Answers 10 November 2009: Bats". United Kingdom Parliament. Retrieved 5 June 2011.
- ^ "UK | Wales | North West Wales | 'Green' road helps bats to cross". BBC News. 2006-05-02. Retrieved 2009-09-12.
- ^ "Bats reject 'safe way' bridges over Norfolk - Suffolk dual carriageway". BBC News. 22 October 2015. Retrieved 27 January 2020.
- ^ Roberts, Geneviève (2007-03-31). "How did the bats cross the road? By using the special 'bat bridge' - Nature, Environment". The Independent. London. Retrieved 2009-09-12.[dead link]
- ^ "Road closure for new aerial bat crossing". BBC News. 30 January 2010. Retrieved 5 June 2011.
- ^ "Norwich NDR bat bridges 'are not working'". BBC News. 26 Jan 2020. Retrieved 26 Jan 2020.
- ^ "Detailed section plan of the NDR" (PDF). Norfolk County Council. 21 Apr 2015. Retrieved 11 Dec 2017.
- ^ "Bridges too far? The £500,000 bat crossings".
- ^ Berthinussen, Anna; Altringham, John; Fenton, Brock (13 June 2012). "Do Bat Gantries and Underpasses Help Bats Cross Roads Safely?". PLOS ONE. 7 (6): e38775. doi:10.1371/journal.pone.0038775. PMC 3374807. PMID 22719941.
- ^ "Bat bridges don't work". University of Leeds. 14 June 2012. Retrieved 15 June 2014.