A bat bridge is a structure of varying construction crossing a new or altered road to aid the navigation of

bat Bats are mammals of the order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most ...

s following the destruction of a

hedge A hedge or hedgerow is a line of closely spaced shrubs and sometimes trees, planted and trained to form a barrier or to mark the boundary of an area, such as between neighbouring properties. Hedges that are used to separate a road from adjoin ...

row, 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. 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. The

Highways Agency National Highways, formerly the Highways Agency and later Highways England, is a State-owned enterprise, government-owned company charged with operating, maintaining and improving Roads in England, motorways and major A roads in England. It al ...

is performing a study of those on the Dobwalls bypass to determine if this assumption is justified.

Usage

Bat structures in the UK

France

The first bridge to be installed in France is on the A65 motorway between junctions for

Roquefort Roquefort is a sheep milk cheese from Southern France, and is one of the world's best known blue cheeses. Though similar cheeses are produced elsewhere, EU law dictates that only those cheeses aged in the natural Combalou caves of Roquefort-sur ...

and

Caloy Caloy is a nickname for Carlos in the Philippines. Notable people known by this name include the following: *Caloy Balcells, nickname for Carlos Balcells (fl. 1985–present), Spanish Filipino bass guitar player * Caloy Garcia, nickname for Carlo ...

in the Landes department. Two additional bat bridges were completed in November 2012 near

Balbigny Balbigny () is a commune in the Loire department in central France. History Balbigny owes its name to a Roman general named Balbinius who based himself here in order to conduct a war. Nothing survives from this period. The earliest identified ...

, on the A89 motorway.

Germany

Two metal bridges were built in 2013 to protect the

Mouse-eared Bat The mouse-eared bats or myotises are a diverse and widespread genus (''Myotis'') of bats within the family Vespertilionidae. The noun "''myotis''" itself is a New Latin construction, from the Greek "''muós'' (meaning "mouse") and "''oûs''" (mea ...

Biberach an der Riss Biberach may refer to: *Biberach an der Riß, a town in Upper Swabia, Germany *Biberach (district), which has Biberach an der Riß as its capital *Biberach, Baden, a municipality in the ''Ortenaukreis'', Germany *Biberach is a part of Roggenburg, B ...

, Baden-Wuerttemberg. The structures cost £375,000 (400,000 €).

Criticism

The overall cost of bat bridges has been criticised in the

House of Lords The House of Lords, also known as the House of Peers, is the Bicameralism, upper house of the Parliament of the United Kingdom. Membership is by Life peer, appointment, Hereditary peer, heredity or Lords Spiritual, official function. Like the ...

by Lord Marlesford. 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.

References

{{reflist

External links

Roads, Bat Bridges and Gantries: A position statement from Bat Conservation Trust
Bats and humans Bat conservation Conservation projects Bridges