Restore habitat connectivity

Overall effectiveness category Likely to be beneficial
Number of studies: 1
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How is the evidence assessed?

Effectiveness

75%
Certainty

40%
Harms

0%

Calculating overall effectiveness category

Background information and definitions

Habitat destruction and fragmentation are important factors in the decline of amphibian populations. Small patches of habitat support smaller populations and if individuals are unable to move to other suitable areas, populations become isolated. This can make them more vulnerable to extinction. Restoring corridors of native vegetation between patches of suitable habitat may help to maintain amphibian populations.

Studies investigating the effects of restoring habitat connectivity with wildlife tunnels are discussed in ‘Threat: Transportation and service corridors – Install culverts or tunnels as road crossings’.

Study locations

Key messages

One before-and-after study in Italy found that restoring connectivity between two wetlands by raising a road on a viaduct, significantly decreased deaths of migrating amphibians.

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

A before-and-after study in 1994–2004 of a brackish and freshwater wetland in southern Tuscany, Italy (Scoccianti 2006) found that restoring connectivity between wetlands, by raising a road on a viaduct, significantly decreased deaths of migrating amphibians. Post-construction, many species were found migrating between wetlands under the viaduct. No remains of amphibians were found on the road post-construction, compared to thousands during some periods pre-construction. For example, after a night rainstorm in July 1997, over 6,500 newly emerged Italian edible frog Rana hispanica juveniles were counted on a 100 m stretch of road. A viaduct 215 m long was constructed in 2003 to raise the road. The supports of the viaduct (1.6 m high) were built on a bank 1 m higher than potential flood waters to prevent mixing of wetlands. Drift-fencing was installed for 300 m from each end of the viaduct along both sides of the road. Amphibian road kills were monitored before and after construction.
Study and other actions tested
Referenced paper
Scoccianti C. (2006) Rehabilitation of habitat connectivity between two important marsh areas divided by a major road with heavy traffic. Acta Herpetologica, 1, 77-79.

Please cite as:

Smith, R.K., Meredith, H. & Sutherland, W.J. (2020) Amphibian Conservation. Pages 9-64 in: W.J. Sutherland, L.V. Dicks, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2020. Open Book Publishers, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

This Action forms part of the Action Synopsis:

Amphibian Conservation

Related Actions

Actions	Effectiveness	Studies	Category
Replant vegetation Action Link	Beneficial	7	Synopsis Link
Create habitat connectivity Action Link	No evidence found (no assessment)	0	Synopsis Link
Clear vegetation Action Link	Likely to be beneficial	9	Synopsis Link