Restore habitat connectivity

How is the evidence assessed?
  • Effectiveness
  • Certainty
  • Harms

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

  1. 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
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

Amphibian Conservation

This Action forms part of the Action Synopsis:

Amphibian Conservation
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

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