Close roads during seasonal amphibian migration

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

Source countries

Key messages


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 1983 of a road in Oberbergischer Kreis, Germany (Karthaus 1985) found that closing the road allowed common toads Bufo bufo to successfully cross. While the road was open none of the young amphibians reached the other side. However, one hour after closure about 100,000 toads were found crossing along a 400 m section of the road. The road was closed for eight days until the migration of amphibians was over in spring.

    Study and other actions tested
  2. A replicated study in 1986 of 114 sites including at least 11 road closure sites, 60 amphibian barrier fences and 23 hand-collected human-assisted crossings in Nordrhein-Westphalia, Germany (Feldmann & Geiger 1989) found that 131,061 amphibians were protected from death on roads during breeding migrations. Between one and 116,515 individuals of 14 species were recorded at the road closure sites, assisted crossings and barrier fences at the 114 sites. Nine sites had a combination of two of the interventions and for 20 sites it was unknown which of the interventions were used.

    Study and other actions tested
Please cite as:

Smith, R.K., Meredith, H. & Sutherland, W.J. (2018) Amphibian Conservation. Pages 9-65 in: W.J. Sutherland, L.V. Dicks, N. Ockendon, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2018. Open Book Publishers, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

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Amphibian Conservation

This Action forms part of the Action Synopsis:

Amphibian Conservation
What Works in Conservation

What Works in Conservation

What Works in Conservation assesses the research looking at whether interventions are beneficial or not. It is based on summarised evidence in synopses, on topics such as amphibians, bats, biodiversity in European farmland, and control of freshwater invasive species. More are available and in progress.

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