Use signage to warn motorists

Overall effectiveness category Unknown effectiveness (limited evidence)
Number of studies: 1
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How is the evidence assessed?

Effectiveness

10%
Certainty

10%
Harms

0%

Calculating overall effectiveness category

Background information and definitions

The number of amphibians killed by vehicles can be high, particularly where their annual migration routes between overwintering and breeding sites cross roads. Signs to warn motorists of amphibian activity can be installed around the densest migration routes.

Study locations

Key messages

One study in the UK found that despite warning signs and human assistance, over 500 toads were killed on some roads.

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 study in 1995 of 76 toad patrol projects, 44 with toad warning road signs in the UK (Froglife 1996) found that despite signs and human assistance in the spring some toads were still killed on the roads. Overall, 65% of patrols reported that up to 100 toads were killed on the road, 28% reported 100–500 were killed and 7% over 500 toads. Only 20% of populations were believed to be stable or increasing. A questionnaire survey of most of the known and established toad patrols was undertaken. Seventy-six replies were obtained.
Study and other actions tested
Referenced paper
Froglife . (1996) Toad patrols: a survey of voluntary effort involved in reducing road traffic-related amphibian mortality in amphibians. Froglife Conservation Report No.1.

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
Use humans to assist migrating amphibians across roads Action Link	Unlikely to be beneficial	6	Synopsis Link
Modify gully pots and kerbs Action Link	Likely to be beneficial	1	Synopsis Link
Close roads during seasonal amphibian migration Action Link	Likely to be beneficial	2	Synopsis Link