Remove or control viperine snakes

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

Effectiveness

50%
Certainty

40%
Harms

0%

Calculating overall effectiveness category

Background information and definitions

Introduced species can have significant effects on native species, particularly on oceanic islands. For example, the viperine snake Natrix maura is an invasive species on Mallorca and as one of the main predators of the threatened midwife toad Alytes muletensis, contributed towards its decline (Guicking et al. 2006).

Guicking D., Griffiths R.A., Moore R.D., Joger U. & Wink M. (2006) Introduced alien or persecuted native? Resolving the origin of the viperine snake (Natrix maura) on Mallorca. Biodiversity and Conservation, 15, 3045–3054.

Study locations

Key messages

One before-and-after study in Mallorca found that numbers of Mallorcan midwife toad larvae increased after intensive, but not less intensive, removal of viperine snakes.

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 1991–2002 of Mallorcan midwife toads Alytes muletensis in Mallorca (Román 2003) found that abundance increased at one of two sites after removal of viperine snakes Natrix maura. At the site with intensive control over three years, no snakes were seen from 1997 and larval toad counts increased from 1,300 in 1991 to 2,200 in 1999. Control was not considered successful by the authors at the second site due to the large snake population and more open habitat. Viperine snakes were controlled by capturing intensive one site in 1991–1993 and by capturing less intensively at the second site in 2002.
Study and other actions tested
Referenced paper
Román A. (2003) The ferreret, the management of a critically ill species. Munibe (Suplemento), 16, 90-99.

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

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This Action forms part of the Action Synopsis:

Amphibian Conservation

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