Collected Evidence: Collected Evidence: Retain riparian buffer strips during timber harvest Twelve studies investigated the effectiveness of retaining buffer strips during timber harvest for amphibians. Six replicated and/or controlled studies in Canada and the USA compared amphibian numbers following clearcutting with or without riparian buffer strips. Five found mixed effects on abundance depending on species and buffer width. One found that amphibian abundance was significantly higher with buffers. Eleven studies, including 10 replicated and/or controlled studies in Canada and the USA and one meta-analysis, compared amphibian numbers in forest with riparian buffers retained during harvest to unharvested forest. Six found mixed effects depending on species or volume of existing downed wood. Four found that abundance and species composition were similar to unharvested forest. Two found that numbers of species and abundance were lower than in unharvested forest. Two of four replicated studies (including one randomized, controlled, before-and-after study) in Canada and the USA found that numbers of amphibian species and abundance were greater in wider riparian buffer strips. Two found that there was no difference in abundance in buffers of different widths.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F747https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F747Wed, 17 Jul 2013 13:42:46 +0100Collected Evidence: Collected Evidence: Remove tree canopy to reduce pond shading One before-and-after study in Denmark found that translocated garlic toads established breeding populations following pond restoration that included canopy removal. One before-and-after study in the USA found that canopy removal did not increase hatching success of spotted salamanders.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F758https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F758Wed, 14 Aug 2013 14:36:22 +0100Collected Evidence: Collected Evidence: Remove the chytrid fungus from ponds One before-and-after study in Mallorca found that pond drying and fungicidal treatment of resident midwife toads reduced levels of infection but did not eradicate chytridiomycosis.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F766https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F766Fri, 16 Aug 2013 16:11:48 +0100Collected Evidence: Collected Evidence: Sterilize equipment when moving between amphibian sites We found no evidence for the effects of sterilizing equipment when moving between amphibian sites on the spread of disease between amphibian populations or individuals. Two randomized, replicated, controlled study in Switzerland and Sweden found that Virkon S disinfectant did not affect survival, mass or behaviour of common frog or common toad tadpoles or moor frog embryos or hatchlings. One of the studies found that bleach significantly reduced survival of common frog and common toad tadpoles.    Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F768https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F768Fri, 16 Aug 2013 16:21:14 +0100Collected Evidence: Collected Evidence: Restrict herbicide, fungicide and pesticide use on and around ponds on golf courses We found no evidence for the effects of restricting herbicide, fungicide or pesticide use on or around ponds on golf courses on amphibian populations. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.    Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F787https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F787Thu, 22 Aug 2013 14:28:06 +0100Collected Evidence: Collected Evidence: Remove or control non-native crayfish We found no evidence for the effects of removing or controlling non-native crayfish on amphibian populations. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.    Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F797https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F797Thu, 22 Aug 2013 14:42:03 +0100Collected Evidence: Collected Evidence: Remove or control invasive cane toads We found no evidence for the effects of removing or controlling invasive cane toads on amphibian populations. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.    Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F798https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F798Thu, 22 Aug 2013 14:43:02 +0100Collected Evidence: Collected Evidence: Sterilize equipment to prevent ranavirus We found no evidence for the effects of sterilizing equipment to prevent ranavirus on the spread of disease between amphibian individuals or populations. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.    Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F801https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F801Thu, 22 Aug 2013 14:46:02 +0100Collected Evidence: Collected Evidence: Remove specific aquatic plantsTwo studies investigating the effects of removing specific aquatic plants are discussed in ‘Threat: Invasive alien and other problematic species – Control invasive plants’.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F815https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F815Thu, 22 Aug 2013 15:10:05 +0100Collected Evidence: Collected Evidence: Remove or control invasive Cuban tree frogs One before-and-after study in the USA found that the abundance of squirrel tree frogs and green tree frogs increased after removal of invasive Cuban tree frogs.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F822https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F822Fri, 23 Aug 2013 10:55:01 +0100Collected Evidence: Collected Evidence: Remove or control invasive bullfrogs One replicated, before-and-after study in the USA found that removing American bullfrogs significantly increased a population of California red-legged frogs. One before-and-after study in the USA and Mexico found that eradicating bullfrogs from the area increased the range of leopard frogs. One replicated, before-and-after study in the USA found that once bullfrogs had been removed, California red-legged frogs were found out in the open twice as frequently.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F825https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F825Fri, 23 Aug 2013 11:19:46 +0100Collected Evidence: Collected Evidence: Remove or control fish using rotenone Three studies (including one replicated study) in Sweden, the UK and USA found that eliminating fish using rotenone increased numbers of amphibian species, abundance and recruitment or newt populations. One review in Australia, the UK and USA found that fish control, which included using rotenone, increased breeding success for four amphibian species. Two replicated studies in Pakistan and the UK found when rotenone was applied, many frogs died and a small number of newts showed symptoms of negative effects.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F828https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F828Wed, 28 Aug 2013 14:25:31 +0100Collected Evidence: Collected Evidence: Remove or control viperine snakes 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.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F830https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F830Wed, 28 Aug 2013 15:01:43 +0100Collected Evidence: Collected Evidence: Remove or control mammals One controlled study in New Zealand found that controlling rats had no significant effect on numbers of Hochstetter’s frog. One controlled study in New Zealand found that survival of Maud Island frogs was significantly higher in a predator-proof enclosure than in the wild. One study in New Zealand found that at 58% of translocated Hamilton's frogs survived the first year within a predator-proof enclosure.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F839https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F839Thu, 29 Aug 2013 15:39:17 +0100Collected Evidence: Collected Evidence: Restore habitat connectivity 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.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F840https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F840Thu, 29 Aug 2013 15:48:56 +0100Collected Evidence: Collected Evidence: Replant vegetation Three studies (including two replicated studies) in Australia, Canada and Spain found that amphibian abundance or community composition was similar to natural sites following tree planting, or became more similar with time since grassland reseeding. One before-and-after study in Australia found that numbers of frog species increased following restoration that included planting shrubs and trees. One replicated, site comparison study in Canada found that following logging, amphibian abundance was lower or similar in forests that were planted and had herbicide treatment compared to those left to regenerate naturally, depending on species and forest age. Four studies (including one replicated study) in Australia, Spain and the USA found that amphibians colonized replanted forest, reseeded grassland and seeded and transplanted upland habitat. Three of the studies investigated restoration following mining. One site comparison study in the USA found that wetlands within reseeded grasslands were used more frequently than those within farmland, but less than those in natural grasslands.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F849https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F849Thu, 05 Sep 2013 13:50:25 +0100Collected Evidence: Collected Evidence: Retain buffer zones around core habitat One before-and-after study in Australia found that grassland restoration that included leaving unmown buffers around ponds increased numbers of frog species. One replicated, site comparison study in the USA found that retaining buffers along ridge tops within harvested forest increased Red Hills salamander abundance, body condition and genetic diversity. One replicated, controlled study in the USA found that retaining unmown buffers around ponds had mixed effects on tadpole survival and mass depending on species and site. One replicated study in the USA found that 30 m buffer zones around wetlands were not sufficient to protect marbled salamanders.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F850https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F850Thu, 05 Sep 2013 14:26:46 +0100Collected Evidence: Collected Evidence: Thin trees within forests Five studies (including four replicated and/or controlled studies) in the USA compared amphibians in thinned to unharvested forest. Two found mixed effects of thinning on abundance, depending on amphibian species and time since harvest. One found that amphibian abundance increased, except for ensatina salamanders. One found a negative overall response (population, physiological and behavioural) of amphibians and one found that thinning did not affect abundance. A meta-analysis of 24 studies in North America found that partial harvest, which included thinning with three other types, decreased salamander populations. One controlled, before-and-after site comparison study in the USA found that high volumes of pre-existing downed wood prevented declines in amphibian populations following thinning. Four studies (including two replicated, controlled studies) in the USA compared amphibians in thinned to clearcut forest. Two found higher amphibian abundance, apart from ensatina salamanders, or a less negative overall response (population, physiological and behavioural) of amphibians in thinned forest. Two found mixed effects on abundance depending on species, life stage and time since harvest. A meta-analysis of 24 studies in North America found that partial harvest, which included thinning with three other types, resulted in smaller reductions in salamander populations than clearcutting. One randomized, replicated, controlled study in the USA found that migrating amphibians used thinned forest a similar amount, or for one species more than unharvested forest and that emigrating salamanders, but not frogs, used it significantly more than clearcuts. One site comparison study in the USA found that thinning decreased the body condition of ensatina salamanders 10 years after harvest. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F852https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F852Thu, 05 Sep 2013 14:53:21 +0100Collected Evidence: Collected Evidence: Retain connectivity between habitat patches One before-and-after study in Australia found that retaining native vegetation corridors maintained populations of eight of 13 frog species over 20 years.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F853https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F853Fri, 06 Sep 2013 11:45:40 +0100Collected Evidence: Collected Evidence: Translocate amphibians Overall, three global reviews and one replicated, before-and-after study in the USA found that 35 of 54 (65%) amphibian translocations that could be assessed resulted in established breeding populations or substantial recruitment to the adult population. A further two translocations resulted in breeding and one in survival following release. One review found that translocations of over 1,000 animals were more successful, but that success was not related to the source of animals (wild or captive), life-stage, continent or reason for translocation.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F854https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F854Fri, 06 Sep 2013 11:49:37 +0100Collected Evidence: Collected Evidence: Translocate great crested newts Four of six studies (including one review and one replicated study) in the UK found that translocated great crested newts maintained or established breeding populations. The review found that populations were present one year after release in 37% of cases and one study found that although translocations maintained a population in the short term, within three years breeding failed in 48% of ponds. One systematic review of 31 great crested newt studies found that there was no conclusive evidence that mitigation that included translocations resulted in self-sustaining populations. One review in the UK found that great crested newts reproduced following 56% of translocations, in some cases there was also release of head-started larvae and/or habitat management.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F858https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F858Fri, 06 Sep 2013 13:32:49 +0100Collected Evidence: Collected Evidence: Translocate natterjack toads Three studies (including one review) in France and the UK found that translocated natterjack toad eggs, tadpoles, juveniles or adults established breeding populations at one site or in 30–70% of cases, some of which also released head-started or captive-bred animals or included habitat management. The review found that re-establishing toads on dune or saltmarsh habitat was more successful than on heathland. One replicated study in the UK found that natterjack toad populations increased at sites established by translocations, particularly with replicated translocations of wild rather than captive-bred toads. Two replicated, before-and-after studies in Estonia and the UK found that translocating natterjack toad eggs or tadpoles resulted in breeding at 8–70% of sites, some of which had been restored.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F859https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F859Fri, 06 Sep 2013 13:48:11 +0100Collected Evidence: Collected Evidence: Translocate frogs Eight of ten studies (including five replicated studies) in New Zealand, Spain, Sweden, the UK and USA found that translocating frog eggs, juveniles or adults established breeding populations at 100% or 79% of sites. Two found that breeding populations of two species were initially established but went extinct within five years or did not establish. Five studies (including one replicated study) in Italy, New Zealand and the USA found that translocated juveniles or adults survived the winter, had high survival, survived up to two years, or up to eight years with predator exclusion. One study in the USA found that survival was lower for Oregon spotted frogs translocated as adults compared to eggs and lower than that of resident frogs. Five studies (including three replicated studies) in Canada, New Zealand and the USA found that translocations of eggs, juveniles or adults resulted in little or no breeding at one or three of four sites. Two studies (including one before-and-after study) in the USA found that 60–100% of translocated frogs left the release site and 35–73% returned to their original pond within 1–32 days. Two before-and-after studies New Zealand and the USA found that frogs lost weight during the 30 days after translocation or became heavier than animals at the donor site.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F861https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F861Fri, 06 Sep 2013 14:31:31 +0100Collected Evidence: Collected Evidence: Restore ponds Fifteen studies investigated the effectiveness of pond restoration for amphibians. One replicated, before-and-after study in Denmark found that pond restoration had mixed effects on European tree frog population numbers depending on site. One replicated, controlled, before-and-after study in the UK found that pond restoration did not increase great crested newt populations. Six replicated, before-and-after studies (including one controlled and one site comparison study) in Denmark, Estonia, Italy and the UK found that pond restoration and creation increased numbers of amphibian species, maintained or increased populations, or increased pond occupancy and ponds with breeding success. One found that numbers of species did not increase. Two before-and-after studies (including one replicated study) in Estonia found that pond restoration, along with terrestrial habitat management, maintained or increased populations of natterjack toads. One systematic review in the UK found that there was no conclusive evidence that mitigation, which often included pond restoration, resulted in self-sustaining great crested newt populations. One small, replicated study in the USA found that pond restoration had mixed effects on spotted salamander hatching success depending on restoration method. One replicated, before-and-after study in the UK found that restoration increased the number of ponds used by breeding natterjack toads. One replicated study in Sweden found that following restoration green toads only reproduced in one of 10 ponds. Three before-and-after studies (including one replicated, controlled study) in Denmark and Italy found that restored and created ponds were colonized by 1–7 species, with 6–65% of ponds colonized and 35% used for breeding.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F878https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F878Thu, 12 Sep 2013 15:17:02 +0100Collected Evidence: Collected Evidence: Restore wetland Seventeen studies investigated the effectiveness of wetland restoration for amphibians. Ten site comparison studies (including eight replicated studies) in Canada and the USA compared amphibian numbers in restored and natural wetlands. Eight found that amphibian abundance, numbers of species and species composition were similar. Two found that the number of species or abundance was lower and species composition different in restored wetlands. One found that restored wetlands were used more or less depending on the habitat surrounding natural wetlands. One global review found that in 89% of cases, restored and created wetlands had similar or higher amphibian abundance or numbers of species to natural wetlands. Seven of nine studies (including six site comparison and/or replicated studies) in Canada, Taiwan and the USA found that wetland restoration increased numbers of amphibian species, with breeding populations establishing in some cases. Three found that numbers of species or abundance did not increase with restoration. Two found mixed effects, with restoration maintaining or increasing abundance of individual species. Three replicated studies (including two site comparison studies) in the USA found that numbers of species in restored wetlands were affected by wetland size, proximity to source ponds and seasonality, but not wetland age. Three studies (including two replicated, site comparison studies) in Taiwan and the USA found that restored wetlands were colonized by three to eight amphibian species. One before-and-after study in the USA found that three target species did not recolonize restored wetlands.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F879https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F879Thu, 12 Sep 2013 15:34:57 +0100
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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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