Collected Evidence: Collected Evidence: Add lime to water bodies to reduce acidification One before-and-after study in the UK found that adding limestone to ponds resulted in establishment of one of three translocated populations of natterjack toads. One replicated, site comparison study in the UK found that species-specific habitat management that included adding limestone to ponds increased natterjack toad populations. One before-and-after study in the UK found that adding limestone to ponds temporarily increased breeding by natterjack toads. Three before-and-after studies (including one controlled, replicated study) in the Netherlands and UK found that adding limestone increased larval and/or egg survival of moor frogs and common frogs and resulted in metamorphosis of natterjack toads at two of three sites. Two before-and-after studies (including one controlled study) in the UK found that adding limestone to ponds resulted in high tadpole mortality and pond abandonment by natterjack toads and higher numbers of abnormal common frog eggs.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F748https%3A%2F%2Fconservationevidence.com%2Factions%2F748Thu, 18 Jul 2013 15:41:50 +0100Collected Evidence: Collected Evidence: Artificially mist habitat to keep it damp One before-and-after study in Tanzania found that installing a sprinkler system to mitigate against a 90% reduction of river flow did not maintain a population of Kihansi spray toads.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F755https%3A%2F%2Fconservationevidence.com%2Factions%2F755Wed, 14 Aug 2013 11:05:17 +0100Collected Evidence: Collected Evidence: Create artificial hibernacula or aestivation sites One replicated, before-and-after study in the UK found that providing artificial hibernacula, along with other terrestrial habitat management, maintained populations of great crested newts. One replicated study in the UK found that created hibernacula were used by common frog and smooth newts, but not great crested newts. One replicated study in the UK found four amphibian species close to hibernacula at two of three sites.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F759https%3A%2F%2Fconservationevidence.com%2Factions%2F759Wed, 14 Aug 2013 15:19:25 +0100Collected Evidence: Collected Evidence: Clear vegetation Six studies (including four replicated studies) in Australia, Estonia and the UK found that vegetation clearance, along with other habitat management and in some cases release of animals, increased numbers of frog species, or increased, stabilized or maintained populations of natterjack toads. One before-and-after study in the UK found that vegetation clearance, along with other habitat management, maintained a population of great crested newts for the first six years, but not in the longer term. One before-and-after study in England found that vegetation clearance, resulted in increased occupancy by natterjack toads.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F761https%3A%2F%2Fconservationevidence.com%2Factions%2F761Fri, 16 Aug 2013 12:06:14 +0100Collected Evidence: Collected Evidence: Add salt to ponds to reduce chytridiomycosis One study in Australia found that following addition of salt to a pond containing the chytrid fungus, a population of green and golden bell frogs remained free of chytridiomycosis for at least six months.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F762https%3A%2F%2Fconservationevidence.com%2Factions%2F762Fri, 16 Aug 2013 14:13:19 +0100Collected Evidence: Collected Evidence: Change mowing regime One before-and-after study in Australia found that restoration that included reduced mowing increased numbers of frog species.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F783https%3A%2F%2Fconservationevidence.com%2Factions%2F783Thu, 22 Aug 2013 13:49:26 +0100Collected Evidence: Collected Evidence: Commercially breed amphibians for the pet trade We found no evidence for the effects of commercially breeding amphibians for the pet trade on wild 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%2Fconservationevidence.com%2Factions%2F794https%3A%2F%2Fconservationevidence.com%2Factions%2F794Thu, 22 Aug 2013 14:37:33 +0100Collected Evidence: Collected Evidence: Augment ponds with ground water to reduce acidification We found no evidence for the effects of augmenting ponds with ground water to reduce acidification effects 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%2Fconservationevidence.com%2Factions%2F803https%3A%2F%2Fconservationevidence.com%2Factions%2F803Thu, 22 Aug 2013 15:00:29 +0100Collected Evidence: Collected Evidence: Artificially shade ponds to prevent desiccation We found no evidence for the effects of artificially shading ponds to prevent desiccation 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%2Fconservationevidence.com%2Factions%2F808https%3A%2F%2Fconservationevidence.com%2Factions%2F808Thu, 22 Aug 2013 15:03:53 +0100Collected Evidence: Collected Evidence: Create microclimate and microhabitat refuges Studies investigating the effects of creating refuges are discussed in ‘Habitat restoration and creation’ and ‘Biological resource use – Leave coarse woody debris in forests’.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F809https%3A%2F%2Fconservationevidence.com%2Factions%2F809Thu, 22 Aug 2013 15:04:30 +0100Collected Evidence: Collected Evidence: Create habitat connectivity We found no evidence for the effects of creating habitat connectivity 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%2Fconservationevidence.com%2Factions%2F811https%3A%2F%2Fconservationevidence.com%2Factions%2F811Thu, 22 Aug 2013 15:06:41 +0100Collected Evidence: Collected Evidence: Add nutrients to new ponds as larvae food source We found no evidence for the effects of adding nutrients, such as zooplankton, to new ponds 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%2Fconservationevidence.com%2Factions%2F812https%3A%2F%2Fconservationevidence.com%2Factions%2F812Thu, 22 Aug 2013 15:07:50 +0100Collected Evidence: Collected Evidence: Add woody debris to ponds We found no evidence for the effects of adding woody debris to ponds 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%2Fconservationevidence.com%2Factions%2F814https%3A%2F%2Fconservationevidence.com%2Factions%2F814Thu, 22 Aug 2013 15:09:29 +0100Collected Evidence: Collected Evidence: Add specific plants to aquatic habitats We found no evidence for the effects of adding specific plants, such as emergent vegetation, to aquatic habitats 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%2Fconservationevidence.com%2Factions%2F816https%3A%2F%2Fconservationevidence.com%2Factions%2F816Thu, 22 Aug 2013 15:10:49 +0100Collected Evidence: Collected Evidence: Control invasive plants One before-and-after study in the UK found that aquatic and terrestrial habitat management that included controlling swamp stonecrop, along with release of captive-reared toadlets, tripled a population of natterjack toads. One replicated, controlled study in the USA found that Oregon spotted frogs laid eggs in areas where invasive reed canarygrass had been mown more frequently than where it was not mown.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F823https%3A%2F%2Fconservationevidence.com%2Factions%2F823Fri, 23 Aug 2013 11:04:26 +0100Collected Evidence: Collected Evidence: Captive breeding frogs Thirty-three studies investigated the success of breeding frogs in captivity. Twenty-three of 33 studies, three of which were reviews and 30 replicated studies, across the world found that amphibians produced egg in captivity, in four cases by captive-bred females. Seven found mixed results, with some species of frogs or 17–50% of captive populations  reproducing successfully in captivity, but with other species difficult to maintain or raise to adults. One found that frogs did not breed successfully in captivity and another that all breeding frogs died. Seventeen of the studies found that captive-bred frogs were raised successfully to hatching, tadpoles, froglets or adults in captivity. One found that froglet survival was low and another that three species were not successfully raised to adulthood. Four replicated studies (including one small study) in,Canada, Fiji, Hong Kong and Italy found that 30–88% of eggs hatched or survival to metamorphosis was 75%, as froglets was 17–51% or to adults was 50–90% in captivity. One review and four replicated studies (including two small studies) in Germany, Italy and the USA found that reproductive success of frogs in captivity depended on temperature or a simulated wet and dry season, but not on whether frogs were housed in high or low maintenance facilities. Three replicated studies (including one small study) in Germany, Australia and Canada found that egg or tadpole development in captivity was affected by parental care, density or temperature.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F835https%3A%2F%2Fconservationevidence.com%2Factions%2F835Thu, 29 Aug 2013 09:25:18 +0100Collected Evidence: Collected Evidence: Captive breeding harlequin toads (Atelopus species) One review and three of five replicated studies (including one small study) in Colombia, Ecuador, Germany and the USA found that harlequin toads reproduced in captivity. One found that eggs were only produced in captivity by simulating a dry and wet season and one found that successful breeding was difficult. One found that captive-bred harlequin toads were raised successfully to metamorphosis in captivity. Two found that most toads died before or after hatching.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F836https%3A%2F%2Fconservationevidence.com%2Factions%2F836Thu, 29 Aug 2013 13:54:34 +0100Collected Evidence: Collected Evidence: Captive breeding Mallorcan midwife toads Two replicated studies in the UK found that Mallorcan midwife toads produced eggs that were raised to metamorphs or toadlets successfully in captivity. One found that clutches dropped by males were not successfully maintained artificially. One replicated study in the UK found that survival to metamorphosis was 85%. One randomized, replicated, controlled study in the UK found that toads bred in captivity for nine or more generations had slower tadpole development, reduction in one predator defence trait and decreased genetic diversity.      Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F837https%3A%2F%2Fconservationevidence.com%2Factions%2F837Thu, 29 Aug 2013 14:21:37 +0100Collected Evidence: Collected Evidence: Captive breeding salamanders (including newts) Four of six replicated studies (including four small studies) in Japan, Germany, the UK and USA found that eggs were produced successfully in captivity, in one case by one captive-bred female. Two found that production of eggs depended on tank habitat or was more successful in semi-natural compared to laboratory conditions. Captive-bred salamanders were raised to yearlings or a small number of larvae or adults in captivity. One review found that four salamander species bred successfully in captivity, but slimy salamanders produced eggs that did not hatch. One replicated study in Japan found that 60% of Japanese giant salamander eggs survived to hatching in captivity. Two replicated studies (including one small study) in Mexico and the USA found that larval development, body condition and survival of captive-bred amphibians were affected by water temperature, density and whether they were raised under laboratory or semi-natural conditions.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F838https%3A%2F%2Fconservationevidence.com%2Factions%2F838Thu, 29 Aug 2013 14:43:51 +0100Collected Evidence: Collected Evidence: Close roads during seasonal amphibian migration Two studies (including one replicated study) in Germany found that large numbers of amphibians were protected from death during breeding migrations at road closure sites and at road closure sites with assisted crossings and barrier fences.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F842https%3A%2F%2Fconservationevidence.com%2Factions%2F842Thu, 29 Aug 2013 15:58:22 +0100Collected Evidence: Collected Evidence: Captive breeding toads Ten replicated studies (including three small studies) in Germany, Italy, Spain, the UK and USA found that toads produced eggs in captivity, in one case by second generation captive females. Eight found that captive-bred toads were raised successfully to tadpoles, toadlets or adults in captivity. Two found that most toads died after hatching or after metamorphosis. Two reviews found mixed results with four species of toad or 21% of captive populations of Puerto Rican crested toad breeding successfully in captivity. Four replicated studies in Germany, Spain and the USA found that reproductive success of captive toads was affected by tank humidity or was higher in outdoor enclosures than indoor tanks. One replicated study in Germany found that survival of European red-bellied toad eggs, tadpoles and juveniles was higher in captivity than the wild.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F848https%3A%2F%2Fconservationevidence.com%2Factions%2F848Thu, 05 Sep 2013 12:44:56 +0100Collected Evidence: Collected Evidence: Create ponds for great crested newts Three before-and-after studies (including two replicated studies) in Germany and the UK found that naturally colonizing, captive-bred and translocated great crested newts established breeding populations at 57–75% of created ponds or sites. One systematic review in the UK found that there was no conclusive evidence that mitigation, which often included pond creation, resulted in self-sustaining populations. Three replicated, before-and-after studies in the UK found that up to 88% of created ponds were colonized by translocated or by small numbers of naturally colonizing great crested newts. One replicated before-and-after study in the UK found that head-started great crested newts reproduced in 38% of created ponds.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F863https%3A%2F%2Fconservationevidence.com%2Factions%2F863Fri, 06 Sep 2013 15:57:48 +0100Collected Evidence: Collected Evidence: Create ponds for green toads Two before-and-after studies (including one controlled study) in Denmark found that pond creation, along with other interventions, significantly increased green toad populations. One replicated, before-and-after study in Sweden found that green toads used 59% and reproduced in 41% of created ponds.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F864https%3A%2F%2Fconservationevidence.com%2Factions%2F864Fri, 06 Sep 2013 16:23:40 +0100Collected Evidence: Collected Evidence: Create ponds for frogs Three of five before-and-after studies (including one replicated study) in Australia, Spain, the UK and USA found that translocated, head-started, captive-bred and naturally colonizing frogs established breeding populations in created ponds. Two found that breeding populations were established at one of four sites by translocated frogs, but were not established by captive-bred frogs. One replicated, before-and-after study in Denmark found that frogs colonized created ponds. One before-and-after study in the Netherlands found that pond creation, along with vegetation clearance, increased a breeding population of European tree frogs. An additional three of four replicated, before-and-after studies in Italy, the UK and USA found that naturally colonizing frog species reproduced in 50–75% of created ponds. Two found that translocated frog species reproduced in only 31% of created ponds, or colonized but did not reproduce successfully. One replicated study in the USA found that survival of translocated Oregon spotted frogs increased with increasing age of created ponds.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F865https%3A%2F%2Fconservationevidence.com%2Factions%2F865Tue, 10 Sep 2013 14:47:43 +0100Collected Evidence: Collected Evidence: Create ponds for amphibians Twenty-eight studies investigated the colonization of created ponds by amphibians in general (rather than by targeted species, which are discussed below). All of the studies found that amphibians used some or all created ponds. Nine site comparison studies (including seven replicated studies) in Australia, Canada, Spain, the UK and USA compared amphibian numbers in created and natural ponds. Five found that numbers of species or breeding species were similar or higher in created ponds, and numbers of ponds colonized were similar. Four found that species composition differed, and comparisons between abundance of individual species, juvenile productivity and size at metamorphosis differed depending on species. One found that numbers of species were similar or lower depending on the permanence of created water bodies. One found that populations in created ponds were less stable. One review and two replicated, before-and-after studies in Denmark and the USA found that amphibians established stable populations in 50–100% of created ponds. Six replicated studies (including one randomized study) in France, the Netherlands, UK and USA found that amphibians used 64–100% and reproduced in 64–68% of created ponds, or used 8–100% and reproduced in 2–62% depending on species. One review and 15 studies (including 12 replicated studies, one of which was randomized) in Europe and the USA found that created ponds were used or colonized by up to 15 naturally colonizing species, up to 10 species that reproduced, as well as by captive-bred amphibians. Five replicated studies (including three site comparison studies) in Denmark, Estonia, France, Italy and the USA found that pond creation, and restoration in three cases, maintained and increased amphibian populations or increased numbers of species. Seven studies (including one review) in Austria, Denmark, Poland, the Netherlands and USA found that use or colonization of or reproductive success in created ponds was affected by pond age, permanence, vegetation cover, surrounding landscape, distance to existing ponds and presence of fish.  Collected Evidencehttps%3A%2F%2Fconservationevidence.com%2Factions%2F869https%3A%2F%2Fconservationevidence.com%2Factions%2F869Wed, 11 Sep 2013 09:16:41 +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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