Collected 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: Raise awareness amongst the general public through campaigns and public information Two studies (including one replicated, before-and-after study) in Estonia and the UK found that raising public awareness, along with other interventions, increased numbers of natterjack toads and created 1,023 ponds for amphibians. One before-and-after study in Mexico found that raising awareness in tourists, increased their knowledge of axolotls. One study in Taiwan found that holding press conferences to publicize frog conservation had no effect on a green tree frog project. Two studies in Panama and the UK found that awareness campaigns reached over 50,000 members of the public each year or trained 1,016 people at 57 events over four years.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F831https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F831Wed, 28 Aug 2013 15:05:54 +0100Collected Evidence: Collected Evidence: Reduce pesticide, herbicide or fertilizer use One study in Taiwan found that halting pesticide use along with habitat management increased a population of Taipei frogs.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F832https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F832Wed, 28 Aug 2013 15:16:38 +0100Collected Evidence: Collected Evidence: Regulate water levels Two studies (including one replicated, site comparison study) in the UK found that habitat management that included maintaining pond water levels increased natterjack toad populations or maintained newt populations. One replicated, controlled study in Brazil found that keeping rice fields flooded after harvest changed amphibian species composition, but not numbers of species or abundance. One replicated, controlled study in the USA found that draining ponds, particularly in the summer, significantly increased abundance and numbers of amphibian species. One before-and-after study in the USA found that maintaining pond water levels enabled successful breeding by dusky gopher frogs.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F833https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F833Wed, 28 Aug 2013 15:19:57 +0100Collected Evidence: Collected Evidence: Use artificial fertilization in captive breeding Three replicated studies (including two randomized studies) in Australia and the USA found that the success of artificial fertilization depended on the type and number of doses of hormones used to stimulate egg production. One replicated study in Australia found that 55% of eggs were fertilized artificially, but soon died.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F834https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F834Wed, 28 Aug 2013 15:57:47 +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%2Fwww.conservationevidence.com%2Factions%2F835https%3A%2F%2Fwww.conservationevidence.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%2Fwww.conservationevidence.com%2Factions%2F836https%3A%2F%2Fwww.conservationevidence.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%2Fwww.conservationevidence.com%2Factions%2F837https%3A%2F%2Fwww.conservationevidence.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%2Fwww.conservationevidence.com%2Factions%2F838https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F838Thu, 29 Aug 2013 14:43:51 +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: Use signage to warn motorists One study in the UK found that despite warning signs and human assistance, over 500 toads were killed on some roads.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F841https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F841Thu, 29 Aug 2013 15:56:32 +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%2Fwww.conservationevidence.com%2Factions%2F842https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F842Thu, 29 Aug 2013 15:58:22 +0100Collected Evidence: Collected Evidence: Leave coarse woody debris in forests Two replicated, controlled studies in the USA found that there was no significant difference in abundance in clearcuts with woody debris retained or removed for eight of nine amphibian species, but that the overall response (population, physiological and behavioural) of amphibians was more negative where woody debris was retained. Two replicated, controlled studies in the USA and Indonesia found that the removal of coarse woody debris from standing forest did not decrease amphibian diversity or overall amphibian abundance, but did reduce species richness in one study. One replicated, controlled study in the USA found that migrating amphibians used clearcuts where woody debris was retained more than where it was removed. One replicated, site comparison study in the USA found that within clearcut forest, survival of juvenile amphibians was significantly higher in piles of woody debris than in open areas, and was similar in wood piles to unharvested forest.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F843https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F843Fri, 30 Aug 2013 15:15:04 +0100Collected Evidence: Collected Evidence: Harvest groups of trees instead of clearcutting Three studies (including two randomized, replicated, controlled, before-and-after studies) in the USA found that compared to clearcutting, harvesting trees in small groups did not result in higher amphibian or salamander abundance. A meta-analysis of 24 studies in North America found that partial harvest, which included harvesting groups or individual trees, thinning and shelterwood harvesting, resulted in smaller reductions in salamander populations than clearcutting Two studies (including one randomized, replicated, controlled, before-and-after study) in the USA found that compared to no harvesting, harvesting trees in small groups significantly decreased salamander abundance and changed species composition. One randomized, replicated, controlled, before-and-after study in the USA found that compared to unharvested plots, the proportion of female salamanders carrying eggs were similar and proportion of eggs per female and juveniles similar or lower in harvested plots that included harvest of groups of trees.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F844https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F844Fri, 30 Aug 2013 15:47:36 +0100Collected Evidence: Collected Evidence: Leave standing deadwood/snags in forests One randomized, replicated, controlled, before-and-after study in the USA found that compared to total clearcutting, leaving dead or wildlife trees did not result in higher abundances of salamanders. Two studies (including one randomized, replicated, controlled, before-and-after study) in the USA found that compared to no harvesting, leaving dead or wildlife trees during clearcutting did not prevent a decrease in salamander abundance or change in species composition. One randomized, replicated, controlled study in the USA found that numbers of amphibian species and abundance were similar with removal or creation of dead trees within forest. One randomized, replicated, controlled, before-and-after study in the USA found that compared to unharvested plots, the proportion of female salamanders carrying eggs, eggs per female or proportion of juveniles were similar or lower in harvested plots that included plots where dead and wildlife trees were left during clearcutting, depending on species and time since harvest.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F845https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F845Fri, 30 Aug 2013 16:07:51 +0100Collected Evidence: Collected Evidence: Use leave-tree harvesting instead of clearcutting Two studies (including one randomized, replicated, controlled, before-and-after study) in the USA found that compared to clearcutting, leaving a low density of trees during harvest did not result in higher salamander abundance. Two studies (including one randomized, replicated, controlled, before-and-after study) in the USA found that compared to no harvesting, leaving a low density of trees during harvest decreased salamander abundance and changed species composition. One randomized, replicated, controlled, before-and-after study in the USA found that compared to unharvested plots, the proportion of female salamanders carrying eggs, eggs per female or proportion of juveniles were similar or lower in harvested plots that included leave-tree harvests, depending on species and time since harvest.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F846https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F846Fri, 30 Aug 2013 16:21:07 +0100Collected Evidence: Collected Evidence: Use patch retention instead of clearcutting We found no evidence for the effect of retaining patches of trees rather than clearcutting on amphibian populations. One replicated study in Canada found that although released red-legged frogs did not show significant movement towards retained tree patches, large patches were selected more and moved out of less than small patches.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F847https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F847Fri, 30 Aug 2013 16:30:32 +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%2Fwww.conservationevidence.com%2Factions%2F848https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F848Thu, 05 Sep 2013 12:44:56 +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: Use shelterwood harvesting instead of clearcutting Three studies (including two randomized, replicated, controlled, before-and-after studies) in the USA found that compared to clearcutting, shelterwood harvesting resulted in higher, similar or initially higher and then similar salamander abundance. A meta-analysis of 24 studies in North America found that partial harvest, which included shelterwood harvesting with three other types, resulted in smaller reductions in salamander populations than clearcutting Two of three studies (including two randomized, replicated, controlled, before-and-after studies) in the USA found that compared to no harvesting, shelterwood harvesting decreased salamander abundance and changed species composition. One found that shelterwood harvesting did not affect salamander abundance. One randomized, replicated, controlled, before-and-after study in the USA found that compared to unharvested plots, the proportion of female salamanders carrying eggs, eggs per female or proportion of juveniles were similar or lower in harvested plots that included shelterwood harvested plots, depending on species and time since harvest.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F851https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F851Thu, 05 Sep 2013 14:42:48 +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 +0100
What Works 2021 cover

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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