Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Exclude domestic animals or wild hogs by fencing Three replicated, site comparison studies in the USA found that excluding livestock from streams or ponds did not increase numbers of amphibian species or overall abundance, but did increase larval abundance and abundance of green frog metamorphs. Two studies found that the abundance of green frogs and/or American toads was higher with grazing. One randomized, replicated, controlled, before-and-after study in the USA found that excluding cattle from ponds did not increase numbers of eggs or larval survival of Columbia spotted frogs. One before-and-after study in the UK found that pond restoration that included livestock exclusion increased pond use by breeding natterjack toads. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F746https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F746Wed, 17 Jul 2013 10:35:16 +0100Collected Evidence: Collected Evidence: Install barrier fencing along roads Seven of eight studies (including one replicated and two controlled studies) in Germany, Canada and the USA found that barrier fencing with culverts decreased amphibian road deaths, or decreased deaths provided that the fence length and material were effective. One found that low numbers of amphibians were diverted by barriers during breeding migrations. One replicated study in the USA found that barriers at least 0.6 m high were required to prevent green frogs and leopard frogs climbing over. Two studies in the Netherlands and USA found that treefrogs and 10% of common toads climbed over barrier fencing during breeding migrations. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F756https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F756Wed, 14 Aug 2013 11:23:38 +0100Collected Evidence: Collected Evidence: Engage volunteers to collect amphibian data (citizen science) Five studies in Canada, the UK and USA found that amphibian data collection projects engaged 100–10,506 volunteers and were active in 16–17 states in the USA. Five studies in the UK and USA found that volunteers undertook 412 surveys, surveyed 121–7,872 sites, swabbed almost 6,000 amphibians and submitted thousands of amphibian records. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F760https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F760Fri, 16 Aug 2013 11:11:34 +0100Collected Evidence: Collected Evidence: Immunize amphibians against chytridiomycosis infection One randomized, replicated, controlled study in the USA found that vaccinating mountain yellow-legged frogs with formalin-killed chytrid fungus did not significantly reduce chytridiomycosis infection rate or mortality. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F765https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F765Fri, 16 Aug 2013 16:05:06 +0100Collected Evidence: Collected Evidence: Create walls or barriers to exclude pollutants One controlled study in Mexico found that installing filters across canals to improve water quality and exclude fish increased weight gain in axolotls. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F771https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F771Tue, 20 Aug 2013 15:11:46 +0100Collected Evidence: Collected Evidence: Create refuges Two replicated, controlled studies (including one randomized study) in the USA and Indonesia found that adding coarse woody debris to forest floors had no effect on the number of amphibian species or overall abundance, but had mixed effects on abundance of individual species. One before-and-after study in Australia found that restoration that included reintroducing coarse woody debris to the forest floor increased frog species. One replicated, before-and-after study in the UK found that creating refugia for great crested newts, along with other interventions, maintained four populations. Two studies (including one replicated study) in New Zealand and the USA found that artificial refugia were used by translocated Hamilton's frogs and hellbenders, although few were used for breeding. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F772https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F772Tue, 20 Aug 2013 15:40:21 +0100Collected Evidence: Collected Evidence: Engage landowners and other volunteers to manage land for amphibians Two before-and-after studies (including one replicated study) in Estonia and Taiwan found that habitat management with participation of volunteers increased natterjack toad and Taipei frog populations. One controlled study in Mexico found that engaging landowners in aquatic habitat management increased axolotl weight. Six studies in Estonia, the USA and UK found that between eight and 41,000 volunteers were engaged in aquatic and terrestrial habitat restoration programmes for amphibians. Individual programmes restored up to 1,023 ponds or over 11,500 km2 of habitat. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F777https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F777Wed, 21 Aug 2013 14:39:26 +0100Collected Evidence: Collected Evidence: Legal protection of species Three reviews (including one systematic review) in the Netherlands and UK (Bosman et al. 2011, Spitzen-van der Sluijs et al. 2011, Lewis 2012) found that legal protection of amphibian species was not effective at protecting populations during development. Two reviews in the UK (Edgar et al. 2005, Lewis 2012) found that the number of great crested newt mitigation licences issued over 10 years increased to over 600 in England and Wales. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F779https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F779Thu, 22 Aug 2013 11:46:02 +0100Collected Evidence: Collected Evidence: Maintain or restore hedges We found no evidence for the effects of maintaining or restoring of hedges 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%2Fconservationevidencejournal.com%2Factions%2F790https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F790Thu, 22 Aug 2013 14:33:36 +0100Collected Evidence: Collected Evidence: Encourage aquatic plant growth as refuge against fish predation We found no evidence for the effects of encouraging aquatic plant growth as refuge against fish predation 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%2Fconservationevidencejournal.com%2Factions%2F796https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F796Thu, 22 Aug 2013 14:40:25 +0100Collected Evidence: Collected Evidence: Maintain ephemeral ponds Studies investigating the effects of regulating water levels or deepening ponds are discussed in ‘Threat: Natural system modifications – Regulate water levels’ and ‘Habitat restoration and creation – Deepen, de-silt or re-profile ponds’. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F805https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F805Thu, 22 Aug 2013 15:02:01 +0100Collected Evidence: Collected Evidence: Deepen ponds to prevent desiccationStudies investigating the effects of deepening ponds are discussed in ‘Habitat restoration and creation – Deepen, de-silt or re-profile ponds’. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F806https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F806Thu, 22 Aug 2013 15:02:40 +0100Collected Evidence: Collected Evidence: Create refuge areas in aquatic habitats We found no evidence for the effects of creating refuge areas in 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%2Fconservationevidencejournal.com%2Factions%2F813https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F813Thu, 22 Aug 2013 15:08:47 +0100Collected Evidence: Collected Evidence: Deepen, de-silt or re-profile ponds Two before-and-after studies in France and Denmark found that pond deepening and enlarging or re-profiling resulted in the establishment of a breeding population of great crested newts or translocated garlic toads. Two studies (including one replicated, controlled study) in the UK and Denmark found that pond deepening and enlarging or dredging increased a population of common frogs or numbers of calling male tree frogs. Four before-and-after studies in Denmark and the UK found that pond deepening, along with other interventions, maintained newt populations and increased populations of European fire-bellied toads or natterjack toads. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F817https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F817Fri, 23 Aug 2013 09:03:23 +0100Collected Evidence: Collected Evidence: Exclude fish with barriers One controlled study in Mexico found that excluding fish using a barrier increased weight gain of axolotls. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F829https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F829Wed, 28 Aug 2013 14:59:09 +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%2Fconservationevidencejournal.com%2Factions%2F843https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F844https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F845https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F845Fri, 30 Aug 2013 16:07:51 +0100Collected Evidence: Collected Evidence: Create ponds for natterjack toads Five before-and-after studies (including three replicated and one controlled study) in the UK and Denmark found that pond creation, along with other interventions, significantly increased natterjack toad populations, or in two cases maintained or increased populations at 75% of sites. One replicated, site comparison study in the UK found that compared to natural ponds, created ponds had lower natterjack toad tadpole mortality from desiccation, but higher mortality from predation by invertebrates. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F866https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F866Tue, 10 Sep 2013 15:47:29 +0100Collected Evidence: Collected Evidence: Create ponds for salamanders (including newts) Three before-and-after studies (including two replicated studies) in France, Germany and the USA found that naturally colonizing alpine newts, captive-bred smooth newts or translocated spotted salamanders established stable breeding populations in 20–100% of created ponds. Two replicated, before-and-after study in France and China found that alpine newts or Chinhai salamanders reproduced in 60–100% of created ponds. One small, replicated, before-and-after study in the USA found that translocated spotted salamanders but not tiger salamanders reproduced in created ponds. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F867https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F867Tue, 10 Sep 2013 15:55:04 +0100Collected Evidence: Collected Evidence: Create ponds for toads Four before-and-after studies (including one replicated study) in Germany, the UK and USA found that translocated and naturally colonizing toads established breeding populations in created ponds, or in one case 33% of created ponds. Two before-and-after studies (including one replicated study) in Denmark and Switzerland found that common toads and midwife toads naturally colonized 29–100% of created ponds, whereas captive-bred garlic toads did not colonize. One before-and-after study in Denmark found that creating and restoring ponds, along with head-starting, increased populations of European fire-bellied toads. One replicated, before-and-after study in Switzerland found that midwife toads reproduced in 16% of created ponds. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F868https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F868Wed, 11 Sep 2013 08:55:34 +0100Collected Evidence: Collected Evidence: Freeze sperm or eggs for future use Nine replicated studies (including three controlled studies) in Austria, Australia, Russia, the UK and USA found that following freezing frog and toad sperm viability depended on species and/or cryoprotectant used. One found that although sperm viability was low following freezing, it could be frozen for up to 58 weeks. Five of the studies and one additional replicated study in Australia found that following freezing, viability of sperm and in one case eggs, also depended on storage temperature, storage method, freezing or thawing rate. Seven replicated studies (including three controlled studies) in Austria, Australia, the UK and USA found that frog and toad sperm viability was greatest following freezing with the cryoprotectant dimethyl sulfoxide, glycerol, sucrose or dimethyl formamide. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F876https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F876Thu, 12 Sep 2013 11:09:04 +0100Collected Evidence: Collected Evidence: Create wetland Fifteen studies investigated the effectiveness of creating wetlands for amphibians. Five site comparison studies (including four replicated studies) in the USA compared created to natural wetlands and found that created wetlands had similar numbers of amphibian species, amphibian abundance or communities depending on depth as natural wetlands. Two of the studies found that created wetlands had fewer amphibian species or lower abundance and different communities compared to natural wetlands. One site comparison study in the USA found that created wetlands had similar numbers of species to adjacent forest. One global review and two site comparison studies (including one replicated study) in the USA combined created and restored wetlands and compared them to natural wetlands and found that numbers of amphibian species and abundance was higher or similar, or higher in 54% of studies and similar in 35% of studies reviewed compared to natural wetlands. Three site comparison studies (including one replicated study) in the USA found that certain amphibian species were only found in created or natural wetlands. One before-and-after study in Australia found that captive-bred green and golden bell frog tadpoles released into a created wetland did not establish a self-sustaining population. Five studies (including two replicated studies) in Kenya and the USA that investigated colonization of created wetlands found that four to 15 amphibian species used or colonized the wetlands. One global review and three studies (including two replicated studies) in the USA found that numbers of amphibian species and amphibian abundance in created wetlands were affected by wetland design, vegetation, water levels, surrounding habitat, fish presence and distance to source wetlands. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F880https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F880Fri, 13 Sep 2013 11:16:59 +0100Collected Evidence: Collected Evidence: Head-start amphibians for release Twenty-two studies head-started amphibians from eggs and monitored them after release. Six of 10 studies (including five replicated studies) in Denmark, Spain, the UK and USA and a global review found that released head-started tadpoles, metamorphs or juveniles established breeding frog populations or increased populations of frogs or toads. Two found mixed results with breeding populations established in 12 of 17 studies reviewed or at two of four sites. Two found that head-started metamorphs or adults did not prevent a frog population decline or establish a breeding toad population. For five of the studies, release of captive-bred individuals, translocation or habitat management were also carried out. Nine of 10 studies (including nine replicated studies) in Australia, Canada, Europe and the USA found that head-started amphibians released as tadpoles, metamorphs or adults metamorphosed successfully, tended to survive the first season, winter or year or bred successfully. One found adult survival was 1–17% over four years and one found limited breeding following the release of adults. Four replicated studies in Australia, the UK and USA found that frog survival to metamorphosis and size at metamorphosis was greater and time to metamorphosis shorter in head-started compared to wild animals. One replicated study in Canada found that young head-started leopard frogs were smaller than those in the wild. One replicated study in Australia found that corroboree frog tadpoles released earlier had higher survival, but metamorphosed two weeks later than those released a month later. Three studies (including one replicated study) in the USA only provided results for head-starting in captivity. Two found that Houston toad eggs could be captive-reared to tadpoles, but only one successfully reared adults. Three studies (including two replicated studies) in Canada and the USA found that during head-starting, amphibian growth rate, size, stress levels and survival was affected by the amount of protein provided, housing density or enclosure location. One found that mass, stress levels and survival were not affected by the amount of food or habitat complexity. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F881https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F881Fri, 13 Sep 2013 13:02:34 +0100Collected Evidence: Collected Evidence: Install culverts or tunnels as road crossings Thirty-two studies investigated the effectiveness of installing culverts or tunnels as road crossings for amphibians. Six of seven studies (including three replicated studies) in Canada, Germany, Italy, Hungary and the USA found that installing culverts or tunnels significantly decreased amphibian road deaths; in one study this was the case only when barrier fencing was also installed. One found no effect on road deaths. Fifteen of 24 studies (including one review and 17 replicated studies) in Australia, Canada, Europe and the USA found that culverts/tunnels were used by amphibians, by 15–85% of amphibians or 3–15 species, or that 23–100% of culverts or tunnels were used by amphibians or used in 12 of 14 studies reviewed. The majority of culverts/tunnels had barrier fencing to guide amphibians to entrances. Four found mixed effects depending on species, or for toads depending on the site or culvert type. Five found that culverts were used by less than 10% of amphibians or were not used. The use of culverts/tunnels was affected by diameter in three of six studies, with wider culverts used more, length in one of two studies, with long culverts avoided, lighting in all three studies, with mixed effects, substrate in three of six studies, with natural substrates used more, presence of water in two of three studies, with mixed effects, entrance location in one and tunnel climate in one study. Six studies (including one replicated, controlled study) in Canada, Spain, the Netherlands and USA investigated the use of culverts with flowing water and found that they were used by amphibians, or rarely used by salamanders or not used, and were used more or the same amount as dry culverts. Certain culvert designs were not suitable for amphibians; one-way tunnels with vertical entry chutes resulted in high mortality of common toads and condensation deposits from steel culverts had very high metal concentrations. One study found that thousands of amphibians were still killed on the road. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F884https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F884Mon, 16 Sep 2013 12:20:30 +0100