Collected Evidence: Collected Evidence: Rear declining bumblebees in captivityWe have captured 22 trials from 13 countries documenting captive rearing of bumblebee colonies by confining mated queens alone (eight trials), with one or more bumblebee workers (seven trials), honey bee workers (one trial), male bumblebee pupae (three trials) or following anaesthetisation with CO2 (four trials). One trial found that over four years of artificial rearing, Bombus terrestris queens gradually decreased in weight. Three trials have tried to rear North American bumblebees now declining or thought to be declining. Two induced spring queens of the half-black bumblebee B. vagans to rear adults in captivity, one trial induced queen yellow-banded bumblebees B. terricola (attempted in all three trials) and red-belted bumblebees B. rufocinctus (only attempted in one trial) to rear adults in captivity. All three trials tried to rear the yellow bumblebee B. fervidus and in all cases the queens laid eggs but the larvae died before becoming adults. One trial found the same pattern for the rusty-patched bumblebee and the American bumblebee B. pensylvanicus. One study reports rearing the large garden bumblebee B. ruderatus, a Biodiversity Action Plan species in the UK. Two trials have reported laboratory rearing of a pocket-making bumblebee, the Neotropical B. atratus. Three replicated trials demonstrated that the pollen diet of captively reared bumblebees influences reproductive success. In one trial, buff-tailed bumblebee B. terrestris colonies fed on freshly frozen pollen produced larger queens that survived better and produced larger colonies themselves than colonies fed on dried, frozen pollen. Two replicated trials demonstrated that B. terrestris workers can produce more offspring when fed types of pollen with a higher protein content. Two replicated experiments showed that an artificial light regime of eight hours light, 16 hours darkness, can reduce the time taken for artificially reared queen B. terrestris to lay eggs, relative to rearing in constant darkness. We have captured two replicated trials examining the effect of different artificial hibernation regimes in B. terrestris. One showed that hibernation of queens at 4-5°C for 45 days enhanced egg-laying and colony formation rates, but hibernated queens produced smaller colonies than non-hibernated queens. The second showed that queens should weigh more than 0.6 g (wet weight) and be hibernated for four months or less to have a good chance of surviving.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F50https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F50Thu, 20 May 2010 20:22:36 +0100Collected Evidence: Collected Evidence: Restore or create grasslands Of 23 studies found, three from the USA, Canada and Iceland found that species richness on restored grassland sites was similar to remnant habitats or higher than unrestored sites. One replicated, randomised study from the USA found that bird diversity was lower on restored grassland sites compared to hayfields or pastures, whilst a small American study found that species richness declined at one of two fields restored to grassland from croplands. Three studies from the USA found that target species used restored grasslands. Two studies from the USA found that CRP fields held disproportionate proportions of total bird populations, or that local population trends were correlated with the amount of CRP land in the area. Six studies from the USA and UK found that the abundances or densities of some, or all, species were higher on restored sites compared to unrestored sites, or were comparable to natural habitats. Two studies found lower abundances of species on restored sites compared to unrestored sites, although the authors of one suggest that drought conditions may have confounded the results. Five studies from the USA found that at least some bird species in restored areas of grassland had higher productivities than birds in unrestored areas; similar or higher productivies than natural habitats; or had high enough productivities to sustain populations. Three studies found that productivities were lower in restored areas than unrestored, or that productivities on restored sites were too low to sustain populations. A replicated study from the USA found that older CRP fields held more nests, but fewer species than young fields. Two replicated American studies found no differences in species richness or abundances between CRP fields and riparian filter strips whether they were sown with warm- or cool-season grasses, whilst another found that more grassland specialist species were found on sites sown with non-native species. A replicated study from the USA found no difference in bird densities between sites seeded with redtop grass and those not seeded. A study from Iceland found that very few birds were found on restored sites, unless they were sown with Nootka lupin.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F361https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F361Tue, 31 Jul 2012 13:44:05 +0100Collected Evidence: Collected Evidence: Provide supplementary food for birds or mammals A total of 18 individual studies investigated the effects of providing supplementary food. Nine studies from France, Sweden and the UK (six replicated studies, of which five controlled and one also randomized and paired) found that the provision of supplementary food increased farmland bird abundance, breeding population size, density, body mass, hatching, nestling growth and fledging rates, increased overwinter survival of a declining house sparrow population and that fed male hen harriers bred with more females than control birds. Two studies did not separate the effects of several other interventions carried out on the same study site. Four studies from the UK and Finland (three replicated studies, of which one controlled and one randomized) found that farmland songbirds and field voles (field voles on unmown plots only) used supplementary food when provided, including the majority of targeted species such as tree sparrow, yellowhammer and corn bunting. Five replicated studies from the UK (of which two also controlled) found that the provision of supplementary food had no clear effect on farmland bird breeding abundance, European turtle dove reproductive success, territory size or territory density, overwinter survival of three stable house sparrow populations, tree sparrow nest box use, or the abundance of weed seeds on the soil surface. One replicated, controlled study from Sweden found no effect of supplementary food provision on common starling clutch size or nestling weight, and lower fledging rates in nests which received supplementary food compared to nests without supplementary food in one year. Four studies from the UK (two replicated of which one was also randomized and controlled) found that the use of supplementary food by farmland birds varied between species and region, depended upon the time of year and proximity to other feeding stations and natural feeding areas. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F648https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F648Thu, 18 Oct 2012 14:20:34 +0100Collected Evidence: Collected Evidence: Create beetle banks Fourteen reports from eight studies out of a total 24 reports from 12 individual studies (including eight replicated studies of which three controlled and four literature reviews) from Denmark and the UK found that beetle banks provide some benefits to farmland biodiversity. Sixteen reports from eight individual studies looked at invertebrates and beetle banks. Five reports from two replicated studies (of which one controlled) and a review found positive effects on invertebrate densities/numbers, distribution, or higher ground beetle density and species diversity in spring and summer but not winter. Six reports from three replicated studies (of which one randomized and controlled) found that invertebrate numbers varied between specific grass species sown on beetle banks. Two replicated studies (one paired and controlled) found that the effect of beetle banks varied between invertebrate groups or families. Five replicated studies (of which two controlled) found lower or no difference in invertebrate densities or numbers on beetle banks relative to other habitats. One review found lesser marsh grasshopper did not forage on two plant species commonly sown in beetle banks. Six studies looked at birds and beetle banks. Two reviews and one replicated controlled trial found positive effects on bird numbers (in combination with other farmland conservation measures) or evidence that birds used beetle banks. Two studies (one replicated site comparison) found mixed effects on birds. One replicated study found no farmland bird species were associated with beetle banks. One replicated, paired, controlled study and a review looked at the effects of beetle banks on plants and found either lower plant species richness on beetle banks in summer, or that grass margins including beetle banks were generally beneficial to plants but these effects were not pronounced on beetle banks. One controlled study and a review found beetle banks acted as nest sites for harvest mice. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F651https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F651Tue, 23 Oct 2012 16:24:44 +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%2Fwww.conservationevidence.com%2Factions%2F881https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F881Fri, 13 Sep 2013 13:02:34 +0100Collected Evidence: Collected Evidence: Use clearcutting to increase understory diversity Eight of 12 studies (including three replicated, randomized, controlled studies) in Belgium, Brazil, Canada, China, Germany, Israel, spain and the USA found that clearcutting increased the cover and species richness of understory plants. Two found it decreased the density and species richness, and two found no effect or mixed effects. Three of six studies (including five replicated, randomized, controlled studies) in Brazil, Canada and Spain found that clearcutting increased the density and species richness of young trees. One found it decreased new tree density and two found no effect or mixed effects depending on the tree species. Three of nine studies (including four replicated, randomized, controlled studies) in Australia, Brazil4, Canada, Japan and the USA found that clearcutting decreased density, species richness and diversity of mature trees. One study found it increased trees species richness .Six studies found no effect or mixed effects on tree density, size and species richness and diversity.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1222https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1222Mon, 23 May 2016 08:58:48 +0100Collected Evidence: Collected Evidence: Crop production: Grow cover crops in arable fieldsCrop yield (24 studies): Six replicated, controlled studies (five randomized) from Spain and the USA found lower cash crop yields in plots with winter cover crops, compared to plots without them, in some comparisons. Three replicated, randomized, controlled studies from Italy and the USA found higher cash crop yields in plots with winter cover crops, compared to plots without them, in some comparisons. Eight replicated, randomized, controlled studies from Italy and the USA found inconsistent differences in cash crop yields (sometimes higher, sometimes lower) between plots with or without cover crops. Seven controlled studies (six replicated, four randomized) from France, Israel, Spain, and the USA found no differences in cash crop yields between plots with or without cover crops. One replicated, randomized, controlled study from the USA found inconsistent differences in cash crop yields between plots with or without summer cover crops. Crop quality (6 studies): Three replicated, controlled studies (two randomized) from Italy, Spain, and the USA found no differences in cash crop quality between plots with or without winter cover crops. Two controlled studies (one replicated and randomized) from the USA found some differences in tomato quality between plots with winter cover crops or fallows. One replicated, randomized, controlled study from the USA found inconsistent differences in cash crop quality between plots with or without winter cover crops. Implementation options (9 studies): Eight studies from Italy, Spain, and the USA found higher cash crop yields in plots that had legumes as winter cover crops, compared to non-legumes. One study from the USA found higher cash crop yields in plots that had a mixture of legumes and grasses, compared to legumes alone.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1351https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1351Tue, 21 Mar 2017 11:54:49 +0000Collected Evidence: Collected Evidence: Crop production: Use no tillage in arable fieldsCrop yield (23 studies) Crops (22 studies): Eight replicated, controlled studies (seven randomized) from Italy and Spain found higher crop yields in plots with no tillage, compared to conventional tillage, in some or all comparisons. Seven replicated, controlled studies (six randomized) from Italy, Lebanon, Spain, and the USA found lower crop yields in plots with no tillage, compared to conventional tillage, in some or all comparisons. Four replicated, randomized controlled studies from Italy and Spain found inconsistent differences in crop yields (sometimes higher with no tillage, sometimes lower). Three replicated, controlled studies (two randomized) from Italy, Portugal, and Spain found similar crop yields in plots with or without tillage. Crop residues (5 studies): Two replicated, randomized, controlled studies from Lebanon and Spain found higher straw yields in plots with no tillage, compared to conventional tillage, in some comparisons. One replicated, randomized, controlled study from Spain found inconsistent straw yields (sometimes higher with no tillage, sometimes lower). Two replicated, controlled studies (one randomized) from Italy and Spain found similar straw yields in plots with or without tillage. Crop quality (6 studies): One replicated, controlled study from Italy found less protein in wheat grains from plots with no tillage, compared to conventional tillage. One replicated, randomized, controlled study from Spain found heavier cereal grains in plots with no tillage, compared to conventional tillage. Two replicated, randomized, controlled studies from Spain found other differences in crop quality, but two replicated, controlled studies from Italy and the USA did not.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1355https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1355Tue, 18 Apr 2017 14:10:16 +0100Collected Evidence: Collected Evidence: Soil: Add compost to the soilOrganic matter (12 studies): Twelve replicated, controlled studies (ten randomized) from Italy, Spain, Syria, Turkey, and the USA found more organic matter in soils with added compost, compared to soils without added compost, in some or all comparisons. Nutrients (10 studies): Six replicated, controlled studies (five randomized) from Italy, Portugal, Spain, and Syria found more nutrients in soils with added compost, compared to soils without added compost, in some or all comparisons. Three replicated, randomized, controlled studies from Italy and the USA found inconsistent differences in nitrogen between soils with or without added compost. One replicated, randomized, controlled study from the USA found no differences in phosphorus between soils with or without added compost. Three replicated, randomized, controlled studies from Italy and Spain found similar pH levels in soils with or without added compost. Soil organisms (10 studies): Six replicated, controlled studies (five randomized) from Italy, Spain, and the USA found more microbial biomass in soils with added compost, compared to soils without added compost, in some or all comparisons. Two replicated, controlled studies from Italy and the USA found similar amounts of microbial biomass in soils with or without added compost. One replicated, randomized, controlled study from Italy found inconsistent differences in bacterial abundance between plots with or without added compost. Two replicated, randomized, controlled studies from Italy and Spain found differences in bacteria communities, in some comparisons. Soil erosion and aggregation (5 studies): Two replicated, controlled studies (one randomized) from Spain found less erosion of soils with added compost, compared to soils without added compost, in some or all comparisons. Four replicated, randomized, controlled studies from Spain and Turkey found that soils with added compost were more stable than soils without added compost, in some or all comparisons. Greenhouse gases (10 studies): Six replicated, controlled studies (five randomized) from Italy, Spain, and the USA found more greenhouse gas in soils with added compost, compared to soils without added compost, in some or all comparisons. Four replicated, randomized, controlled studies from Spain found no differences in greenhouse gas between soils with or without added compost. Implementation options (2 studies): One replicated, randomized, controlled study from Syria found more nitrogen in soils with compost added every two years, compared to soils with compost added every four years. One replicated, randomized, controlled study from Italy found inconsistent differences in bacteria abundance between soils with different amounts of added compost.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1362https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1362Mon, 08 May 2017 13:08:46 +0100Collected Evidence: Collected Evidence: Soil: Plant or maintain ground cover in orchards or vineyardsOrganic matter (12 studies): Ten studies (eight replicated, randomized, and controlled, and two site comparisons) from Chile, France, Spain, and the USA found more organic matter in soils with ground cover, compared to soils without ground cover, in some or all comparisons. Two meta-analyses of studies from Mediterranean climates also found more organic matter in plots with ground cover. Implementation options (4 studies): One study from France found more organic matter in soils with permanent ground cover, compared to temporary ground cover, in one of three comparisons. Two studies from the USA found similar amounts of organic matter in soils with resident vegetation or seeded cover crops. One study from Spain found more organic matter where cover crops were incorporated into the soil. Nutrients (12 studies) Nitrogen (9 studies): Five studies (four replicated, randomized, and controlled, and one site comparison) from Chile and Spain found more nitrogen in soils with ground cover, compared to soils without ground cover, in some or all comparisons. One replicated, randomized, controlled study from the USA found less nitrogen in soils with ground cover, in some comparisons. Two replicated, randomized, controlled studies from Spain and the USA found inconsistent differences in nitrogen between soils with or without ground cover. One replicated site comparison from France found similar amounts of nitrogen in soils with or without ground cover. Implementation options (5 studies): Two studies from Spain and the USA found more nitrogen in soils that were cover cropped with legumes, compared to non-legumes, in some or all comparisons. Two studies from vineyards in the USA found similar amounts of nitrogen in soils with resident vegetation or seeded cover crops. One of these studies also found similar amounts of nitrogen in soils with different types of seeded cover crops, and in soils with or without tillage (both with ground cover). One study from Spain found more nitrogen where cover crops were incorporated into the soil. Phosphorus (4 studies): One replicated site comparison from France found more phosphorus in soils with ground cover, compared to bare soils, in one of six comparisons. Two studies (one replicated, randomized, and controlled, and one site comparison) from Spain and the USA found less phosphorus in soils with seeded cover crops, compared to tilled soils, in some comparisons. One replicated, randomized, controlled study from Chile found similar amounts of phosphorus in soils with seeded cover crops and bare soils. Implementation options (3 studies): One study from France found more phosphorus in soils with permanent ground cover, compared to temporary ground cover, in one of three comparisons. One study from the USA found similar amounts of phosphorus in soils with resident vegetation or seeded cover crops. One study from Spain found different amounts of phosphorus in soils with different types of seeded cover crops. Potassium (3 studies): One replicated, randomized, controlled study from Chile found more potassium in soils with seeded cover crops, compared to bare soils. Two site comparisons (one replicated) from France and Spain found similar amounts of potassium in soils with ground cover, compared to tilled or bare soil. Implementation options (1 study): One study from the USA found similar amounts of potassium in soils with resident vegetation or seeded cover crops. pH (4 studies): Two studies (one replicated, randomized, and controlled, and one site comparison) from Spain and the USA found lower pH levels in soils with ground cover, compared to soils without ground cover. One replicated, randomized, controlled study from Chile found higher pH levels in soils with ground cover. One replicated site comparison from France found similar pH levels in soils with or without ground cover. Soil organisms (6 studies) Microbial biomass (4 studies): Four replicated studies (three randomized and controlled, one site comparison) from France and the USA found more microbial biomass in soils with ground cover, compared to bare or tilled soils, in some or all comparisons. Implementation options (1 study): One study from France found more microbial biomass in soils with permanent ground cover, compared to temporary ground cover, in some comparisons. Fungi (2 studies): One replicated, controlled study from the USA found more symbiotic fungi (mycorrhizae) in soils with seeded cover crops, compared to tilled soils, in some comparisons, but found similar numbers of roots that were colonized by mycorrhizae. One replicated, randomized, controlled study from the USA found inconsistent differences in mycorrhizae in soils with seeded cover crops or tilled soils. Bacteria (1 study): One replicated, randomized, controlled study from Spain found more bacteria, but similar levels of bacterial diversity, in soils with ground cover, compared to bare soils. Nematodes (1 study): One replicated site comparison from France found more nematodes in soils with ground cover, compared to bare soils. Implementation options (1 study): One study from France found more nematodes in soils with permanent ground cover, compared to temporary ground cover, in one of three comparisons. Soil erosion and aggregation (10 studies) Soil erosion (7 studies): Six replicated, randomized, controlled studies from Chile, Italy, Spain, and the USA found less erosion of soils with ground cover, compared to bare or tilled soils, in some comparisons or all comparisons. One replicated, controlled study from France found similar amounts of erosion in plots with or without ground cover. Implementation options (1 study): One study from Italy found the least erosion with permanent cover crops, and the most erosion with temporary cover crops. Soil aggregation (5 studies): Four replicated, randomized, controlled studies from Chile and Spain found that soil aggregates were more water-stable in plots with seeded cover crops, compared to tilled or bare soils, in some or all comparisons. One site comparison from Spain found inconsistent differences in water stability between soils with seeded cover crops and bare soils. Greenhouse gases (3 studies): Two replicated, randomized, controlled studies from a vineyard in the USA found more carbon dioxide or nitrous oxide in soils with cover crops, compared to tilled soils. One replicated, randomized, controlled study from an olive orchard in Spain found similar amounts of carbon dioxide in soils with cover crops, compared to tilled soils. Implementation options (1 study): One study from the USA found similar amounts of carbon dioxide in soils with different types of ground cover.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1367https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1367Mon, 15 May 2017 14:10:27 +0100Collected Evidence: Collected Evidence: Other biodiversity: Restore habitat along watercoursesAmphibians (1 study): One replicated site comparison from the USA found similar numbers of amphibian species in restored and remnant sites. Birds (8 studies): Two replicated site comparisons from Spain and the USA found similar numbers of bird species in restored and remnant sites. Two replicated site comparisons from the USA found fewer bird species in restored riparian sites, compared to remnant sites. One replicated site comparison from Spain found similar numbers of birds and bird species in restored contaminated sites and uncontaminated sites. One replicated site comparison from the USA found that an endangered bird nested in restored sites, and had similar nesting success in restored and remnant sites. One replicated site comparison from the USA found that bird populations increased with the area of restored habitat in the landscape, in some comparisons. One replicated site comparison from the USA found similar levels of nest parasitism in restored and remnant sites. Fish (1 study): One before-and-after site comparison from the USA found differences in fish communities, before and after changing river flow. Invertebrates (3 studies): One replicated site comparison from the USA found fewer native ants, but similar numbers of invasive ants, in restored sites, compared to remnant sites. One before-and-after site comparison from the USA found similar numbers of freshwater invertebrates in restored and reference sites, after restoration. One replicated, before-and-after study from the USA found more invertebrates and invertebrate species in plots with added gravel, compared to plots without added gravel, in some comparisons. One replicated before-and-after study from France found relatively more alien species after restoring river flow. Mammals (2 studies): Two replicated site comparisons from the USA found similar numbers of mammal species in restored and remnant sites. Plants (11 studies) Abundance (6 studies): Four replicated site comparisons from Spain and the USA found lower plant cover in restored sites, compared to remnant sites. One of these studies also found higher cover of exotic plants, but another one did not. One replicated, paired site comparison from the USA found similar numbers of flowers in restored and remnant sites. One replicated site comparison from the USA found more seeds, but fewer native seed, in orchards next to restored riparian habitats, compared to orchards next to remnant habitats. One replicated site comparison from the USA found similar exotic plant cover in remnant and restored forests. Diversity (6 studies): Two replicated studies from the USA found fewer native plant species in restored forests, compared to remnant forests. One of these studies also found more exotic species, but another one did not. One replicated site comparison from the USA found more plant species in restored sites, compared to remnant sites. One replicated, paired site comparison from the USA found similar numbers of flower species in restored and remnant sites. One replicated site comparison from the USA found fewer seed species and native seed species in orchards next to restored riparian habitats, compared to remnant riparian habitats. One controlled study from the USA found different plant communities in restored and unrestored habitats. Survival (2 studies): One replicated study from the USA found that about one-third of planted willows survived for one year. One site comparison from the USA found that some species survived after planting, as part of riparian restoration, but others did not. Habitat suitability (1 study): One replicated site comparison from the USA found that vegetation at one of five sites met the criteria for Bell’s Vireo nesting habitat. Size (1 study): One replicated site comparison from the USA found smaller elderberry plants in restored sites. Reptiles (1 study): One replicated site comparison from the USA found similar numbers of reptile species in remnant and restored sites. Implementation options (7 studies) Plants (3 studies): One study from the USA found more tree, shrub, vine, and perennial species, higher canopy cover, and higher native tree cover, in older restored plots, compared to younger restored plots, but this study also found fewer annual plant species, lower vegetation cover, lower annual forb cover, and lower grass cover. One study from the USA found an increase in native species and overstorey cover in restored sites, over time, but it found similar numbers of species and overstorey cover in sites planted at different densities. One study from the USA found that willow cuttings planted on the stream bottom had a higher survival rate than those planted on the streambank or terrace. Birds (3 studies): Three studies from the USA found more birds or bird species in older restored plots, compared to younger restored plots. One of these studies also found that the populations of some bird species increased with tree-planting density. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1416https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1416Fri, 19 May 2017 09:54:10 +0100Collected Evidence: Collected Evidence: Conduct veterinary screens of animals before reintroducing/translocating them One before-and-after study in Brazil found that most reintroduced golden lion tamarins did not survive over seven years, despite undergoing pre-release veterinary screens, alongside other interventions. One study in Brazil found that most reintroduced black lion tamarins that underwent veterinary screens, alongside other interventions, survived over four months. One before-and-after study in Malaysia found that 90% of reintroduced Müller's Bornean gibbons did not survive despite undergoing veterinary screens, alongside other interventions. One controlled study in Indonesia found that reintroduced Bornean agile gibbons that underwent veterinary screens, alongside other interventions, behaved similarly to wild gibbons. Two studies, including one controlled, in Malaysia and Indonesia found that most translocated orangutans that underwent veterinary screens, along with other interventions, survived translocation and the first three months post-translocation. Four studies, including three before-and-after studies, in Liberia, the Republilc of Congo and Guinea found that most reintroduced chimpanzees that underwent veterinary screens, alongside other interventions, survived over 1-5 years. One before and after study in Uganda found that a reintroduced chimpanzee repeatedly returned to human settlements after undergoing pre-release veterinary screens, alongside other interventions. Five studies, including four before-and-after studies, in Belize, French Guiana, Madagascar, Congo and Gabon found that most reintroduced or translocated primates that underwent veterinary screens, alongside other interventions, survived at least four months or increased in population size. Five studies, including four before-and-after studies, in French Guiana, Madagascar, South Africa and Vietnam found that most reintroduced or translocated primates were assumed to have died post-release despite undergoing pre-release veterinary screens, alongside other interventions. One controlled study in Kenya found that a population of translocated olive baboons were still surviving 16 years after translocation when veterinary screens were applied alongside other interventions. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1553https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1553Thu, 19 Oct 2017 20:15:52 +0100Collected Evidence: Collected Evidence: Allow primates to adapt to local habitat conditions for some time before introduction to the wild Two studies in Brazil and Thailand found that reintroduced primate populations were smaller after 12-17 months and one study in Belize found primate populations increased five years after allowing individuals to adapt to local habitat conditions before introduction into the wild, alongside other interventions. One study found that a reintroduced population of black howler monkeys had a birth rate of 20% after they were allowed to adapt to local habitat conditions before introduction into the wild, along with other interventions. Seven studies in Brazil, Madagascar, Malaysia, French Guiana, South Africa found that a minority of primates survived for at least 15 weeks to 12 years after allowing them to adapt to local habitat conditions before introduction into the wild, along with other interventions. Four studies in Belize, Brazil, Gabon, South Africa found that the majority of primates survived for at least four to 12 months. One study in Vietnam found that half of reintroduced pygmy slow lorises survived for at least two months. Two before-and-after studies in Gabon and the Republic of Congo found that a majority of western lowland gorillas survived for nine months to four years after allowing them to adapt to local habitat conditions before introduction into the wild, along with other interventions. Three studies in Liberia and the Congo found that a majority of chimpanzees survived for at least three to five years after allowing them to adapt to local habitat conditions before introduction into the wild, along with other interventions. One before-and-after study in Uganda found that a chimpanzee repeatedly returned to human settlements after allowing it to adapt to local habitat conditions before introduction into the wild, along with other interventions. A study in Indonesia found that Sumatran orangutans that were allowed to adapt to local habitat conditions before introduction performed less well than individuals that were directly released into the forest, alongside other interventions. One controlled study in Indonesia found that after being allowed to adapt to local habitat conditions a pair of introduced Bornean agile gibbons had a similar diet to wild gibbons. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1564https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1564Fri, 20 Oct 2017 10:08:36 +0100Collected Evidence: Collected Evidence: Reintroduce primates into habitat where the species is present Four before-and-after studies in Guinea and the Republic of Congo found that the majority of reintroduced chimpanzees survived for at least one to five years after reintroduction into habitat where the species was present, alongside other interventions. One study in Uganda found that a reintroduced chimpanzee repeatedly returned to human settlements after reintroduction intro habitat where the species was present, alongside other interventions, while a study in Senegal found that a reintroduced chimpanzee was reunited with its mother. One study in Malaysia found that a majority of reintroduced orangutans survived reintroduction intro habitat where the species was present, alongside other interventions. One controlled study in Malaysia found that a reintroduced population of orangutans had declined 33 years after reintroduction into habitat where the species was present, alongside other interventions. One study in Belize found that primate population increased five years after reintroduction into habitat where the species was present, alongside other interventions, while one study in Thailand found that primate population declined post-reintroduction. Six studies in Brazil, French Guiana, Indonesia, Madagascar, and South Africa found that a minority of primates survived for at least fifteen weeks to seven years after reintroduction into habitat where the species was present, alongside other interventions. Five studies in Brazil, French Guiana, Gabon, and South Africa found that a majority of primates survived for at least two months to one year. Two controlled studies in Madagascar and Indonesia found that reintroduced primates had similar diets to individuals in wild populations after reintroduction into habitat where the species was present, alongside other interventions. One controlled study in Indonesia found that reintroduced primates showed similar behaviour to wild individuals after reintroduction into habitat where the species was present, alongside other interventions. One study in Brazil found that a reintroduced muriqui rejoined a wild group after reintroduction into habitat where the species was present, alongside other interventions. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1591https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1591Fri, 20 Oct 2017 13:46:00 +0100Collected Evidence: Collected Evidence: Provide supplementary food to increase reproduction/survival Twenty-four studies evaluated the effects on mammals of providing supplementary food to increase reproduction/survival. Nine studies were in the USA, two were in Canada, two were in South Africa, two were in Poland, and one each was in Sweden, the Netherlands, eSwatini, Spain, Portugal, Slovenia, Austria, Norway and Sweden and one was across North America and Europe. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (18 STUDIES) Abundance (8 studies): Four of eight studies (incuding four controlled, two site comparisons and five before-and-after studies) in the USA, Canada, South Africa, Poland and Austria found that supplementary feeding increased the abundance or density of bank voles, red squirrels, striped mice, brown hyena and black-backed jackals. One study found a temporary increased in prairie vole abundance. The other three studies found supplementary feeding not to increase abundance or density of white-footed mice, northern flying squirrels, Douglas squirrels or Eurasian otters. Reproduction (8 studies): Four of five controlled studies (three also replicated) in the USA, South Africa, Norway and Sweden, Sweden and Spain, found that supplementary food increased the proportion of striped mice that were breeding, the number of arctic fox litters and the size of prairie vole litters. However, there was no increase in the number of arctic fox cubs in each litter or the proportion of female Iberian lynx breeding. One of two replicated studies (one site comparison and one controlled), in the Netherlands and the USA, found that supplementary feeding increased the number of young wild boar produced and recruited in to the population. The other study found that the number of mule deer produced/adult female did not increase. A review of studies across North America and Europe found that supplementary feeding increased ungulate reproductive rates in five of eight relevant studies. Survival (9 studies): Four of eight studies (including seven controlled studies and two before-and-after studies) in the USA, Canada, Poland and Spain, found that supplementary feeding increased survival of mule deer, bank voles, northern flying squirrels and eastern cottontail rabbits. Five studies found no increase in survival for white-tailed deer, Douglas squirrels, mule deer, Rocky Mountain bighorn sheep lambs or Iberian lynx. A review of studies across North America and Europe found that supplementary feeding increased ungulate survival in four out of seven relevant studies. Condition (4 studies): One of three studies (including two controlled and two before-and-after studies) in Poland, the USA, and Canada, found that supplementary food lead to weight gain or weight recovery in bank voles. One study found no body mass increase with supplementary feeding in northern flying squirrels and Douglas squirrels. The third study found mixed results, with supplementary feeding increasing weight gains in some cotton rats, depending on their sex, weight and the time of year. A review of studies from across North America and Europe found that different proportions of studies found supplementary feeding to improve a range of measures of ungulate condition. BEHAVIOUR (6 STUDIES) Use (2 studies): A replicated, controlled study in Sweden found that supplementary food increased occupancy of Arctic fox dens. A replicated study in Portugal found that artificial feeding stations were used by European rabbits. Behaviour (4 studies): Two of three replicated studies (two also controlled), in eSwatini, Slovenia and the USA, found that supplementary feeding led to reduced home range sizes or shorter movements of red deer and elk. The third study found home ranges and movement distances to be similar between fed and unfed multimammate mice. One replicated study in Poland found that supplementary feeding of ungulates altered brown bear behaviour. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2367https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2367Tue, 26 May 2020 16:24:30 +0100Collected Evidence: Collected Evidence: Release translocated mammals into fenced areas Twenty-four studies evaluated the effects of releasing translocated mammals into fenced areas. Nine studies were in Australia, six studies were in South Africa, two studies were in the USA and one study was in each of India, China, Spain, Hungary, Namibia and South Africa and France. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (22 STUDIES) Abundance (5 studies): Five studies (one replicated) in the USA, Australia and South Africa found that following translocation into fenced areas, 18 African elephant populations, tule elk, brushtail possum and elk and bison increased in number and following eradiation of invasive species a population of translocated and released captive-bred burrowing bettongs increased. A replicated, controlled study in Spain found that the abundance of translocated European rabbits was higher in areas fenced to exclude predators than unfenced areas. Reproductive success (7 studies): Two replicated, controlled studies in France and Spain found that after translocation, reproductive success of common hamsters and European rabbits was higher inside than outside fenced areas or warrens. Four studies (one replicated, controlled) in China and South Africa found that following translocation into a fenced area, Père David's deer, lions, translocated and captive-bred African wild dogs and one of two groups of Cape buffalo reproduced. A study in Australia found that four of five mammal populations released into a predator-free enclosure and one population released into a predator-reduced enclosure reproduced, whereas two populations released into an unfenced area with ongoing predator management did not survive to breed. Survival (13 studies): Two replicated, controlled studies in Spain and France found that after translocation, survival rates of common hamsters and European rabbits were higher inside than outside fenced areas or warrens. A study in Australia found that four of five mammal populations released into a predator-free enclosure and one population released into a predator-reduced enclosure survived, whereas two populations released into an unfenced area with ongoing predator management did not persist. Five studies in India, China, South Africa, Namibia and South Africa and Australia found that following translocation into fenced areas, most black rhinoceroses and greater Indian rhinoceroses, Père David's deer, most oribi and offspring of translocated golden bandicoots survived for between one and 10 years. Two studies in Australia found that only two of five translocated numbats survived over seven months and western barred bandicoots did not persist. A study in South Africa found that translocated and captive-bred African wild dogs released into fenced reserves in family groups had high survival rates. A study in Australia found that following release into fenced areas, a translocated population of red-tailed phascogales survived longer than a released captive-bred population. A replicated, controlled study in South Africa found that after translocation to a fenced reserve with holding pens, survival of released lions was higher than that of resident lions. Condition (3 studies): A replicated, before-and-after study in Australia found that eastern bettongs translocated into fenced predator proof enclosures increased in body weight post-release, with and without supplementary food. A replicated study in South Africa found that following translocation into fenced reserves, stress hormone levels of African elephants declined over time. A study in Australia found that golden bandicoots descended from a population translocated into a fenced area free from non-native predators, maintained genetic diversity relative to the founder and source populations. BEHAVIOUR (2 STUDIES) Use (2 studies): A site comparison study in Australia found that following translocation into a predator-free fenced area, woylies developed home ranges similar in size to those of an established population outside the enclosure. A study in Hungary found that one fifth of translocated European ground squirrels released into a fenced area with artificial burrows remained in the area after release. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2467https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2467Wed, 03 Jun 2020 09:40:35 +0100Collected Evidence: Collected Evidence: Release translocated/captive-bred mammals in areas with invasive/problematic species eradication/control Twenty-two studies evaluated the effects of releasing translocated or captive-bred mammals in areas with eradication or control of invasive or problematic species. Sixteen studies were in Australia, four were in the USA, and one in the UK. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (21 STUDIES) Abundance (4 studies): A replicated study in Australia found that increasing amounts of regular predator control increased population numbers of released captive-bred eastern barred bandicoots. Two studies in Australia found that following eradication or control of invasive species, a population of translocated and released captive-bred burrowing bettongs increased and a population of translocated western barred bandicoots increased over four years. A study in Australia found that following the release of captive-bred bridled nailtail wallabies and subsequent predator controls, numbers increased over a three years, but remained low compared to the total number released. Reproductive success (2 studies): A study in Australia found that four of five captive-bred mammal populations released into a predator-free enclosure and one population released into a predator-reduced enclosure produced a second generation, whereas two populations released into an unfenced area with ongoing predator management did not survive to reproduce. A study in Australia found that most female captive-reared black-footed rock-wallabies released into a large predator-free fenced area reproduced. Survival (18 studies): Ten studies (one controlled, three replicated, two before-and-after studies) in Australia, and the UK found that following the eradication/control of invasive species (and in some cases release into a fenced area), a translocated population of woylies, western barred bandicoots and red-tailed phascogales survived over four years, released captive-bred eastern barred bandicoots survived up to three years at five of seven sites, offspring of translocated golden bandicoots survived three years, over half of released captive-reared black-footed rock-wallabies survived over two years, captive-bred water voles survived for at least 20 months or over 11 months at over half of release sites, most released captive-bred hare-wallabies survived at least two months, most captive-bred eastern barred bandicoots survived for over three weeks. A replicated study in Australia found that after the control of invasive species, four translocated populations of burrowing bettongs died out within four months. A review of studies in Australia found that in seven studies where red fox control was carried out before or after the release of captive-bred eastern-barred bandicoots, survival varied. A study in Australia found that four of five captive-bred mammal populations released into a predator-free enclosure and one population released into a predator-reduced enclosure survived, whereas two populations released into an unfenced area with ongoing predator management did not. A study in Australia found that captive-bred bridled nailtail wallabies released from holding pens in areas where predators had been controlled had similar annual survival rates to that of wild-born translocated animals. Two studies (one replicated) in the USA found that where predators were managed, at least half of released captive-bred black-footed ferrets survived more than two weeks, but that post-release mortality was higher than resident wild ferrets. A before-and-after study in the USA found following the onset of translocations of black bears away from an elk calving site, survival of the offspring of translocated elk increased. Condition (2 studies): A study Australia found that wild-born golden bandicoots, descended from a translocated population released into a predator-free enclosure, maintained genetic diversity relative to the founder and source populations. A replicated, before-and-after study in Australia found that one to two years after release into predator-free fenced reserves, translocated eastern bettongs weighed more and had improved nutritional status compared to before release. BEHAVIOUR (1 STUDY) Behaviour change (1 study): A replicated, before-and-after study in the USA found that translocated Utah prairie dogs released after the control of native predators into an area with artificial burrows showed low site fidelity and different pre- and post-release behaviour. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2469https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2469Wed, 03 Jun 2020 14:51:14 +0100Collected Evidence: Collected Evidence: Install overpasses over roads/railways Twenty-two studies evaluated the effects on mammals of installing overpasses over roads or railways. Seven studies were in Canada, three were in Spain, three were in Australia, two were in Sweden, one each was in the Netherlands, Germany, Croatia and the USA, and three (including two reviews) were conducted across multiple countries. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (4 STUDIES) Survival (4 studies): Four studies (including three before-and-after studies), in Canada, Sweden and Australia, found that overpasses (in combination with roadside fencing) reduced collisions between vehicles and mammals. In two of these studies, data from overpasses and underpasses were combined for analysis. BEHAVIOUR (21 STUDIES) Use (21 studies): Nineteen studies, in North America, Europe and Australia, found that overpasses were used by mammals. A wide range of mammals was reported using overpasses, including rodents and shrews, rabbits and hares, carnivores, ungulates, bears, marsupials and short-beaked echidna. A review of crossing structures in Australia, Europe and North America found that overpasses were used by a range of mammals, particularly larger mammal species. A global review of crossing structures (including overpasses) found that all studies reported that the majority of crossings were used by wildlife. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2526https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2526Mon, 08 Jun 2020 13:33:46 +0100Collected Evidence: Collected Evidence: Modify fishing trap/pot configuration Twenty-three studies examined the effects of modifying fishing trap or pot configuration on marine fish populations. Five studies were in the Atlantic Ocean (USA, Brazil, Canary Islands, Canada). Three studies were in each of the Bothnian Sea (Sweden), the Baltic Sea (Poland, Sweden), the Tasman Sea (Australia) and the Indian Ocean (Kenya, South Africa). One study was in each of the Kattegat (Denmark), the Mediterranean Sea (Spain), the Adriatic Sea (Italy), the Southern Ocean (Australia), the Pacific Ocean (Canada) and the Barents Sea (Norway).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Survival (1 study): One replicated, controlled study in the Bothnian Sea found that survival of small herring escaped from a pontoon fish trap through a size-sorting grid was similar to trap-caught herring that did not pass through a grid. BEHAVIOUR (0 STUDIES) OTHER (22 STUDIES) Reduction of unwanted catch (20 studies): Sixteen of 20 replicated studies (11 controlled, one randomized, paired and controlled, one randomized and controlled, two paired and controlled and one randomized) and one before-and-after study in the Atlantic Ocean, Baltic Sea, Mediterranean Sea, Southern Ocean, Tasman Sea, Adriatic Sea, Bothnian Sea, Indian Ocean, Pacific Ocean, the Kattegat and the Barents Sea, found that modifications to trap configuration (various, including using a different trap type, increased mesh size and fitting an escape device) reduced the unwanted (undersized, discarded or non-commercial target) catches of fish (overall, or all of multiple study species), brown trout, black sea bass, herring, bluethroat wrasse and leatherjacket, cod, protected rockfishes, whitefish, black sea bass, American eel and winter flounder, sharks/rays and of salmon and rainbow trout in one of two cases, compared to unmodified conventional traps or traps of other designs. One of these also found that the number of unwanted species (fish and invertebrates) was lower in modified traps. Three other studies, found that trap modification or type had no effect on unwanted catches of white croaker, non-commercial fish or undersized Atlantic cod, and non-target haddock catches were increased. However, one of these also reported that traps (creels) did not catch high proportions of immature fish, unlike bottom trawls. Improved size-selectivity of fishing gear (4 studies): Three of four replicated studies (two controlled and one randomized, paired and controlled) in the Baltic Sea, Tasman Sea, Indian Ocean and Atlantic Ocean found that traps or pots modified with a square mesh escape window or larger mesh sizes improved the size-selectivity of Atlantic cod, black sea bass and most fish species compared to smaller mesh and/or standard gear. The other found that increasing mesh size of a trap escape panel had no effect on size-selectivity of panga. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2702https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2702Mon, 14 Dec 2020 10:32:58 +0000Collected Evidence: Collected Evidence: Use a different design or configuration of size-sorting escape grid/system in trawl fishing gear (bottom and mid-water) Twenty-three studies examined the effects of using a different design or configuration of size-sorting escape grid/system in trawl fishing gear on marine fish populations. Ten studies were in the Atlantic Ocean (Canada, USA, Brazil, Spain, Norway). Five studies were in the Barents and/or Norwegian Sea (Norway). Two studies were in the Kattegat and Skagerrak (Denmark/Sweden). One study was in each of the Arafura Sea (Australia), the Greenland Sea (Norway), the North Sea (Norway), the North Pacific Ocean (USA) and the Indian Ocean (Australia). One study was in a laboratory (Japan).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) OTHER (23 STUDIES) Reduction of unwanted catch (17 studies): Six of 16 replicated studies (eight paired and controlled, three controlled, one randomized and controlled, and one paired) in the Atlantic Ocean, a laboratory, Arafura Sea, Barents Sea, Kattegat and Skagerrak, Greenland Sea, North Sea, Pacific Ocean and the Indian Ocean, and one controlled study in the Barents Sea found that using a different design or configuration of size-sorting escape grid/system in trawl nets reduced the unwanted (undersized, non-target, discarded) catches of all or most of the fish species assessed, compared to standard or other grid designs/configurations. Four studies found that the effect of using different escape grids on the reduction of unwanted catch varied with fish species, light conditions, and the type of trawl net used. The other six found that, overall, using a different escape grid did not reduce unwanted fish catch. Improve size-selectivity of fishing gear (7 studies): Three of seven replicated studies (three controlled, one paired and controlled) in the Barents/Norwegian Sea, the Atlantic Ocean and the Greenland Sea found that different types or configurations of size-sorting escape grid systems in trawl nets resulted in better size-selectivity for unwanted redfish and Greenland halibut and of commercial target hake compared to other designs or configurations. Three studies found that the effect of using a different design or configuration of size-sorting escape grid/system on improving the size-selectivity of trawls varied between fish species compared to standard or other escape grid designs. The other study found that a new design of grid system did not improve the size-selectivity of unwanted redfish compared to an existing system. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2728https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2728Mon, 25 Jan 2021 16:30:19 +0000Collected Evidence: Collected Evidence: Directly plant non-woody plants: freshwater wetlands Twenty-four studies evaluated the effects, on vegetation, of directly planting emergent, non-woody plants in freshwater wetlands. Sixteen studies were in the USA. There was one study in each of Guam, the Netherlands, Israel, Ireland, the UK, Italy, Australia and China. Two pairs of studies in Minnesota and South Dakota took place in the same area but used different experimental set-ups. VEGETATION COMMUNITY Community composition (1 study): One replicated, site comparison study around fresh/brackish lakes in Australia reported that as planted rush stands aged, their near-shore plant community became more similar to that behind mature natural rush stands. Overall richness/diversity (9 studies): Two studies (including one replicated, randomized, controlled) in freshwater marshes in China and the USA reported that planting herbs increased plant species richness and/or diversity for up to five years. Two controlled studies in freshwater marshes in the USA reported that planted and unplanted sites had similar plant species richness after 2–3 years. Three studies in the USA, the UK and Australia compared plant species richness in marshes that had been planted with herbs (sometimes along with other interventions) and natural marshes, and reported that it was never higher in planted marshes. Three studies involving freshwater marshes in Guam, the USA and Italy simply quantified plant species richness for up to 13 years after planting herbs (along with other interventions). Characteristic plant richness/diversity (1 study): One replicated, paired, controlled study in freshwater wetlands in the USA found that plots planted with wetland-characteristic herbs had a similar richness of wetland-characteristic plant species, after three years, to unplanted plots. VEGETATION ABUNDANCE Overall abundance (4 studies): One before-and-after study of a freshwater marsh and wet meadow in China found that vegetation cover was greater five years after planting herbs than in the year before planting. One replicated, paired, controlled study in freshwater wetlands in the USA found that plots planted with herbs had similar overall vegetation cover, after three years, to unplanted plots. One replicated, site comparison study around fresh/brackish lakes in Australia found that as planted rush stands aged, the density of plants in adjacent near-shore vegetation became more similar to mature natural stands. One study in a freshwater marsh in the USA simply quantified vegetation cover and density over 1–9 years after planting herbs (along with other interventions). Characteristic plant abundance (1 study): One replicated, paired, controlled study in freshwater wetlands in the USA found that plots planted with wetland-characteristic herbs had greater cover of wetland-characteristic plants, after three years, than unplanted plots. Individual species abundance (13 studies): Thirteen studies quantified the effect of this action on the abundance of individual plant species. For example, one replicated, paired, controlled study in freshwater wetlands in the USA found that both planted herb species had greater cover in planted than unplanted plots, after three years. Three studies in the UK, the USA and Australia compared the abundance of herb species where they had been planted to their abundance in natural marshes: two found that the planted species was more dense in planted than natural areas after 5–14 years, and one found that planted rush stands became more dense (i.e. more like natural stands) as they aged. VEGETATION STRUCTURE Overall structure (1 study): One replicated, site comparison study around fresh/brackish lakes in Australia reported that as planted rush stands aged, their width increased – becoming more like mature natural stands. Height (4 studies): One replicated, site comparison study around fresh/brackish lakes in Australia reported that as planted rush stands aged, their maximum height increased – becoming more like mature natural stands. One before-and-after study of a freshwater marsh and wet meadow in China found that vegetation was taller five years after planting herbs than in the year before planting. One site comparison study of wet meadows in the USA reported that sedge tussocks in a restored meadow were shorter than sedge tussocks in natural meadows, 11–14 years after planting (along with other interventions). One replicated study in wet basins in the USA simply reported an increase in the average height of a herb species over three growing seasons after it was planted. Diameter/perimeter/area (1 study): One site comparison study of wet meadows in the USA reported that sedge tussocks in a restored meadow had a smaller perimeter than sedge tussocks in natural meadows, 11–14 years after planting (along with other interventions). Basal area (1 study): One site comparison study of wet meadows in the USA reported that the basal area of sedge tussocks was lower in a restored meadow than in natural meadows, 11–14 years after planting (along with other interventions). Individual plant size (2 studies): Two replicated studies in wet meadow restoration sites in the USA reported that the size of Carex stricta seedlings increased over two months or three growing seasons after planting. This was true for the average number of shoots/plant and biomass/plant. OTHER Survival (14 studies): Nine studies (eight replicated) in the USA and Israel quantified survival rates of individual herbs planted in freshwater wetlands. Survival rates ranged from 0% to 100% after 1–3 growing seasons. Eight studies (including five replicated and two before-and-after) in Guam, the USA, the Netherlands and Israel reported 0% survival or absence of planted (or sown) herb species, in at least some cases, after three months to seven years. Proposed factors affecting survival included elevation/water levels, herbivory, time of planting and plug type. Growth (2 studies): Two studies monitored true growth of individual herbs (rather than changes in average height of survivors). The two studies (one replicated) in Ireland and the USA reported that herbs grew over 1–2 growing seasons after planting. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3256https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3256Sat, 10 Apr 2021 13:26:49 +0100Collected Evidence: Collected Evidence: Create pit habitats (1–50 mm) on intertidal artificial structures Twenty-two studies examined the effects of creating pit habitats on intertidal artificial structures on the biodiversity of those structures. Ten studies were on open coastlines in the UK, the Netherlands and the Azores, six were on island coastlines in the Singapore Strait, three were in estuaries in southeast Australia and the UK, one was in a port in the Netherlands, one was in an estuary and on an open coastline in the UK, and one was on island coastlines in the Singapore Strait and in estuaries in the UK. COMMUNITY RESPONSE (16 STUDIES) Overall community composition (9 studies): Four of six replicated, controlled studies (including four randomized and two before-and-after studies) in Australia, Singapore and the UK found that creating pit habitats on intertidal artificial structures altered the combined macroalgae and invertebrate community composition on structure surfaces. One study found that creating pits did not alter the community composition. One found that creating pits, along with grooves, small protrusions and ridges, had mixed effects depending on the size and arrangement of pits and other habitats and the site, while one found that varying the pit size and arrangement had no significant effect. Three of these studies, along with three other replicated, controlled studies (including one that was randomized) in the UK and Singapore, reported that pit habitats, along with grooves and ridges in one, supported macroalgae, invertebrate and/or fish species that were absent from structure surfaces without added habitats. Fish community composition (1 study): One replicated, randomized, controlled study in Singapore found that pit habitats created on an intertidal artificial structure, along with grooves, altered the fish community composition on and around structure surfaces, and supported species that were absent from surfaces without pits and grooves. Overall richness/diversity (12 studies): Eight of 12 replicated controlled studies (including six randomized and two before-and-after studies) in the UK and Singapore found that creating pit habitats on intertidal artificial structures, along with grooves, or grooves, small protrusions and ridges in two studies, increased the combined macroalgae and invertebrate species richness and/or diversity on structure surfaces. Two studies found that creating pits did not increase the species richness, while two found that creating pits, along with grooves or using environmentally-sensitive material, had mixed effects depending on the site. One of the studies found that varying the pit size and arrangement resulted in higher species richness, while one found that this had mixed effects depending on the shore level. Two of the studies found that varying the pit size did not affect species richness. One of them found that increasing the density and fragmentation of pits, along with grooves, had mixed effects on species richness. Algal richness/diversity (1 study): One replicated, randomized, controlled study in Singapore reported that creating pits on an intertidal artificial structure, along with grooves and small ridges, increased the macroalgal species richness on structure surfaces. Invertebrate richness/diversity (2 studies): One of two replicated, randomized, controlled studies in Australia and the Azores reported that creating pits on an intertidal artificial structure increased the limpet and periwinkle species richness on structure surfaces, and that their richness and diversity varied depending on the pit arrangement. One found that creating pits did not affect the limpet species richness, regardless of the pit size. Fish richness/diversity (1 study): One replicated, randomized, controlled study in Singapore found that creating pit habitats on an intertidal artificial structure, along with grooves, increased the fish species richness on and around structure surfaces. POPULATION RESPONSE (15 STUDIES) Overall abundance (5 studies): Two of five replicated, controlled studies (including three randomized and two before-and-after studies) in Singapore and the UK found that creating pit habitats on intertidal artificial structures, along with grooves in one study, increased the combined macroalgae and invertebrate abundance on structure surfaces. One study found that creating pits decreased their abundance and one found no effect. One found that creating pits, along with grooves, small protrusions and ridges, had mixed effects on abundance depending on the pit size and arrangement, shore level and site. Algal abundance (4 studies): Three of four replicated, controlled studies (including two randomized and two paired sites studies) in the Netherlands, Singapore and the Azores found that creating pit habitats on intertidal artificial structures, along with grooves and small ridges in one study, did not increase the macroalgal abundance on structure surfaces. One study found that creating pits had mixed effects on abundance depending on the pit size and arrangement and the site. Invertebrate abundance (9 studies): Three of eight replicated, controlled studies (including six randomized and two paired sites studies) in the Azores, the Netherlands, Australia and the UK found that creating pit habitats on intertidal artificial structures did not increase the combined invertebrate or mobile invertebrate abundance on structure surfaces. Three studies found that creating pits, along with grooves in one study, had mixed effects on barnacle and/or mobile invertebrate abundances, depending on the site, the species, the size of animals, and/or the pit size and arrangement. Two studies found that creating pits, along with using environmentally-sensitive material in one, increased barnacle and/or mobile invertebrate abundances. Two of the studies found that the pit size or arrangement did not affect abundances, while two found that the effects of pit size and arrangement varied depending on the site and species. One replicated randomized study in the UK found that increasing pit density increased periwinkle abundance, but pit arrangement did not. Fish abundance (1 study): One replicated, randomized, controlled study in Singapore found that creating pit habitats on an intertidal artificial structure, along with grooves, increased the fish abundance on and around structure surfaces. BEHAVIOUR (6 STUDIES) Use (5 studies): Two replicated, randomized, controlled studies in the Azores reported that occupancy of pit habitats created on intertidal artificial structures by limpets and/or periwinkles varied depending on the pit size and arrangement, the size of animals, the species and/or site. Three replicated studies (including two paired sites, controlled studies) in the Netherlands and in Singapore and the UK reported that pit habitats were used by periwinkles, macroalgae and invertebrates. Fish behaviour change (1 study): One replicated, randomized, controlled study in Singapore found that creating pit habitats on an intertidal artificial structure, along with grooves, increased the number of bites fishes took from structure surfaces. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3475https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3475Tue, 21 Sep 2021 12:58:05 +0100Collected Evidence: Collected Evidence: Breed reptiles in captivity: Lizards Twenty-three studies evaluated the effects of breeding lizards in captivity. Ten studies were in the USA, three were in Australia, two were in the UK and one was in each of Switzerland, an unknown location, the Arabian Peninsula, Mexico, Italy, Spain, Bahamas and Jamaica and the USA. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (23 STUDIES) Abundance (2 studies): One replicated study in Spain reported that a captive-breeding programme for large psammodromus lizards produced 365 juveniles for release over two years. One replicated study in Australia reported that captive populations of Lister’s geckos and Christmas Island blue-tailed skinks at two facilities grew or remained stable over 4–5 years. Reproductive success (22 studies): Eighteen studies (including seven replicated studies) in the USA, Switzerland, an unknown location, the Arabian Peninsula, Mexico, Italy, Spain the UK and Australia reported that captive lizards produced one or more clutches of 2–21 eggs, 3–12 eggs/year or gave birth to 21 live young. Eleven of the studies reported hatching success of 45–96%. Three of the studies reported hatching success of 0–40%, 0–43% or 0–100%. One of the studies reported hatching success of <10%. One of the studies also found that hatching success for Australian painted dragon eggs was similar across all incubation temperatures used, but higher for eggs laid earlier in the season. One of two studies (including one replicated study) in Jamaica and the USA and the Bahamas reported that captive breeding programmes lasting 19 and 24 years produced 73 and five Jamaican iguana hatchlings respectively. The other study reported that over 2.5 years, captive San Salvador rock iguanas produced only a single hatchling. One controlled study in the USA found that captive-reared western fence lizard females housed individually or in pairs produced more clutches with fewer infertile eggs compared to females kept in groups of four or eight. One replicated, before-and-after study in the USA found that curious skinks kept in smaller breeding groups and provided nutrient rich food produced more clutches of eggs than skinks that were kept in larger groups and given regular food. Survival (9 studies): Seven studies (including four replicated studies) in an unknown location, Mexico, Italy, the USA and the UK reported that 4–23 captive-bred lizards, or some individuals, survived for six weeks or at least six months to three years, or that individuals of three species survived to reach adult size. Two studies in the USA reported that one of three and eight of 10 captive-bred lizards died within one day or 18 months. Condition (1 study): One controlled study in the USA reported that giant horned lizard eggs incubated at 26.5°C produced larger hatchlings compared to those incubated at 28°C. BEHAVIOUR (1 STUDY) Use (1 study): One study in the USA reported that captive female Yuman fringe-toed lizards selected an 8:1 sand:water mixture when laying eggs. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3756https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3756Tue, 14 Dec 2021 14:27:51 +0000Collected Evidence: Collected Evidence: Rear declining species in captivity Twenty-two studies evaluated the effects of rearing declining species of butterfly and moth in captivity. Seven studies were in each of the UK and South Africa, two were in the USA, one was in each of the UK and France, Spain, Belgium, Poland and Israel, and one was a review. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (22 STUDIES) Abundance (6 studies): Three studies in the UK and the USA reported that populations of large copper, large white and monarch butterflies were successfully reared in captivity for 12 generations or >25 years. One study in the UK reported that a captive population of marsh fritillary increased in size over two years. One study in Poland reported that all captive-reared scarce large blue caterpillars died within 35 days. One review reported that attempts to rear caterpillars of four species of large blue had mixed success. Reproductive success (5 studies): One controlled study in the UK reported that female large copper laid more eggs, and these eggs had a higher hatching success, in a cage kept in a greenhouse than in a cage kept outside. One study in South Africa reported that a Dickson’s copper butterfly laid eggs in captivity in the presence of black cocktail ants from the site where she emerged but not from 10 km away. One study in the UK found that female large white from a population kept in captivity for >25 years laid more eggs than females from a population in its third generation in captivity. One study in the UK reported that Fisher’s estuarine moths successfully bred in captivity. One study in South Africa reported that wild-caught, gravid scarce mountain copper butterflies laid eggs but none hatched. Survival (14 studies): Five of six studies (including one replicated, controlled study, four controlled studies and one site comparison study) in the UK, the UK and France, Spain, Belgium and Poland found that large copper, large blue, mountain Alcon blue, cranberry fritillary and scarce large blue caterpillars had higher survival rates when reared on plants or in ant nests at a lower than higher density, in ant nests without queens or with winged females present than with queens or without winged females, when reared at 20 °C than 25 °C, and when reared with ants collected from sites where parasitic butterfly species occur than from sites where parasites do not occur. The sixth study found that mountain Alcon blue caterpillars had a similar survival rate in ant nests with or without queens present. Two of these studies, and one replicated, randomized, paired, controlled study in the USA, found that the survival of large blue, mountain Alcon blue and monarch caterpillars differed when reared in ant nests of different species or on different species of milkweed. Two site comparison studies in the UK and the USA found that large copper and Puget blue eggs had a similar survival rate to the caterpillar and adult stage whether they were laid in captivity or collected from the wild and reared in captivity. One of these studies also found that Puget blue caterpillars kept in refrigerators while overwintering had a lower survival than caterpillars kept in environmental chambers or outside. Three of four studies in South Africa and the UK reported that some wild-collected Brenton blue butterfly, Karkloof blue butterfly and Fishers’ estuarine moth eggs hatched, survived as caterpillars for three months or to adulthood, bred in captivity and the resulting captive population survived for at least eight generations. The other study reported that wild-collected Brenton blue butterfly eggs hatched in captivity and those caterpillars reared with only Pyllanthus incurvatus leaves died whereas all caterpillars also given Indigofera erecta leaves survived to the fourth instar of development. One study in South Africa reported that wild-caught final instar Cape Peninsula butterfly caterpillars reared in an artificial pugnacious ant nest successfully pupated and became adults, but captive-hatched first instar Cape Peninsula and Riley’s skolly butterfly caterpillars placed next to a nest did not survive to pupation. Condition (5 studies): Two studies (including one controlled study) in the UK and the USA found that adult large white from a population kept in captivity for >25 years were heavier, and had smaller wings, than individuals from a population in its third generation in captivity, and captive-reared Puget blue adults were smaller than wild-caught butterflies. One of these studies also found that Puget blue caterpillars raised in environmental chambers or outdoor enclosures reached a similar size as adults. One replicated, controlled study in Spain found that mountain Alcon blue caterpillars reared in ant colonies with winged females were lighter than caterpillars reared in colonies without winged females. One replicated, controlled study in Israel found that spring webworm caterpillars fed vegetation from cattle-grazed pasture had a similar growth rate to caterpillars fed vegetation from an ungrazed paddock. One study in South Africa reported that Brenton blue butterfly caterpillars reared on Indigofera erecta leaves with no ants became dwarf adults, but those reared on whole Indigofera plants with an ant colony became full-sized adults. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3916https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3916Wed, 10 Aug 2022 18:16:38 +0100Collected Evidence: Collected Evidence: Plant nectar flower mixture/wildflower strips Twenty-three studies evaluated the effects of planting nectar flower mixtures, or wildflower strips, on butterflies and moths. Eleven studies were in the UK, six were in Switzerland, two were in the USA, and one was in each of Sweden, Finland and Germany. COMMUNITY RESPONSE (20 STUDIES) Richness/diversity (20 studies): Eight of thirteen studies (including twelve replicated studies, two randomized studies, five controlled studies, one before-and-after study, and eight site comparison studies) in the UK, Switzerland, Finland and Germany found that sown wildflower strips had a higher species richness and diversity of all butterflies, generalist butterflies, and moths than conventional field margins, unsown margins, cropped fields or conventional grassland. One of these studies also found that the species richness of specialist butterflies was similar in sown wildflower strips, cropped fields and conventional grassland. Four studies found that the species richness of butterflies was similar between sown wildflower strips and cropped fields, cropped margins, unsown strips or extensively managed meadows. The other study found that, five years after sowing wildflower strips, butterfly species richness, but not diversity had increased at one of two study sites. One replicated, randomized, paired, controlled study in the UK found that the species richness of butterflies and moths was similar on farms managed under agri-environment schemes, including with sown wildflower strips, and on conventionally managed farms. Two replicated studies (including one randomized, controlled study and one site comparison study) in the UK and Sweden found that field margins sown with wildflowers had a greater species richness of butterflies than grass-only field margins. One of two replicated, paired, controlled studies (including one randomized study) in the USA and the UK found that plots sown with a mix of wildflowers had a greater species richness of caterpillars than plots sown with a single flower species. The other study found that plots sown with either complex or simpler flower mixes had a similar species richness of butterflies. Two replicated studies (including one randomized, controlled study) in the UK found that wildflower plots sown with phacelia, borage or lucerne had a higher species richness or diversity of butterflies and moths than plots sown with other flower species. POPULATION RESPONSE (16 STUDIES) Abundance (17 studies): Ten studies (including nine replicated studies, three randomized studies, three controlled studies and seven site comparison studies) in the UK, Switzerland and Finland found that sown wildflower strips had a higher abundance of all butterflies, generalist butterflies, specialist butterflies and meadow brown butterflies than conventional field margins, unsown margins, cropped fields, cropped margins, conventional grassland or extensively managed meadows. However, one of these studies only found this effect in one of two study years. Two of these studies also found that the abundance of specialist butterflies and meadow brown caterpillars was similar in sown wildflower strips and unsown margins, cropped fields and conventional grassland, and one found that the abundance of caterpillars was lower in sown wildflower strips than in conventional grassland. One replicated, randomized, paired, controlled study in the UK found that the abundance of butterflies and micro-moths was higher on farms managed under agri-environment schemes, including with sown wildflower strips, than on conventionally managed farms, but the abundance of other moths was similar. Two replicated studies (including one randomized, controlled study and one site comparison study) in the UK and Sweden found that field margins sown with wildflowers had a higher abundance of butterflies than grass-only field margins. One replicated, randomized, controlled study in the UK found that farms with wildflower strips (along with other enhanced agri-environment scheme options) had a higher abundance of some butterflies, but a lower abundance of other butterflies, than farms with simpler agri-environment scheme management such as grass-only margins. One of two replicated, paired, controlled studies (including one randomized study) in the USA and the UK found that plots sown with one of three wildflower mixes had a higher abundance of moths than plots sown with two other mixes or a single flower species. The other study found that plots sown with either complex or simple flower mixes had a similar abundance of butterflies. One replicated, randomized, controlled study in the UK found that wildflower plots sown with lucerne had a higher abundance of butterflies than plots sown with borage, chicory or sainfoin. BEHAVIOUR (2 STUDIES) Use (2 studies): Two studies (including one replicated study) in the UK and the USA reported that sown nectar flower plots and tropical milkweed plots were used by six species of butterflies and moths and monarch butterflies and caterpillars. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3932https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3932Fri, 12 Aug 2022 06:26:40 +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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