Collected Evidence: Collected Evidence: Translocate bumblebee colonies in nest boxesWe have captured three small trials in the 1950s and early 1960s testing the effect of translocating bumblebee colonies in nest boxes. Two trials in Canada provided evidence of queen death and one of these showed lower colony productivity following translocation. Just one, a UK trial, concluded that early bumblebee Bombus pratorum colonies adapt well to being moved.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F53https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F53Thu, 20 May 2010 01:34:59 +0100Collected Evidence: Collected Evidence: Restore heathlandOne small trial of early-stage lowland heath restoration activity did not have an adverse effect on bumblebee diversity at one site in southeast England. Two replicated trials in Dorset indicated that long-term restoration of dry lowland heath can restore a bee community similar to that on ancient heaths. One of these studies showed that the community of conopid flies parasitizing bumblebees remained impoverished 15 years after heathland restoration began. We found no evidence on interventions to conserve bees on upland heath or moorland.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F9https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F9Thu, 20 May 2010 03:20:44 +0100Collected Evidence: Collected Evidence: Leave field margins unsprayed within the crop (conservation headlands)Two replicated controlled trials in England showed that conservation headlands do not attract more foraging bumblebees than conventional crop fields. One replicated trial found fewer bees on conservation headlands than in naturally regenerated, uncropped field margins in England.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F29https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F29Thu, 20 May 2010 13:15:26 +0100Collected Evidence: Collected Evidence: Use coloured baits to reduce accidental mortality during predator control Two replicated and controlled trials in the USA found that dyed baits were consumed at significantly lower rates than control baits. A replicated, randomised and controlled trial in Australia found no differences in consumption rates of dyed and control baits. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F182https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F182Fri, 01 Jun 2012 16:40:17 +0100Collected Evidence: Collected Evidence: Use mowing techniques to reduce chick mortality A review from the UK found a large increase in corncrake Crex crex populations in the UK following a scheme to delay mowing and promote corncrake-friendly mowing techniques. One replicated controlled study from the UK and a review from the UK found lower levels of mortality of corncrakes and Eurasian skylark Alauda arvensis when wildlife-friendly mowing techniques were used, compared to other techniques.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F192https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F192Wed, 27 Jun 2012 17:30:44 +0100Collected Evidence: Collected Evidence: Sow crops in spring rather than autumn A replicated, controlled, paired sites study from Sweden found more bird species on areas with spring sown cereals, compared with winter cereals. A before-and-after study from the UK found that several species bred in the study site for the first time after the start of spring sowing. Three studies from Sweden and the UK, two replicated and controlled, found population increases after the start of spring sowing, or higher populations on sites with spring-sown cereals, compared to sites with winter cereals. A before-and-after study from the UK found that ten species did not increase after spring sowing began. No species decreased. A replicated, controlled paired sites study from Sweden found that the benefits of spring-sowing decreased with the proportion of autumn-sown crops in the surrounding area. A replicated, controlled study from Sweden found that hatching success was lower on spring-sown crops than autumn sown.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F207https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F207Sun, 15 Jul 2012 17:16:58 +0100Collected Evidence: Collected Evidence: Plant cereals for whole crop silageA replicated, controlled trial in the UK found that seed-eating birds used CBWCS fields, especially those planted with barley, more than other crops in both summer and winter. Insect-eating species used other crops and grassland more.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F225https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F225Tue, 17 Jul 2012 15:12:29 +0100Collected Evidence: Collected Evidence: Use wildlife refuges to reduce hunting disturbance Three studies from the USA and Europe found that bird densities were higher in refuges where hunting was prohibited, compared to areas with hunting. In addition, two studies found that more birds used hunting-free areas during the open season and on hunting days. No studies investigated the population-level impacts of these refuges.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F278https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F278Tue, 24 Jul 2012 12:34:46 +0100Collected Evidence: Collected Evidence: Use prescribed burning on Australian sclerophyll forest Two of three studies from Australia found no differences in bird species richness in burned sites compared to unburned areas. Three studies found differences in species assemblages in burned and unburned areas, with some species lost and others gained from areas after fire.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F319https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F319Thu, 26 Jul 2012 14:44:29 +0100Collected Evidence: Collected Evidence: Use prescribed burning on coastal habitats Of three studies captured, one replicated, controlled, paired sites study from the USA found that there was a fall in breeding seaside sparrow numbers on a burned site in the year it was burned. The next year, numbers were higher than on an unburned site. A controlled study in Argentina found that tall-grass specialist species were lost from burned areas in the year of burning, but that some habitats recovered by the following year. A replicated controlled study from the USA found no differences in nest predation rates between burned and unburned areas for two years after burning.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F323https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F323Thu, 26 Jul 2012 16:24:19 +0100Collected Evidence: Collected Evidence: Use fire suppression/control Two out of three before-and-after studies, from Australia and the UK, found that five species of bird (including noisy scrub-bird, the target species of one study) increased following fire suppression measures. A before-and-after study in the USA found that open habitat species declined in a pine forest site after fire exclusion, whilst mesic woodland species appeared. A before-and-after study from the UK found that five bird species declined following fire suppression.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F324https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F324Thu, 26 Jul 2012 16:35:35 +0100Collected Evidence: Collected Evidence: Coppice trees Of three studies, one, a before-and-after study in the UK found that a population of European nightjars increased following a series of management interventions, including the coppicing of some birch trees. Two before-and-after studies from the UK and the USA found that the use of coppices by some bird species declined over time. The UK study also found that overall species richness decreased with age, but that some species were more abundant in older stands.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F329https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F329Fri, 27 Jul 2012 14:58:36 +0100Collected Evidence: Collected Evidence: Manage woodland edges for birds We captured three studies of two experiments, of which one, a before-and-after study from the UK, found an increase in the local population of European nightjars following several management interventions, including the management of woodland edges for birds. Two studies of a replicated, controlled paired sites experiment in the USA found that bird abundances were higher in woodland edges with border-edge cuts and that predation on artificial nests was lower than in uncut edges. Scrub- and edge-nesting species were more abundant. Overall species richness and nest success did not differ different between treatments.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F334https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F334Sat, 28 Jul 2012 14:12:39 +0100Collected Evidence: Collected Evidence: Mow or cut reedbeds Of three studies captured, one controlled study from the Netherlands found that warblers nested at lower densities in cut areas of reeds. Productivity and success did not vary between treatments. An unreplicated study from Denmark found that geese grazed at the highest densities on reedbeds cut 5–12 years previously. One replicated study investigated changing water levels in addition to cutting reeds in the UK and found that management did not affect great bittern breeding productivity but did appear to delay territory establishment.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F340https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F340Sat, 28 Jul 2012 20:15:58 +0100Collected Evidence: Collected Evidence: Reduce predation by translocating predatorsTwo studies from France and the USA found local population increases or reduced predationfollowing the translocation of predators away from an area.  A study in Saudi Arabia found that predation was no lower when predators were translocated from the bird release site.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F393https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F393Thu, 09 Aug 2012 13:39:34 +0100Collected Evidence: Collected Evidence: Leave some areas unburned during prescribed burning Two studies evaluated the effects on butterflies and moths of leaving some areas unburned during prescribed burning. Both studies were in the USA. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Abundance (2 studies): One replicated study in the USA reported that the abundance of Karner blue butterflies increased over 2–3 years in oak savannas and prairies where unburned patches were left during prescribed burning. One replicated, site comparison study in the USA found that six out of nine specialist butterfly species were more abundant, one was less abundant, and two had similar abundance in pine barrens and prairies where unburned areas were left during prescribed burning compared to at sites without unburned areas. BEHAVIOUR (1 STUDY) Use (1 study): One replicated study in the USA reported that Karner blue butterflies were recorded using all 11 unburned patches which were surveyed within oak savannas and prairies managed by burning. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3879https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3879Thu, 21 Jul 2022 16:45:55 +0100Collected Evidence: Collected Evidence: Mechanically remove mid-storey or ground vegetation to create fire breaks Two studies evaluated the effects on butterflies and moths of mechanically removing mid-storey or ground vegetation to create fire breaks. One study was in Portugal and the other was in France. COMMUNITY RESPONSE (2 STUDIES) Richness/diversity (2 studies): One replicated, site comparison study in Portugal found that cork oak woodlands with more recent or more regular mechanical clearance of woody understorey vegetation had a greater species richness of butterflies than woodlands cleared less frequently or longer ago. One replicated, paired, controlled study in France reported that shrublands where trees and/or bushes were mechanically cleared to create firebreaks had a similar species richness of butterflies to a shrubland where grazing was used to suppress vegetation. POPULATION RESPONSE (1 STUDY) Abundance (1 study): One replicated, site comparison study in Portugal found that cork oak woodlands with more recent or more regular mechanical clearance of woody understorey vegetation had a higher abundance of butterflies than woodlands cleared less frequently or longer ago. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3881https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3881Thu, 21 Jul 2022 17:04:10 +0100Collected Evidence: Collected Evidence: Stop using herbicides on pavements and road verges Two studies evaluated the effects on butterflies and moths of stopping the use of herbicides on pavements and road verges. One study was in the USA and the other was in Canada. COMMUNITY RESPONSE (2 STUDIES) Richness/diversity (2 studies): One replicated, paired, site comparison study in the USA found that restored roadside prairies where herbicide application was restricted had a greater species richness of butterflies than verges dominated by non-native weeds and grasses with no restrictions on herbicide application. One replicated, site comparison study in Canada found that transmission lines (road verges and power lines) which were neither sprayed with herbicide nor mown had a similar species richness of butterflies to sprayed and mown transmission lines. POPULATION RESPONSE (2 STUDIES) Abundance (2 studies): One replicated, paired, site comparison study in the USA found that restored roadside prairies where herbicide application was restricted had a greater abundance of butterflies than verges dominated by non-native weeds and grasses with no restrictions on herbicide application. One replicated, site comparison study in Canada found that transmission lines (road verges and power lines) which were neither sprayed with herbicide nor mown had a greater abundance of northern pearl crescent and pearl crescent butterflies, but similar total butterfly abundance, compared to sprayed and mown transmission lines. Survival (1 study): One replicated, paired, site comparison study in the USA found that butterflies had a lower mortality risk on restored roadside prairies where herbicide application was restricted than on verges dominated by non-native grasses with no restrictions on herbicide application. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3899https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3899Tue, 09 Aug 2022 15:00:37 +0100Collected Evidence: Collected Evidence: Maintain traditional orchards to benefit butterflies and moths Two studies evaluated the effects of maintaining traditional orchards on butterflies and moths. One study was in each of the USA and Germany. COMMUNITY RESPONSE (2 STUDIES) Community composition (1 study): One replicated, site comparison study in Germany found that managed orchards had a similar community composition of butterflies and burnet moths to abandoned orchards. Richness/diversity (2 studies): One replicated, site comparison study in Germany found that managed orchards had a similar species richness of butterflies and burnet moths to abandoned orchards. One controlled study in the USA found that an unmanaged and a partially managed orchard had a greater species richness and diversity of leaf-eating arthropods (including caterpillars) than a commercially managed orchard. POPULATION RESPONSE (1 STUDY) Abundance (1 study): One replicated, site comparison study in Germany found that managed orchards had a lower abundance of butterflies and burnet moths than abandoned orchards. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3917https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3917Thu, 11 Aug 2022 11:04:20 +0100Collected Evidence: Collected Evidence: Manage vineyards to benefit butterflies and moths Two studies evaluated the effects on butterflies and moths of managing vineyards to benefit butterflies and moths. One study was in each of the USA and Spain. COMMUNITY RESPONSE (2 STUDIES) Richness/diversity (2 studies): One of two replicated, site comparison studies (including one paired study) in the USA and Spain found that grass strips between vine rows had a greater species richness of butterflies than the vine rows themselves, and vineyards managed with fewer chemicals had a greater species richness of butterflies than conventionally managed vineyards. The other study found that vineyards managed to encourage native plants, and where insecticide was rarely used, had a similar species richness of butterflies to conventionally managed vineyards. POPULATION RESPONSE (1 STUDY) Abundance (1 study): One replicated, paired, site comparison study in the USA found that vineyards managed to encourage native plants, and where insecticide was rarely used, had a greater abundance of butterflies than conventionally managed vineyards. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3919https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3919Thu, 11 Aug 2022 11:19:09 +0100Collected Evidence: Collected Evidence: Increase crop diversity across a farm or farmed landscape      Two studies evaluated the effects on butterflies and moths of increasing crop diversity across a farm or farmed landscape. Both studies were in Switzerland. COMMUNITY RESPONSE (2 STUDIES) Richness/diversity (2 studies): Two replicated, site comparison studies in Switzerland found that farms and landscapes with a greater number of habitats or crop types had a similar species richness of butterflies to farms and landscapes with fewer different habitats or crop types. POPULATION RESPONSE (1 STUDY) Abundance (1 study): One replicated, site comparison study in Switzerland found that farms with a greater number of habitats had a similar abundance of butterflies to farms with fewer different habitats. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3921https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3921Thu, 11 Aug 2022 16:45:18 +0100Collected Evidence: Collected Evidence: Undersow spring cereals, with clover for example Two studies evaluated the effects on butterflies and moths of undersowing spring cereals. One study was in the UK and one was in Switzerland. COMMUNITY RESPONSE (2 STUDIES) Richness/diversity (2 studies): One replicated, randomized, controlled study in the UK found that spring barley undersown with a mix of grasses and legumes had a higher species richness of butterflies than extensively or conventionally managed grassland. One replicated, site comparison study in Switzerland found that farms with a larger area of in-field agri-environment scheme options, including undersown cereals, had a similar species richness of butterflies to farms with a smaller area of in-field agri-environment scheme POPULATION RESPONSE (2 STUDIES) Abundance (2 studies): One replicated, randomized, controlled study in the UK found that spring barley undersown with a mix of grasses and legumes had a higher abundance of butterflies, but a lower abundance of caterpillars, than extensively or conventionally managed grassland. One replicated, site comparison study in Switzerland found that farms with a larger area of in-field agri-environment scheme options, including undersown cereals, had a similar abundance of butterflies to farms with a smaller area of in-field agri-environment scheme BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3926https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3926Thu, 11 Aug 2022 17:09:12 +0100Collected Evidence: Collected Evidence: Manage woodland edges for maximum habitat heterogeneity Two studies evaluated the effects on butterflies and moths of managing woodland edges for maximum habitat heterogeneity. One study was in Belgium and the other was in Finland. COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): One replicated, paired, controlled, before-and-after study in Finland found that two years after felling 5-m-wide woodland edges, and thinning 20-m-wide adjacent forest, the combined species richness of butterflies, diurnal moths and bumblebees was higher than before management or in unmanaged woodland edges. POPULATION RESPONSE (2 STUDIES) Abundance (2 studies): One replicated, site comparison study in Belgium found that scalloped woodland edges had a higher abundance of brown hairstreak eggs than straight woodland edges. One replicated, paired, controlled, before-and-after study in Finland found that two years after felling 5-m-wide woodland edges and thinning 20-m-wide adjacent forest, the abundance of specialist butterflies was higher than before management or on unmanaged woodland edges. BEHAVIOUR (0 STUDIES)  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3942https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3942Sat, 13 Aug 2022 14:57:49 +0100Collected Evidence: Collected Evidence: Raise cutting height on grasslands Two studies evaluated the effects on butterflies and moths of raising cutting height on grasslands. One study was in each of the UK and Switzerland. COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): One replicated, randomized, controlled study in the UK found that intensively managed grassland plots cut to 10 cm in May and July had a similar species richness of butterflies to plots cut to 5 cm. POPULATION RESPONSE (1 STUDY) Abundance (1 study): One replicated, randomized, controlled study in the UK found that intensively managed grassland plots cut to 10 cm in May and July had a similar abundance of butterflies and caterpillars to plots cut to 5 cm. Survival (1 study): One replicated, randomized, paired, controlled study in Switzerland found that the survival of large white caterpillars in grassland plots cut to 9 cm was similar to in plots cut to 6 cm2. Condition (1 study): One replicated, randomized, paired, controlled study in Switzerland found that a similar proportion of wax model caterpillars were damaged when meadows were cut to 9 cm or 6 cm. BEHAVIOUR (0 STUDIES)  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3968https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3968Sun, 14 Aug 2022 10:38:54 +0100Collected Evidence: Collected Evidence: Use motor bar mowers rather than rotary mowers Two studies evaluated the effects on butterflies and moths of using motor bar mowers rather than rotary mowers. Both studies were in Switzerland. COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): One replicated, site comparison study in Switzerland found that farms managed with more in-field agri-environment scheme options, including using bar mowers instead of rotary mowers, had a similar species richness of butterflies to farms with fewer agri-environment scheme options. POPULATION RESPONSE (2 STUDIES) Abundance (1 study): One replicated, site comparison study in Switzerland found that farms managed with more in-field agri-environment scheme options, including using bar mowers instead of rotary mowers, had a similar abundance of butterflies to farms with fewer agri-environment scheme options. Survival (1 study): One replicated, randomized, paired, controlled study in Switzerland1 found that fewer large white caterpillars were killed when meadows were harvested using a hand-pushed bar mower than with a tractor-pulled rotary mower. Condition (1 study): One replicated, randomized, paired, controlled study in Switzerland found that fewer wax model caterpillars were damaged when meadows were harvested using a hand-pushed bar mower than with a tractor-pulled rotary mower. BEHAVIOUR (0 STUDIES)  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3969https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3969Sun, 14 Aug 2022 10:39:04 +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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