Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Delay mowing or first grazing date on pasture or grassland Eight studies from the Netherlands, Sweden and the UK (three replicated and controlled of which one also randomized and one European systematic review) found that delaying mowing or grazing dates resulted in benefits to some or all plants, invertebrates or birds studied. These benefits included: higher plant species richness, higher densities of two rare arable weeds, more insect species and individuals visiting flowers, greater abundance of some spiders and ground beetles, increased breeding wading bird densities, and increased Eurasian skylark productivity. Three reviews found the UK corncrake population increased after measures including delaying mowing dates were introduced. Six studies from Finland, the Netherlands, Sweden, Switzerland and the UK (including three replicated controlled trials of which one was also randomized and a European systematic review) found that delaying mowing or grazing dates on grassland had no clear effect on plant species richness, ground beetle communities, abundance of some insects and spiders, or population trends of wading bird species. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F131https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F131Mon, 14 Nov 2011 22:17:17 +0000Collected Evidence: Collected Evidence: Delay haying/mowing Two reviews from the UK found that the population of corncrakes Crex crex increased following the implementation of two initiatives to encourage farmers to delay mowing (and provide cover and use corncrake-friendly techniques). A replicated and controlled paired sites study from the Netherlands found no evidence that waders and other birds were more abundant in fields with delayed mowing, compared to paired controls. A replicated and controlled before-and-after study from the Netherlands found that fields with delayed mowing held more birds than controls, but did so before the start of the scheme. Population trends did not differ between treatments. A replicated, controlled study from the USA found that destruction of nests by machinery was lower and late-season nesting higher in late-cut fields, compared with early-cut fields. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F223https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F223Tue, 17 Jul 2012 14:29:48 +0100Collected Evidence: Collected Evidence: Delay mowing or first grazing date on pasture or grasslandNatural enemy abundance: One replicated, randomised, controlled study found fewer predatory spiders with delayed cutting. Three studies from the UK (two of them replicated, randomised and controlled) found no change in insect predator numbers and one replicated study from Sweden found mixed effects between different predator groups. Natural enemy diversity: One replicated study from Sweden found a decrease in ant diversity with delayed cutting and one replicated, randomised, controlled study from the UK found no effect on spider and beetle diversity. Pests: One of two replicated, randomised, controlled studies from the UK and USA found more pest insects in late-cut plots and one found no effect. Insects in general: Four replicated, randomised, controlled studies measured the abundance of insect groups without classifying them as pests or natural enemies. One UK study found lower numbers in late-cut plots, while two found effects varied between groups. Two studies from the UK and USA found no effect on insect numbers. Crops studied were barley, bird’s-foot trefoil, clovers, fescues, rapeseed, ryegrass, other grasses and wheat.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F727https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F727Thu, 30 May 2013 13:34:12 +0100Collected Evidence: Collected Evidence: Delay herbicide useNatural enemies: Two randomised, replicated, controlled trials from Australia and Denmark found more natural enemies when herbicide treatments were delayed. One of the studies found some but not all natural enemy groups benefited and fewer groups benefitted early in the season. Weeds: One randomised, replicated, controlled study found more weeds when herbicide treatments were delayed. Insect pests and damage: One of two randomised, replicated, controlled studies from Canada and Denmark found more insect pests, but only for some pest groups, and one study found fewer pests in one of two experiments and for one of two crop varieties. One study found lower crop damage in some but not all varieties and study years. Yield: One randomised, replicated, controlled study found lower yields and one study found no effect. Crops studied were beet and oilseed.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F774https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F774Tue, 20 Aug 2013 16:05:25 +0100Collected Evidence: Collected Evidence: Deepen ponds to prevent desiccationStudies investigating the effects of deepening ponds are discussed in ‘Habitat restoration and creation – Deepen, de-silt or re-profile ponds’. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F806https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F806Thu, 22 Aug 2013 15:02:40 +0100Collected Evidence: Collected Evidence: Deepen, de-silt or re-profile ponds Two before-and-after studies in France and Denmark found that pond deepening and enlarging or re-profiling resulted in the establishment of a breeding population of great crested newts or translocated garlic toads. Two studies (including one replicated, controlled study) in the UK and Denmark found that pond deepening and enlarging or dredging increased a population of common frogs or numbers of calling male tree frogs. Four before-and-after studies in Denmark and the UK found that pond deepening, along with other interventions, maintained newt populations and increased populations of European fire-bellied toads or natterjack toads. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F817https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F817Fri, 23 Aug 2013 09:03:23 +0100Collected Evidence: Collected Evidence: Demarcate and enforce boundaries of protected areas We found no evidence for the effects of demarcating and enforcing boundaries of protected areas on primate populations. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1582https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1582Fri, 20 Oct 2017 13:04:42 +0100Collected Evidence: Collected Evidence: Deploy fishing gear at selected depths to avoid unwanted species Five studies examined the effect of deploying fishing gear at selected depths to avoid unwanted species on marine fish populations. Three studies were in the Atlantic Ocean (Florida, Brazil, Canary Islands), and one study was in each of the Pacific Ocean (Hawaii) and the Tasman Sea (Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (5 STUDIES) Reduction of unwanted catch (5 studies): Four of five replicated studies (three controlled, one paired and controlled) in the Pacific Ocean, Atlantic Ocean and the Tasman Sea found that deploying fishing gear (longlines, handlines and traps) at selected depths, including above the seabed instead of on it, reduced the unwanted catches of five of 17 fish species, three of eight shark/ray species, non-commercially targeted fish species and Harrison’s dogfish, compared to depths usually fished. The other study found that different shark species were hooked at different depths in the water column during bottom-set longlining deployments.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2683https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2683Mon, 30 Nov 2020 16:26:13 +0000Collected Evidence: Collected Evidence: Deploy fishing gear at selected times (day/night) to avoid unwanted species Two studies examined the effect of deploying fishing gear at selected times on marine fish populations. Both studies were in the South Pacific Ocean (Lake Wooloweyah, Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES) Reduction of unwanted catch (2 studies): One of two replicated, controlled studies in the South Pacific Ocean found that trawling for prawns during the day reduced the overall catch of unwanted fish by number, but not weight, compared to usual night trawling, and the effect differed by species. The other study found that powered handlining in the day avoided catches of Harrison’s dogfish at shallower, but not deeper seamounts, compared to the night. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2684https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2684Mon, 30 Nov 2020 16:40:44 +0000Collected Evidence: Collected Evidence: Decrease the circumference or diameter of the codend of a trawl net Thirteen studies examined the effects of decreasing the circumference or diameter of a trawl codend on marine fish populations. Four studies were in the Tasman Sea (Australia) and three studies were in the North Sea (UK, Norway). Two studies were in the Adriatic Sea (Italy) and two were in the Baltic Sea (Denmark/ Germany). One study and one review were in the Northeast Atlantic Ocean (Northern Europe). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (13 STUDIES) Reduction of unwanted catch (6 studies): Two of six replicated, controlled studies (three paired, and one randomized and paired) in the Tasman Sea, Adriatic Sea and Northeast Atlantic Ocean found that bottom trawl nets of smaller circumferences reduced discarded catch of fish in three of five cases and of total discarded catch (fish and invertebrates) in one of two areas, but not overall, compared to standard trawls. Two studies found that reduced circumference codends reduced non-target or discarded fish catch in three of 12 cases and for one of four species. The two other studies found that discarded fish catch was not reduced in smaller circumference codends. Improve size-selectivity of fishing gear (8 studies): Four of eight replicated, controlled studies (one paired) in the North Sea, Adriatic Sea and Baltic Sea, and one review in the Northeast Atlantic Ocean, found that decreasing the circumference or diameter of the codend of trawl gear (bottom trawls and seines) improved the size-selectivity of haddock, Atlantic cod, whiting and European hake and red mullet, compared to larger circumferences/diameters. One also found the effect was the same across two codend mesh sizes, and one also found the effect was greater in diamond mesh with the netting orientation turned by 90° compared to standard diamond mesh. Two studies found that a decrease in codend circumference/diameter improved size-selectivity of haddock and saithe in one of two cases, and of one of three fish species. The other study found that a smaller circumference codend reduced size-selectivity of the gear for one of three fish species and was similar for the other two. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2706https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2706Thu, 17 Dec 2020 14:51:11 +0000Collected Evidence: Collected Evidence: Deploy patrol boats We found no studies that evaluated the effects of deploying patrol boats on marine fish populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2738https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2738Tue, 02 Feb 2021 15:08:05 +0000Collected Evidence: Collected Evidence: Deploy fishing gear at times when mammals are less active We found no studies that evaluated the effects of deploying fishing gear at times when mammals are less active on marine and freshwater mammal populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2792https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2792Thu, 04 Feb 2021 16:31:14 +0000Collected Evidence: Collected Evidence: Deploy fishing gear at different depths One study evaluated the effects on marine mammals of deploying fishing gear at different depths. The study was in the Arafura Sea (Australia). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (1 STUDY) Reduction in entanglements/unwanted catch (1 study): One controlled study in the Arafura Sea found that fishing nets deployed 4.5 m below the water surface had fewer entanglements of dolphins than surface nets. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2793https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2793Thu, 04 Feb 2021 16:33:47 +0000Collected Evidence: Collected Evidence: Delay or cease operations if marine and freshwater mammals are detected within a specified zone We found no studies that evaluated the effects of delaying or ceasing operations if marine and freshwater mammals are detected within a specified zone on marine and freshwater mammal populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2898https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2898Mon, 08 Feb 2021 16:09:16 +0000Collected Evidence: Collected Evidence: Deposit soil/sediment and introduce vegetation: freshwater marshesWe found no studies that evaluated the combined effects, on vegetation, of depositing soil/sediment to form the physical structure of freshwater marshes and introducing vegetation. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3194https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3194Wed, 07 Apr 2021 13:40:54 +0100Collected Evidence: Collected Evidence: Deposit soil/sediment and introduce vegetation: brackish/salt marshes Six studies evaluated the combined effects, on vegetation, of depositing soil/sediment to form the physical structure of brackish/salt marshes and introducing vegetation. All six studies were in the USA. Several sites, and even the same data from some sites, were used in multiple studies. VEGETATION COMMUNITY Overall extent (2 studies): Two replicated, site comparison studies of salt marshes in the USA compared the overall area of emergent vegetation in marshes created by depositing sediment and planting vs natural marshes. One study found that created and natural marshes had similar vegetation coverage after 2–23 years. The other study reported that created marshes had slightly lower vegetation coverage than nearby natural marshes after 2–4 years. Community types (1 study): One replicated, site comparison study in the USA found that four of four plant community types had similar coverage in created and natural salt marshes after 3–15 years. For most marshes, creation involved depositing sediment and planting herbs. Community composition (1 study): One replicated, before-and-after, site comparison study in the USA reported that the overall plant community in salt marshes created by depositing sediment and planting herbs/shrubs was <36% similar to nearby natural salt marshes, after 2–4 years. VEGETATION ABUNDANCE Overall abundance (1 study): One paired, site comparison study in the USA found that salt marshes created by depositing sediment and planting/sowing herbs typically contained at least as much vegetation (biomass and density) as natural marshes, after 1–4 years. Individual species abundance (4 studies): Four studies quantified the effect of this action on the abundance of individual plant species. For example, two studies (one review, one site comparison) in the USA found that salt marshes created by depositing sediment and introducing vegetation typically contained a similar amount (density and/or biomass) of cordgrasses Spartina spp. to nearby natural marshes, after 1–9 years. Meanwhile, one paired, site comparison study in the USA reported that whether created marshes contained a higher, lower or similar cordgrass density to natural marshes depended on plot elevation. VEGETATION STRUCTURE Overall structure (2 studies): One replicated, site comparison study in the USA found that salt marshes created (mostly) by depositing sediment and planting herbs contained larger patches of vegetation with straighter edges than natural marshes, after 3–15 years. One replicated, paired, site comparison study in the USA reported that created salt marshes contained a similar proportion of edge habitat to nearby natural salt marshes, after 2–23 years. Height (2 studies): Two site comparison studies in the USA compared the height of cordgrasses Spartina sp. in created and nearby natural marshes. One study (also paired) found that created marshes typically contained cordgrass of similar height to natural marshes, after 1–4 growing seasons. The other study reported that cordgrass was shorter in created than natural marshes, after 7–9 years. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3195https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3195Wed, 07 Apr 2021 13:41:27 +0100Collected Evidence: Collected Evidence: Deposit soil/sediment and introduce vegetation: freshwater swampsWe found no studies that evaluated the combined effects, on vegetation, of depositing soil/sediment to form the physical structure of freshwater swamps and introducing vegetation. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3196https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3196Wed, 07 Apr 2021 13:41:44 +0100Collected Evidence: Collected Evidence: Deposit soil/sediment and introduce vegetation: brackish/saline swampsWe found no studies that evaluated the combined effects, on vegetation, of depositing soil/sediment to form the physical structure of brackish/saline swamps and introducing vegetation. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3197https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3197Wed, 07 Apr 2021 13:41:58 +0100Collected Evidence: Collected Evidence: Deposit soil/sediment to form physical structure of freshwater marshes Two studies evaluated the effects, on vegetation, of depositing soil/sediment to form the physical structure of freshwater marshes (without introducing vegetation). One study was in the USA and one was in the Netherlands. VEGETATION COMMUNITY Community types (1 study): One replicated, paired, site comparison study in the Netherlands reported that marshes created by depositing sand at lake margins contained fewer plant community types, after 8–16 years, than mature natural marshes. VEGETATION ABUNDANCE Overall abundance (2 studies): One site comparison study in the USA reported that plant stem density was similar, after 4–10 years, in marshes created by depositing sediment and in natural marshes, but that vegetation cover was lower in the created marshes. One replicated, paired, site comparison study in the Netherlands reported that marshes created by depositing sand at lake margins contained similar vegetation biomass to nearby natural marshes after 8–16 years. VEGETATION STRUCTURE Height (1 study): One site comparison study in the USA reported that a freshwater marsh created by depositing sediment contained vegetation of a similar height to nearby natural marshes after 4–10 years. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3235https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3235Fri, 09 Apr 2021 15:01:56 +0100Collected Evidence: Collected Evidence: Deposit soil/sediment to form physical structure of brackish/salt marshes Four studies evaluated the effects, on vegetation, of depositing soil/sediment to form the physical structure of brackish/salt marshes (without introducing vegetation). Three studies were in the USA and one study was in Italy. Two studies took place in the same marsh, but in different areas. VEGETATION COMMUNITY Overall extent (1 study): One replicated study in a lagoon in Italy quantified the area of vegetation on sediment deposited up to 19 years previously (average six years four months, with 61% vegetation coverage). Community types (2 studies): Two replicated studies in coastal wetlands in the USA and Italy quantified the coverage of brackish or salt marsh plant communities on sediment deposited up to 19 years previously. Community composition (1 study): One replicated, site comparison study on the coast of the USA reported that the composition of the plant community that developed on deposited sediment depended on the time since deposition and the elevation of the sediment. Areas of sediment that were of a similar elevation to natural marshes (or slightly lower) developed (or were developing) a similar overall plant community composition to the natural marshes. Overall richness/diversity (1 study): One replicated study in an estuary in the USA reported that 1–2 plant species had colonized areas of deposited sediment after 4–8 years. VEGETATION ABUNDANCE VEGETATION STRUCTURECollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3236https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3236Fri, 09 Apr 2021 15:02:12 +0100Collected Evidence: Collected Evidence: Deposit soil/sediment to form physical structure of freshwater swampsWe found no studies that evaluated the effects on vegetation, of depositing soil/sediment to form the physical structure of freshwater swamps (without introducing vegetation). ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3237https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3237Fri, 09 Apr 2021 15:02:24 +0100Collected Evidence: Collected Evidence: Deposit soil/sediment to form physical structure of brackish/saline swampsWe found no studies that evaluated the effects on vegetation, of depositing soil/sediment to form the physical structure of brackish/saline swamps (without introducing vegetation). ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3238https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3238Fri, 09 Apr 2021 15:02:32 +0100Collected Evidence: Collected Evidence: Deploy fishing gear at different depths Three studies evaluated the effects of deploying fishing gear at different depths on reptile populations. One study was in each of Canada, off the coast of Mexico and the Atlantic. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Survival (1 study): One replicated, randomized, paired study in Canada found that no turtles died in floated nets, but some died in submerged nets. Condition (1 study): One replicated, randomized, paired study in Canada found that turtles caught in floated nets were less at risk of drowning than those caught in submerged nets. BEHAVIOUR (0 STUDIES) OTHER (3 STUDIES) Unwanted catch (3 studies): Two of three studies (including two replicated studies) in Canada, Mexico and the Atlantic found that bottom-set fishing nets with fewer buoys caught fewer sea turtles than standard nets or that fewer loggerhead turtles were caught when longline hooks were set below 22 m deep, but the number of leatherback turtles caught was unaffected by hook depth. The other study found that floated and submerged nets caught a similar number of turtle species. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3547https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3547Wed, 08 Dec 2021 09:29:51 +0000Collected Evidence: Collected Evidence: Design the route of roads to maximize habitat block size We found no studies that evaluated the effects on butterflies and moths of designing the route of roads to maximize habitat block size. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3851https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3851Tue, 05 Jul 2022 11:33:46 +0100Collected Evidence: Collected Evidence: Delay cutting or first grazing date on grasslands to create variation in sward height Seven studies evaluated the effects on butterflies and moths of delaying cutting or first grazing dates on grasslands. Two studies were in Germany and one was in each of the UK, Hungary, Switzerland, Austria and Sweden. COMMUNITY RESPONSE (4 STUDIES) Community composition (1 study): One replicated, site comparison study in Austria found that the community composition of butterflies and day-flying moths was different between early-mown and late-mown grasslands. Richness/diversity (3 studies): One of three replicated, controlled studies (including two randomized studies and two paired studies) in the UK, Germany and Switzerland found that, in one of four years, grassland plots cut once/year in July had a higher species richness of butterflies than plots cut once/year in May. One study found that, in one of three years, grassland strips mulched once/year in September had a lower species richness of butterflies than strips mown once/year after 10 June. The third study found that meadows mown 1–2 times/year after 15 July had a similar species richness of butterflies and burnet moths to meadows mown twice/year after 15 June. POPULATION RESPONSE (6 STUDIES) Abundance (6 studies): Three of four replicated, controlled studies (including three randomized studies and three paired studies) in the UK, Germany, Hungary and Switzerland found that grassland cut once/year in July or September had a greater abundance of butterflies, burnet moths and caterpillars than grassland cut once or twice per year in May or June, but in two of the cases only in one of four or two of three years. The fourth study found that meadows mown once/year in September had a similar abundance of scarce large blue butterflies to meadows mown once/year in May, and abundance remained stable in September-mown meadows but decreased over time in May-mown meadows. One site comparison study in Germany found that a meadow mown once/year after the flight season of tufted marbled skipper had a lower density of eggs than a meadow mown before the flight season. One replicated, site comparison study in Sweden found that meadows where grazing commenced after 15 June (together with a lower stocking density) had a higher abundance of clouded Apollo butterflies than meadows where grazing commenced before 15 June (together with a higher stocking density). BEHAVIOUR (1 STUDY) Use (1 study): One replicated, site comparison study in Austria found that short-tailed blue showed a preference for late-mown meadows, but marbled white and meadow brown preferred early-mown meadows. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3967https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3967Sun, 14 Aug 2022 10:38:44 +0100