Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Maintain species-rich, semi-natural grassland Nineteen studies evaluated the effects on butterflies and moths of maintaining species-rich, semi-natural grassland. Five studies were in Germany, four were in the USA, two were in each of Switzerland and the Czech Republic, and one was in each of Finland and Russia, China, Italy, Spain, Hungary and Austria. COMMUNITY RESPONSE (12 STUDIES) Community composition (6 studies): Four replicated, site comparison studies in the USA, the Czech Republic, Austria and Germany found that the community composition of butterflies, day-flying moths and nocturnal moths was different between summer cattle-grazed, early-mown and late-mown grassland, between mown and grazed grassland, and between prairies managed by cattle grazing and/or rotational burning. However, one of these studies found that the community composition of butterflies was similar in mown and grazed grassland. Two replicated, site comparison studies in the Czech Republic and Germany found that species-rich grassland managed by grazing or mowing had a similar community composition of butterflies and burnet moths to abandoned grassland. One replicated, site comparison study in Switzerland found that meadows managed by mowing at least twice/year after mid-June had a different community composition of butterflies to sown wildflower strips. Richness/diversity (11 studies): Three of six site comparison studies (including five replicated studies) in Germany, the USA, Russia and Finland, Italy and the Czech Republic found that the species richness of butterflies was similar on semi-natural grassland managed by light grazing or by annual mowing in July or August, and on prairies managed by cattle grazing and/or rotational burning. One study found that the species richness of butterflies was higher in grassland managed by sheep and cattle grazing than in grassland mown annually for hay in June. One study found that the species richness of moths was higher in grassland managed by annual mowing than grassland managed by grazing, and the species richness of butterflies was highest in grasslands where mowing was staggered throughout the year, with some areas left uncut. The sixth study found that in some areas, the species richness of specialist and grassland butterflies was higher in prairies managed by two-year rotational haying, and in other areas it was higher in prairies managed by grazing, but in all cases richness was higher at sites longer after they were last managed. Two replicated, site comparison studies in Germany found that species-rich grasslands managed by summer-grazing, grazing or mowing had a similar species richness of butterflies and burnet moths and nocturnal moths to unmanaged grassland. However, one of these studies also found that grasslands managed by mowing had a lower species richness of nocturnal moths than unmown grassland. Two replicated, site comparison studies in Germany and Hungary found that old meadows mown in July and lightly grazed or annually mown meadows had a higher species richness of adult butterflies and caterpillars than recently established set-aside or cereal crops. One replicated, site comparison study in Switzerland found that meadows mown at least twice/year after mid-June had a similar species richness of butterflies to sown wildflower strips. POPULATION RESPONSE (16 STUDIES) Abundance (16 studies): Five of ten site comparison studies (including nine replicated studies) in Germany, the USA, Russia and Finland, Italy, Spain and the Czech Republic found that semi-natural grasslands had a similar abundance of butterflies generally, and individual species of butterflies and moth caterpillars, when managed by extensive sheep, sheep and goat, cattle or livestock grazing compared to annual or occasional mowing, or rotational mowing or burning. Four of these studies found that grasslands managed by cattle, sheep or livestock grazing had a higher abundance of butterflies generally, and individual species of butterflies and moth caterpillars, than grasslands managed by annual mowing, rotational burning or unmanaged grasslands. Three of these studies found that grasslands managed by haying had a higher abundance of individual butterfly species than grasslands managed by grazing or burning or unmanaged grasslands. Four of these studies found that specific butterfly species and all butterflies were less abundant in mown, grazed or rotationally burned grassland than in unmanaged, rotationally burned or grazed and burned grassland. The ninth study found that in some areas, the abundance of specialist and grassland butterflies was higher in prairies managed by two-year rotational haying or by grazing, but in all cases abundance was higher at sites longer after they were last managed. One of three replicated, site comparison studies in Germany and Switzerland found that traditional hay meadows mown once/year in June or July had a higher abundance of heath fritillary adults and caterpillars than old, abandoned meadows. One study found that summer-grazed or mown grasslands had a higher abundance of farmland butterflies and burnet moths, but a lower abundance of woodland butterflies and burnet moths, than abandoned grasslands. The third study found that mown grasslands had a lower abundance of moths than unmown grasslands, but grazed grasslands had a similar abundance of moths to ungrazed grasslands. Two replicated, site comparison studies in China and Switzerland found that semi-natural grasslands managed by grazing or cutting twice/year after mid-June had a lower abundance of marsh fritillary eggs and caterpillars and adult butterflies than ungrazed margins and intercrops or sown wildflower strips. One replicated, site comparison study in Hungary found that semi-natural grasslands managed by either light grazing or mowing once/year in May or June had a higher abundance of butterflies than conventional wheat fields. Survival (1 study): One replicated, site comparison study in China found that marsh fritillary eggs had a similar survival rate in uncultivated, grazed meadows and cultivated, ungrazed field margins and intercrops, but the survival of caterpillars was higher in the grazed meadows. BEHAVIOUR (5 STUDIES) Use (5 studies): Two replicated, site comparison studies in Austria and Germany found that 14 species of moth preferred grazed pastures while 24 others avoided them, and three species of butterfly and ten nocturnal moths preferred mown meadows, while 19 nocturnal moth species avoided them. One replicated, site comparison study in Spain found that meadows managed by summer-grazing or hay-mowing were more likely to be occupied by grizzled skipper and painted lady than unmanaged meadows, but small pearl-bordered fritillary occurred less frequently in grazed meadows than in hay meadows or abandoned meadows. One replicated, site comparison study in Finland and Russia found that three of 37 butterfly species preferred meadows which were mown annually in July or August to cattle-grazed pasture, but the other 34 species showed no preference. One replicated, site comparison study in China found that uncultivated, grazed meadows were less likely to be occupied by marsh fritillary eggs and caterpillars than cultivated field margins and intercrops.Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3908https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3908Wed, 10 Aug 2022 11:31:24 +0100Collected Evidence: Collected Evidence: Cease grazing on grassland to allow early succession Twenty-six studies evaluated the effects on butterflies and moths of ceasing grazing on grassland to allow early succession. Five studies were in the UK, four were in each of Germany and the USA, three were in each of Sweden and Finland, two were in each of Spain and the Czech Republic, and one was in each of Switzerland, Europe and Israel. COMMUNITY RESPONSE (14 STUDIES) Community composition (3 studies): Two replicated, site comparison studies in the Czech Republic and Germany found that the community composition of butterflies and moths in grasslands which had been abandoned for >5 years or an unspecified length of time was similar to grasslands managed by grazing or mowing (results not distinguished). One replicated, controlled, before-and-after study in Spain found that after grazing and mowing management was abandoned, over 6 years the butterfly community became dominated by generalist species, and species with fewer generations/year. Richness/diversity (12 studies): Six of nine replicated studies (including one randomized, controlled study, one paired, site comparison, and seven site comparisons) in Germany, the USA, Finland, Sweden and the Czech Republic found that grasslands which had been not been grazed for >5 years, or an unspecified length of time, in one case with burning, had a similar species richness of butterflies and day-flying, burnet or all moths to grasslands grazed by cattle, horses and cattle or a mix of livestock (in two studies grazing and mowing were not distinguished) or grazed with cattle and burned. One of these studies also found that grasslands abandoned for 5–15 years had a greater species richness than grasslands grazed by sheep. A further two studies found that grasslands which had been abandoned for >5–20 years or many years had a lower species richness of butterflies than grazed grasslands (in one study grazing and mowing were not distinguished). The other study found that butterfly species richness was higher in grasslands where grazing ceased 2–9 years ago than those abandoned >10 years ago or those currently grazed. Three replicated studies (including one randomized, controlled study and two site comparison studies) in Switzerland, Germany and the UK found that grasslands which had been abandoned for 4, 5–10 or >10 years had a higher species richness of butterflies and day-flying moths and nocturnal moths than extensively grazed, recently abandoned or commercially grazed grasslands. Two of these studies also found that grassland abandoned for 4 or 5–10 years had a similar species richness of butterflies and day-flying moths and all moths to grassland lightly grazed by cattle or sheep/sheep and cattle. POPULATION RESPONSE (24 STUDIES) Abundance (24 studies): Six of 20 replicated studies (including one paired, controlled, before-and-after study, three randomized controlled studies, and 15 site comparison studies) in Germany, the USA, the UK, Switzerland, Finland, Sweden, Spain, the Czech Republic and Israel found that grasslands which had been abandoned for 1-25 years had a higher abundance of Scotch argus, butterflies and day-flying moths, nocturnal moths, caterpillars, and of small insects including caterpillars, than grasslands grazed by goats, sheep and/or cattle. Two of these studies only found a difference compared to grazing at commercial/intensive, not low, densities. Four of the studies found that grasslands which had been abandoned for two weeks, 5–20 years or an undetermined time had a lower abundance of butterflies and spring webworm caterpillars than grasslands grazed by cattle or a mix of livestock (in two studies grazing and mowing were not distinguished). A further four of the studies found that grasslands which had been abandoned for 5-15 years had a similar abundance of butterflies, burnet moths, day-flying moths and meadow neb moth caterpillars to grasslands grazed by sheep, horses and cattle or a mix of livestock. A further four of the studies found that in grasslands which had been abandoned for >10 years, many years or an unspecified number of years, and in one case with burning, abundance or density was mixed depending on butterfly and moth species compared to grasslands grazed by cattle or unspecified grazers or grazed with cattle and burned. The other study found that butterfly density was higher in grasslands where grazing ceased 2–9 years ago than those abandoned >10 years ago or those currently grazed. Two replicated studies (including one controlled, before-and-after study and one site comparison study) in Spain and Germany found that grasslands which had been abandoned for 1–6 years or an unspecified time period had a higher abundance of woodland and hedgerow butterflies and burnet moths, but a lower abundance of grassland or farmland species, than grasslands managed by grazing and/or mowing (results not distinguished). Two studies also found that the large blue and silver-studded blue went extinct in some abandoned meadows. One replicated, site comparison study in Sweden found that grasslands which were ungrazed for the year had a lower abundance of clouded Apollo butterflies than lightly grazed grasslands, but a higher abundance than heavily grazed grasslands. One review in Europe reported that ceasing grazing on grassland benefitted six out of 67 butterfly species of conservation concern. BEHAVIOUR (3 STUDIES) Use (3 studies): One replicated, paired, site comparison study in Germany found that grassland which had been abandoned for >5 years had a similar occurrence of hoary bell moth caterpillars to grassland grazed by sheep. One replicated, site comparison study in the UK found that a similar proportion of grasslands which had been abandoned for one year, and grazed grasslands, contained >20 marsh fritillary caterpillar webs. One replicated, site comparison study in Spain found that grizzled skipper and painted lady occurred less frequently, but small pearl-bordered fritillary occurred more frequently, in meadows which had been abandoned for at least 1–2 years than in meadows managed by grazing or mowing (results not distinguished). Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3956https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3956Sun, 14 Aug 2022 10:36:11 +0100Collected Evidence: Collected Evidence: Reduce grazing intensity on grassland by reducing stocking density Fourteen studies evaluated the effects on butterflies and moths of reducing grazing intensity on grassland by reducing stocking density. Four studies were in the UK, two were in each of Sweden and Germany, one was in each of the USA, Belgium and the Netherlands, Europe and Switzerland. COMMUNITY RESPONSE (8 STUDIES) Richness/diversity (8 studies): Five of eight replicated studies (including two randomized, controlled studies and six site comparison studies) in the UK, Sweden, Germany, the USA and Switzerland found that grasslands grazed with lower stocking densities of sheep, cattle or a mix of sheep, cattle and horses had a greater species richness of adult butterflies, all moths and burnet moths than grassland grazed at higher stocking densities. However, one of these studies also found that butterfly and burnet moth caterpillar species richness was similar at sites with low and high stocking densities. Two of the other studies found that grasslands grazed with lower stocking densities of cattle and horses or unspecified grazing animals had a similar species richness of butterflies and burnet moths to grassland grazed at higher stocking densities. The other study found that, in one of two study years, grasslands grazed with cattle at a low density had lower species richness than grasslands grazed at moderate density. POPULATION RESPONSE (12 STUDIES) Abundance (11 studies): Eight replicated studies (including four controlled studies and four site comparison studies) in the UK, Germany, the USA and Sweden found that grasslands grazed with lower stocking densities of sheep, cattle or both (in one case combined with a later start to grazing) had a greater abundance of all butterflies, butterflies with grass host plants, all moths, burnet moths, their caterpillars or specific species (in two cases as part of combined invertebrate counts) than grasslands grazed at higher stocking densities. The three studies on caterpillars only found a higher abundance at two out of three sites or in earlier or later sampling periods, and one of the studies found that sites with low and high intensity grazing had a similar abundance of butterfly and burnet moth caterpillars. Two replicated, site comparison studies in Sweden and Switzerland found that grasslands grazed with lower stocking densities of cattle and horses or unspecified grazing animals had a similar abundance of butterflies and burnet moths to grassland grazed at higher stocking densities. One review of studies in Europe reported that reducing grazing intensity benefitted 41 out of 67 butterfly species of conservation concern, but did not distinguish between reducing stocking density and seasonal removal of livestock. Survival (1 study): One site comparison study in Belgium and the Netherlands reported that the survival of Glanville fritillary caterpillar nests was similar between grasslands with low and high stocking density of sheep. Condition (1 study): One site comparison study in Belgium and the Netherlands found that after 6–10 days of sheep grazing, fewer Glanville fritillary caterpillar nests were damaged in a grassland with lower stocking density than in a grassland with higher stocking density, but there was no difference after two months. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3959https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3959Sun, 14 Aug 2022 10:37:16 +0100Collected Evidence: Collected Evidence: Increase grazing intensity or cutting frequency on grassland Five studies evaluated the effects on butterflies and moths of increasing grazing intensity or cutting frequency on grassland. Two studies were in Germany, and one study was in each of the Czech Republic, the USA and Israel. COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): One replicated, site comparison study in Germany found that at intensively grazed sites species richness of adult butterflies and burnet moths was lower than at sites with low or no grazing, but caterpillar richness was lower in intensively grazed and low grazing sites than in sites with no grazing. POPULATION RESPONSE (5 STUDIES) Abundance (5 studies): Four studies (including one replicated, randomized, paired, controlled study, one replicated, site comparison study, and two site comparison studies) in Germany, the USA and Israel found that grasslands managed with more intensive grazing or with grazing in addition to rotational burning had a lower abundance of all adult butterflies, adult burnet moths, adult regal fritillaries and spring webworm caterpillar nests than ungrazed grasslands, lightly or moderately grazed grasslands or rotationally burned grasslands with occasional light grazing. However, one of these studies found that, while intensively grazed sites had lower butterfly and burnet moth caterpillar abundance than ungrazed sites, there was no difference in caterpillar abundance between ungrazed and lightly grazed sites. One before-and-after study in the Czech Republic reported that after increasing the cutting frequency on traditional meadows (under agri-environment scheme prescriptions) the abundance of Danube clouded yellow decreased. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3962https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3962Sun, 14 Aug 2022 10:37:50 +0100Collected Evidence: Collected Evidence: Use rotational grazing Six studies evaluated the effects on butterflies and moths of using rotational grazing. Three studies were in France, two were in the USA and one was in the UK. COMMUNITY RESPONSE (5 STUDIES) Community composition (1 study): One replicated, site comparison study in the USA found that rotational, cattle-grazed grasslands had a similar butterfly community to continuously grazed or patch-burned grasslands. Richness/diversity (5 studies): Two of four replicated studies (including one randomized, controlled study, two controlled studies and one site comparison study) in France and the USA found that rotational cattle- and sheep-grazed grasslands had a greater species richness of butterflies and burnet moths than continuously grazed or patch-burned grassland. Another of these studies found that rotationally sheep-grazed grassland had a similar species richness of butterflies and burnet moths to continuously grazed grassland. The other study found that rotational cattle-grazed pastures had a greater species richness of butterflies than constantly grazed pastures but only at a high, not low, stocking density. One replicated, site comparison study in the USA found that rotationally managed grasslands, including some rotationally grazed grasslands, which were last managed longer ago had a higher species richness of butterflies than more recently managed grasslands. POPULATION RESPONSE (6 STUDIES) Abundance (6 studies): Two of four replicated, controlled studies (including two randomized studies and one paired study) in France and the UK found that rotational cattle- and sheep-grazed grassland had a higher abundance of butterflies and burnet moths and caterpillars (along with other invertebrates) than continuously grazed grasslands. However, one of these studies only found this in the first of three years of management. Another of these studies found that rotationally sheep-grazed grassland had a similar abundance of butterflies and burnet moths to continuously grazed grassland. The other study found that rotational cattle-grazed pastures had a higher abundance of butterflies than constantly grazed pastures but only at a high, not low stocking density. One replicated, site comparison study in the USA found that the abundance of two species was higher, two species were lower and the other five species did not differ in rotationally cattle-grazed grasslands compared to continuously grazed or patch-burned grasslands. One replicated, site comparison study in the USA found that rotationally managed grasslands, including some rotationally grazed grasslands, which were last managed longer ago had a higher abundance of butterflies than more recently managed grasslands. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3965https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3965Sun, 14 Aug 2022 10:38:22 +0100