Collected Evidence: Collected Evidence: Reintroduce laboratory-reared bumblebee colonies to the wildSeven replicated trials have monitored the success of laboratory-reared colonies of bumblebees introduced to the environment. In four of the trials (three in the UK, one in Canada) colonies were left to develop until new queens were produced or the founding queen died. In two of these (both in the UK), the numbers of queens/colony were very low or zero. In two trials, good numbers of new queens were produced. Rates of social parasitism by cuckoo bees Bombus [Psithyrus] spp. in colonies released to the wild are variable. Two replicated trials in Canada and the UK found high rates (25-66% and 79% respectively). The UK trial showed that parasitism was reduced by placing colonies in landscapes with intermediate rather than very high nectar and pollen availability, late, rather than early in the season. Five other replicated trials reported no social parasites. We have not found evidence to compare rates of parasitism in artificial nest boxes with the rate in natural nests. Two replicated trials examined the effects of supplementary feeding for bumblebee colonies placed in the field. One, in Canada, found supplementary feeding improved the reproductive success of captive-reared colonies, but did not reduce their parasite load. The other trial, in the USA, found supplementary feeding did not increase colony productivity. One small scale trial in Norway showed that colonies of the buff-tailed bumblebee B. terrestris prefer to forage more than 100 m from their nest sites.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F52https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F52Thu, 20 May 2010 02:59:51 +0100Collected Evidence: Collected Evidence: Convert to organic farmingEvidence on the impact of organic farming on wild bees is equivocal. Three replicated trials in Europe or Canada have shown that the abundance of wild bees is higher under organic arable farming than under conventional farming. One of these showed that bee diversity is higher in organically farmed wheat fields and in mown fallow strips adjacent to them. Three replicated trials in Europe or the USA have found no significant difference in the numbers of bumblebees (two trials), bumblebee species (one trial), or wild bees visiting flowering crops (one trial) between conventional and organic arable farms.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F25https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F25Thu, 20 May 2010 07:02:08 +0100Collected Evidence: Collected Evidence: Exclude livestock from semi-natural habitat (including woodland) Seven studies (including four replicated controlled trials of which one also randomized, and a review) from Ireland, Poland and the UK looked at the effects of excluding livestock from semi-natural habitats. Three studies (including one replicated controlled and randomized study) from Ireland and the UK found that excluding livestock benefited plants and invertebrates. Three studies (one replicated controlled and one replicated paired sites comparison) from Ireland and the UK found that excluding grazing did not benefit plants or birds. Two studies (one replicated and controlled, one review) from Poland and the UK found that the impact of excluding grazing as a tool in habitat restoration was neutral or mixed.    Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F150https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F150Sat, 14 Jan 2012 15:15:55 +0000Collected Evidence: Collected Evidence: Provide or retain un-harvested buffer strips Four replicated studies from Canada and the USA  found that wider buffer strips retained a bird community more similar to that of uncut forest than narrower strips. Two replicated and controlled studies from the USA found that several forest-specialist species were absent from buffers up to 70 m wide. Two replicated and controlled studies from the USA found that richness was higher in buffers <100 m wide, compared to wider strips or forest. A replicated, controlled study in the USA (6) found that thinned buffer strips had lower abundances of forest species than unthinned strips, but higher abundances of early successional species. A replicated study from the USA (4) found that species richness was similar between 20–50 m buffers and original forest. A replicated study from the USA found that bird abundances were higher in 20–50 m wide buffer strips than in original forest. A replicated study in the USA found no differences in productivity of birds nests between buffer strips wider than 350 m, compared to those thinner than 250 m. Whilst a replicated, controlled study from the USA found that predation of artificial nests was significantly higher in buffer strips compared with continuous forest, but that there was no diffrerence between narrow and wide buffers. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F161https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F161Tue, 15 May 2012 14:59:57 +0100Collected Evidence: Collected Evidence: Create uncultivated margins around intensive arable or pasture fields for birds A replicated, controlled study from the USA found that three sparrow species found on uncultivated margins were not found on mown field edges. A replicated study from Canada found fewer species in uncultivated margins than in hedges or in trees planted as windbreaks. Three replicated studies from the USA and UK, one controlled, found that some birds were associated with uncultivated margins, or that birds were more abundant on margins than on other habitats. One study found that these effects were very weak. Four replicated studies (two of the same experiment) from the UK, two controlled, found that uncultivated margins contained similar numbers of birds in winter, or that several species studied did not show associations with margins. A replicated, controlled study from the UK found that yellowhammers Emberiza citrinella used uncultivated margins more than crops in early summer, but use fell in uncut margins in late summer. Cut margins however, were used more than other habitat types late in summer. A replicated study from the UK found high rates of survival for grey partridge Perdix perdix released in margins.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F190https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F190Sat, 16 Jun 2012 19:47:53 +0100Collected Evidence: Collected Evidence: Set longlines at night to reduce seabird bycatch Six out of eight studies from fisheries around the world found lower rates of seabird bycatch on longlines set at night, compared with during the day, or with previously collected data. However, effects seemed to depend on the species caught. Two studies found higher rates of bycatch on night-set longlines, due to high numbers of white-chinned petrels Procellaria aequinoctialis or northern fulmars Fulmarus glacialis being caught at night.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F283https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F283Tue, 24 Jul 2012 13:04:04 +0100Collected Evidence: Collected Evidence: Use prescribed burning on shrublands One controlled study from the USA, of eight captured, found that overall bird densities were similar between burned and unburned areas, whilst a replicated and controlled study found that species numbers and bird densities did not vary between areas burned in summer and those burned in winter. Three studies found that some species were more abundant on areas that were burned, compared to those managed differently, or not at all. Four studies found that the densities of individual species were similar or lower on burned areas compared to control areas or those under different management. A before-and-after study found that sage sparrows chose different nest sites before burning compared to after. A controlled study found no differences in greater sage grouse movement between burned and unburned areas.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F321https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F321Thu, 26 Jul 2012 15:10:30 +0100Collected Evidence: Collected Evidence: Employ grazing in non-grassland habitats One of eight studies, a replicated, controlled study on savannas in Kenya found more bird species on grazed site, compared with unmanaged sites. These differences were not present during drought years. A before-and-after study from the Netherlands found the number of species in a mixed habitat wetland site declined after the number of grazing animals increased. Three studies (two replicated) from a variety of habitats in Sweden, the Netherlands and Kenya found that the overall number of birds, or the densities of some species were higher in grazed than ungrazed sites, or increased after the introduction of grazing. The Kenyan study found differences were not present in drought years. Four studies from several habitats in Europe and Kenya found that some species were found at lower densities, or not found at all, on grazed sites compared to ungrazed sites or those under different management. Five studies from several habitats from across the world found no differences in the abundances or densities of some or all species between grazed sites and those that were ungrazed or under different management. Two replicated studies from the UK found that productivity of northern lapwing and grey partridge was lower in grazed sites compared to ungrazed. One study examined several interventions at the same time. A replicated study from the UK found that songbirds and invertebrate-eating species were more common on rough-grazed habitats than intensive pasture, but that crows were less so.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F350https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F350Sun, 29 Jul 2012 15:22:08 +0100Collected Evidence: Collected Evidence: Control predators not on islands for wildfowl Six out of seven studies, mostly from North America found higher reproductive success of ducks when mammalian predators were removed. A before-and-after study found higher survival of captive-bred brown teal Anas chlorotis following feral cat Felis catus control. One meta-analysis from the USA and Canada found that ducks on sites with mammalian predator removal did not have higher reproductive success and trends in reproductive success were no more positive than on sites without predator control.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F386https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F386Wed, 08 Aug 2012 16:53:51 +0100Collected Evidence: Collected Evidence: Clean birds following oil spills Three studies from South Africa and Australia found high survival of rehabilitated penguins and plovers or similar survival to un-oiled birds. However a large study from the USA and Canada found that rehabilitated common guillemots Uria aalge had significantly lower survival than untreated birds. Three studies from South Africa and Australia found that rehabilitated birds bred, with one finding that rehabilitated birds had similar breeding success to un-oiled birds. However, this study found that birds rehabilitated after a second spill were less likely to breed, whilst two other studies found that rehabilitated birds had lower success than un-oiled birds.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F448https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F448Thu, 23 Aug 2012 16:12:49 +0100Collected Evidence: Collected Evidence: Plant new hedges Two studies from France and the UK compared newly planted hedges with control areas. Both (including one replicated trial) found newly planted hedges had higher abundance, species richness or diversity of beetles or spiders than crop fields or field margins. The replicated study also found vascular plant species diversity and grass species richness were higher in newly planted hedges than recently established grass field margins. A review found newly established hedges supported more ground beetles than older hedges. A small-scale study from the UK found that local hawthorn plants exhibited better growth and were more stock proof than those of eight other provenances. A literature review found lower pest outbreaks in areas with new hedges. A replicated study in the UK found that the diversity of arthropods supported by newly planted hedges varied between seven different plant species An unreplicated site comparison study in Germany found that two out of 85 ground beetle species used newly planted hedges as stepping stones for dispersal. Results from the same study found that invertebrates that moved passively (attached to mammals and birds), such as snails, benefited most from the hedge-islands compared to actively moving ground beetles and harvestmen. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F538https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F538Tue, 11 Sep 2012 15:38:22 +0100Collected Evidence: Collected Evidence: Convert or revert arable land to permanent grassland All seven individual studies (including four replicated studies, of which two also controlled and a review) looking at the effects of reverting arable land to grassland found no clear benefit to wildlife. The studies monitored UK birds in winter and summer, wading birds in Denmark, grey partridges, brown hares in the UK, and plants in the Czech Republic. One of the studies, a controlled before-and-after study from the UK, showed that grey partridge numbers fell significantly following the reversion of arable fields to grassland.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F561https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F561Tue, 25 Sep 2012 12:33:31 +0100Collected Evidence: Collected Evidence: Release birds as adults or sub-adults, not juveniles Three replicated studies found that malleefowl Leipoa ocellata, houbara bustards Chlamydotis undulata macqueenii and cackling geese Branta hutchinsii released as sub-adults, not juveniles had higher survival rates. A replicated study from New Zealand found lower survival for black stilts Himantopus novaezelandiae released as sub-adults, compared with juveniles. Two replicated studies from Hawaii and Saudi Arabia found lower survival for Hawaiian geese Branta sandvicensis and bustards released as wing-clipped sub-adults, compared with birds released as juveniles. Three replicated studies found no differences in survival between ducks, vultures and ibises released at different ages, but a second study of the vulture release programme found that birds released when more than three years old had lower reproductive success than birds released at an earlier stage.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F636https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F636Sun, 14 Oct 2012 23:39:47 +0100Collected Evidence: Collected Evidence: Maintain traditional water meadows (includes management for breeding and/or wintering waders/waterfowl) Four studies from Belgium, Germany, the Netherlands and the UK (including two site comparisons of which one also replicated) found that maintaining traditional water meadows resulted in an increased population size or number of territories of northern lapwing, common redshank and black-tailed godwit and increased plant species richness. However one of these studies also found common snipe declined on all sites under management to maintain traditional water meadows, and another of the studies found that differences in numbers of birds were present before meadow bird management. Two studies (a replicated study and a review of European studies) found that managing traditional water meadows by grazing had mixed impacts on wildlife and that the productivity of northern lapwings was too low to sustain populations on three of the four water meadows managed for waders. A randomized, replicated, controlled trial in the Netherlands found that cutting in June maintained relatively stable vegetation and a review found mowing could be used to maintain water meadows but had variable effects on plant species richness. One replicated site comparison from the Netherlands found more birds bred on 12.5 ha plots with management for wading birds (in combination with per-clutch payments), however at the field scale there was no difference in bird abundance or species richness between conventionally managed fields and those managed for birds.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F696https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F696Fri, 07 Dec 2012 09:05:54 +0000Collected Evidence: Collected Evidence: Employ areas of semi-natural habitat for rough grazing (includes salt marsh, lowland heath, bog, fen) A series of site comparison studies from the UK found that areas of heathland that had been re-seeded with grass to improve livestock grazing were avoided by nesting whimbrels but were the main early spring feeding areas for them. There was no difference in whimbrel chick survival between areas of heathland re-seeded with grass and those that had not. Two replicated studies from the UK found higher butterfly abundance and species richness and a higher frequency of occurrence of songbirds and invertebrate-feeding birds on areas of grazed semi-natural upland grassland than grazed improved pasture. However members of the crow family showed the opposite trend. A review found excluding cattle from fenland reduced the number of plant species, and that low-medium grazing levels could have positive effects on fenland biodiversity but may need to be accompanied by additional management such as mowing. One study from the UK found northern lapwing nest survival and clutch size were greater on ungrazed than grazed marshes. A replicated site comparison from the UK found the proportion of young grey partridges was negatively associated with rough grazing (in combination with several other interventions). Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F697https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F697Fri, 07 Dec 2012 15:57:06 +0000Collected Evidence: Collected Evidence: Use mowing techniques to reduce mortality Eight studies investigated the effects of different mowing techniques on wildlife. Seven studies (including four replicated trials of which one randomized, and one controlled and three reviews) from Germany, Ireland, Switzerland and the UK found that using specific mowing techniques can reduce mortality or injury in birds, mammals, amphibians or invertebrates. A review found the UK corncrake population increased around the same period that Corncrake Friendly Mowing schemes were introduced. One replicated trial found that changing the mowing pattern reduced the number of corncrake chicks killed. Sixty-eight percent of chicks escaped mowing when fields were mown from the centre outwards, compared to 45% during conventional mowing from the field edge inwards. Six studies looked at the effects of using different mowing machinery. Two studies (one review, one randomized, replicated trial) found bar mowers and one report found double chop mowers caused less damage or lower mortality among amphibians and/or invertebrates than other types of mowing machinery. A review found evidence that twice as many small mammals were killed by rotary disc mowers with conditioners compared to double blade mowers. Two studies found that using a mechanical processor or conditioner killed or injured more invertebrates than without a conditioner, however one replicated controlled study found mower-conditioners resulted in higher Eurasian skylark nest survival than using a tedder. A review of studies found that skylark chick survival was four times higher when wider mowing machinery was used, whilst a replicated controlled trial found skylark nest survival was highest when swather mowers and forage harvesters were used.    Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F698https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F698Sun, 09 Dec 2012 10:30:37 +0000Collected Evidence: Collected Evidence: Use alley croppingParasitism, infection and predation: Two of four studies from Kenya and the USA (including three randomised, replicated, controlled trials) found that effects of alley cropping on parasitism varied between study sites, sampling dates, pest life stages or the width of crop alleys. Two studies found no effect on parasitism. One study found mixed effects on fungal infections in pests and one study found lower egg predation. Natural enemies: One randomised, replicated, controlled study from Kenya found more wasps and spiders but fewer ladybirds. Some natural enemy groups were affected by the types of trees used in hedges. Pests and crop damage: Two of four replicated, controlled studies (two also randomised) from Kenya, the Philippines and the UK found more pests in alley cropped plots. One study found fewer pests and one study found effects varied with pest group and between years. One study found more pest damage to crops but another study found no effect. Weeds: One randomised, replicated, controlled study from the Philippines found mixed effects on weeds, with more grasses in alley cropped than conventional fields under some soil conditions. Yield: One controlled study from the USA found lower yield and one study from the Philippines reported similar or lower yields. Costs and profit: One study from the USA found lower costs but also lower profit in alley cropped plots. Crops studied were alfalfa, barley, cowpea, maize, pea, rice and wheat.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F718https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F718Thu, 30 May 2013 10:53:35 +0100Collected Evidence: Collected Evidence: Leave part of the crop or pasture unharvested or uncutNatural enemies: We found eight studies from Australia, Germany, Hungary, New Zealand, Switzerland and the USA that tested leaving part of the crop or pasture unharvested or unmown. Three (including one replicated, controlled trial) found an increase in abundance of predatory insects or spiders in the crop field or pasture that was partly uncut, while four (including three replicated, controlled trials) found more predators in the unharvested or unmown area itself. Two studies (one replicated and controlled) found that the ratio of predators to pests was higher in partially cut plots and one replicated, controlled study found the same result in the uncut area. Two replicated, controlled studies found differing effects between species or groups of natural enemies. Predation and parasitism: One replicated, controlled study from Australia found an increase in predation and parasitism rates of pest eggs in unharvested strips. Pests: Two studies (including one replicated, controlled study) found a decrease in pest numbers in partially cut plots, one of them only for one species out of two. Two studies (one replicated, the other controlled) found an increase in pest numbers in partially cut plots, and two studies (including one replicated, controlled study) found more pests in uncut areas. Crops studied were alfalfa and meadow pasture.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F725https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F725Thu, 30 May 2013 13:16:14 +0100Collected Evidence: Collected Evidence: Use taste-aversion to reduce predation of livestock by mammals to deter human-wildlife conflict Nine studies evaluated the effects of using taste-aversion to reduce predation of livestock by mammals to deter human-wildlife conflict. Six studies were in the USA, two were in Canada and one was at an unnamed location. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (9 STUDIES) Human-wildlife conflict (9 studies): Three of seven replicated studies (including three controlled studies), in the USA, Canada and at an unnamed location, found that coyotes killed fewer sheep, rabbits or turkeys after taste-aversion treatment. The other four studies found that taste-aversion treatment did not reduce killing by coyotes of chickens, sheep or rabbits. A replicated, before-and-after study in the USA found that taste-aversion treatment reduced egg predation by mammalian predators whilst a replicated, controlled, paired sites study in the USA found no such effect. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2429https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2429Mon, 01 Jun 2020 15:38:40 +0100Collected Evidence: Collected Evidence: Attach an electropositive deterrent to fishing gear Nine studies examined the effect of attaching an electropositive deterrent to fishing gear on marine fish populations. Three studies were in the Atlantic Ocean (USA, Canada, Bahamas). One study was in each of the Gulf of Alaska (USA), the South Pacific Ocean (Australia) and the Tasman Sea (Australia). One study was a global systematic review and two studies were in laboratory facilities (USA).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (4 STUDIES) Behaviour change (4 studies): Three of four replicated studies (one paired and controlled, one randomized and controlled, one randomized, and one controlled) in the Atlantic Ocean, Tasman Sea, and in laboratory conditions, found that the presence of potentially deterrent materials attached near the bait reduced the frequency of feeding attempts and bait consumption of spiny dogfish, great hammerhead and draughtboard sharks compared to the absence of deterrent materials. The other study found that a potentially deterrent material did not reduce bait consumption by bonnethead and young lemon sharks compared to non-deterrents. One of the studies also found that the bait consumption behaviour of commercially valuable Pacific halibut was unaffected by deterrent materials. OTHER (5 STUDIES) Reduction of unwanted catch (5 studies): Two of four replicated, controlled studies (one randomized) in the Gulf of Alaska, the Pacific Ocean and the Atlantic Ocean found that fishing gear (longlines and traps) fitted with electropositive deterrent materials caught fewer unwanted spiny dogfish, longnose skate, sharks and rays, and fewer undersized halibut, compared to standard fishing gear or gears with non-deterrent materials. The other two studies, and a global systematic review found that electropositive deterrents on fishing gear resulted in similar catches of unwanted spiny dogfish, sharks (total catch), blue shark and sharks and rays (total catch), compared to gear with no deterrents. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2696https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2696Thu, 03 Dec 2020 12:05:21 +0000Collected Evidence: Collected Evidence: Use an alternative commercial fishing method Nine studies examined the effects of using an alternative commercial fishing method on marine fish populations. One study was in each of the Arafura Sea (Australia), the Greenland and Norwegian Seas (Norway), the Norwegian Sea (Norway), the Atlantic Ocean (Portugal), the Mediterranean Sea (Italy), the Gulf of Maine (USA), the Coral Sea (Australia), the Tyrrhenian Sea (Italy) and the Kattegat and Skagerrak (Sweden).  COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (9 STUDIES) Reduction of unwanted catch (9 studies): Seven of nine replicated studies (two controlled, one randomized, controlled, one paired, controlled) in the Arafura Sea, Greenland/Norwegian Sea, Norwegian Sea, Atlantic Ocean, Mediterranean Sea, Gulf of Maine, Coral Sea, Tyrrhenian Sea and Kattegat and Skagerrak found that using an alternative method of fishing caught fewer discarded fish species and reduced the catches of unwanted (discarded or non-commercial species) fish overall, and of immature halibut, haddock, Atlantic cod, bluefin tuna and over half of the individual fish species. One study found that an alternative fishing method caught larger (and more likely to be mature) unwanted hammerhead sharks. The other study found that sizes of striped sea bream, annular sea bream and red mullet were similar in catches between gear types. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2730https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2730Wed, 27 Jan 2021 17:06:17 +0000Collected Evidence: Collected Evidence: Introduce an overall catch limit (quota cap or total allowable catch) by fishery or fleet Nine studies examined the effects of introducing overall catch limits by fishery or fleet on marine fish populations. Three studies were worldwide, two studies were in the South Atlantic Ocean (Namibia/South Africa), two studies were in the North Sea (Northern Europe), and one study was in each of the North Sea and Atlantic Ocean (Scotland) and the North Atlantic Ocean (Canada).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (6 STUDIES) Abundance (5 studies): Four before-and-after studies (two replicated) in the South Atlantic Ocean, the North Atlantic Ocean and the North Sea reported that following the introduction of overall catch limits for fish there was a higher abundance or biomass of hakes, Atlantic herring and Atlantic halibut, compared to before. One replicated, controlled study of fish stocks worldwide found that overfished stocks of tunas and billfishes had faster increases of biomass when managed using overall catch limits, compared to stocks with other types of control or no management. Reproductive success (1 study): A global review reported that after overall catch limits and minimum landing size were introduced there was strong recruitment of broadbill swordfish for one key stock, while recruitment for four other stocks could not be assessed due to limited data. Survival (2 studies): One before-and-after study and one replicated, controlled study in the North Atlantic Ocean and worldwide found that for fish species with overall catch limits there was a decrease or lower fishing mortality, compared either to before implementation or to stocks without catch limits and those with other controls. BEHAVIOUR (0 STUDIES) OTHER (3 STUDIES) Reduction of unwanted catch (1 study): One replicated, before-and-after study in the North Sea and North Atlantic Ocean found that overall catch limits did not reduce unwanted megrim catch despite a reduction in discards, however this was due to retention of more small but legal-sized megrim, previously discarded. Reduction of fishing effort (1 study): One replicated, before-and-after study in the North Sea found that when annual total allowable catch limits were changed (increased or decreased), half of the otter trawl fleet had corresponding changes in fishing effort (increased or decreased), but there were no changes for the beam trawl fleet. Stock status (1 study): One global systematic review found that in terms of reaching biomass-based management targets fisheries with fleet-wide catch quotas were no different to fisheries managed either by catch shares or effort controls. However, along with catch share fisheries, fewer catch quota stocks were over-exploited than those with effort controls. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3811https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3811Thu, 26 May 2022 15:07:14 +0100Collected Evidence: Collected Evidence: Remove or control non-native or problematic plants Nine studies evaluated the effects on butterflies and moths of removing or controlling non-native or problematic plants. Five studies were in the USA and one was in each of Poland, South Africa, Australia and Mauritius. COMMUNITY RESPONSE (2 STUDIES) Richness/diversity (2 studies): Two studies (including one replicated, paired, site comparison study and one controlled study) in Mauritius and the USA found that sites where invasive plants were removed by weeding or cutting and applying herbicide (in one case along with fencing to exclude non-native pigs and deer) had a greater species richness of butterflies than untreated sites. One of these studies also found that sites where Chinese privet was removed had a similar species richness of butterflies to sites which had not been invaded. POPULATION RESPONSE (8 STUDIES) Abundance (7 studies): Four of six studies (including three controlled studies, one before-and-after study and two site comparison studies) in Poland, South Africa, the USA and Mauritius found that sites where trees and shrubs were removed or invasive plants were cut to a similar height to native plants, or removed by weeding or cutting and applying herbicide (in one case along with fencing to exclude non-native pigs and deer), had a greater abundance of Apollo butterflies, a higher density of Fender’s blue eggs, or higher total abundance of butterflies, compared to before removal or untreated sites. One of these studies also found that sites where Chinese privet was removed had a similar abundance of butterflies to sites which had not been invaded. The fifth study found that in plots where herbicide was applied to control invasive grasses, the abundance of Columbia silvery blue eggs and caterpillars was similar to unsprayed plots. The sixth study found that, after prescribed burning, an area where bracken fern was also removed had fewer Brenton blue butterfly eggs than an area without removal. One study in Australia reported that a population of purple copper butterfly caterpillars translocated to an area where invasive plants had been removed, along with host plant translocation and other habitat management, increased in number compared to at the time of translocation. Survival (2 studies): One replicated, randomized, paired, controlled study in the USA found that in plots where herbicide was applied to control invasive grasses, the survival of Columbia silvery blue eggs and caterpillars was similar to unsprayed plots. One replicated, randomized, controlled study in the USA found that one herbicide commonly used to control invasive grasses reduced the survival of snowberry checkerspot caterpillars, but two other herbicides did not affect the survival of snowberry checkerspot, Edith’s checkerspot or Baltimore checkerspot caterpillars. BEHAVIOUR (4 STUDIES) Use (3 studies): Two of three randomized, controlled studies (including two replicated, paired studies and one before-and-after study) in the USA found that sites where invasive oat-grass was cut to a similar height to native plants, or where Eastern white pine was removed, were used more by Fender’s blue and frosted elfin butterflies than untreated sites. The third study found that habitat use by Columbia silvery blue butterflies was similar in plots where herbicide was applied to control invasive grasses and in unsprayed plots. Behaviour change (1 study): One before-and-after study in Poland found that removal of trees and shrubs, in addition to the release of captive bred adults and pupae, allowed adults from two previously separated populations of Apollo butterflies to mix. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3890https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3890Thu, 28 Jul 2022 15:02:05 +0100Collected Evidence: Collected Evidence: Employ areas of semi-natural habitat for rough grazing (includes salt marsh, lowland heath, bog, fen) Nine studies evaluated the effects on butterflies and moths of employing areas of semi-natural habitat for rough grazing. Three studies were in Germany, two were in each of the UK and the Netherlands, and one was in each of China and Canada. COMMUNITY RESPONSE (5 STUDIES) Community composition (1 study): One controlled study in Germany found that after 16–18 years of sheep grazing, lightly grazed and ungrazed saltmarshes had a different community of micro-moths to heavily grazed saltmarsh. Richness/diversity (4 studies): Two replicated, site comparison studies (including one paired study) in the Netherlands and Canada found that calcareous coastal dunes and shrubsteppe managed by cattle or pony grazing for 4–13 or 6–40 years had a similar species richness of butterflies (in one case combined with all pollinators) to unmanaged land or dunes managed by cutting. One controlled study in Germany found that saltmarsh managed by light sheep grazing for 15–18 years had a greater species richness of micro-moths than moderately or heavily grazed marsh, but a similar species richness to ungrazed marsh. One replicated, site comparison study in the UK found that upland rough grassland managed by livestock grazing had a greater species richness of butterflies than permanently or partially grazed improved grassland. POPULATION RESPONSE (7 STUDIES) Abundance (7 studies): Two of four studies (including two controlled studies, one before-and-after study and two site comparison studies) in the UK, the Netherlands, China and Canada found that fenland and calcareous coastal dunes managed by cattle or pony grazing for two or 4–13 years had a higher abundance of large copper eggs and four of 13 species of butterfly than unmanaged land or dunes managed by cutting. One study found that meadow steppe grazed by cattle, goats or sheep for 1–5 years had a lower abundance of butterflies and moths than ungrazed steppe. The fourth study found that shrubsteppe grazed by cattle for 6–40 years had a similar abundance of pollinators (including butterflies) to ungrazed shrubsteppe. Two controlled studies (including one replicated, paired study) in Germany found that saltmarsh managed by light sheep grazing for 15–18 or 19–22 years had a higher total abundance of micro-moths, and of two out of seven caterpillars, than moderately or heavily grazed, or ungrazed marsh. However, one of these studies also reported that the abundance of four other caterpillars was lower in lightly or heavily grazed marsh than in ungrazed marsh. One replicated, site comparison study in the UK found that upland rough grassland managed by livestock grazing had a higher abundance of butterflies than permanently or partially grazed improved grassland. BEHAVIOUR (2 STUDIES) Use (2 studies): Two replicated, site comparison studies in the Netherlands found that calcareous coastal dunes and heathland managed by cattle or pony, or year-round horse and sheep, grazing for five or 4–13 years were more likely to be occupied by brown argus and Alcon large blue than unmanaged land or habitat managed by cutting, grazing and sod cutting, or summer-only cattle and sheep grazing. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3944https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3944Sat, 13 Aug 2022 14:58:18 +0100Collected Evidence: Collected Evidence: Provide or retain set‐aside areas in farmland Nine studies evaluated the effects of providing or retaining set-aside areas in farmland on butterflies and moths. Three studies were in the UK, and one was in each of Germany, Ireland, Switzerland, Hungary, Finland and the USA. COMMUNITY RESPONSE (5 STUDIES) Community composition (1 study): One replicated, site comparison study in Germany found that butterfly communities in older set-aside fields included species which were less migratory, spent longer as caterpillars, and had fewer generations/year than species found in newer set-aside fields. Richness/diversity (5 studies): Three of four replicated studies (including one randomized, controlled study and three site comparison studies) in Germany, Ireland, Hungary and Finland found that sown or naturally regenerating set-aside had a greater species richness of butterflies and day-flying moths than cereal fields or pasture, especially when the set-aside was sown with less competitive grasses. One of these studies found a higher species richness of butterflies and day-flying moths in second-year set-aside than in first-year set-aside, but another found no difference in butterfly species richness between 1–3-year-old set-aside. The other study found that set-aside fields had a similar species richness of butterflies and moths to arable and pasture fields. One replicated, site comparison study in the USA found that set-aside fields had a similar species richness of butterflies to native prairies. POPULATION RESPONSE (8 STUDIES) Abundance (8 studies): Two of five replicated studies (including one randomized, controlled study and four site comparison studies) in the UK, Ireland, Hungary and Finland found that the abundance of butterflies and day-flying moths in sown set-aside was higher than in cereal fields, especially when the set-aside was sown with less competitive grasses. One of these studies found a higher abundance of butterflies and day-flying moths in second-year set-aside than in first-year set-aside, but another found no difference in butterfly abundance between 1–3-year-old set-aside. The other three studies found that fallow and stubble set-aside had a similar abundance of adult butterflies and butterfly and moth caterpillars to arable fields and pasture. Two site comparison studies (including one replicated study) in the UK and Switzerland found that set-aside fields had a similar abundance of butterfly and moth adults and caterpillars to uncultivated field boundaries and extensively farmed land. One replicated, site comparison study in the USA found that set-aside fields had a similar abundance of butterflies to native prairies in their first year, but a lower abundance of butterflies thereafter. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3980https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3980Thu, 18 Aug 2022 10:53:43 +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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