Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Leave unharvested cereal headlands in arable fields We have captured no evidence for the effects on farmland wildlife of leaving unharvested cereal headlands. '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%2F646https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F646Wed, 17 Oct 2012 17:14:41 +0100Collected Evidence: Collected Evidence: Maintain upland heath/moorland Of 15 individual studies from the UK, eight (including three replicated, controlled trials, of which one also randomized) found that appropriate management can help to maintain the conservation value of upland heath or moorland. Of these eight studies, four tested the effectiveness of excluding or reducing grazing. Impacts included increases in the abundance of Scottish primrose and other broadleaved plant species, heather cover and numbers of true bugs, biomass of arthropods associated with the bird diet, number and diversity of moths and benefits to black grouse. Among other treatments, repeated cutting and grazing by goats were found to be effective in controlling the dominance of certain grass species. A review found management under the Environmentally Sensitive Areas scheme had broadly positive effects on moorland birds and a reduction in grazing benefited most bird species and increased heath vegetation and heather cover. A replicated before-and-after study found that moorland management under the Environmentally Sensitive Area scheme maintained the number of plant species in two out of three areas. Three studies (including one before-and-after trial) reported mixed results for invertebrates or birds, where management to maintain upland heath or moorland benefited some but not all species or where the effect depended on the vegetation type. Treatments tested included reducing grazing intensity and grouse moor management (burning and predator control). Four studies (including one controlled site comparison and two reviews) found that reducing the intensity of livestock grazing reduced the abundance of soil organisms including invertebrates, bacteria or fungi. A randomized, replicated before-and-after study found that heather cover declined over nine years on a moorland site managed under the Environmentally Sensitive Areas scheme in which grazing intensity had increased. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F647https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F647Wed, 17 Oct 2012 17:51:16 +0100Collected Evidence: Collected Evidence: Provide supplementary food for birds or mammals A total of 18 individual studies investigated the effects of providing supplementary food. Nine studies from France, Sweden and the UK (six replicated studies, of which five controlled and one also randomized and paired) found that the provision of supplementary food increased farmland bird abundance, breeding population size, density, body mass, hatching, nestling growth and fledging rates, increased overwinter survival of a declining house sparrow population and that fed male hen harriers bred with more females than control birds. Two studies did not separate the effects of several other interventions carried out on the same study site. Four studies from the UK and Finland (three replicated studies, of which one controlled and one randomized) found that farmland songbirds and field voles (field voles on unmown plots only) used supplementary food when provided, including the majority of targeted species such as tree sparrow, yellowhammer and corn bunting. Five replicated studies from the UK (of which two also controlled) found that the provision of supplementary food had no clear effect on farmland bird breeding abundance, European turtle dove reproductive success, territory size or territory density, overwinter survival of three stable house sparrow populations, tree sparrow nest box use, or the abundance of weed seeds on the soil surface. One replicated, controlled study from Sweden found no effect of supplementary food provision on common starling clutch size or nestling weight, and lower fledging rates in nests which received supplementary food compared to nests without supplementary food in one year. Four studies from the UK (two replicated of which one was also randomized and controlled) found that the use of supplementary food by farmland birds varied between species and region, depended upon the time of year and proximity to other feeding stations and natural feeding areas. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F648https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F648Thu, 18 Oct 2012 14:20:34 +0100Collected Evidence: Collected Evidence: Maintain wood pasture and parkland A randomized, replicated, controlled trial in Sweden found that annual mowing maintained the highest number of plant species on wood pasture. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F649https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F649Fri, 19 Oct 2012 13:59:40 +0100Collected Evidence: Collected Evidence: Restore or create upland heath/moorland A small unreplicated trial of heather moorland restoration in northern England found that mowing and flail cutting along with grazing could be used to control the dominance of purple moor grass. The same study found moorland restoration benefited one bird species, with one or two pairs of northern lapwing found to breed in the area of restored moorland, where none had bred prior to restoration. A review from the UK concluded that vegetation changes took place very slowly following the removal of grazing to restore upland grassland to heather moorland. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F650https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F650Tue, 23 Oct 2012 13:03:29 +0100Collected Evidence: Collected Evidence: Create beetle banks Fourteen reports from eight studies out of a total 24 reports from 12 individual studies (including eight replicated studies of which three controlled and four literature reviews) from Denmark and the UK found that beetle banks provide some benefits to farmland biodiversity. Sixteen reports from eight individual studies looked at invertebrates and beetle banks. Five reports from two replicated studies (of which one controlled) and a review found positive effects on invertebrate densities/numbers, distribution, or higher ground beetle density and species diversity in spring and summer but not winter. Six reports from three replicated studies (of which one randomized and controlled) found that invertebrate numbers varied between specific grass species sown on beetle banks. Two replicated studies (one paired and controlled) found that the effect of beetle banks varied between invertebrate groups or families. Five replicated studies (of which two controlled) found lower or no difference in invertebrate densities or numbers on beetle banks relative to other habitats. One review found lesser marsh grasshopper did not forage on two plant species commonly sown in beetle banks. Six studies looked at birds and beetle banks. Two reviews and one replicated controlled trial found positive effects on bird numbers (in combination with other farmland conservation measures) or evidence that birds used beetle banks. Two studies (one replicated site comparison) found mixed effects on birds. One replicated study found no farmland bird species were associated with beetle banks. One replicated, paired, controlled study and a review looked at the effects of beetle banks on plants and found either lower plant species richness on beetle banks in summer, or that grass margins including beetle banks were generally beneficial to plants but these effects were not pronounced on beetle banks. One controlled study and a review found beetle banks acted as nest sites for harvest mice. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F651https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F651Tue, 23 Oct 2012 16:24:44 +0100Collected Evidence: Collected Evidence: Leave headlands in fields unsprayed (conservation headlands) Twenty-two studies from 14 replicated, controlled experiments (of which two randomized) including two reviews, from a total of 32 studies from 20 experiments (of which 17 replicated, controlled) including three reviews from Finland, Germany, the Netherlands, Sweden and the UK that investigated species richness and diversity of farmland wildlife found that conservation headlands contained higher species richness or diversity of invertebrates or plants than other habitat types. Twelve studies (including a review) from ten replicated experiments (of which eight controlled and three controlled and randomized) found that some or all invertebrates or plants investigated did not have higher species richness or diversity on conservation headlands compared to other habitat types. This included both replicated, controlled studies investigating bee diversity. Two replicated studies from the UK found that unfertilized conservation headlands had more plant species than fertilized conservation headlands. Positive effects of conservation headlands on abundances or behaviours of some or all species investigated were found by 27 studies from 15 replicated experiments (of which 13 controlled) including five reviews out of a total of 36 studies from 20 experiments (17 replicated, controlled) including five reviews from Finland, Germany, the Netherlands, Sweden and the UK that investigated birds (some studies looked at number of visits), mammals (some studies looked at number of visits), invertebrates and plant abundance/cover. One review from the UK found a positive effect on grey partridge populations but did not separate the effects of several other interventions including conservation headlands. Nineteen studies from 13 replicated (12 controlled) experiments and a review from Finland, Germany, the Netherlands and the UK found that some or all species of birds, invertebrates or plants investigated were at similar, or lower, abundances on conservation headlands compared to other management. One review from the UK and a study in Germany found conservation headlands had a positive effect on plants and some, but not all invertebrates, or rare arable weeds but did not specify how. All eight studies from the UK and Sweden that investigated species’ productivity, from three replicated (two controlled) experiments including two reviews found that grey partridge productivity or survival was higher in conservation headlands (or in sites with conservation headlands), compared to other management. One replicated study from the UK found that conservation headlands did not increase the proportion of young grey partridges in the population. A before-and-after study from the UK found that some invertebrates in conservation headlands survived pesticide applications to neighbouring fields. A review found crop margins reduce the effects of spray drift on butterflies. A replicated study from Germany and a review found that conservation headlands appeared to prevent or reduce the establishment and spread of pernicious weeds. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F652https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F652Wed, 31 Oct 2012 09:36:44 +0000Collected Evidence: Collected Evidence: Reduce chemical inputs in grassland management A total of 16 studies (including five reviews) investigated the effects of reducing inputs in permanent grasslands. Six studies from the Netherlands, Switzerland and the UK (including one review and four replicated studies of which one was also controlled and one a randomized and controlled before-and-after trial) found that stopping fertilizer inputs in permanent grassland resulted in an increase in plant species richness, reduced the rate of plant species loss and attracted a higher abundance or species richness of some or all invertebrates studied. One review from the Netherlands found that low fertilizer input grasslands favour common meadow bird species. One review found a study showing that densities of some invertebrates were higher in unfertilized plots compared with those receiving nitrogen inputs. Two replicated, controlled trials from the Czech Republic and the UK (one randomized) found that applying fertilizer to permanent grasslands reduced plant species richness or diversity and that the effects on plant communities were still apparent 16 years after the cessation of fertilizer application. Four studies from Ireland, the Netherlands and the UK (including two replicated trials of which one randomized and one controlled and a review) found that reducing fertilizer inputs on grassland had no clear or rapid effect on plant species richness. A review found no clear effect of reducing fertilizer inputs on the density of soil-dwelling invertebrates. One replicated study found that fertilizer treatment only affected seed production of a small number of meadow plants. One replicated study from the UK found lower invertebrate abundance on plots with reduced fertilizer inputs but the differences were not significant. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F694https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F694Sat, 01 Dec 2012 17:52:25 +0000Collected Evidence: Collected Evidence: Leave overwinter stubbles Eighteen studies (including four reviews and one systematic review) investigated the effects of overwinter stubbles on farmland wildlife. Thirteen studies from Finland, Switzerland and the UK (six replicated trials, including two site comparisons, four reviews and a systematic review) found evidence that leaving overwinter stubbles provides some benefits to plants, insects, spiders, mammals and farmland birds. These benefits include higher densities of farmland birds in winter, increased grey partridge productivity, and increased cirl bunting population size (in combination with several other conservation measures) and territory density. One replicated site comparison study from the UK found evidence that leaving overwinter stubbles had inconsistent or no effects on farmland bird numbers. Three studies found only certain bird species showed positive associations with overwinter stubbles. Two replicated studies (of which one also randomized and controlled) found that only Eurasian skylark or both Eurasian skylark and Eurasian linnet benefited, out of a total 23 and 12 farmland bird species tested respectively. One study found that only grey partridge and tree sparrow showed positive population responses to areas with overwinter stubbles. Two studies from the UK (one randomized, one replicated and controlled) found that different farmland bird species benefited from different stubble heights. One replicated site comparison found mixed effects between different stubble management options on seed-eating bird abundance. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F695https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F695Sun, 02 Dec 2012 12:01:18 +0000Collected 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: Control predatory mammals and birds (foxes, crows, stoats and weasels) A total of nine individual studies from France and the UK (including five replicated controlled studies and a systematic review) looked at the effects of removing predators on birds. Three studies found controlling predatory mammals or birds (sometimes alongside other interventions) increased the abundance or population size of some birds. One of these studies from the UK found numbers of nationally declining songbirds increased on a site where predators were controlled, but there was no overall difference in bird abundance, species richness or diversity between predator control and no-control sites. Five studies (two replicated and controlled, two before-and-after trials) from the UK found some evidence for increased productivity, nest or reproductive success or survival of birds following bird or mammal predator control (sometimes alongside other interventions). A randomized, replicated, controlled study found hen harrier breeding success was no different between areas with and without hooded crow removal. A global systematic review including evidence from European farmland found that reproductive success of birds increased with predator removal. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F699https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F699Thu, 20 Dec 2012 13:08:22 +0000Collected Evidence: Collected Evidence: Pay farmers to cover the cost of conservation measures (as in agri-environment schemes) Twenty-six studies from four European countries (including one UK systematic review and three European reviews) looked at the effects of agri-environment schemes on birds. Twenty-four studies (including one systematic review, six site comparisons and nine reviews) found increases in population size, density or more favourable population trends of some or all birds studied on sites with agri-environment schemes compared to non-scheme sites (some of these differences were seasonal). Eleven studies (including one systematic review and four reviews) found negative or no effects. One UK study found higher numbers of some birds where higher tier management was in place, another UK study found no difference between Entry Level or Higher Level Stewardship Scheme fields. One study from the Netherlands found that not all agri-environment scheme agreements were sited in ideal locations for black-tailed godwit. Eleven studies from five European countries (including three replicated paired site comparisons and two reviews) looked at the effects of agri-environment schemes on plants. Seven studies (including three replicated paired site comparisons and one European review) found agri-environment schemes maintained or had little or no effect on plants, plant diversity or species richness. Three studies found increases in plant species richness in areas with agri-environment schemes, two found decreases. A replicated site comparison study from Estonia found higher flower abundance on farms with agri-environment schemes in two out of four areas. A review found Environmentally Sensitive Areas in England had contributed to halting the loss of semi-natural grassland habitats but were less effective at enhancing or restoring grassland biodiversity. Ten studies from three European countries (including two replicated paired site comparisons and a review) looked at the effects of agri-environment schemes on invertebrates. Six studies (including two replicated site comparisons) showed agri-environment schemes maintained or had little or no effect on some invertebrates in terms of diversity, abundance, species richness or bee colony growth. Five studies found increases in abundance or species richness of some invertebrates. A UK study found agri-environment scheme prescriptions had a local but not a landscape-scale effect on bee numbers. Four studies (including two replicated site comparisons and a review) from the UK looked at the effects of agri-environment schemes on mammals. One study found positive effects, three studies found mixed effects in different regions or for different species. Three of the studies above found higher numbers of wildlife on land before agri-environment schemes were introduced. However two studies collecting baseline data found no difference in the overall number of birds or earthworms and soil microorganisms between areas with and without agri-environment schemes. A review found two out of three agri-environment schemes in Europe benefited wildlife. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F700https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F700Fri, 21 Dec 2012 14:38:13 +0000Collected Evidence: Collected Evidence: Restore or create traditional orchards We have captured no evidence for the effects of restoring or creating traditional orchards on farmland wildlife. '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%2F701https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F701Mon, 07 Jan 2013 13:15:28 +0000Collected Evidence: Collected Evidence: Maintain species-rich, semi-natural grassland Of 22 studies (including eleven replicated trials, three reviews and a systematic review) from the Czech Republic, Finland, Germany, Russia, Slovenia, Switzerland and the UK, 13 identified management regimes that maintained species-rich grassland. Four of these studies were replicated, controlled trials (including two randomized). Nine studies (including two randomized, replicated before-and-after trials) from Switzerland and the UK examined the effectiveness of existing or historical agri-environment schemes: seven testing the effectiveness of the Environmentally Sensitive Areas scheme in England and two testing the effectiveness of the Ecological Compensation Areas scheme in Switzerland. All except one reported mixed results, with the schemes broadly maintaining plant species richness, but being less effective, for example, in enhancing species richness, preserving the highest quality sites, or overcoming the effects of past intensive management. One study found six Environmentally Sensitive Areas were of ‘outstanding’ significance for their lowland grassland, containing >40% of the English resource of a grassland type. A replicated site comparison study found that on average 86% of Swiss Ecological Compensation Area litter meadows were of ‘good ecological quality’ compared with only 20% of hay meadow Ecological Compensation Areas. Twelve studies (including a systematic review, six replicated trials of which two also controlled and randomized, and three reviews) from the Czech Republic, Finland, Germany, Slovenia, Switzerland and the UK tested the effects of management treatments on species richness or vegetation quality usually involving combinations of mowing, grazing or no fertilizer but some also tested the effectiveness of mulching or burning. All of these studies identified management treatments which benefited or maintained species richness or vegetation quality. One site comparison from Finland and northwest Russia found that butterfly species richness, diversity and total abundance did not differ significantly between mown meadows and grazed pastures and that grassland age and origin had a greater impact on butterfly communities than present management. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F702https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F702Mon, 28 Jan 2013 11:44:12 +0000Collected Evidence: Collected Evidence: Maintain traditional orchards Two replicated site comparisons from Germany and Switzerland found that, on average, 12% of traditional orchards in Swiss Ecological Compensation Areas were of ‘good ecological quality’, and traditional orchards under a German agri-environment scheme did not have more plant species than paired control sites. Traditional orchards in Ecological Compensation Areas appeared to offer little benefit to birds. A replicated, controlled site comparison study in Germany found that plant species richness was higher on mown orchards than grazed or abandoned ones, but numbers of species and brood cells of bees and wasps did not differ. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F703https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F703Tue, 29 Jan 2013 13:17:09 +0000Collected Evidence: Collected Evidence: Reduce grazing intensity on grassland (including seasonal removal of livestock) Of 27 individual studies (including 10 replicated, controlled trials, four reviews and one systematic review) from France, Germany, Ireland, the Netherlands and the UK, 15 (including three randomized, replicated, controlled trials) from four countries found benefits to birds, plants or invertebrates in response to reducing grazing intensity on permanent grassland (including seasonal removal of livestock). Of these 15 studies, six (including one randomized, replicated, controlled trial) found that reducing grazing intensity throughout the year increased the abundance and diversity of plants (Tallowin et al. 2005, Marriott et al. 2009), frequency of certain plant species, invertebrate diversity, usage by geese and the number of northern lapwing and common redshank. Six studies (including three replicated controlled trials of which two randomized) found that excluding or delaying summer grazing increased plant species diversity, invertebrate abundance and benefited breeding Eurasian skylark. A review found a study that showed that removing autumn grazing after a silage cut increased the winter abundance of seed-eating birds. A review and a replicated controlled study from the UK found that reduced grazing intensity or seasonal removal of livestock increased the number of invertebrates, plant seed heads and foraging skylark, and that some bird species preferred plots with seasonal removal of livestock. Three studies (including one randomized, replicated, controlled trial) from the Netherlands and the UK found no benefit to plants or invertebrates from reduced grazing intensity. One randomized, replicated controlled trial excluded grazing in autumn/winter and another study excluded grazing in the summer. A further study found that reducing grazing intensity throughout the year did not increase plant diversity. Nine studies from France, Germany and the UK reported mixed results for some or all species or wildlife groups considered (including one randomized, replicated, controlled trial and two reviews and a systematic review). Of these, eight studies found that reduced grazing intensity throughout the year benefited some species but not others, one found that the impact depended on the type of vegetation grazed, and one found benefits to bee and wasp abundance but not species richness. One study found that the response of birds to removal of summer grazing varied between functional groups and depended on time of year. A UK review found that reduced grazing benefited invertebrates, plants, rodents and some but not all birds. A systematic review of the effects of grazing intensity on meadow pasture concluded that intermediate levels of grazing are usually optimal for plants, invertebrates and birds but that trade-offs are likely to exist between the requirements of different taxa. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F704https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F704Tue, 29 Jan 2013 17:33:20 +0000Collected Evidence: Collected Evidence: Mark fencing to avoid bird mortality We have captured no evidence for the effects of marking fencing to avoid bird mortality on farmland wildlife. '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%2F706https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F706Mon, 11 Feb 2013 09:51:33 +0000