Collected Evidence: Collected Evidence: Create uncultivated margins around intensive arable or pasture fields Thirty-nine studies (including 13 replicated controlled trials of which three also randomized and four reviews) from eight European countries compared wildlife on uncultivated margins with other margin options. Twenty-four found benefits to some wildlife groups (including 11 replicated controlled trials of which one also randomised, and four reviews). Nineteen studies (including one randomized, replicated, controlled trial) from Germany, Ireland, Lithuania, Norway, the Netherlands and the UK found uncultivated margins support more invertebrates (including bees) and/or higher plant diversity or species richness than conventionally managed field margins or other field margin options. One replicated, controlled study showed that uncultivated margins supported more small mammal species than meadows and farmed grasslands. Four studies (two replicated UK studies, two reviews) reported positive associations between birds and field margins including food provision. A review from the UK found grass margins (including naturally regenerated margins) benefited plants and some invertebrates. Fifteen studies (including one randomized, replicated, controlled trial) from Germany, the Netherlands, Norway and the UK found that invertebrate and/or plant species richness or abundance were lower in naturally regenerated than conventionally managed fields or sown margins. Six studies (including one randomized, replicated, controlled trial) from Belgium, Germany and the UK found uncultivated margins did not have more plant or invertebrate species or individuals than cropped or sown margins. A review found grass margins (including naturally regenerated margins) did not benefit ground beetles. Five studies (including three replicated controlled trials) from Ireland and the UK reported declines in plant species richness and invertebrate numbers in naturally regenerated margins over time. One replicated trial found that older naturally regenerated margins (6-years old) had more invertebrate predators (mainly spiders) than newly established (1-year old) naturally regenerated margins. Five studies (including one replicated, randomized trial) from the Netherlands and the UK found that cutting margins had a negative impact on invertebrates or no impact on plant species. One replicated controlled study found cut margins were used more frequently by yellowhammers when surrounding vegetation was >60 cm tall. Seven studies (including four replicated controlled trials and a review) from Ireland, the Netherlands, Norway and the UK reported increased abundance or biomass of weed species in naturally regenerated margins. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F63https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F63Tue, 04 Oct 2011 14:51:45 +0100Collected Evidence: Collected Evidence: Reduce management intensity on permanent grasslands (several interventions at once) A total of 32 individual studies from the Czech Republic, Germany, Ireland, the Netherlands, Switzerland and the UK looked at the effects on farmland wildlife of reducing management intensity on permanent grasslands. Twenty-two studies found benefits to some or all wildlife groups studied. Eleven studies (including four replicated site comparisons and three reviews) found reduced management intensity on permanent grassland benefited plants. Sixteen studies (including eight site comparisons of which four paired and three reviews) found benefits to some or all invertebrates. Five studies (including two replicated site comparisons, of which one paired, and a review) found positive effects on some or all birds. Twenty-one studies from six European countries found no clear effects of reducing management intensity on some or all plants, invertebrates or birds. Seven studies (including two replicated paired site comparisons and a review) found no clear effect on plants. Ten studies (including four site comparisons and one paired site comparison) found mixed or no effects on some or all invertebrates. Two studies (one review, one site comparison) found invertebrate communities on less intensively managed grasslands were distinct from those on intensively managed grasslands. Four studies (including three site comparisons, of which one paired and two replicated) found no clear effects on bird numbers or species richness. Five studies from four European countries found negative effects of reducing management intensity on plants, invertebrates or birds. Two studies (one review, one replicated trial) found some plant species were lost under extensive management. Two studies (one paired site comparison) found more invertebrates in grasslands with intensive management. One paired site comparison found fewer wading birds on grasslands with reduced management intensity than on conventionally managed grassland.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F69https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F69Mon, 24 Oct 2011 19:11:58 +0100Collected Evidence: Collected Evidence: Apply 'cross compliance' environmental standards linked to all subsidy payments We have captured no evidence for the effects of applying 'cross compliance' environmental standards for all subsidy payments 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%2F70https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F70Mon, 24 Oct 2011 20:59:15 +0100Collected Evidence: Collected Evidence: Implement food labelling schemes relating to biodiversity-friendly farming (organic, LEAF marque) We have captured no evidence for the effects of implementing food labelling schemes relating to biodiversity-friendly farming (organic, LEAF marque) 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%2F71https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F71Mon, 24 Oct 2011 21:01:42 +0100Collected Evidence: Collected Evidence: Reduce field size (or maintain small fields) We have captured no evidence for the effects of reducing field size (or maintaining small fields) 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%2F72https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F72Mon, 24 Oct 2011 21:03:24 +0100Collected Evidence: Collected Evidence: Manage stone-faced hedge banks to benefit wildlife We have captured no evidence for the effects of managing stone-faced hedge banks to benefit wildlife 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%2F73https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F73Mon, 24 Oct 2011 21:04:36 +0100Collected Evidence: Collected Evidence: Restore or maintain dry stone walls We have captured no evidence for the effects of restoring or maintaining dry stone walls 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%2F74https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F74Mon, 24 Oct 2011 21:05:33 +0100Collected Evidence: Collected Evidence: Protect in-field trees (includes management such as pollarding and surgery) We have captured no evidence for the effects of protecting in-field trees 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%2F75https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F75Mon, 24 Oct 2011 21:07:09 +0100Collected Evidence: Collected Evidence: Plant in-field trees (not farm woodland)We have captured no evidence for the effects of planting in-field trees 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%2F76https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F76Mon, 24 Oct 2011 21:08:23 +0100Collected Evidence: Collected Evidence: Maintain in-field elements such as field islands and rockpiles We have captured no evidence for the effects of maintaining in-field elements such as field islands and rockpiles, 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%2F77https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F77Mon, 24 Oct 2011 21:09:32 +0100Collected Evidence: Collected Evidence: Provide foraging perches (eg. for shrikes) We have captured no evidence for the effects of providing foraging perches (eg. for shrikes) 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%2F79https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F79Mon, 24 Oct 2011 21:12:45 +0100Collected Evidence: Collected Evidence: Provide nest boxes for bees (solitary bees or bumblebees) Ten studies (nine replicated trials and a review of studies) from Germany, Poland and the UK of solitary bee nest boxes all showed the nest boxes were readily used by bees. Two replicated studies found the local population size or number of emerging red mason bees increased when nest boxes were provided. One replicated trial in Germany showed that the number of occupied solitary bee nests almost doubled over three years with repeated nest box provision at a given site. Two replicated trials tested bumblebee nest boxes and both found very low uptake, 2% or less. Occupancy rates of solitary bee nest boxes, where reported (two replicated studies), were between 1 and 26% of available cavities. Five studies (four replicated trials and a review of studies) report the number of bee species found in the nest boxes – between 4.6 and 33 species. One replicated study from Germany found nest boxes should be placed 150-600 m from forage resources (Gathmann & Tscharntke 2002). A replicated study from Poland found the highest production of red mason bees per nest was from nesting materials of reed stems or wood. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F80https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F80Mon, 24 Oct 2011 21:15:42 +0100Collected Evidence: Collected Evidence: Release captive-bred individuals into the wild to restore or augment wild populations of pigeonsA single review of a captive-release programme in Mauritius found that that released pink pigeons Nesoenas mayeri had a first year survival of 36%.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F628https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F628Sun, 14 Oct 2012 22:54:33 +0100Collected Evidence: Collected Evidence: Release captive-bred individuals into the wild to restore or augment wild populations of parrots A before-and-after study from Venezuela found that the local population of yellow-shouldered amazons Amazona barbadensis increased significantly following the release of captive-bred birds, along with other interventions. A replicated study in Costa Rica and Peru found high survival and some breeding of scarlet macaw Ara macao after release. Three replicated studies in the USA, Dominican Republic and Puerto Rico found low survival in released birds (4–41% in the first year after release), although the Puerto Rican study also found that released birds bred successfully.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F629https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F629Sun, 14 Oct 2012 22:56:19 +0100Collected Evidence: Collected Evidence: Release captive-bred individuals into the wild to restore or augment wild populations of songbirds A before-and-after study in Mauritius describes the establishment of a population of Mauritius fody Foudia rubra following the release of captive-bred individuals. Four studies of three release programmes on Hawaii found high survival of all three species released (Hawaiian crows Corvus hawaiiensis and two thrushes: omao Myadestes obscurus and puaiohi M. palmeri), with the two thrushes successfully breeding. The authors in one note that many of the released puaiohi dispersed from the release site, meaning that repopulating specific areas may require multiple releases. A replicated, controlled study from the USA found that San Clemente loggerhead shrike Lanius ludovicianus mearnsi pairs with captive-bred females had lower reproductive success than pairs where both parents were wild-bred.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F630https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F630Sun, 14 Oct 2012 23:05:39 +0100Collected Evidence: Collected Evidence: Use appropriate populations to source released populations A replicated study from Sweden and a small study from France found that birds sourced from populations distant from where they were released were less successful than birds from the area. In Sweden, released white storks Ciconia ciconia from North Africa produced fewer than half the chicks as those that naturally re-colonised, whilst both studies found that storks and little bustards Tetrax tetrax were less likely to migrate than birds originating in the release area.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F631https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F631Sun, 14 Oct 2012 23:16:17 +0100Collected Evidence: Collected Evidence: Use holding pens at release sites Three replicated and one small study from three release programmes in Saudi Arabia, the USA and Canada found that released birds had higher survival or were more likely to pair up if kept at release sites in holding pens before release. A replicated study in the USA found lower survival for thick-billed parrots Rhynchopsitta pachyrhyncha released in holding pens, compared to birds released without preparation. A review of northern bald ibis Geronticus eremita conservation found that holding pens successfully prevented most birds from migrating (which resulted in 100% mortality), although some 200 birds ‘escaped’ over 25 years.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F632https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F632Sun, 14 Oct 2012 23:22:45 +0100Collected Evidence: Collected Evidence: Clip birds’ wings on release Two studies from Saudi Arabia and Hawaii found that bustards and geese had lower survival when released in temporary exclosures with clipped wings, compared to birds released with unclipped wings. A review of cackling goose Branta hutchinsii conservation found that wing-clipped or moulting wild adult geese proved a better strategy than releasing young geese. A review of northern bald ibis (waldrapp) Geronticus eremita conservation found no differences in survival between birds released with clipped and unclipped wings in Israel.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F633https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F633Sun, 14 Oct 2012 23:29:34 +0100Collected Evidence: Collected Evidence: Release birds in groupsA replicated study from New Zealand found that released black stilts Himantopus novaezelandiae were more likely to move long distances after release if they were released in larger groups.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F634https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F634Sun, 14 Oct 2012 23:34:47 +0100Collected Evidence: Collected Evidence: Release birds in ‘coveys’ A replicated study in Saudi Arabia found that houbara bustard Chlamydotis undulata macqueenii survival was low when chicks were released in coveys with flightless females. A review of cackling goose Branta hutchinsii conservation and a replicated study in England found that geese and grey partridge Perdix perdix releases were more  successful for birds released in coveys than for young birds released on their own or adults released in pairs.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F635https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F635Sun, 14 Oct 2012 23:35:50 +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: Use ‘anti-predator training’ to improve survival after release A review from Pakistan and a small trial from Saudi Arabia found that pheasants and bustards had higher survival after release, when given pre-release predator training, compared to birds without training, many of which were predated. The Saudi Arabian study found that introducing a model fox (as opposed to a live predator) to cages did not increase post-release survival. Introducing a live fox to the cage increased post-release survival more than other techniques used.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F637https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F637Sun, 14 Oct 2012 23:49:41 +0100Collected Evidence: Collected Evidence: Use ‘flying training’ before releaseA replicated study from the Dominican Republic found that captive-reared Hispaniolan parrots Amazona ventralis had higher initial survival if they were given pre-release predator training, although this difference was not present a year after release.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F638https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F638Sun, 14 Oct 2012 23:51:20 +0100Collected Evidence: Collected Evidence: Provide supplementary food after release Three studies from found that malleefowl Leipoa ocellata, Andean condors Vultur gryphus and pink pigeons Nesoenas mayeri used supplementary food when it was provided after release. A replicated, controlled study from Australia found that malleefowl had higher survival when supplied with supplementary food. A study in Peru found that supplementary food could be used to increase the foraging range of condors after release, or to guide them back to suitable feeding areas.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F639https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F639Sun, 14 Oct 2012 23:54:01 +0100Collected Evidence: Collected Evidence: Use microlites to help birds migrateA review of northern bald ibis Geronticus eremita conservation found that a group of birds followed a microlite from Austria to Italy but none made the return journey.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F640https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F640Sun, 14 Oct 2012 23:58:53 +0100
What Works 2021 cover

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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