Collected Evidence: Collected Evidence: Provide grass strips at field margins for beesThree replicated controlled trials in the UK have monitored wild bees on uncropped grassy field margins. Evidence of the effects on bees is mixed. One trial showed that 6 m wide grassy field margins enhanced the abundance, but not diversity, of wild bees at the field boundary. One trial showed that 6 m wide grassy field margins enhanced the abundance and diversity of bumblebees within the margin. A third, smaller scale trial showed neither abundance nor diversity of bumblebees was higher on sown grassy margins than on cropped margins.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F14https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F14Thu, 20 May 2010 10:42:47 +0100Collected Evidence: Collected Evidence: Provide nest boxes for stingless beesOne replicated trial tested nest boxes placed in trees for the stingless bee Melipona quadrifasciata in Brazil and found no uptake.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F49https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F49Thu, 20 May 2010 11:16:43 +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: Provide medicated grit for grouse A controlled study in England found that red grouse had higher productivity in areas where medicated grit was provided. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F112https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F112Mon, 24 Oct 2011 22:12:09 +0100Collected Evidence: Collected Evidence: Provide nest boxes for birds Two studies (including one before and after study) from the Netherlands and the UK found that following the provision of nest boxes there was an increase in the number of Eurasian kestrel clutches and breeding tree sparrows. One replicated study from Switzerland found the number of Eurasian wryneck broods in nest boxes declined over five years whilst the number of Eurasian hoopoe broods increased. Eight studies from Finland, the Netherlands, Sweden, Switzerland and the UK (six were replicated) found that nest boxes in agricultural habitats were occupied by Eurasian kestrel, long-eared owl, common starling, tits Parus spp., tree sparrow, stock dove and jackdaw, and Eurasian wryneck and Eurasian hoopoe. Whilst two studies from the UK (a replicated, paired site study and a controlled study) found that carrion crows did not nest in artificial trees and tree sparrows showed a preference for nest boxes in wetland habitat, compared to those in farmland sites. Two replicated studies from Sweden found that nest success within boxes was related to the amount of pasture available and nest boxes positioned higher above the ground had higher occupancy, numbers of eggs and numbers of hatched young.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F155https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F155Sat, 14 Jan 2012 15:49:39 +0000Collected Evidence: Collected Evidence: Provide or retain set-aside areas in farmland We found 34 studies comparing use of set-aside areas with control farmed fields. Two were reviews, none were randomized, replicated, controlled trials. Of these, 20 (from Austria, Finland, Germany and the UK) showed benefits to or higher use by all wildlife groups considered. Twelve (from Finland, Germany, Ireland, Sweden and the UK) found some species or groups used set-aside more than crops, others did not. Two studies (all from the UK) found no effect, one found an adverse effect of set-aside. Three of the studies, all looking at skylarks, went beyond counting animal or plant numbers and measured reproductive success. Two from the UK found higher nest survival or productivity on set-aside than control fields. One from the UK found lower nest survival on set-aside. Fifteen studies (from Belgium, Germany, Sweden and the UK) monitored wildlife on set-aside fields, or in landscapes with set-aside, without directly comparing with control fields or landscapes. Three looked at set-aside age and found more plants or insects on set-aside more than a year old. Two compared use of different non-crop habitats and found neither insects nor small mammals preferred set-aside. Two showed increased bird numbers on a landscape scale after set-aside was introduced, amongst other interventions. Eight looked at effects of set-aside management such as use of fertilizer and sowing or cutting regimes. A systematic review from the UK found significantly higher densities of farmland birds on fields removed from production and under set-aside designation than on conventionally farmed fields in both winter and summer. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F156https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F156Thu, 29 Mar 2012 19:03:54 +0100Collected Evidence: Collected Evidence: Provide or retain set-aside areas in farmland Three replicated studies and a review of five studies from Europe and North America examining species richness or diversity found that more species were found on set-aside than on crops. One found fewer species on set-aside than other agricultural habitats. All 21 studies, including a systematic review, 12 replicated experiments and two reviews, from Europe and North America that investigated population trends or habitat associations found that some species were found at higher densities or used set-aside more than other habitats, or were found on set-aside. Four studies (three replicated) from the UK found that some species were found at lower densities on set-aside compared to other habitats. Three of four replicated studies from the UK found that waders and Eurasian skylarks had higher productivities on set-aside, compared to other habitats. One study found that skylarks nesting on set-aside had lower productivity compared to those on cereal crops, and similar productivities to those on other crops. One replicated paired study from the UK found that rotational set-aside was used more than non-rotational set-aside, a replicated paired study found no differences between rotational and non-rotational set-aside. A review from Europe and North America found that naturally regenerated set-aside held more birds and more species than sown set-aside. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F175https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F175Sun, 27 May 2012 15:10:59 +0100Collected Evidence: Collected Evidence: Provide food for vultures to reduce mortality from diclofenacA before-and-after trial in Pakistan found that oriental white-backed vulture Gyps bengalensis mortality rates were significantly lower when supplementary food was provided, compared to when it was not.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F456https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F456Wed, 29 Aug 2012 14:30:48 +0100Collected Evidence: Collected Evidence: Provide nesting material for wild birds A replicated study in the UK found that songbirds used feathers provided at a very low rate and nest construction did not appear to be resource limited. A replicated, controlled study from Australia found that four species of egrets used supplementary nesting material provided, preferentially taking material from raised platforms over water compared to plots on dry land.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F501https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F501Tue, 04 Sep 2012 16:23:14 +0100Collected Evidence: Collected Evidence: Provide nesting habitat for birds that is safe from extreme weather A small from New Zealand found Chatham Island oystercatchers Haematopus chathamensis used raised nest platforms made from car tyres (designed to raise nests above the level of storm surges). The success of these nests is not reported. Two replicated, controlled studies from the USA found that the nesting success of terns and waders was no higher on specially raised areas of nesting substrate, compared to unraised areas, with one study finding that a similar proportion of nests were lost to flooding in raised and unraised areas.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F504https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F504Thu, 06 Sep 2012 13:55:55 +0100Collected Evidence: Collected Evidence: Provide legal protection of forests from development We found no evidence for the effects of providing legal protection of forests from development. '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%2F1169https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1169Thu, 19 May 2016 09:37:01 +0100Collected Evidence: Collected Evidence: Provide financial incentives not to graze We found no evidence for the effects of providing financial incentives not to graze on forests. '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%2F1177https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1177Thu, 19 May 2016 10:30:27 +0100Collected Evidence: Collected Evidence: Provide fuel efficient stoves We found no evidence for the effects of providing fuel efficient stoves on forests. '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%2F1183https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1183Thu, 19 May 2016 10:41:54 +0100Collected Evidence: Collected Evidence: Provide medicine to local communities to control killing of primates for medicinal purposes We found no evidence for the effects of providing medicine to local communities to control the killing of primates for medicinal purposes on primate populations. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1472https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1472Tue, 17 Oct 2017 14:33:00 +0100Collected Evidence: Collected Evidence: Provide monetary benefits to local communities for sustainably managing their forest and its wildlife (e.g. REDD, employment) One before-and-after study in Belize found that numbers of black howler monkeys increased by 138% over 13 years after local communities received monetary benefits, alongside other interventions. One before-and-after study in the Republic of Congo found that most central chimpanzees reintroduced to an area where local communities received monetary benefits, alongside other interventions, survived over five years. One before-and-after study in Rwanda, Uganda and the Democratic Republic of Congo found that numbers of mountain gorillas declined by 28% over 41 years despite the implementation of development projects in nearby communities, alongside other interventions. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1509https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1509Wed, 18 Oct 2017 15:15:52 +0100Collected Evidence: Collected Evidence: Provide non-monetary benefits to local communities for sustainably managing their forest and its wildlife (e.g. better education, infrastructure development) One before-and-after study in the Republic of Congo found that 70% of the central chimpanzees reintroduced to an area where local people were provided non-monetary benefits, alongside other interventions, survived over seven years. One before-and-after study in India found that numbers of hoolock gibbons increased by 66% over five years after providing local communities with alternative income, alongside other interventions. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1510https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1510Wed, 18 Oct 2017 15:39:00 +0100Collected Evidence: Collected Evidence: Provide new technologies to reduce pressure on wild biological resources We found no studies that evaluated the effects, on peatland vegetation, of providing new technologies (e.g. fuel-efficient stoves) to reduce pressure on wild biological resources. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1748https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1748Mon, 27 Nov 2017 21:29:05 +0000Collected Evidence: Collected Evidence: Provide live natural prey to captive mammals to foster hunting behaviour before release Three studies evaluated the effects of providing live natural prey to captive mammals to foster hunting behaviour before release. One study was in Spain, one was in the USA and one was in Botswana. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Survival (2 studies): Two studies in Spain and Botswana found that a rehabilitated Iberian lynx and wild-born but captive-reared orphaned cheetahs and leopards that were provided with live natural prey in captivity survived for between at least three months and 19 months after release. BEHAVIOUR (1 STUDY) Behaviour change (1 study): A controlled study in the USA found that captive-bred black-footed ferrets fed on live prairie dogs took longer to disperse after release but showed greater subsequent movements than did ferrets not fed with live prairie dogs. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2518https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2518Mon, 08 Jun 2020 09:14:03 +0100Collected Evidence: Collected Evidence: Provide more small artificial breeding sites rather than fewer large sites One study evaluated the effects on mammals of providing more small artificial breeding sites rather than fewer larger sites. This study was in Spain. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Abundance (1 study): A replicated, controlled study in Spain found that smaller artificial warrens supported higher rabbit densities than did larger artificial warrens. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2595https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2595Thu, 11 Jun 2020 14:54:25 +0100Collected Evidence: Collected Evidence: Provide food/salt lick to divert mammals from roads or railways Three studies evaluated the effects of providing food or salt licks to divert mammals from roads. One study was in the USA, one was in Norway and one was a review of studies from across North America and Europe. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Survival (2 studies): A replicated, controlled study in the USA found that intercept feeding reduced mule deer road deaths along two of three highways in one of two years. A replicated, site comparison study in Norway found that intercept feeding reduced moose collisions with trains. BEHAVIOUR (1 STUDY) Behaviour change (1 study): A review of feeding wild ungulates in North America, and Europe found that feeding diverted ungulates away from roads in one of three studies. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2617https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2617Fri, 12 Jun 2020 09:14:13 +0100Collected Evidence: Collected Evidence: Provide mammals with escape routes from canals Five studies evaluated the effects on mammals of providing mammals with escape routes from canals. Two studies were in Germany and one each was in the USA, the Netherlands and Argentina. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Survival (2 studies): One of two studies (one before-and-after), in Germany and the USA, found that ramps and ladders reduced mule deer drownings whilst the other study found that ramps and shallow-water inlets did not reduce mammal drownings. BEHAVIOUR (3 STUDIES) Use (3 studies): Three studies (one replicated) in Germany, the Netherlands and Argentina, found that ramps and other access or escape routes out of water were used by a range of medium-sized and large mammals species. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2638https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2638Fri, 12 Jun 2020 13:06:54 +0100Collected Evidence: Collected Evidence: Provide new technologies to reduce harvesting pressure on vegetationWe found no studies that evaluated the effects, on vegetation or human behaviour, of providing new technologies to reduce harvesting pressure on vegetation in marshes or swamps.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3014https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3014Wed, 31 Mar 2021 14:22:01 +0100Collected Evidence: Collected Evidence: Provide general protection for marshes or swamps Three studies evaluated the overall effects, on vegetation or human behaviour, of providing general protection for marshes or swamps. There was one study in each of Puerto Rico, China and Canada. VEGETATION COMMUNITY Overall extent (3 studies): Two studies in China and Canada reported that the area of wetlands (including habitats other than marshes or swamps) in their study regions declined over 10–29 years, despite general protection of wetlands. However, in China, the decline was slower than in a previous period without protection. One before-and-after study of mangrove forests in Puerto Rico reported that their area increased following legal protection. VEGETATION ABUNDANCE   VEGETATION STRUCTURE Overall structure (1 study): One before-and-after study in China reported degradation in wetland landscape structure over 29 years when wetlands were generally protected. However, the decline was slower than in a previous period when wetlands were not protected. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3385https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3385Mon, 12 Apr 2021 09:30:20 +0100Collected Evidence: Collected Evidence: Provide or maintain hedgerows on farmland One study evaluated the effects of providing or maintaining linear features on reptile populations. This study was in Madagascar. COMMUNITY RESPONSE (1 STUDY) Community composition (1 study): One site comparison study in Madagascar found that reptile communities in cultivated areas with hedges were more similar to those found in forests than were communities from cultivated areas without hedges. The study also found that more reptile species were found only areas with hedges than only in areas without hedges. POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3519https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3519Tue, 07 Dec 2021 14:42:00 +0000
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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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