Collected Evidence: Collected Evidence: Reduce tillageEvidence on whether reduced tillage or no tillage benefits ground-nesting bees is mixed. Two replicated trials on squash Cucurbita spp. farms in the USA had contrasting results. One showed no difference in the abundance of bees between tilled and untilled farms, the other found three times more squash bees Peponapis pruinosa on no-till farms than on conventional farms.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F11https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F11Thu, 20 May 2010 19:41:46 +0100Collected Evidence: Collected Evidence: Reduce tillage A total of 42 individual studies (including seven replicated, controlled and randomized studies and six reviews) from Belgium, Denmark, France, Germany, Hungary, Ireland, Lithuania, the Netherlands, Slovakia, Switzerland and the UK investigated the effects of reducing tillage on farmland wildlife. Thirty-four studies (of which 21 were replicated and controlled and seven also randomized, and five reviews) from nine European countries found some positive effects on earthworms, some invertebrates (other than earthworms), weeds or farmland birds, of reducing tillage compared to conventional management. Positive effects included increased biomass, species richness or abundance of earthworms, greater abundance of some invertebrates other than earthworms, increased numbers of some weeds and/or weed species, higher Eurasian skylark nest density, earlier laying date and shorter foraging distances on reduced tillage fields, and greater abundance of some birds - including Eurasian skylark, seed-eating songbirds and gamebirds in late winter on non-inversion or conservation tillage. A review found tillage had negative effects on invertebrate numbers and no-till systems had more invertebrate bird food resources. Twenty-six studies (of which 13 replicated and controlled and three also randomized, and five reviews) from nine European countries found reducing tillage had either negative, no effect or no consistent effects on abundance, biomass, or species richness of some invertebrates (other than earthworms), earthworm abundance, biomass, or species richness, number of different plant species found as seeds, number of some weed species, mammal abundance, some bird species, and one study found bird preferences for conservation tillage fields decreased over time. Two studies found that crop type affected the number of weeds under different tillage regimes. One small replicated trial in the UK compared bird numbers under two different forms of reduced tillage, and found more birds from species that make up the ‘Farmland Bird Index’ on broadcast than non-inversion tillage fields. Two studies looked at the long-term effects of reduced tillage on earthworms (after ten years). One study found higher earthworm biomass under reduced tillage, the other study found earthworm abundance was the same between conventional and reduced tillage plots. Three of the studies mentioned above did not distinguish between the effects of reducing tillage and reduced pesticide and/or fertilizer inputs.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F126https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F126Mon, 14 Nov 2011 18:00:22 +0000Collected Evidence: Collected Evidence: Reduce tillage Four replicated and controlled studies from North America and Canada and the UK and two literature reviews found that some or all bird groups had higher species richness or diversity on reduced-tillage fields, compared to conventional field in some areas. Two replicated and controlled studies from Canada and the UK and a review found that some measures of diversity were lower, or no different, on reduced-tillage fields, compared to conventional fields. Five replicated and controlled studies from the USA and Europe, a small study and two reviews all found that some bird species are found at higher densities on fields with reduced tillage than conventional fields. Five replicated and controlled studies from the USA, Canada and Europe, and a review found that some or all species were found at similar or lower densities on reduced-tillage fields compared to conventional fields, with one finding that preferences decreased over time (possibly due to extreme weather) and another finding that preferences were only found in spring. Two controlled studies (one replicated) and a review found evidence for higher productivity, nesting success or earlier laying on reduced tillage fields, compared to conventional fields. One controlled study found no evidence for greater success or larger chicks on reduced-tillage fields.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F211https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F211Mon, 16 Jul 2012 17:11:41 +0100Collected Evidence: Collected Evidence: Reduce visitor group size We found no intervention-based studies examining the effects of reducing visitor numbers on bird populations. However, a single, replicated study in forests in Spain in 2004 (Remacha et al. 2011) found that fewer birds, but not fewer species, were observed as visitor number increased. This effect was largely due to decreases in collared dove Streptopelia decaocto presence and serin Serinus serinus abundance. Remacha, C., Perez-Tris, J. & Antonio Delgado, J. (2011) Reducing visitors’ group size increases the number of birds during educational activities: Implications for management of nature-based recreation,Journal of Environmental Management, 92, 1564–1568. '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%2F312https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F312Wed, 25 Jul 2012 17:36:40 +0100Collected Evidence: Collected Evidence: Reduce tillage We found no evidence for the effects of reduced tillage on amphibian 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%2F789https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F789Thu, 22 Aug 2013 14:32:49 +0100Collected Evidence: Collected Evidence: Regulate water levels Two studies (including one replicated, site comparison study) in the UK found that habitat management that included maintaining pond water levels increased natterjack toad populations or maintained newt populations. One replicated, controlled study in Brazil found that keeping rice fields flooded after harvest changed amphibian species composition, but not numbers of species or abundance. One replicated, controlled study in the USA found that draining ponds, particularly in the summer, significantly increased abundance and numbers of amphibian species. One before-and-after study in the USA found that maintaining pond water levels enabled successful breeding by dusky gopher frogs.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F833https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F833Wed, 28 Aug 2013 15:19:57 +0100Collected Evidence: Collected Evidence: Regularly remove traps and snares around agricultural fields We found no evidence for the effects of regularly removing traps and snares around agricultural fields 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%2F1433https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1433Tue, 17 Oct 2017 10:17:41 +0100Collected Evidence: Collected Evidence: Regularly de-activate/remove ground snares One before-and-after study in the Democratic Republic of Congo and Rwanda found that mountain gorilla numbers increased over five years in an area that was patrolled for snares, alongside other interventions. One before-and-after study in the Democratic Republic of Congo, Rwanda and Uganda found that a mountain gorilla population declined in an area where snares were removed regularly, alongside other interventions. One before-and-after study in Ghana found that the number of snares declined in an area where they were regularly removed, alongside other interventions. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1475https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1475Tue, 17 Oct 2017 17:15:09 +0100Collected Evidence: Collected Evidence: Regularly and continuously provide supplementary food to primates Two studies in China and The Gambia found that after regularly providing supplementary food, along with other interventions, primate populations increased. Two studies in Thailand and Malaysia found that populations declined after regular provision of supplementary food, alongside other interventions. Three studies in Brazil, South Africa, and Indonesia found that the majority of primates survived after being regularly provided supplementary food, along with other interventions. One study in Liberia found that after regular provision of supplementary food, along with other interventions, the majority of introduced chimpanzees survived for at least one year. One controlled study in Madagascar found that after a year of regular food supplimentation, along with other interventions, introduced black-and-white ruffed lemurs showed different diets compared to a resident wild group of the same species. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1526https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1526Thu, 19 Oct 2017 09:53:52 +0100Collected Evidence: Collected Evidence: Regularly provide supplementary food to primates during resource scarce periods only One before-and-after study in the Republic of Congo found that the majority of chimpanzees survived for at least five years after supplementary feeding in resource scarce periods, alongside other interventions. One before-and-after study in Kenya found that wild olive baboons survived for at least 17 years after supplementary feeding in drought periods soon after translocation, alongside other interventions. One controlled study in Madagascar found that the diet of black-and-white ruffed lemurs was similar to that of wild individuals after supplementary feeding in resource scarce periods, alongside other interventions. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1527https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1527Thu, 19 Oct 2017 09:59:24 +0100Collected Evidence: Collected Evidence: Regularly disinfect clothes, boots etc. One controlled, before-and-after study in Rwanda, Uganda and Congo found that numbers of mountain gorillas increased by 168% over 41 years while being visited by researchers and tourists whose clothes were disinfected, alongside other interventions. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1547https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1547Thu, 19 Oct 2017 17:33:18 +0100Collected Evidence: Collected Evidence: Regularly play TV & radio announcements to raise primate conservation awareness One before-and-after study in the Republic of Congo found that most reintroduced central chimpanzees whose release was broadcasted by multiple media means, alongside other interventions, survived over five years post-reintroduction. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1569https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1569Fri, 20 Oct 2017 11:42:52 +0100Collected Evidence: Collected Evidence: Reduce water level of flooded peatlands We found no studies that evaluated the effects, on peatland vegetation, of reducing the water level in unnaturally flooded peatlands. ‘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%2F1757https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1757Mon, 27 Nov 2017 21:34:20 +0000Collected Evidence: Collected Evidence: Regularly clean bat boxes to increase occupancy We found no studies that evaluated the effects of regularly cleaning artificial bat roosts to increase occupancy on bat populations. ‘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%2F2038https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2038Wed, 05 Dec 2018 18:31:05 +0000Collected Evidence: Collected Evidence: Regulate the use, dosage and disposal of agrichemicals We found no studies that evaluated the effects of regulating the use, dosage and disposal of agrichemicals on subtidal benthic invertebrate populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2198https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2198Tue, 22 Oct 2019 13:09:55 +0100Collected Evidence: Collected Evidence: Reduce underwater noise (other than sonar) We found no studies that evaluated the effects of reducing underwater noise on subtidal benthic invertebrate populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2209https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2209Tue, 22 Oct 2019 13:20:54 +0100Collected Evidence: Collected Evidence: Refill disused borrow pits One study examined the effects of refilling disused borrow pits on subtidal benthic invertebrate populations. The study was in Barnegat Bay estuary (USA).   COMMUNITY RESPONSE (1 STUDY) Overall richness/diversity (1 study): One before-and-after, site comparison study in Barnegat Bay estuary found that overall invertebrate species richness and diversity increased at a disused borrow pit after being refilled with sediments but remained lower than at a natural non-dredged site. POPULATION RESPONSE (1 STUDY) Overall abundance (1 study): One before-and-after, site comparison study in Barnegat Bay estuary found that overall invertebrate abundance increased at a disused borrow pit after being refilled with sediments but remained lower than at a natural non-dredged site. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2251https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2251Wed, 23 Oct 2019 09:51:36 +0100Collected Evidence: Collected Evidence: Regulate farming to allow gradual regeneration of marshes or swampsWe found no studies that evaluated the effects, on marsh/swamp vegetation, of regulating farming to allow gradual habitat regeneration.   ‘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%2F2951https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2951Mon, 22 Mar 2021 13:40:41 +0000Collected Evidence: Collected Evidence: Reduce the slope of subtidal artificial structures We found no studies that evaluated the effects of reducing the slope of subtidal artificial structures on the biodiversity of those structures. This means we did not find any studies that directly evaluated this intervention during our literature searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3442https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3442Fri, 20 Aug 2021 10:09:55 +0100Collected Evidence: Collected Evidence: Reduce the slope of intertidal artificial structures Two studies examined the effects of reducing the slope of intertidal artificial structures on the biodiversity of those structures. The studies were in an estuary in southeast Australia. COMMUNITY RESPONSE (1 STUDY) Overall richness/diversity (1 study): One before-and-after study in Australia reported that reducing the slope of an intertidal artificial structure, along with creating rock pools, increased the combined macroalgae, invertebrate and fish species richness on the structure. POPULATION RESPONSE (1 STUDY) Algal abundance (1 study): One replicated, controlled study in Australia found that reducing the slope of an intertidal artificial structure did not increase the macroalgal abundance on structure surfaces. Invertebrate abundance (1 study): One replicated, controlled study in Australia found that reducing the slope of an intertidal artificial structure did not increase the oyster or mobile invertebrate abundance on structure surfaces. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3461https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3461Tue, 14 Sep 2021 12:39:58 +0100Collected Evidence: Collected Evidence: Regulate temperature of water discharged from power plants One study evaluated the effects of regulating temperature of water discharged from power plants. This study was in the USA. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (1 STUDY) Use (1 study): One study in the USA reported that power plant water cooling canals were occupied by a population of American crocodiles. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3495https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3495Mon, 06 Dec 2021 12:12:00 +0000Collected Evidence: Collected Evidence: Regulate planning permission for gas/filling stations at reptile sites We found no studies that evaluated the effects on reptile populations of regulating planning permission for gas/filling stations at reptile sites. ‘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%2F3579https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3579Wed, 08 Dec 2021 15:24:55 +0000Collected Evidence: Collected Evidence: Regulate artificial lighting during vulnerable periods We found no studies that evaluated the effects on reptile populations of regulating artificial lighting during vulnerable periods. ‘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%2F3596https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3596Wed, 08 Dec 2021 16:27:08 +0000Collected Evidence: Collected Evidence: Regulate water levels One study evaluated the effects of regulating water levels on reptile populations. This study was in France. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Abundance (1 study): One controlled, before-and-after study in France found that autumn–spring marsh flooding with moderate levels of grazing in autumn–winter led to higher numbers of European pond turtles than winter–spring flooding with high levels of grazing in spring–summer. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3660https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3660Fri, 10 Dec 2021 10:51:46 +0000Collected Evidence: Collected Evidence: Reduce the size of surface features when prospecting for or extracting underground products One study evaluated the effects on butterflies and moths of reducing the size of surface features when prospecting for or extracting underground products. This study was in Canada. COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): One replicated, site comparison study in Canada found that narrow corridors used for prospecting for oil had a lower species richness of butterflies than wide corridors, but were similar to undisturbed forest. POPULATION RESPONSE (1 STUDY) Abundance (1 study): One replicated, site comparison study in Canada found that narrow corridors used for prospecting for oil had a lower abundance of butterflies than wide corridors, but were similar to undisturbed forest. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3845https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3845Tue, 05 Jul 2022 11:09:11 +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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