Collected Evidence: Collected Evidence: Use fire suppression/control Two out of three before-and-after studies, from Australia and the UK, found that five species of bird (including noisy scrub-bird, the target species of one study) increased following fire suppression measures. A before-and-after study in the USA found that open habitat species declined in a pine forest site after fire exclusion, whilst mesic woodland species appeared. A before-and-after study from the UK found that five bird species declined following fire suppression.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F324https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F324Thu, 26 Jul 2012 16:35:35 +0100Collected Evidence: Collected Evidence: Use false brood parasite eggs to discourage brood parasitismA replicated, controlled experiment in the USA found lower parasitism rates for red-winged blackbird Agelaius phoeniceus nests with false or real brown-headed cowbird Molothrus ater eggs added to them.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F444https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F444Thu, 23 Aug 2012 16:03:29 +0100Collected Evidence: Collected Evidence: Use flashing lights to reduce mortality from artificial lightsA randomised, replicated and controlled trial from the USA found that fewer dead birds were found beneath control towers that used only flashing lights, as opposed to those using both flashing and continuous lights.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F470https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F470Wed, 29 Aug 2012 16:31:10 +0100Collected Evidence: Collected Evidence: Use fencing to enclose large herbivores (e.g. deer) We found no evidence of the effects of using fencing to enclose large herbivores 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%2F1199https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1199Thu, 19 May 2016 13:15:58 +0100Collected Evidence: Collected Evidence: Use fertilizer Six of eight studies (including five replicated, randomized, controlled) in the USA, Finland, Brazil, Australia and Switzerland found that applying fertilizer increased total plant cover, understory plant biomass , size of young trees, relative  biomass of grasses (out of total biomass of all plants) and cover of plant species that were seeded artificially. Five of the studies found no effect of applying fertilizer on plant biomass, plant cover, seedling abundance, tree growth and tree seedling diversity.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1248https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1248Fri, 03 Jun 2016 11:30:08 +0100Collected Evidence: Collected Evidence: Use fertilizer after tree planting Two replicated, controlled studies in Canada and Portugal found that applying fertilizer after planting increased the size of the planted trees. One randomized, replicated, controlled study in Australia found that soil enhancers including fertilizer had a mixed effect on seedling survival and height. Three studies (including two randomized, replicated, controlled study) in France and Australia found no effect of applying fertilizer on the size and survival rate or health of planted trees.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1260https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1260Mon, 06 Jun 2016 10:48:59 +0100Collected Evidence: Collected Evidence: Use fences as biological corridors for primates We found no evidence for the effects of using fences as biological corridors 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%2F1426https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1426Tue, 17 Oct 2017 09:31:52 +0100Collected Evidence: Collected Evidence: Use fences to exclude livestock from shrublands  Two replicated, controlled, randomized studies (one of which was also a before-and-after trial) and one controlled before-and-after trial in the UK found that using fences to exclude livestock increased shrub cover or abundance. Two replicated, controlled, randomized studies in Germany and the UK found that using fences increased shrub biomass or the biomass and height of individual heather plants. Two controlled studies (one of which was a before-and-after study) in Denmark and the UK found that heather presence or cover was higher in fenced areas that in areas that were not fenced. However, one site comparison study in the USA found that using fences led to decreased cover of woody plants. Three replicated, controlled studies (one of which was a before and after study) in the USA and the UK found that fencing either had a mixed effect on shrub cover or did not alter shrub cover. One randomized, replicated, controlled, paired study in the UK found that using fences to exclude livestock did not alter the number of plant species, but did increase vegetation height and biomass. One controlled, before-and-after study in the UK found that fenced areas had lower species richness than unfenced areas. One randomized, replicated, controlled, before-and-after trial in the UK and one site comparison study in the USA found that using fences to exclude livestock led to a decline in grass cover. However, four controlled studies (one of which a before-and-after trial) in the USA, the UK, and Finland found that using fences did not alter cover of grass species. One site comparison study in the USA and one replicated, controlled study in the UK recorded an increase in grass cover. One controlled study in Finland found that using fences to exclude livestock did not alter the abundance of herb species and one site comparison in the USA found no difference in forb cover between fenced and unfenced areas. One replicated, controlled study in the USA found fencing had a mixed effect on herb cover. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1545https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1545Thu, 19 Oct 2017 17:12:06 +0100Collected Evidence: Collected Evidence: Use fences to exclude large herbivores One controlled study in the USA found that using fences to exclude deer increased the height of shrubs, but not shrub cover. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1662https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1662Sun, 22 Oct 2017 15:03:54 +0100Collected Evidence: Collected Evidence: Use fences or barriers to protect planted vegetation We found no studies that evaluated the effects of using fences or barriers to protect planted peatland vegetation. ‘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%2F1839https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1839Tue, 28 Nov 2017 08:55:19 +0000Collected Evidence: Collected Evidence: Use flags to reduce predation of livestock by mammals to reduce human-wildlife conflict Five studies evaluated the effects on mammals of using flags to reduce predation of livestock by mammals to reduce human-wildlife conflict. Three studies were in the USA, one was in Italy and one was in Canada. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (5 STUDIES) Human-wildlife conflict (5 studies): Three studies (including two before-and-after studies and a controlled study), in Italy, Canada and the USA, found that flags hanging from fence lines (fladry) deterred crossings by wolves but not by coyotes. A further replicated, controlled study in the USA found that electric fences with fladry were not crossed by wolves. A replicated, controlled, before-and-after study in the USA found that fladry did not reduce total deer carcass consumption by a range of carnivores. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2421https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2421Mon, 01 Jun 2020 13:54:30 +0100Collected Evidence: Collected Evidence: Use fencing/netting to reduce predation of fish stock by mammals to reduce human-wildlife conflict We found no studies that evaluated the effects of using fencing or netting to reduce predation of fish stock by mammals to reduce human-wildlife conflict. '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 effectsCollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2454https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2454Tue, 02 Jun 2020 11:11:38 +0100Collected Evidence: Collected Evidence: Use fencing to protect water sources for use by wild mammals We found no studies that evaluated the effects of using fencing to protect water sources for use by wild mammals. ‘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%2F2493https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2493Thu, 04 Jun 2020 15:02:50 +0100Collected Evidence: Collected Evidence: Use fencing to exclude grazers or other problematic species Three studies evaluated the effects on mammals of using fencing to exclude grazers or other problematic species. One study was in each of the USA, Australia and Spain. COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): A controlled, before-and-after study in Australia found that after fencing to exclude introduced herbivores, native mammal species richness increased. POPULATION RESPONSE (3 STUDIES) Abundance (3 studies): Two controlled studies (including one replicated, paired sites study) in Spain and Australia found that using fences to exclude large or introduced herbivores increased the abundance of Algerian mice and native mammals. A replicated, paired sites study in the USA found that in areas fenced to exclude livestock grazing and off-road vehicles, abundance of black-tailed hares was lower compared to in unfenced areas. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2495https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2495Thu, 04 Jun 2020 15:18:53 +0100Collected Evidence: Collected Evidence: Use fencing to exclude predators or other problematic species Ten studies evaluated the effects on mammals of using fencing to exclude predators or other problematic species. Four studies were in Australia, four were in the USA and two were in Spain. COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): A site comparison study in Australia found that fencing which excluded feral cats, foxes and rabbits increased small mammal species richness. POPULATION RESPONSE (10 STUDIES) Abundance (4 studies): Two of three studies (including two replicated, controlled studies), in Spain, Australia and the USA, found that abundances of European rabbits and small mammals were higher within areas fenced to exclude predators or other problematic species, compared to in unfenced areas. The third study found that hispid cotton rat abundance was not higher with predator fencing. A replicated, controlled study in Spain found that translocated European rabbit abundance was higher in fenced areas that excluded both terrestrial carnivores and raptors than in areas only accessible to raptors. Reproductive success (1 study): A replicated, controlled study in USA found that predator exclosures increased the number of white-tailed deer fawns relative to the number of adult females. Survival (7 studies): Four of six studies (including four replicated, controlled studies) in Spain, Australia and the USA, found that fencing to exclude predators did not increase survival of translocated European rabbits, hispid cotton rats, southern flying squirrels or western barred bandicoots. The other two studies found that persistence of populations of eastern barred bandicoots and long-haired rats was greater inside than outside fences. A controlled, before-and-after study in the USA found that electric fencing reduced coyote incursions into sites frequented by black-footed ferrets. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2497https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2497Thu, 04 Jun 2020 15:36:46 +0100Collected Evidence: Collected Evidence: Use fire to deter crop damage by mammals to reduce human-wildlife conflict Two studies evaluated the effects on mammals of using fire to deter crop damage by mammals to reduce human-wildlife conflict. One study was in Zimbabwe and one was in India. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES) Human-wildlife conflict (2 studies): A replicated study in Zimbabwe found that a combination of large fires and people with drums and dogs repelled African elephants from crops faster than did a combination of people with dogs and slingshots, drums and burning sticks. A study in India found that fire reduced the chance of Asian elephants damaging crops. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2499https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2499Thu, 04 Jun 2020 15:39:38 +0100Collected Evidence: Collected Evidence: Use flags to signal the legal nationality of a fishing vessel We found no studies that evaluated the effects of using a flag to identify the legal nationality of a fishing vessel on marine fish 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%2F2768https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2768Wed, 03 Feb 2021 10:10:41 +0000Collected Evidence: Collected Evidence: Use fences or barriers to protect freshwater wetlands planted with non-woody plants Four studies evaluated the effects, on vegetation, of using fences or barriers to protect freshwater wetlands planted with emergent, non-woody plants. There was one study in each of Canada, the Netherlands, Israel and the USA. VEGETATION COMMUNITY Community composition (1 study): One replicated, site comparison study in the USA found that amongst planted/sown lakeshores, those protected with fences or wave breaks contained different wetland plant communities, after 1–6 years, than those without fences or wave breaks. VEGETATION ABUNDANCE Individual species abundance (1 study): One replicated, controlled study at the edge of a freshwater lake in the Netherlands found that amongst plots planted with lakeshore bulrush Scirpus lacustris, those from which wildfowl had been excluded contained a greater density and biomass of lakeshore bulrush, after 1–2 years, than those that remained open to wildfowl. VEGETATION STRUCTURE   OTHER Survival (2 studies): Two replicated, paired, controlled studies in freshwater wetlands in Canada and Israel reported that protecting emergent herbs, with silt screens or herbivore fencing, increased survival rates over 12–18 months after planting. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3328https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3328Sun, 11 Apr 2021 13:14:37 +0100Collected Evidence: Collected Evidence: Use fences or barriers to protect brackish/saline wetlands planted with non-woody plantsWe found no studies that evaluated the effects, on vegetation, of using fences or barriers to protect brackish/saline wetlands planted with emergent, non-woody plants.   ‘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%2F3329https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3329Sun, 11 Apr 2021 13:14:53 +0100Collected Evidence: Collected Evidence: Use fences or barriers to protect freshwater wetlands planted with trees/shrubs Five studies evaluated the effects, on vegetation, of using fences or barriers to protect freshwater wetlands planted with trees/shrubs. Four studies were in the USA and one was in Australia. VEGETATION COMMUNITY   VEGETATION ABUNDANCE Tree/shrub abundance (1 study): One replicated, paired, controlled study in a floodplain swamp clearing in the USA found that amongst plots sown with tree seeds, fencing to exclude deer had no significant effect on total tree seedling density after three years. VEGETATION STRUCTURE Height (2 studies): One replicated, paired, controlled study in a floodplain swamp clearing in the USA found that amongst plots sown with tree seeds, those also fenced to exclude deer contained taller tree seedlings, after three years, than those left unfenced. One replicated, paired, controlled study in created freshwater wetlands in the USA found that the average height of white cedar Thuja occidentalis saplings typically increased by a similar amount, between two and five years after planting, in plots fenced to exclude deer and plots left unfenced. OTHER Survival (3 studies): One replicated, paired, controlled study in floodplain swamps in Australia reported that planted swamp gum Eucalyptus camphora seedlings had a much higher survival rate, over one year, in plots fenced to exclude mammals than in open plots. Two replicated, paired, controlled studies in freshwater wetlands in the USA reported that exclusion fencing sometimes increased survival of planted tree seedlings but sometimes had no clear or significant effect. This depended on factors such as the season of planting, seedling elevation, and site. Growth (1 study): One replicated, randomized, controlled study in a nutria-invaded wetland in the USA found that planted baldcypress Taxodium distichum seedlings grew more, over one growing season, when protected than when left unprotected. Plastic guards increased height and diameter growth rates. Sticky, insect-repellent oil increased the growth rate for height, but not diameter. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3330https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3330Sun, 11 Apr 2021 13:15:05 +0100Collected Evidence: Collected Evidence: Use fences or barriers to protect planted brackish/saline wetlands planted with trees/shrubs One study evaluated the effects, on vegetation, of using fences or barriers to protect brackish/saline wetlands planted with trees/shrubs. The study was in the USA. VEGETATION COMMUNITY   VEGETATION ABUNDANCE   VEGETATION STRUCTURE Height (1 study): One replicated, paired, controlled study in exposed coastal sites in the USA found that red mangrove Rhizophora mangle propagules planted within full-length plastic shelters had grown taller than propagules planted without shelter in three of four comparisons, made 22–129 days after planting. OTHER Survival (1 study): One replicated, paired, controlled study in exposed coastal sites in the USA reported that full-length plastic shelters increased the survival rate of planted red mangrove Rhizophora mangle propagules over 4–8 months, but that full-length bamboo shelters and below-ground plastic shelters had no clear effect on survival. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3331https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3331Sun, 11 Apr 2021 13:15:17 +0100Collected Evidence: Collected Evidence: Use flotation devices to support planted vegetationWe found no studies that evaluated the effects of using flotation devices to support emergent vegetation planted in wetlands.   ‘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%2F3340https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3340Sun, 11 Apr 2021 16:45:23 +0100Collected Evidence: Collected Evidence: Use fencing to prevent reptiles from accessing facilities We found no studies that evaluated the effects on reptile populations of using fencing to prevent reptiles from accessing facilities. ‘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%2F3499https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3499Mon, 06 Dec 2021 16:08:27 +0000Collected Evidence: Collected Evidence: Use fire suppression/control We found no studies that evaluated the effects of using fire suppression or control on butterflies and moths. ‘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%2F3880https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3880Thu, 21 Jul 2022 16:55:51 +0100Collected Evidence: Collected Evidence: Use fencing to reduce pesticide and nutrient run-off into margins, waterways and ponds We found no studies that evaluated the effects on butterflies and moths of using fencing to reduce pesticide and nutrient run-off into margins, waterways and ponds. ‘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%2F3893https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3893Tue, 09 Aug 2022 13:04:52 +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.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.


Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust