Collected Evidence: Collected Evidence: Relocate access points to bat roosts within developments Two studies evaluated the effects of relocating access points to bat roosts within building developments on bat populations. One study was in Ireland and one in the UK. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (2 STUDIES)      Use (2 studies): One before-and-after study in Ireland found that fewer brown long-eared bats used a roost after the access points were relocated, and no bats were observed flying through them. One before-and-after study in the UK found that few lesser horseshoe bats used an alternative access point with a ‘bend’ design to re-enter a roost in a building development, but the number of bats using the roost increased after an access point with a ‘straight’ design was installed. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F946https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F946Tue, 10 Dec 2013 13:55:15 +0000Collected Evidence: Collected Evidence: Retain existing bat roosts and access points within developments Three studies evaluated the effects of retaining existing bat roosts and access points within developments on bat populations. Two studies were in the UK and one was in Ireland. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (3 STUDIES) Use (3 studies): One before-and-after study in Ireland found similar numbers of brown long-eared bats roosting within an attic after existing access points were retained during renovations. One replicated, before-and-after study in the UK found that four of nine bat roosts retained within developments were used as maternity colonies, in two cases by similar or greater numbers of bats after development had taken place. One review in the UK found that bats used two-thirds of retained and modified bat roosts after development, and retained roosts were more likely to be used than newly created roosts. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F947https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F947Tue, 10 Dec 2013 14:08:36 +0000Collected Evidence: Collected Evidence: Create alternative bat roosts within developments Eleven studies evaluated the effects of creating alternative bat roosts within developments on bat populations. Nine studies were in Europe and two were in the USA. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (11 STUDIES)     Use: (11 studies): Two replicated studies in the USA and UK found that bats did not use any of the alternative roosts provided in bat houses or a purpose-built bat wall after exclusion from buildings. Three studies (two replicated) in the USA and UK and one review in the UK found that bat boxes or bat lofts/barns were used by bats at 13–74% of development sites, and bat lofts/barns were used by maternity colonies at one of 19 development sites. Three of five before-and-after studies in Portugal, Ireland, Spain and the UK found that bat colonies used purpose-built roosts in higher or similar numbers after the original roosts were destroyed. The other two studies found that bats used purpose-built roosts in lower numbers than the original roost. One review in the UK found that new bat boxes/lofts built to replace destroyed roosts were four times less likely to be used by returning bats than roosts retained during development. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F949https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F949Fri, 20 Dec 2013 09:21:55 +0000Collected Evidence: Collected Evidence: Change timing of building work One study evaluated the effects of changing the timing of building work on bat populations. The study was in Ireland. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (1 STUDY)      Use (1 study): One before-and-after study in Ireland found that carrying out roofing work outside of the bat maternity season, along with retaining bat access points, resulted in a similar number of brown long-eared bats continuing to use a roost within an attic. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F950https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F950Fri, 20 Dec 2013 09:23:40 +0000Collected Evidence: Collected Evidence: Protect brownfield or ex-industrial sites One study evaluated the effects of protecting brownfield or ex-industrial sites on bat populations. The study as in the USA. COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): One study in the USA found that five bat species were recorded within a protected urban wildlife refuge on an abandoned manufacturing site. POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES)  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F953https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F953Fri, 20 Dec 2013 09:36:12 +0000Collected Evidence: Collected Evidence: Create or restore bat foraging habitat in urban areas Three studies evaluated the effects of creating or restoring bat foraging habitat in urban areas on bat populations. One study in each of the UK and USA evaluated green roofs and one study in the USA evaluated restored forest fragments. COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): One replicated, controlled, site comparison study in the USA found no difference in species richness over green roofs and conventional unvegetated roofs. POPULATION RESPONSE (3 STUDIES) Abundance (3 studies): One site comparison study in the USA found higher bat activity (relative abundance) in two of seven restored forest fragments in urban areas than in two unrestored forest fragments. One replicated, controlled, site comparison study in the UK found greater bat activity over ‘biodiverse’ green roofs than conventional unvegetated roofs, but not over ‘sedum’ green roofs. One replicated, controlled, site comparison study in the USA found greater bat activity for three of five bat species over green roofs than over conventional unvegetated roofs. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F954https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F954Fri, 20 Dec 2013 09:44:25 +0000Collected Evidence: Collected Evidence: Create tree plantations on agricultural land Three studies evaluated the effects of creating tree plantations on agricultural land on bat populations. The three studies were in Australia. COMMUNITY RESPONSE (3 STUDIES) Richness/diversity (3 studies): Three replicated, site comparison studies in Australia found no difference in the number of bat species in agricultural areas with and without plantations of native trees. POPULATION RESPONSE (3 STUDIES) Abundance (3 studies): Two of three replicated, site comparison studies in Australia found no difference in bat activity (relative abundance) in agricultural areas with and without plantations of native trees. The other study found higher bat activity in plantations next to remnant native vegetation than in isolated plantations or over grazing land. In all three studies, bat activity was lower in plantations compared to original forest and woodland remnants. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F958https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F958Fri, 20 Dec 2013 10:09:11 +0000Collected Evidence: Collected Evidence: Create artificial water sources Five studies evaluated the effects of creating artificial water sources for bats on bat populations. One study was in each of the USA, Germany, South Africa, Israel and Mexico. COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): One replicated, paired sites study in South Africa found a similar number of bat species over farm ponds and in grassland/crops, trees, vineyards or orchards. POPULATION RESPONSE (5 STUDIES) Abundance (5 studies): Five replicated studies (including four site comparisons and one paired sites study) in Israel, the USA, Germany, South Africa and Mexico found that bat activity (relative abundance) was similar or higher over reservoirs and waste water treatment pools, heliponds and drainage ditches, retention ponds and farm/cattle ponds compared to over natural wetlands, nearby vineyards, surrounding forest or grassland/crops, trees and orchards. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F959https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F959Fri, 20 Dec 2013 10:14:31 +0000Collected Evidence: Collected Evidence: Use organic farming instead of conventional farming Twelve studies evaluated the effects of using organic farming instead of conventional farming on bat populations. Eight studies were in Europe, two in the USA, one in Canada and one in Chile. COMMUNITY RESPONSE (7 STUDIES) Community composition (1 study): One replicated, paired sites study in the USA found that the composition of bat species did not differ between organic and non-organic farms. Richness/diversity (7 studies): Five of seven replicated, paired sites or site comparison studies in Europe, the USA, Canada and Chile found that the number of bat species did not differ between organic and non-organic farms. The other two studies found more bat species on organic farms than non-organic farms. POPULATION RESPONSE (12 STUDIES) Abundance (12 studies): Five of nine replicated, paired sites or site comparison studies in Europe, the USA, Canada and Chile found that overall bat activity (relative abundance) and common pipistrelle activity did not differ between organic and non-organic farms. The other four studies found higher overall bat activity, bat feeding activity, Brazilian free-tailed bat activity, and activity of four of seven bat species on organic farms than non-organic farms. Two replicated, paired sites and site comparison studies in the UK found higher activity of Myotis species over water and rivers on organic farms than non-organic farms, but no differences were found for other species or habitats. One replicated, site comparison study in France found higher activity for two of three bat species over organic fields than two of three types of conventionally managed fields. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F961https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F961Fri, 20 Dec 2013 10:21:14 +0000Collected Evidence: Collected Evidence: Pay farmers to cover the costs of conservation measures (e.g. agri-environment schemes) Three studies evaluated the effects of agri-environment schemes on bat populations. The three studies were in the UK. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (3 STUDIES) Abundance (3 studies): Two of three replicated, paired sites studies in the UK found that overall bat activity (relative abundance) or the occurrence of six bat species did not differ significantly between farms managed under agri-environment schemes and those managed conventionally. One of the studies found that agri-environment scheme farms had similar activity of five bat species, and lower activity of one bat species, compared to conventional farms. The other study found lower overall bat activity and activity of pipistrelle species on agri-environment scheme farms than conventional farms. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F962https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F962Fri, 20 Dec 2013 10:25:45 +0000Collected Evidence: Collected Evidence: Retain or plant native trees and shrubs amongst crops (agroforestry) Eight studies evaluated the effects of retaining or planting native trees and shrubs amongst crops on bat populations. Four studies were in Mexico, three were in South America and one was in Tanzania. COMMUNITY RESPONSE (7 STUDIES) Community composition (1 study): One replicated, site comparison study in Tanzania found different compositions of bat species in coffee plantations with different amounts and types of shade cover. Richness/diversity (7 studies): Four of six replicated, site comparison studies in Columbia, Mexico and Costa Rica found a similar number of bat species in shaded and unshaded coffee plantations, and in coffee plantations with different amounts and types of shade cover. The two other studies found more bat species and higher bat diversity in coffee, cacao and banana plantations with varied shade cover, than in plantations with a single shade species or no shade. One replicated, site comparison study in Tanzania found more bat species in shaded coffee plantations than in traditional mixed agroforestry systems with natural forest vegetation. POPULATION RESPONSE (6 STUDIES) Abundance (5 studies): Two replicated, site comparison studies in Mexico captured more bats in coffee plantations with varied shade cover than in plantations with a single shade species. One replicated, site comparison study in Mexico found higher activity (relative abundance) of forest bat species in plantations with a varied shade cover than in plantations with a single shade species, but the opposite was true for open habitat bat species. One replicated, site comparison study in Costa Rica found no difference in the number of bats captured between cacao and banana shade plantations and unshaded monocultures. One replicated, site comparison study in Tanzania found greater bat occurrence in shaded coffee plantations than in traditional mixed agroforestry systems with natural forest vegetation. Condition (1 study): One replicated, site comparison study in Columbia found that great fruit-eating bats captured in ‘silvopastoral’ areas that used agroforestry, along with no chemicals, had higher body weights and body condition scores than those in conventional farming areas. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F963https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F963Fri, 20 Dec 2013 10:35:13 +0000Collected Evidence: Collected Evidence: Modify turbine placement to reduce bat fatalities We found no studies that evaluated the effects of modifying turbine placement to reduce bat fatalities. ‘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%2F965https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F965Fri, 20 Dec 2013 11:22:00 +0000Collected Evidence: Collected Evidence: Retain a buffer between turbines and habitat features used by bats We found no studies that evaluated the effects of retaining a buffer between turbines and habitat features used by bats 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%2F966https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F966Fri, 20 Dec 2013 11:23:15 +0000Collected Evidence: Collected Evidence: Deter bats from turbines using radar We found no studies that evaluated the effects of deterring bats from wind turbines using radar 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%2F967https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F967Fri, 20 Dec 2013 11:25:11 +0000Collected Evidence: Collected Evidence: Deter bats from turbines using ultrasound Four studies evaluated the effects of deterring bats from wind turbines using ultrasound on bat populations. The four studies were in the USA. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (3 STUDIES) Survival (3 studies): Three replicated, randomized, controlled studies (one with a before-and-after trial in the second year) in the USA found mixed results. In the first year of one study, 21-51% fewer bats were killed at turbines with an ultrasonic deterrent fitted than at control turbines, but in the second year, from 2% more to 64% fewer bats were killed at turbines with ultrasonic deterrents fitted. One study found that using an ultrasonic deterrent emitting a constant or pulsed signal had mixed effects on the fatality rates of three bat species. One study found that using ultrasonic deterrents resulted in fewer fatalities for two of three bat species. BEHAVIOUR (1 STUDY) Behaviour change (1 study): One paired sites study in the USA found fewer bats flying near one of two wind turbines with an ultrasonic deterrent compared to turbines without, but the effect of the deterrent overall was not significant. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F968https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F968Fri, 20 Dec 2013 11:30:12 +0000Collected Evidence: Collected Evidence: Remove turbine lighting to reduce bat and insect attraction We found no studies that evaluated the effects of removing turbine lighting to reduce bat and insect attraction 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%2F969https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F969Fri, 20 Dec 2013 12:15:27 +0000Collected Evidence: Collected Evidence: Prevent turbine blades from turning at low wind speeds ('feathering') Six studies evaluated the effects of preventing turbine blades from turning at low wind speeds on bat populations. Five studies were in the USA and one was in Canada. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (6 STUDIES) Survival (6 studies): Five of six studies (including five replicated, controlled studies and one before-and-after study) in the USA and Canada found that preventing turbine blades from turning at low wind speeds (‘feathering’), or feathering along with increasing the wind speed at which turbines become operational (‘cut-in speed’) resulted in fewer bat fatalities than at conventionally operated turbines. The other study found that automatically feathering turbine blades at low wind speeds did not reduce bat fatalities. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F970https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F970Fri, 20 Dec 2013 12:19:55 +0000Collected Evidence: Collected Evidence: Automatically reduce turbine blade rotation when bat activity is high Two studies evaluated the effects of automatically reducing turbine blade rotation when bat activity is high on bat populations. One study was in Germany, and one in the USA. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Survival (2 studies): Two replicated studies (one randomized, controlled and one paired sites study) in Germany and the USA found that automatically reducing the rotation speed of wind turbine blades when bat activity is predicted to be high resulted in fewer bat fatalities for all bat species combined and for five bat species. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F971https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F971Fri, 20 Dec 2013 12:34:12 +0000Collected Evidence: Collected Evidence: Close off potential access points on turbines to prevent roosting bats We found no studies that evaluated the effects of closing off potential access points on turbines to prevent roosting bats 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%2F972https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F972Fri, 20 Dec 2013 12:35:38 +0000Collected Evidence: Collected Evidence: Provide artificial subterranean bat roosts to replace roosts in reclaimed mines We found no studies that evaluated the effects of providing artificial subterranean bat roosts to replace roosts in reclaimed mines 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%2F974https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F974Fri, 20 Dec 2013 12:43:16 +0000Collected Evidence: Collected Evidence: Relocate bats from reclaimed mines to alternative subterranean roost sites We found no studies that evaluated the effects of relocating bats from reclaimed mines to alternative subterranean roost sites 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%2F975https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F975Fri, 20 Dec 2013 12:43:57 +0000Collected Evidence: Collected Evidence: Install underpasses or culverts as road/railway crossing structures for bats Eight studies evaluated the effects of installing underpasses or culverts as road crossing structures for bats. Seven studies were in Europe and one in Australia. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (8 STUDIES)      Use (8 studies): Eight studies (including six replicated studies) in Germany, Ireland, the UK, Australia and France found that bats used underpasses and culverts below roads, and crossed over the roads above them, in varying proportions. One replicated, site comparison study in Australia found that bat species adapted to cluttered habitats used small culverts and underpasses more than bat species adapted to open or edge habitats. One replicated, site comparison study in France found that the use of underpasses by five bat species was influenced by underpass type and height, road width, and the amount of forest and hedgerows in the surrounding landscape. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F976https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F976Fri, 20 Dec 2013 14:08:31 +0000Collected Evidence: Collected Evidence: Install overpasses as road/railway crossing structures for bats Four studies evaluated the effects of installing overpasses as road crossing structures for bats. Three studies were in Europe and one in Australia. COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): One site comparison study in Australia found that the same number of bat species were recorded at an overpass and in nearby forest and bushland. POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (3 STUDIES)      Use (3 studies): Two replicated studies (including one site comparison) in Ireland and France found that two or three bat species/species groups used overpasses but up to three-quarters of bats crossed the road below at traffic height or crossed at other nearby locations. One study in the UK found that an overpass with planters was used by two-thirds of crossing bats, and an unvegetated overpass with a paved road over it was not used by crossing bats. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F977https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F977Fri, 20 Dec 2013 14:10:25 +0000Collected Evidence: Collected Evidence: Install bat gantries or bat bridges as road/railway crossing structures for bats Three studies evaluated the effects of installing bat gantries as road crossing structures for bats. Two studies were in the UK and one in France. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (3 STUDIES)      Use (3 studies): Two replicated studies (including one site comparison) in the UK found that fewer bats used bat gantries than crossed the road below at traffic height, and one bat gantry was not used at all. One replicated study in France found that a temporary bat gantry was used by three bat species/species groups, but almost half of crossing bats flew over the road at other locations. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F978https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F978Fri, 20 Dec 2013 14:12:20 +0000Collected Evidence: Collected Evidence: Install green bridges as road/railway crossing structures for bats One study evaluated the effects of installing green bridges as road crossing structures for bats. The study was in the UK. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (1 STUDY)      Use (1 study): One study in the UK found that a green bridge was used by 97% of bats crossing a road. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F979https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F979Fri, 20 Dec 2013 14:13:21 +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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