Collected 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 +0000Collected Evidence: Collected Evidence: Install hop-overs as road/railway crossing structures for bats We found no studies that evaluated the effects of hop-overs as road/railway crossing structures for 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%2F980https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F980Fri, 20 Dec 2013 14:14:29 +0000Collected Evidence: Collected Evidence: Divert bats to safe crossing points over or under roads/railways with plantings or fencing One study evaluated the effects of diverting bats using an artificial hedgerow on bat populations. The study was in Switzerland. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (1 STUDY)      Use (1 study): One controlled, before-and-after study in Switzerland found that up to one fifth of lesser horseshoe bats within a colony flew along an artificial hedgerow to commute. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F981https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F981Fri, 20 Dec 2013 14:16:34 +0000Collected Evidence: Collected Evidence: Deter bats from roads/railways using lighting We found no studies that evaluated the effects of deterring bats from roads/railways using lighting 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%2F982https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F982Fri, 20 Dec 2013 14:27:40 +0000Collected Evidence: Collected Evidence: Replace or improve habitat for bats around roads/railways We found no studies that evaluated the effects of replacing or improving habitat around roads/railways 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%2F983https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F983Fri, 20 Dec 2013 14:28:33 +0000Collected Evidence: Collected Evidence: Use selective or reduced impact logging instead of conventional logging Four studies evaluated the effects of using selective or reduced impact logging instead of conventional logging on bat populations. Two studies were in the Neotropics, one study was in Italy and one in Germany. COMMUNITY RESPONSE (1 STUDY) Community composition (1 study): One replicated, controlled, site comparison study in Trinidad found that the composition of bat species differed between selectively logged and conventionally logged forest. Richness/diversity (1 study): One replicated, site comparison study in Germany found similar bat diversity in selectively logged and conventionally logged forest. POPULATION RESPONSE (3 STUDIES) Abundance (3 studies): One replicated, site comparison study in Germany found similar overall bat activity (relative abundance) in selectively logged and conventionally logged forest. One review of 41 studies in the Neotropics found that reduced impact logging had a smaller effect on bat abundance than conventional logging. One replicated, site comparison study in Italy found greater bat activity at two of three sites that used selective logging techniques to open up the forest canopy rather than leaving the canopy intact. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F989https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F989Fri, 20 Dec 2013 14:41:00 +0000Collected Evidence: Collected Evidence: Use prescribed burning Fifteen studies evaluated the effects of prescribed burning on bat populations. Thirteen studies were in the USA and two were in Australia. COMMUNITY RESPONSE (2 STUDIES) Community composition (2 studies): One of two replicated studies (one before-and-after with paired sites, one site comparison) in Australia found that the composition of bat species differed between burned and unburned woodland sites. The other study found that the composition of bat species was similar between unlogged forest blocks burned every two or four years and unburned blocks. Richness/diversity (1 study): One replicated, randomized, site comparison study in Australia found more bat species in unlogged forest blocks burned every four years than in blocks burned every two years or unburned blocks. POPULATION RESPONSE (9 STUDIES) Abundance (9 studies): Two replicated, site comparison studies (including one controlled study) in the USA found that the activity (relative abundance) of open habitat bat species and evening bats increased with the number of prescribed fires, but there was no effect on other bat species, including cluttered habitat bat species. Four replicated, before-and-after or site comparison studies (including two controlled studies) in the USA and Australia found that prescribed burning, prescribed burning along with thinning or prescribed burning every four years resulted in higher overall bat activity or activity of Florida bonneted bats. One site comparison study in the USA found that two of seven sites that had been burned alongside other restoration practices had higher bat activity than unrestored sites. One replicated, randomized, site comparison study in the USA found that three of four burning and thinning treatments resulted in higher overall bat activity. One replicated, controlled, site comparison study in the USA found similar activity of three bat species in burned and unburned tree stands. BEHAVIOUR (6 STUDIES)      Use (5 studies): One replicated, controlled before-and-after study in the USA found that more female northern myotis bats roosted in burned than unburned forest. Two replicated, controlled, site comparison studies in the USA found that fewer female northern myotis bats and male Indiana bats roosted in burned than unburned forest. One replicated study in the USA found that evening bats roosted in burned but not unburned forest. One replicated, paired sites study in the USA found that burned sites had a higher occupancy of five bat species/species groups than unburned sites, and burn severity had a negative effect on the occupancy of two bat species/species groups. Behaviour change (4 studies): Two replicated, controlled, site comparison studies in the USA found no difference in roost switching frequency or the distance between roost trees for female northern myotis bats and male Indiana bats in burned and unburned forests. One replicated, controlled, before-and-after study in the USA found that female northern myotis home ranges and core areas did not differ in size between burned and unburned forests, but home ranges were closer to burned forest than unburned forest. One replicated, site comparison study in the USA found that home ranges of female Rafinesque’s big-eared bats were located similar distances to burned and unburned forest, and male home ranges were closer to unburned forest. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1006https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1006Fri, 20 Dec 2013 17:26:46 +0000Collected Evidence: Collected Evidence: Use low intensity lighting Three studies evaluated the effects of using low intensity lighting on bat populations. The three studies were in the UK. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Abundance (2 studies): One replicated, randomized, controlled study in the UK found that activity (relative abundance) of lesser horseshoe bats, but not myotis bats, was higher along hedges with medium or low intensity lighting than hedges with high intensity lighting. One replicated, randomized, controlled study in the UK found that activity of myotis bats, but not common pipistrelles, was higher along treelined roads with street lights dimmed to an intensity of 25% than roads with streetlights dimmed to 50% or left undimmed. BEHAVIOUR (1 STUDY)         Behaviour change (1 study): One replicated, controlled study in the UK found that more soprano pipistrelles emerged from two roosts when the intensity of red lights was reduced by placing filters over them. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1018https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1018Fri, 20 Dec 2013 17:58:34 +0000Collected Evidence: Collected Evidence: Provide bat boxes for roosting bats Forty-four studies evaluated the effects of providing bat boxes for roosting bats on bat populations. Twenty-seven studies were in Europe, nine studies were in North America, four studies were in Australia, two studies were in South America, and one study was a worldwide review. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (44 STUDIES) Uptake (9 studies): Nine replicated studies in Europe and the USA found that the number of bats using bat boxes increased by 2–10 times up to 10 years after installation. Use (43 studies): Forty-one of 43 studies (including 34 replicated studies and two reviews) in Europe, the USA, South America, and Australia found that bats used bat boxes installed in forest or woodland, forestry plantations, farmland, pasture, wetlands, urban areas and buildings, bridges, underpasses or unknown habitats. The other two studies in the USA and UK found that bats displaced from buildings did not use any of 43 bat houses of four different designs or 12 heated bat boxes of one design. One review of 109 studies across Europe, North America and Asia found that 72 bat species used bat boxes, although only 18 species commonly used them, and 31 species used them as maternity roosts. Twenty-two studies (including 17 replicated studies, one before-and-after study and two reviews) found bats occupying less than half of bat boxes provided (0–49%). Nine replicated studies found bats occupying more than half of bat boxes provided (54–100%). OTHER (23 STUDIES) Bat box design (16 studies): Three studies in Germany, Portugal and Australia found that bats used black bat boxes more than grey, white or wooden boxes. One of two studies in Spain and the USA found higher occupancy rates in larger bat boxes. One study in the USA found that bats used both resin and wood cylindrical bat boxes, but another study in the USA found that resin bat boxes became occupied more quickly than wood boxes. One study in the UK found higher occupancy rates in concrete than wooden bat boxes. One study in the USA found that Indiana bats used rocket boxes more than wooden bat boxes or bark-mimic roosts. One study in Spain found that more bats occupied bat boxes that had two compartments than one compartment in the breeding season. One study in Lithuania found that bat breeding colonies occupied standard and four/five chamber bat boxes and individuals occupied flat bat boxes. Four studies in the USA, UK, Spain and Australia found bats selecting four of nine, three of five, three of four and one of five bat box designs. One study in the UK found that different bat box designs were used by different species. One study in Costa Rica found that bat boxes simulating tree trunks were used by 100% of bats and in group sizes similar to natural roosts. Bat box position (11 studies): Three studies in Germany, Spain and the USA found that bat box orientation and/or the amount of exposure to sunlight affected bat occupancy, and one study in Spain found that orientation did not have a significant effect on occupancy. Two studies in the UK and Italy found that bat box height affected occupancy, and two studies in Spain and the USA found no effect of height. Two studies in the USA and Spain found higher occupancy of bat boxes on buildings than on trees. One study in Australia found that bat boxes were occupied more often in farm forestry sites than in native forest, one study in Poland found higher occupancy in pine relative to mixed deciduous stands, and one study in Costa Rica found higher occupancy in forest fragments than in pasture. One study in the USA found higher occupancy rates in areas where bats were known to roost prior to installing bat boxes. One review in the UK found that bat boxes were more likely to be occupied when a greater number of bat boxes were installed across a site. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1024https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1024Fri, 20 Dec 2013 18:17:59 +0000Collected Evidence: Collected Evidence: Maintain bat roosts in road/railway bridges and culverts Two studies evaluated the effects of maintaining bat roosts within road bridges on bat populations. One study was in Ireland and one in the USA. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (2 STUDIES)      Use (2 studies): One before-and-after study in Ireland found that a maternity colony of Daubenton’s bats continued to roost in a road bridge over a river in similar numbers after crevices were retained during repair work. One review in the USA found that when bat roosts were maintained during bridge replacement works, Yuma myotis and Mexican free-tailed bats recolonised most roosts in similar numbers to before the works, but pallid bats did not return. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1966https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1966Tue, 04 Dec 2018 18:03:09 +0000Collected Evidence: Collected Evidence: Create spaces for roosting bats in road/railway bridges and culverts One study evaluated the effects of creating spaces for roosting bats in road bridges. The study was in the USA. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (1 STUDY)         Use (1 study): One review in the USA found that spaces created in road bridges for roosting bats to replace those lost during bridge works were recolonized by bats in similar or greater numbers to the original roosts at four of eight sites. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1967https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1967Tue, 04 Dec 2018 18:07:53 +0000Collected Evidence: Collected Evidence: Deter bats from roads/railways using ultrasound We found no studies that evaluated the effects of deterring bats from roads/railways using ultrasound 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%2F1968https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1968Tue, 04 Dec 2018 18:10:24 +0000Collected Evidence: Collected Evidence: Minimize road lighting to reduce insect attraction We found no studies that evaluated the effects of minimizing road lighting to reduce 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%2F1969https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1969Tue, 04 Dec 2018 18:13:16 +0000Collected Evidence: Collected Evidence: Avoid planting fruit trees alongside roads/railways in areas with fruit bats We found no studies that evaluated the effects of avoiding planting fruit trees alongside roads/railways in areas with fruit 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%2F1970https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1970Tue, 04 Dec 2018 18:13:59 +0000Collected Evidence: Collected Evidence: Use red lighting rather than other lighting colours Three studies evaluated the effects of red lighting on bat populations. Two studies were in the Netherlands and one was in the UK. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Abundance (2 studies): One replicated, controlled, site comparison study in the Netherlands found that red lighting resulted in higher activity (relative abundance) for one of three bat species groups than white or green lighting. One site comparison study in the Netherlands found that culverts illuminated with red light had similar activity of commuting Daubenton’s bats as culverts illuminated with white or green light. BEHAVIOUR (1 STUDY)         Behaviour (1 study): One replicated, controlled study in the UK found that more soprano pipistrelles emerged from a roost when lit with red light than when lit with white light, but no difference was found between red and blue lights. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2021https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2021Wed, 05 Dec 2018 18:06:28 +0000Collected Evidence: Collected Evidence: Legally protect bat habitats Five studies evaluated the effects of legally protecting bat habitats on bat populations. Four studies were in Europe and one was in India. COMMUNITY RESPONSE (2 STUDIES) Community composition (1 study): One replicated, site comparison study in India found that the composition of bat species was similar in protected forest and unprotected forest fragments. Richness/diversity (2 studies): Two replicated, site comparison or paired sites studies in Europe and India found that the number of bat species did not differ between protected and unprotected forests or forest fragments. One replicated, site comparison study in France found that protected sites had a greater number of bat species than unprotected sites. POPULATION RESPONSE (4 STUDIES) Abundance (4 studies): One replicated, site comparison study in the UK found that the activity (relative abundance) of Daubenton’s bats was higher over rivers on farms in protected areas than in unprotected areas. One replicated, paired sites study in Europe found that the activity of common noctule bats was higher in protected forests than unprotected forests, but bat activity overall did not differ. Two replicated, site comparison studies in France and India found higher overall bat activity, higher activity of three of six bat species/species groups and a greater number of bats in protected sites and forests than unprotected sites and forests. BEHAVIOUR (1 STUDY)         Use (1 study): One study in Spain found that the distributions of 10 of 11 bat species overlapped with areas designated to protect them significantly more than by chance. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2045https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2045Thu, 06 Dec 2018 15:34:12 +0000Collected Evidence: Collected Evidence: Change timing of maintenance work at road/railway bridges and culverts We found no studies that evaluated the effects of changing the timing of maintenance work at road/railway bridges and culverts 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%2F2940https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2940Fri, 12 Feb 2021 17:47:15 +0000Collected Evidence: Collected Evidence: Exclude bats from roosts during maintenance work at road/railway bridges and culverts We found no studies that evaluated the effects of excluding bats from roosts during maintenance work at road/railway bridges and culverts 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%2F2941https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2941Fri, 12 Feb 2021 17:48:45 +0000Collected Evidence: Collected Evidence: Provide alternative bat roosts during maintenance work at road/railway bridges and culverts One study evaluated the effects of providing alternative bat roosts during maintenance work at road bridges. The study was in the USA. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (1 STUDY)         Use (1 study): One review in the USA found that bat houses provided as alternative roosts during bridge replacement works were used by fewer Mexican free-tailed bats than the original roost at one site and were not used by bats at all at three sites. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2942https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2942Fri, 12 Feb 2021 17:51:31 +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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