Collected 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: 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: Use shelterwood cutting instead of clearcutting One study evaluated the effects of using shelterwood cutting instead of ‘gap release’ cutting on bat populations. The study was in Australia. We found no studies that evaluated the effects of shelterwood cutting instead of clearcutting. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (1 STUDY)      Use (1 study): One site comparison study in Australia found more Gould’s long-eared bats roosting in remnant trees within forests that had been shelterwood harvested than in forests harvested using gap release methods. Comparisons were not made with clearcutting. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F990https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F990Fri, 20 Dec 2013 15:27:30 +0000Collected Evidence: Collected Evidence: Thin trees within forest and woodland Eleven studies evaluated the effects of thinning trees within forest and woodland on bat populations. Six studies were in the USA, four were in Australia and one was in Canada. COMMUNITY RESPONSE (2 STUDIES) Richness/diversity (2 studies): One replicated, site comparison study in Australia recorded the same bat species in thinned and unthinned forest, except for the chocolate wattled bat, which was not recorded in forests with unthinned regrowth. One replicated, site comparison study in Australia found that forest thinned up to 20 years previously had higher bat diversity than unthinned forest, but sites thinned more than 20 years previously did not differ. POPULATION RESPONSE (11 STUDIES) Abundance (11 studies): Five of six replicated, site comparison studies (including two paired sites studies and one controlled study) in the USA and Australia found higher overall bat activity (relative abundance) in thinned or thinned and burned forest than unthinned forest. The other study found similar overall bat activity in thinned and unthinned stands. One replicated, randomized, site comparison study in the USA found higher overall bat activity for three of four types of thinning and burning treatments. One replicated, site comparison study in Australia found that forest thinned up to eight years previously or more than 20 years previously had higher bat activity than unthinned forest, but sites thinned 8–20 years previously did not differ. Three replicated, controlled studies (including one site comparison and one before-and-after study) in Canada and Australia found that thinning increased the activity of some bat species but not others. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F991https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F991Fri, 20 Dec 2013 15:31:59 +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: 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: Install and maintain gates at mine entrances to restrict public access Nine studies evaluated the effects of installing gates at mine entrances on bat populations. Eight studies were in the USA and one in Australia. COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): One replicated, before-and-after study in the USA found that fewer bat species entered mines after gates were installed. POPULATION RESPONSE (3 STUDIES) Abundance (3 studies): Two replicated, site comparison or before-and-after studies in the USA and Australia found fewer bats in mines or at mine entrances after gates were installed. One replicated, controlled, before-and-after study in the USA found that bat activity (relative abundance) remained stable or increased at five of seven gated mines, and decreased at two gated mines. BEHAVIOUR (6 STUDIES)      Use (2 studies): One before-and-after study in the USA found that 43 of 47 mines continued to be used 12 years after gates were installed, however bats abandoned four mines with ‘ladder’ design gates. One replicated study in the USA found that gate design and time since gate installation had varied effects on the presence of four bat species. Behaviour change (4 studies): Four replicated, before-and-after or site comparison studies in the USA and Australia found that bats at mine entrances circled more and entered mines less after gates were installed. OTHER (2 STUDIES) Collisions with gates (1 study): One replicated, controlled, before-and-after study in the USA found that up to 7% of bats at mine entrances collided with mine gates. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1963https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1963Tue, 04 Dec 2018 16:43:00 +0000Collected Evidence: Collected Evidence: Create artificial hollows and cracks in trees for roosting bats One study evaluated the effects of creating artificial hollows and cracks in trees for roosting bats. The study was in Australia. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (1 STUDY)      Use (1 study): One replicated study in Australia found that eight of 16 artificial hollows cut into trees for bats, birds and marsupials with two different entrance designs were used by roosting long-eared bats. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2047https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2047Fri, 07 Dec 2018 12:36:39 +0000Collected Evidence: Collected Evidence: Restore or create forest or woodland Two studies evaluated the effects of restoring forests on bat populations. One study was in Brazil and one in Australia. COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): One site comparison study in Brazil found that a reforested area had significantly lower bat diversity than a native forest fragment. POPULATION RESPONSE (1 STUDY) Abundance (1 study): One replicated, controlled, site comparison study in Australia found that forests restored after mining had significantly higher or similar bat activity (relative abundance) as unmined forests for five of seven bat species. BEHAVIOUR (0 STUDIES)      Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2050https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2050Fri, 07 Dec 2018 12:43:26 +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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