Collected Evidence: Collected Evidence: Raise water levels in ditches or grassland Seven studies from Denmark, the Netherlands and the UK (two replicated controlled studies and two before-and-after studies) found that raising water levels in ditches or grassland was associated with increased bird numbers, breeding bird numbers, plant species that favour wet conditions, and invertebrate numbers or biomass in agricultural landscapes. Two replicated studies from the Netherlands and the UK found that raising water levels resulted in a net loss of plant species and did not affect lapwing foraging rate. A review found three studies reporting that re-wetting soils on old arable fields is not an effective method of reducing nutrient levels and restoring species-rich grassland. A replicated study from the UK found that unflooded pastures contained a high biomass of soil macroinvertebrates of importance to breeding wading birds. A controlled, randomized study from the Netherlands found that raising the water level resulted in a more rapid establishment of species typical of wet grassland, than vegetation management. A review of agri-environment schemes from the UK found studies that suggested more expensive agri-environment scheme options for wetland habitats, such as controlling water levels, were more effective at providing good habitat for wading birds than easier-to-implement options. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F121https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F121Tue, 01 Nov 2011 21:14:13 +0000Collected Evidence: Collected Evidence: Manually control or remove midstorey and ground-level vegetation (including mowing, chaining, cutting etc) in forests Of fifteen studies captured, one, a replicated controlled study from the USA, found higher bird species richness in areas with midstorey thinning, compared to control areas. One study from the USA found similar bird species richness in areas with mid- and understorey control, compared to other management types. A study from Canada found fewer species in treated sites than controls. Seven studies from Europe and the USA found that total bird densities or those of some species or guilds were higher in areas with mid- or understorey management, compared to before management or to areas without management. Four of these studies used understorey removal as part of a wider management regime. Five studies from the USA and Canada found that densities of some species were lower in areas with midi or understorey control, or that overall bird densities did not different between managed and unmanaged areas. Two of these studies investigated several interventions at once. A replicated controlled study from the USA found similar survival for black-chinned hummingbirds in areas with understorey management, compared to areas with other interventions. Two replicated, controlled studies from Canada found higher nest survival in forests with removal of deciduous trees, compared to controls. A controlled study found that northern bobwhite chicks had greater foraging success in areas with cleared understorey vegetation compared to burned areas, but lower than under other managements. A replicated, controlled study from the USA found that midstorey control did not appear to affect competition between species for nesting sites.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F335https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F335Sat, 28 Jul 2012 14:20:23 +0100Collected Evidence: Collected Evidence: Provide calcium supplements to increase survival or reproductive success Eight studies from across the world, including a literature review from across the world found evidence for positive effects of calcium supplementation on several bird species. Positive effects included lower incidence of bone disease, higher fledging succes, larger broods, higher quality eggs or chicks and better physical condition of female parents. Not all species reacted similarly. Six studies including a literature review did not find any evidence for increased reproductive success in at least one of the species supplied with supplementary calcium. One replicated study from Europe found that birds took calcium supplied, and birds at polluted sites took more than those at cleaner sites. The effects on fitness were not monitored.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F559https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F559Sun, 23 Sep 2012 15:19:49 +0100Collected Evidence: Collected Evidence: Thin trees within forests: effects on young trees Six of twelve studies (including two replicated, randomized, controlled studies) in Japan and the USA found that thinning trees in forests increased the density of young trees. One study found that thinning decreased the density of young trees. Five found no effect or mixed effects on the density of young trees. One replicated, controlled study in the USA found no effect of thinning on the density of oak acorns. One controlled study in Peru found that thinning increased the growth rate of young trees. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1210https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1210Thu, 19 May 2016 15:49:33 +0100Collected Evidence: Collected Evidence: Log/remove trees within forests: effects on understory plants Five of ten studies (including four replicated, randomized, controlled studies) in Bolivia, Canada, India and the USA found that logging trees in forests increased the density and cover of understory plants. Five studies found no effect or mixed effects. Four of seven studies (including one replicated, randomized, controlled study) in Australia, Canada and the USA found that logging trees in forests increased species richness and diversity of understory plants. Three studies found no effect.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1273https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1273Mon, 13 Jun 2016 09:29:47 +0100Collected Evidence: Collected Evidence: Pest regulation: Use no tillage in arable fieldsPest regulation (0 studies) Crop damage (1 study): One replicated, controlled study from Syria found no differences in most diseases between plots with no tillage or conventional tillage, but found a higher incidence of Aschochyta blight in plots with no tillage. Ratio of natural enemies to pests (0 studies) Pest numbers (9 studies) Weeds (8 studies): Three replicated, controlled studies (two randomized) from Italy and Spain found more weeds in plots with no tillage, compared to conventional tillage, in some comparisons. Four replicated, controlled studies (three randomized) from Italy, Spain, and the USA found inconsistent differences in weeds (sometimes more weeds in plots with no tillage, sometimes fewer). One replicated, randomized, controlled study from Lebanon found similar numbers of weeds in plots with or without tillage. Weed species (4 studies): One replicated, randomized, controlled study from Italy found more weed species in plots with no tillage, compared to conventional tillage. Three replicated, controlled studies (two randomized) from Italy and Spain found similar numbers of weed species in plots with or without tillage. Other pests (1 study): One replicated, controlled study from Italy found fewer parasitic plants (broomrapes) in plots with no tillage, compared to conventional tillage. Natural enemy numbers (1 study): One replicated, controlled study from the USA found similar numbers of predatory mites in plots with or without tillage.Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1397https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1397Fri, 19 May 2017 09:00:38 +0100Collected Evidence: Collected Evidence: Other biodiversity: Use fewer grazersAmphibians (0 studies) Birds (0 studies) Invertebrates (1 study): One replicated, randomized, controlled study in wet grasslands in the USA found more families of insects in streams in areas grazed by cattle at lower, compared to higher, intensities. Mammals (0 studies) Plants (11 studies) Abundance (11 studies): Six studies (four replicated, randomized, and controlled) in grasslands or wood pasture in the USA, Chile, and Israel found higher cover of some species of plants, herbaceous plants, or native plants in areas grazed by cattle or sheep at lower, compared to higher, intensities. One controlled study in forest in Israel found higher cover of woody vegetation in areas with lower grazing intensity. Four of these studies also found lower cover or biomass of some groups of plants in sites with lower grazing intensity. Four studies in grasslands in the USA and Israel found no effect of grazing intensity on biomass, cover, or abundance of plants. Diversity (6 studies): Three replicated, randomized, controlled studies in grasslands and wet grasslands in the USA and Israel found no differences in plant diversity between sites with different cattle-grazing intensities, in some or all comparisons. One of these also found higher diversity in some comparisons and lower diversity in others. One replicated, randomized, controlled study in wet grasslands in the USA found that plant community composition differed in sites with different cattle-grazing intensities, in some comparisons. Two replicated, randomized, controlled studies in grasslands and wet grasslands in Israel and the USA found no differences in the number of plant species between sites with different cattle grazing intensities, in some or all comparisons. One of these studies also found more species in some comparisons and fewer species in others. One controlled study in wood pasture in Chile found fewer native species and more non-native species in paddocks with lower sheep-grazing intensities. Survival (3 studies): Three controlled studies (two replicated and randomized) in grasslands in the USA and forests in Israel found no difference in native grass, tree, or shrub survival in areas grazed by cows at lower, compared to higher, intensities. Reptiles (0 studies) Implementation options (0 studies)Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1418https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1418Fri, 19 May 2017 11:23:37 +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%2Fconservationevidencejournal.com%2Factions%2F1545https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1545Thu, 19 Oct 2017 17:12:06 +0100Collected Evidence: Collected Evidence: Reintroduce primates into habitat where the species is absent One study in The Gambia found that a population of reintroduced chimpanzees increased over 25 years after reintroduction into habitat where the species was absent, alongside other interventions. One controlled study in Indonesia found that all Sumatran orangutans survived for at least three months after reintroduction into habitat where the species was absent, alongside other interventions. One before-and-after study in the Republic of Congo found that a majority of reintroduced gorillas survived for at least four years after reintroduction into habitat where the species was absent, alongside other interventions. One study in Thailand found that a reintroduced population of lar gibbons declined over three years following reintroduction into habitat where the species was absent, alongside other interventions. One study in India found that a population of reintroduced rhesus monkeys persisted for at least four years after reintroduction. Six studies (including four before-and-after studies) in Belize, Gabon, Madagascar, Malaysia, South Africa, and Vietnam found that a majority of primates survived for two to thirty months after reintroduction into habitat where the species was absent, alongside other interventions. Two studies in Malaysia and Vietnam found that a minority of primates survived after between three months and 12 years. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1590https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1590Fri, 20 Oct 2017 13:38:29 +0100Collected Evidence: Collected Evidence: Rehabilitate injured/orphaned primates One before-and-after study in Brazil found that most reintroduced golden lion tamarins did not survive over seven years, despite being rehabilitated, alongside other interventions. Two before-and-after studies in South Africa found that most reintroduced vervet monkeys survived over six months after being rehabilitated before release, alongside other interventions. Two before-and-after studies in the Republic of Congo found that most reintroduced chimpanzees survived over 3.5–5 years after undergoing pre-release rehabilitation, alongside other interventions. One study in The Gambia found that numbers of reintroduced chimpanzees that underwent pre-release rehabilitation, alongside other interventions, increased by 38% over 25 years. One review on bonobos, chimpanzees and gorillas in 13 African countries found that rehabilitated bonobos living in sanctuaries did not reproduce but the reproductive rate of chimpanzees was 14% and of gorillas was 2%. One controlled study in Indonesia found that Bornean agile gibbons that were rehabilitated before release, alongside other interventions, behaved similarly to wild gibbons. One controlled study in Malaysia found that numbers of reintroduced orangutans decreased by 33% over 33 years, despite orangutans being rehabilitated before release. One controlled study in Indonesia found that most translocated orangutans that were rehabilitated before release, along with other interventions, survived over three months. One before-and-after, site comparison study in the Congo and Gabon found that most western lowland gorillas that were rehabilitated before release, alongside other interventions, survived over four years. One before-and-after study in Gabon found that one out of two western lowland gorillas that were reintroduced died despite being rehabilitated, alongside other interventions. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1597https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1597Fri, 20 Oct 2017 14:47:02 +0100Collected Evidence: Collected Evidence: Cover peatland with organic mulch (after planting) Twelve studies evaluated the effects, on peatland vegetation, of adding organic mulch after planting peatland plants. Nine studies were in bogs (one being restored as a fen). Two studies were in fens. One was in a tropical peat swamp. Germination (1 study): One replicated, controlled, before-and-after study in a bog in Germany found that mulching after sowing seeds increased germination rates for two species (a grass and a shrub), but had no effect on three other herb species. Survival (3 studies): Two replicated, paired, controlled studies in a fen in Sweden and a bog in the USA reported that mulching increased survival of planted vegetation (mosses or sedges). One replicated, paired, controlled study in Indonesia reported that mulching with oil palm fruits reduced survival of planted peat swamp tree seedlings. Growth (1 study): One replicated, randomized, paired, controlled, before-and-after study in a fen in the USA reported that mulching increased growth of transplanted sedges. Cover (9 studies): Six studies (including four replicated, randomized, paired, controlled, before-and-after) in bogs in Canada and the USA and a fen in Sweden found that mulching after planting increased vegetation cover (specifically total vegetation, total mosses/bryophytes, Sphagnum mosses or vascular plants after 1–3 growing seasons). Three replicated, randomized, paired, controlled, before-and-after studies in degraded bogs in Canada found that mulching after planting had no effect on vegetation cover (Sphagnum mosses or fen-characteristic plants). Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1828https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1828Tue, 28 Nov 2017 08:51:42 +0000Collected Evidence: Collected Evidence: Create artificial reefs Twelve studies examined the effects of creating artificial reefs on subtidal benthic invertebrate populations. Three studies were in the Mediterranean Sea (Italy); three were in the North Atlantic Ocean (USA, Portugal, France); one in the Firth of Lorn (UK); two in the North Pacific Ocean (USA); one in the English Channel (UK), one in the Gulf of Mexico (USA); and one in the Yellow Sea (China).   COMMUNITY RESPONSE (8 STUDIES) Overall community composition (3 studies): Two site comparison studies (one replicated) in the English Channel and North Atlantic Ocean found that invertebrate communities growing on artificial reefs were different to that of natural reefs. One replicated study the North Pacific Ocean found that invertebrate community composition changed over time on an artificial reef. Overall richness/diversity (6 studies): Two site comparison studies (one replicated) in the Mediterranean Sea and North Atlantic Ocean found that invertebrate species richness and/or diversity on the artificial reef or in the sediments inside and adjacent to the reef area were lower compared to on natural reefs or in nearby natural sediments. One replicated, site comparison study in the Gulf of Mexico found that artificial breakwaters had more species of nekton compared to adjacent mudflats. One site comparison study in English Channel recorded 263 taxa on the artificial reef, including at least nine not recorded on nearby natural reefs but excluding at least 39 recorded on natural reefs. One replicated study in the North Pacific Ocean found a 49% increase in species richness over five years on an artificial reef. One study in the North Atlantic Ocean found that artificial reefs hosted at least five species of large mobile invertebrates. Mollusc richness/diversity (1 study): One replicated, site comparison study in the Mediterranean Sea found that mollusc species richness and diversity were lower on artificial reefs compared to natural reefs. Worm community composition (1 study): One replicated, site comparison study in the North Pacific Ocean found that polychaete worm community composition was similar at one of two artificial reefs compared to a natural reef. Worm richness/diversity (1 study): One replicated, site comparison study in the North Pacific Ocean found that polychaete worm species richness and diversity were similar at one of two artificial reefs compared to a natural reef, but lower at the second artificial reef. POPULATION RESPONSE (12 STUDIES) Overall abundance (10 studies): One of two site comparison studies (one replicated) in the Mediterranean Sea found that abundance of invertebrates in the sediment was lower at the reef sites than in nearby natural sediments, but increased in the sediments directly adjacent to the reefs, while the other study found that abundance was similar in the sediments inside and directly adjacent to the artificial reef area, but lower than in nearby natural sediments. Of five site comparison studies (four replicated) in the North Pacific Ocean, the North Atlantic Ocean, the Gulf of Mexico and the Yellow Sea, one found that invertebrate biomass was higher on the artificial reef than in adjacent natural sediments, two that invertebrate abundance and biomass and nekton abundance were similar on artificial reefs and natural habitats (reef; mudflat), and two found mixed effects on abundances of invertebrates. One site comparison study in the English Channel reported that the abundances of some species were lower on the artificial reef compared to natural reefs. One replicated study in the North Pacific Ocean reported an 86% increase in invertebrate abundance growing on an artificial reef over five years. One study in the North Atlantic Ocean found that two of five species at one artificial reef, and three of seven at another, were recorded during >50% of dives. Overall condition (1 study): One replicated, site comparison study in the Yellow Sea found mixed effects of creating an artificial reef on the sizes of mobile invertebrates. Mollusc abundance (1 study): One replicated, site comparison study in the Mediterranean Sea found that mollusc abundance was lower on artificial reefs compared to natural reefs. Crustacean abundance (1 study): One replicated, site comparison in the Firth of Lorn found that abundances of edible crabs and velvet swimming crabs were typically higher on artificial than natural reefs. OTHER (1 STUDY) Biological production (1 study): One site comparison study in North Atlantic Ocean found that secondary production was higher from invertebrates growing on an artificial reef than from invertebrates in adjacent natural sediments. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2258https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2258Wed, 23 Oct 2019 10:26:30 +0100Collected Evidence: Collected Evidence: Use guardian animals (e.g. dogs, llamas, donkeys) bonded to livestock to deter predators to reduce human-wildlife conflict Twelve studies evaluated the effects of using guardian animals (e.g. dogs, llamas, donkeys) bonded to livestock to deter mammals from predating these livestock to reduce human-wildlife conflict. Four studies were in the USA, two were in Kenya and one each was in Solvakia, Argentina, Australia, Cameroon, South Africa, and Namibia. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (12 STUDIES) Human-wildlife conflict (12 studies): Four of seven studies, (including four site comparison studies), in the USA, Kenya, Solvakia, Australia and Cameroon, found that guardian animals reduced attacks on livestock by predators. The other three studies reported mixed results with reductions in attacks on some but not all age groups or livestock species and reductions for nomadic but not resident pastoralists. Two studies, (including one site comparison study and one before-and-after study), in Argentina and Namibia, found that using dogs to guard livestock reduced the killing of predators by farmers but the number of black-backed jackals killed by farmers and dogs combined increased. A replicated, controlled study in the USA found that fewer sheep guarded by llamas were predated by carnivores in one of two summers whilst a replicated, before-and-after study in South Africa found that using dogs or alpacas to guard livestock reduced attacks by predators. A randomized, replicated, controlled study in USA found that dogs bonded with livestock reduced contact between white-tailed deer and domestic cattle. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2433https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2433Tue, 02 Jun 2020 08:41:54 +0100Collected Evidence: Collected Evidence: Restore former mining sites Twelve studies evaluated the effects of restoring former mining sites on mammals. Eleven studies were in Australia and one was in the USA. COMMUNITY RESPONSE (8 STUDIES) Species richness (8 studies): A review in Australia found that seven of 11 studies indicated that rehabilitated areas had lower mammal species richness compared to unmined areas. Four of five replicated, site comparison studies, in Australia, found that mammal species richness was similar in restored mine areas compared to unmined areas or higher in restored areas (but similar when considering only native species). One study found that species richness was lower in restored compared to in unmined areas. A replicated, controlled study in Australia found that thinning trees and burning vegetation as part of mine restoration did not increase small mammal species richness. A replicated, site comparison study in Australia found that restored mine areas were recolonized by a range of mammal species within 10 years. POPULATION RESPONSE (5 STUDIES) Abundance (5 studies): A review of rehabilitated mine sites in Australia found that only two of eight studies indicated that rehabilitated areas had equal or higher mammal densities compared to those in unmined areas. One of three replicated, site comparison studies, in the USA and Australia, found that small mammal density was similar on restored mines compared to on unmined land. One study found that for three of four species (including all three native species studied) abundance was lower in restored compared to unmined sites and one study found mixed results, including that abundances of two out of three focal native species were lower in restored compared to unmined sites. A replicated, controlled study in Australia found that thinning trees and burning vegetation as part of mine restoration did not increase small mammal abundance. BEHAVIOUR (2 STUDIES) Use (2 studies): A replicated, site comparison study in Australia found that most restored former mine areas were not used by koalas while another replicated site comparison study in Australia found quokka activity to be similar in revegetated mined sites compared to in unmined forest. OTHER (1 STUDY) Genetic diversity (1 study): A site comparison study in Australia found that in forest on restored mine areas, genetic diversity of yellow-footed antechinus was similar to that in unmined forest. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2490https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2490Thu, 04 Jun 2020 14:08:11 +0100Collected Evidence: Collected Evidence: Use repellents that taste bad (‘contact repellents’) to deter crop or property damage by mammals to reduce human-wildlife conflict Twelve studies evaluated the effects of using repellents that taste bad (‘contact repellents’) to deter crop or property damage by mammals to reduce human-wildlife conflict. Nine studies were in the USA, two were in the UK and one was in Italy. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES) OTHER (12 STUDIES) Human-wildlife conflict (12 studies): Five of 11 controlled studies (including 10 replicated studies), in the USA, Italy and the UK, of a range of contact repellents, found that they reduced herbivory or consumption of baits. The other six studies reported mixed results with at least some repellents at some concentrations deterring herbivory, sometimes for limited periods. A replicated, controlled study in the USA found that a repellent did not prevent chewing damage by coyotes. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2509https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2509Thu, 04 Jun 2020 16:44:38 +0100Collected Evidence: Collected Evidence: Install barrier fencing along roads Twelve studies evaluated the effects on mammals of installing barrier fencing along roads. Eight studies were in the USA, one each was in Canada, Germany and Brazil and one spanned the USA, Canada and Sweden. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (9 STUDIES) Survival (9 studies): Three controlled studies, in the USA, Germany and Brazil, found that roadside fencing or equivalent barrier systems reduced the numbers of mammals, including wildcats and coypu, killed by vehicles on roads. Two before-and-after studies, in the USA, found that roadside fencing with one-way gates to allow escape from the road, reduced the number of collisions between vehicles and deer. A study in the USA found that a 2.7-m-high fence did not reduce road-kills of white-tailed deer compared to a 2.2-m-high fence. A controlled, before-and-after study in the USA found that barrier fencing with designated crossing points did not significantly reduce road deaths of mule deer. A replicated, controlled, before-and-after study in Canada found that electric fences, (along with an underpass beneath one highway), reduced moose-vehicle collisions. A review of fencing studies from USA, Canada and Sweden, found that longer fencing along roadsides led to a greater reduction of collisions between large mammals and cars than did shorter fence sections. BEHAVIOUR (5 STUDIES) Behaviour change (5 studies): A controlled, before-and-after study in the USA found that 2.3-m-high fencing in good condition prevented most white-tailed deer accessing a highway. A replicated, controlled, before-and-after study in Canada found that electric fences reduced moose access to highways. Three studies (two replicated), in the USA, found that higher fences (2.4–2.7 m) prevented more white-tailed deer from entering highways than did fences that were 2.2 m high, 1.2 m high with outriggers or 1.2–1.8 m high. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2567https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2567Tue, 09 Jun 2020 14:55:48 +0100Collected Evidence: Collected Evidence: Thin trees within forest Twelve studies evaluated the effects on mammals of thinning trees within forests. Six studies were in Canada and six were in the USA. COMMUNITY RESPONSE (2 STUDIES) Species richness (2 studies): A replicated, site comparison study the USA found that in thinned tree forest stands, there was similar mammal species richness compared to in unthinned stands. A replicated, controlled study in Canada found that thinning of regenerating lodgepole pine did not increase small mammal species richness 12–14 years later. POPULATION RESPONSE (8 STUDIES) Abundance (8 studies): Three of eight replicated, controlled and replicated, site comparison studies, in the USA and Canada, found that thinning trees within forests lead to higher numbers of small mammals. Two studies showed increases for some, but not all, small mammal species with a further study showing an increase for one of two squirrel species in response to at least some forest thinning treatments. The other two studies showed no increases in abundances of small mammals or northern flying squirrels between 12 and 14 years after thinning. BEHAVIOUR (4 STUDIES) Use (4 studies): Three of four controlled and comparison studies (three also replicated, one randomized) in Canada found that thinning trees within forests did not lead to greater use of areas by mule deer, moose or snowshoe hares. The other study found that a thinned area was used more by white-tailed deer than was unthinned forest. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2650https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2650Sat, 13 Jun 2020 18:09:47 +0100Collected Evidence: Collected Evidence: Hand-rear orphaned or abandoned marine and freshwater mammal young Twelve studies evaluated the effects of hand-rearing orphaned or abandoned marine and freshwater mammal young. Four studies were in the North Pacific Ocean (USA), two studies were in captive facilities (USA), and one study was in each of the North Atlantic Ocean (USA), the Indian River Lagoon (USA), the Salish Sea (USA), the Guerrero Lagoon (USA), the South Atlantic Ocean (Brazil) and water bodies in Florida (USA). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (11 STUDIES) Reproductive success (1 study): One replicated study in the South Atlantic Ocean found that most captive-reared Antillean manatees released back into the wild reproduced. Survival (11 studies): Three studies (including one replicated and controlled study) in the North Pacific Ocean, and the Indian River Lagoon found that a gray whale calf, three Steller sea lion pups, and a common bottlenose dolphin calf that were released after being reared in captivity survived during post-release monitoring periods of between three days to three months. Two replicated studies in the South Atlantic Ocean and water bodies in Florida found that approximately three-quarters of Antillean manatees and two-thirds of Florida manatees that were captive-reared and released were known to survive for at least one year, and some survived for more than seven years. Three studies in the North Atlantic Ocean, the North Pacific Ocean and the Guerrero Lagoon found that three West Indian manatee calves, seven Hawaiian monk seal pups and one Antillean manatee calf that were captive-reared either died before or after release, had to be returned to captivity after release, or survived in the wild only with supplemental feeding. Two studies at captive facilities found that a captive-reared grey whale calf and five pygmy and dwarf sperm whale calves increased in body weight but were either not released or died in captivity. One controlled study in the North Pacific Ocean found that captive-reared, released Pacific harbour seal pups had similar survival estimates to wild pups. BEHAVIOUR (3 STUDIES) Behaviour change (3 studies): Two controlled studies (including one replicated study) in the North Pacific Ocean found that captive-reared and released Pacific harbour seal pups and Steller sea lion pups had similar diving behaviour to wild pups. One controlled study in the Salish Sea found that captive-reared and released harbour seal pups travelled greater distances and further from the release site than wild pups born at the same site and in the same season. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2926https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2926Tue, 09 Feb 2021 10:51:31 +0000Collected Evidence: Collected Evidence: Exclude wild vertebrates: freshwater marshes Twelve studies evaluated the effects, on vegetation, of physically excluding wild vertebrates from freshwater marshes. Six studies were in the USA. Three studies were in the Netherlands, two were in Australia and one was in Canada. The problematic vertebrates were birds in five studies, mammals in four studies, fish in one study, and mixed taxa in two studies. Two studies were conducted in the same area, but with different experimental set-ups. VEGETATION COMMUNITY Overall extent (1 study): One before-and-after study in a freshwater marsh in Canada found that after two years of excluding common carp Cyprinus carpio, the area of emergent vegetation was similar to the area expected based on the water level and historical data (when carp were present). Community composition (1 study): One replicated, randomized, paired, controlled study in freshwater marshes in Australia found that areas fenced to exclude wild mammals typically had a similar overall plant community composition to open areas, over 14 years. Overall richness/diversity (4 studies): Three replicated, randomized, paired, controlled studies in freshwater marshes in the USA and Australia reported that fencing to exclude wild mammals had no clear or significant effect on total plant species richness. One replicated, paired, controlled study in freshwater marshes in the Netherlands found that fenced plots had higher emergent plant species richness than open plots, but similar diversity. VEGETATION ABUNDANCE Overall abundance (7 studies): Seven replicated, controlled studies (three also randomized and paired) involving freshwater marshes in the USA, the Netherlands and Australia found that areas fenced to exclude wild vertebrates contained at least as much vegetation as open areas – and typically more. This was true for biomass (fenced > open in six of six studies), cover (fenced > open in two of two studies) and stem density (fenced similar to open in one of one studies). Vegetation was monitored over the winter immediately after fencing, or after 1–4 growing seasons. Individual species abundance (8 studies): Eight studies quantified the effect of this action on the abundance of individual plant species. For example, seven replicated, controlled studies (four also paired, two also randomized) in freshwater marshes in the USA, the Netherlands and Australia found that dominant plant species had similar or greater abundance in areas fenced to exclude wild vertebrates, after 1–3 growing seasons, than in areas open to wild vertebrates. The dominant species included switchgrass Panicum virgatum, cordgrasses Spartina spp. and wild rice Zizania aquatica. VEGETATION STRUCTURE Height (1 study): One replicated, paired, controlled study in freshwater marshes in the USA found that plots fenced to exclude Canada geese Branta canadensis contained taller wild rice Zizania aquatica than open plots in two of three comparisons. In the other comparison, after two years of goose control, fenced and open plots contained wild rice of a similar height. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3132https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3132Mon, 05 Apr 2021 12:15:49 +0100Collected Evidence: Collected Evidence: Restore former mining or energy production sites Thirteen studies evaluated the effects of restoring former mining or energy production sites on reptile populations. Nine studies were in Australia, two were in the USA, one was in Spain and one was on Reunion Island. COMMUNITY RESPONSE (8 STUDIES) Community composition (4 studies): Two of four site comparison studies (including two replicated studies) in Austalia and Spain found that restored mining areas hosted different reptile communities than unmined areas. One study found that reptile communities in the oldest restored areas were most similar to unmined areas. The other study found that restored mining areas that were seeded or received topsoil had similar community composition compared to surrounding unmined forests. Richness/diversity (5 studies): Two replicated, site comparison studies and one review in Australia found that restored mining sites had lower reptile species richness than unmined sites. One replicated, before-and-after, site comparison study in Spain found that after restoration, reptile species richness increased steadily over a six-year period. One replicated, site comparison study in Australia found that restored areas supported most of typical reptile species found in the wider habitat. POPULATION RESPONSE (8 STUDIES) Abundance (7 studies): Five of six replicated, site comparison studies and one review in Australia found that in restored mining areas reptiles tended to be less abundant than in unmined areas. The other study found mixed effects of restoration on reptile abundance. One replicated, controlled study in Australia found that restored areas that were thinned and burned 10–18 years after restoration began had higher reptile abundance than restored areas that were not thinned and burned. Reproductive success (2 studies): One review in Australia found that one study reported reptiles breeding in restored mining areas. One study on Reunion Island found that four of 34 and eight of 40 artificial egg laying sites in restored mining areas were used by Reunion day geckos nine months and two years after installation respectively. Condition (1 study): One review of restoration of mining sites in Australia found that three of three studies indicated that reptile size or condition was similar in restored mines and undisturbed areas. BEHAVIOUR (5 STUDIES) Use (4 studies): Three studies (including one replicated, site comparison study) in Australia and the USA found that restored mining areas were occupied by up to 14 snake, five turtle and one lizard species, or that generalist reptile species colonized restoration sites more quickly than did specialist species. One replicated, controlled study in Australia found that Napoleon’s skinks reintroduced to a restored mining site all moved to an unmined forest within one week of release. Behaviour change (1 studies): One review of restoration of mining sites in Australia reported that one of one studies indicated that there were changes in behaviour of lizards between restored mines and undisturbed areas. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3497https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3497Mon, 06 Dec 2021 12:43:42 +0000Collected Evidence: Collected Evidence: Install exclusion devices on fishing gear: Tortoises, terrapins, side-necked & softshell turtles Thirteen studies evaluated the effects of installing exclusion devices on fishing gear on tortoise, terrapin, side-necked & softshell turtle populations. Ten studies were in the USA, two were in Canada and one was in Australia. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Survival (1 study): One replicated, randomized, paired, controlled study in the USA found that fewer turtles died in hoop nets with an exclusion device than in unmodified traps. BEHAVIOUR (1 STUDY) Use (1 study): One randomized, controlled trial in the USA found mixed effects of crab pot exclusion devices on use of pots by diamondback terrapins depending on the device design. OTHER (13 STUDIES) Unwanted catch (13 studies): Eight of 13 controlled studies (including seven replicated, paired studies) in the USA, Australia and Canada found that crab pots, fyke nets, hoop nets and eel traps with exclusion devices caught fewer turtles, diamond back terrapins and short-necked turtles than unmodified gear. Two studies also found that modified gear caught smaller short-necked turtles and diamondback terrapins than unmodified gear. Three studies found mixed effects of exclusion devices on unwanted catch of turtles and diamondback terrapins depending on the device design. The other two studies found that that crab pots with wire exclusion devices or magnetized exclusion devices caught a similar number of diamondback terrapins compared to unmodified pots. One study also found that crab pots with wire exclusion devices caught larger diamondback terrapins than pots with plastic exclusion devices. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3590https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3590Wed, 08 Dec 2021 16:11:04 +0000Collected Evidence: Collected Evidence: Breed reptiles in captivity: Snakes – Vipers Thirteen studies evaluated the effects of breeding vipers in captivity. Nine studies were in the USA, three were in unknown locations and one was in Columbia. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (13 STUDIES) Reproductive success (13 studies): Thirteen studies in the USA, Columbia and unknown locations reported that 1–4 female vipers, including three captive-bred offsping, produced litters of 1–18 live young or clutches of 1–26 eggs with hatching success of 63–81%. One study also reported that none of three Chocoan bushmaster eggs that were removed and incubated artificially fully developed. Survival (5 studies): Three studies in the USA and one in an unknown location reported that of 10–49 captive-bred young snakes, 1–9 died soon after birth or within three months. One study also reported that one pair of adult adders died shortly after arriving in captivity. One study in an unknown location reported that four captive-bred Radde’s vipers survived for at least eight months Condition (1 study): One study in an unknown location reported that two of 10 captive-bred Nikolsky's adders had some physical deformities. BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES) Offspring sex ratio (2 studies): Two studies in the USA and an unknown location reported that the sex ratio of captive-bred lower California rattlesnakes was 2:12 and Russell's vipers was 8:6 females to males. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3753https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3753Tue, 14 Dec 2021 13:32:11 +0000Collected Evidence: Collected Evidence: Relocate nests/eggs to a nearby natural setting (not including hatcheries): Sea turtles Thirteen studies evaluated the effects of relocating nests/eggs to a nearby natural setting on sea turtle populations. Five studies were in the USA, two were in Suriname and the US Virgin Islands and one was in each of Costa Rica, Ascension Island, Brazil and Cape Verde. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (12 STUDIES) Reproductive success (12 studies): Four of 12 controlled studies (including three replicated, randomized studies) in the USA, Suriname, US Virgin Islands, Costa Rica, Ascension Island, Brazil and Cape Verde found that relocated sea turtle nests had lower hatching success than natural nests in six of seven years, in 26 of 29 years, or lower hatching success than nests laid above the tidal zone, or that nests relocated >10 days after being laid had lower hatching and emergence success than natural nests or nests relocated within 12 hours. One of those studies also found that relocating nests within 12 hours had mixed effects on hatching and emergence success compared to natural nests. One study also found that two different egg collecting methods resulted in either more dead early stage or late-stage embryos. Four of the studies found that relocated sea turtle nests had similar hatching and emergence success or hatching success compared to natural nests and specifically compared to those laid in safer parts of the beach or above the high tide line. One of those studies also found that relocated nests experienced similar levels of predation by ghost crabs as natural nests. One of the studies also found that fewer relocated nests failed completely due to tidal flooding compared to natural nests. One of the studies found that relocated loggerhead turtle nests had higher hatching success than natural nests. One of the studies found that relocated leatherback turtle nests had higher hatching success compared to natural nests that were washed over by sea swells, but similar hatching success compared to natural nests that were not washed over by sea swells. The other two studies found that relocating sea turtle nests had mixed effects on hatching or hatching and emergence success compared to natural nests. One of those studies also found that in years when leatherback turtle nests were relocated, fewer were lost to erosion than when no relocations took place. Condition (1 study): One replicated, randomized, controlled study in the USA found that hatchlings from relocated loggerhead turtle nests were a similar size to hatchlings from natural nests. BEHAVIOUR (0 STUDIES) OTHER (1 STUDY) Offspring sex ratio (1 study): One replicated, randomized, controlled study in Suriname found that relocated leatherback turtle nests produced all female hatchlings, whereas 30–100% of hatchlings from naturally incubated nests were female. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3781https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3781Wed, 15 Dec 2021 14:46:00 +0000Collected Evidence: Collected Evidence: Increase or maintain the proportion of natural or semi‐natural habitat in the farmed landscape Twelve studies evaluated the effects of increasing or maintaining the proportion of natural or semi-natural habitat in the farmed landscape on butterflies and moths. Three studies were in Switzerland, two were in each of Germany, Sweden and the UK, and one was in each of the USA, Malaysia, and New Zealand. COMMUNITY RESPONSE (11 STUDIES) Richness/diversity (11 studies): Nine of eleven studies (including one replicated, randomized, controlled study, one before-and-after study and eight replicated, site comparison studies) in Germany, Sweden, Malaysia, Switzerland, the UK, and New Zealand found that the species richness of butterflies, burnet moths and all moths was higher on farms with a greater proportion of semi-natural habitat or with a greater proportion of woodland in the surrounding landscape, or after semi-natural habitat had been created, compared to conventional farmland or farmland with a greater proportion of arable land in the surrounding landscape. One study found that species richness of butterflies in oil palm plantations was higher where ground coverage of weeds had been maintained but similar whether or not epiphyte or fern coverage was maintained. The eleventh study found that the species richness of butterflies was similar on farms with different proportions of semi-natural habitat. POPULATION RESPONSE (8 STUDIES) Abundance (8 studies): Six replicated studies (including one randomized, controlled study and five site comparison studies) in Sweden, the UK, New Zealand, and Switzerland found that the abundance of butterflies and moths was higher on farms with a greater proportion of semi-natural habitat, or in semi-natural habitat compared to conventional farmland. One of two replicated, site comparison studies in the USA and Sweden found that the abundance of four out of eight species of butterflies was higher on farms surrounded by woodland, but the abundance of least skipper was lower on farms with more semi-natural habitat. The other study found that overall butterfly abundance was similar on farms surrounded by different proportions of woodland and arable land. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3910https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3910Wed, 10 Aug 2022 14:34:14 +0100Collected Evidence: Collected Evidence: Reduce management intensity on permanent grasslands (several interventions at once) Twelve studies evaluated the effects on butterflies and moths of reducing management intensity on permanent grasslands. Seven studies were in Switzerland, three were in the UK, and one was in each of Greece and Germany. COMMUNITY RESPONSE (12 STUDIES) Community composition (2 studies): Two replicated studies (including one controlled study and one site comparison study) in Switzerland found that the composition of butterfly communities differed between low-input and intensively managed grasslands. One of these studies found that low-input grasslands tended to have more butterfly species whose caterpillars feed on a single host plant, have one generation/year and poor dispersal ability. Richness/diversity (11 studies): Six of 10 studies (including five controlled studies and five site comparison studies) in Switzerland, the UK, Greece and Germany found that less intensively managed grasslands had a higher species richness of butterflies and moths than conventionally managed grasslands, although two of these studies only found a difference in one of two years or regions. The other four studies found that less intensively managed grasslands had a similar species richness of butterflies and moths to conventionally managed grasslands. However, one of these studies also found that less intensively managed grassland had more specialist species of moths, and species of conservation concern, than conventionally managed grassland. One before-and-after study in the UK found that after grazing was reduced and chemical application stopped, the species richness of large moths increased. POPULATION RESPONSE (5 STUDIES) Abundance (5 studies): Three of four replicated studies (including two controlled studies and two site comparison studies) in Switzerland, the UK and Germany found that low-input or unfertilized, ungrazed grassland managed with a single cut had a higher abundance of butterflies, micro-moths and declining macro-moths than intensively managed grassland. Two of these studies also found that the abundance of caterpillars and of all macro-moths was similar between less intensively and more intensively managed grasslands. The other study found that less intensively managed grassland had a similar abundance of moths to more intensively managed grassland. One before-and-after study in the UK found that after grazing was reduced and chemical application stopped, the total abundance of large moths and the abundance of five out of 23 butterfly species increased, but the abundance of two butterfly species decreased. BEHAVIOUR (1 STUDY) Use (1 study): One replicated, site comparison study in Germany reported that 24 out of 58 moth species preferred less intensively managed grasslands, but 12 species preferred more intensively managed grasslands. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3958https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3958Sun, 14 Aug 2022 10:37:05 +0100
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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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