Collected Evidence: Collected Evidence: Foster eggs or chicks of gannets and boobies with wild conspecificsA small controlled study in Australia found that Australasian gannet chicks Morus serrator were lighter, and hatching and fledging success lower in nests which had an additional egg or chick added. However, overall productivity was (non-significantly) higher in experimental nests.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F507https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F507Thu, 06 Sep 2012 14:17:32 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of waders with wild conspecifics Two small trials in North America found that piping plovers Charadrius melodus accepted chicks introduced into their broods, although in one case the chick died later the same day. A replicated study from New Zealand found that survival of fostered black stilts Himantopus novasezelandiae was higher for birds fostered to conspecifics rather than a closely related species.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F508https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F508Thu, 06 Sep 2012 14:30:39 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of vultures with wild conspecificsTwo small studies, one a New World vulture and one of an Old World species found that single chicks were successfully adopted by foster conspecifics, although in one case this led to the death of one of the foster parents’ chicks.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F509https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F509Thu, 06 Sep 2012 14:34:30 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of raptors with wild conspecifics Ten out of 11 studies from across the world found that fostering raptor chicks to wild conspecifics had high success rates. A single study from the USA found that only one of six eggs fostered to wild bald eagle Haliaeetus leucocephalus nests were hatched and raised. The authors suggest that the other eggs may have been infertile. A replicated study from Spain found that Spanish imperial eagle Aquila adalberti chicks were no more likely to survive to fledging if they were transferred to foster nests from three chick broods (at high risk from siblicide), compared to chicks left in three-chick broods. A replicated study from Spain found that young (15–20 years old) Montagu's harrier Circus pygargus chicks were successfully adopted, but three older (27–29 day old) chicks were rejected.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F510https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F510Thu, 06 Sep 2012 14:42:31 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of owls with wild conspecifics A replicated study in the USA found high fledging rates for barn owl Tyto alba chicks fostered to wild pairs. A replicated controlled study from Canada found that captive-reared burrowing owl Athene cunicularia chicks fostered to wild nests did not have significantly lower survival or growth rates than wild chicks.    Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F511https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F511Thu, 06 Sep 2012 15:57:35 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of cranes with wild conspecificsA small study in Canada found high rates of fledging for whooping crane Grus americana eggs fostered to first time breeders (which normally have very low fertility).  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F512https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F512Thu, 06 Sep 2012 16:13:08 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of woodpeckers with wild conspecifics Three studies from the USA found that red-cockaded woodpecker Picoides borealis chicks fostered to conspecifics had high fledging rates. One small study found that fostered chicks survived better than chicks translocated with their parents.    Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F514https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F514Thu, 06 Sep 2012 16:29:20 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of parrots with wild conspecifics A replicated study from Venezuela found that yellow-shouldered Amazon Amazona barbadensis chicks had high fledging rates when fostered to conspecific nests in the wild. A second replicated study from Venezuela found significantly lower poaching rates of yellow-shouldered Amazons Amazona barbadensis when chicks were moved to foster nests closer to a field base.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F515https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F515Thu, 06 Sep 2012 16:34:58 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of petrels and shearwaters with wild non-conspecifics (cross-fostering)A replicated and partially controlled study from Hawaii found that Newell’s shearwater Puffinus newelli eggs fostered to wedge-tailed shearwater P. pacificus nests had high fledging rates.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F516https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F516Thu, 06 Sep 2012 16:54:21 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of waders with wild non-conspecifics (cross-fostering) A replicated and controlled study from the USA found that killdeer Charadrius vociferus eggs incubated and raised by spotted sandpipers Actitis macularia had similar fledging rates to parent-reared birds. A replicated and controlled study from New Zealand found that cross-fostering black stilt Himantopus novasezelandiae chicks to black-winged stilt H. himantopus nests significantly increased nest success, but that cross-fostered chicks had lower success than chicks fostered to conspecifics’ nests.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F517https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F517Thu, 06 Sep 2012 17:03:55 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of ibises with wild non-conspecifics (cross-fostering)A 2007 literature review describes attempting to foster northern bald ibis Geronticus eremite chicks with cattle egrets Bubulcus ibis as unsuccessful.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F518https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F518Thu, 06 Sep 2012 17:07:49 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of cranes with wild non-conspecifics (cross-fostering)Two studies from the USA found low fledging success for cranes fostered to non-conspecifics’ nests.    Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F519https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F519Thu, 06 Sep 2012 17:13:19 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of songbirds with wild non-conspecifics (cross-fostering) A replicated study from the USA found that the survival of cross-fostered yellow warbler Dendroica petechia chicks was lower than previously-published rates for the species, although incubation and nestling periods were very similar. A replicated and controlled study from Norway found that the success of cross-fostering small songbirds varied depending on the species of chick and foster birds. However, only great tits P. major raised by blue tits P. caeruleus had lower pairing success than control birds, whilst blue tits raised by coal tits P. ater had higher recruitment than controls, or those raised by great tits.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F520https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F520Thu, 06 Sep 2012 17:37:20 +0100Collected Evidence: Collected Evidence: Freeze semen for use in artificial insemination A small controlled trial in the USA found that using frozen semen for artificial insemination resulted in lower fertility in falcons, and a second small trial from the USA found that an American kestrel Falco sparverius had only 33% fertility when inseminated with frozen semen. A small trial from the USA found that fertility rates were highest when semen contained 10% dimethyl sulphoxide (DMSO, a cryoprotectant), compared to semen containing 6% or 8% DMSO.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F602https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F602Sat, 13 Oct 2012 16:27:01 +0100Collected Evidence: Collected Evidence: Grow non-crop plants that produce chemicals that attract natural enemiesNatural enemies: Four studies from China, Germany, India and Kenya tested the effects of growing plants that produce chemicals that attract natural enemies. Three (including one replicated, randomised, controlled trail) found higher numbers of natural enemies in plots with plants that produce attractive chemicals, and one found that the attractive plant also attracted natural enemies in lab studies. One found no effect on parasitism but the plant used was found not to be attractive to natural enemies in lab studies. Pests: All four studies found a decrease in either pest population or pest damage in plots with plants that produce chemicals that attract natural enemies. Yield: One replicated, randomised, controlled study found an increase in crop yield in plots with plants that produce attractive chemicals. Crops studied were lettuce, orange, safflower and sorghum.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F724https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F724Thu, 30 May 2013 13:11:05 +0100Collected Evidence: Collected Evidence: Freeze sperm or eggs for future use Nine replicated studies (including three controlled studies) in Austria, Australia, Russia, the UK and USA found that following freezing frog and toad sperm viability depended on species and/or cryoprotectant used. One found that although sperm viability was low following freezing, it could be frozen for up to 58 weeks. Five of the studies and one additional replicated study in Australia found that following freezing, viability of sperm and in one case eggs, also depended on storage temperature, storage method, freezing or thawing rate. Seven replicated studies (including three controlled studies) in Austria, Australia, the UK and USA found that frog and toad sperm viability was greatest following freezing with the cryoprotectant dimethyl sulfoxide, glycerol, sucrose or dimethyl formamide.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F876https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F876Thu, 12 Sep 2013 11:09:04 +0100Collected Evidence: Collected Evidence: Grow cover crops beneath the main crop (living mulches) or between crop rowsBiodiversity: One randomized, replicated study from Spain found that cover crops increased bacterial numbers and activity. Erosion: Two studies from France and the USA showed reduced erosion under cover crops. One controlled study showed that soil stability was highest under a grass cover, and one randomized replicated study found that cover crops reduced soil loss. Soil organic matter: Two controlled trials from India and South Africa (one also randomized and replicated) found that soil organic matter increased under cover crops, and one trial from Germany found no effect on soil organic matter levels. SOIL TYPES COVERED: gravelly-sandy loam, sandy loam, sandy, silty loam.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F897https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F897Mon, 30 Sep 2013 14:24:18 +0100Collected Evidence: Collected Evidence: Grow cover crops when the field is emptyBiodiversity: One controlled, randomized, replicated experiment in Martinique found that growing cover crops resulted in more diverse nematode communities. One replicated trial from the USA found greater microbial biomass under ryegrass compared to a ryegrass/vetch cover crop mix. Soil structure: Three randomized, replicated studies from Denmark, Turkey and the UK found that growing cover crops improved soil structure and nutrient retention. One trial found higher soil porosity, interconnectivity and lower resistance in soil under cover crops, and one found reduced nitrate leaching. Soil organic carbon: One replicated study from Denmark and one review based mainly in Japan found increased soil carbon levels under cover crops. One study also found soil carbon levels increased further when legumes were included in cover crops. Soil organic matter: One replicated study from Denmark and three controlled, randomized, replicated studies from Australia and the USA measured the effect of growing cover crops. Three found increased nitrogen levels under cover crops, three found increased carbon, and one found increased nitrates. One trial showed that they increased regardless of whether those crops were legumes or not. Two studies from Europe (including one controlled, replicated trial) found no marked effect on soil organic matter levels. Yield: One replicated trial from the USA found higher tomato yield from soils which had been under a ryegrass cover crop. SOIL TYPES COVERED: clay, loam, sandy clay, sandy-loam, silty-clay, silty-loam.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F898https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F898Mon, 30 Sep 2013 15:43:24 +0100Collected Evidence: Collected Evidence: Fostering appropriate behaviour to facilitate rehabilitation Two before-and-after studies in Brazil found that most reintroduced golden lion tamarins did not survive over 1–7 years, despite being fostered to survive in the wild, alongside other interventions but in one study they reproduced successfully which partly compensated mortality. Two before-and-after studies in Liberia and Congo found that most reintroduced chimpanzees that were fostered to facilitate reintroduction, alongside other interventions, survived over 1-3.5 years. One before-and-after study in Uganda found that a reintroduced chimpanzee repeatedly returned to human settlements despite being fostered to facilitate reintroduction, alongside other interventions. One controlled study in Indonesia found that reintroduced orangutans that were fostered natural behaviour, alongside other interventions, did not act more like wild orangutans than individuals that were not fostered. One study in Indonesia found that reintroduced orangutans that were fostered to facilitate reintroduction, alongside other interventions, fed on fewer plant species and spent more time building nests. One site comparison study in Vietnam found that all reintroduced pygmy slow lorises were assumed dead despite being fostered natural behaviour prior to release, alongside other interventions. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1600https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1600Fri, 20 Oct 2017 15:00:07 +0100Collected Evidence: Collected Evidence: Genetically modify non-native, invasive or other problematic species We found no studies that evaluated the effects of genetically modifying non-native, invasive or other problematic species on subtidal benthic invertebrate populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2170https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2170Tue, 22 Oct 2019 12:19:50 +0100Collected Evidence: Collected Evidence: Graze herbivores on pasture, instead of sustaining with artificial foods One study evaluated the effects of grazing mammalian herbivores on pasture, instead of sustaining with artificial foods. This study was in South Africa. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Reproductive success (1 study): A site comparison study in South Africa found that a population of roan antelope grazed on pasture had a higher population growth rate than populations provided solely with imported feed. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2398https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2398Thu, 28 May 2020 10:46:59 +0100Collected Evidence: Collected Evidence: Gather coarse woody debris into piles after felling Two studies evaluated the effects on mammals of gathering coarse woody debris into piles after felling. Both studies were in Canada. COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): A randomized, replicated, controlled study in Canada found higher mammal species richness where coarse woody debris was gathered into piles. POPULATION RESPONSE (2 STUDIES) Abundance (2 studies): One of two randomized, replicated, controlled studies in Canada found higher counts of San Bernardino long-tailed voles where coarse woody debris was gathered into piles. The other study found higher small mammal abundance at one of three plots where debris was gathered into piles. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2653https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2653Sat, 13 Jun 2020 18:38:30 +0100Collected Evidence: Collected Evidence: Graze with livestock after seeding/planting Seven studies examined the effects of grazing with livestock after seeding/planting on grassland vegetation. Five studies were in Europe, one study was in New Zealand and one was in the USA. VEGETATION COMMUNITY (5 STUDIES) Overall richness/diversity (2 studies): One replicated, randomized, paired, controlled study in Italy found that grazing with livestock after sowing seeds increased plant species richness compared to sowing without grazing. One replicated, controlled study in the UK found that grazing with livestock after sowing seeds reduced plant species richness compared to cutting vegetation after sowing. Sown/planted species richness/diversity (2 studies): One replicated study in the UK found that grazing with cattle after sowing seeds increased sown species richness compared to grazing with sheep. One replicated, randomized, controlled study in New Zealand found that grazing with sheep continuously after sowing seeds did not alter sown species richness compared to grazing on rotation. Native/non-target species richness/diversity (1 study): One replicated, controlled study in the USA found that grazing with cattle after sowing seeds increased native plant species richness compared to sowing without grazing. VEGETATION ABUNDANCE (4 STUDIES) Characteristic plant abundance (1 study): One replicated, controlled study in Hungary found that grazing with livestock after sowing seeds did not alter the cover of target plant species compared to sowing without grazing. Sown/planted species abundance (2 studies): One replicated study in the UK found that grazing with cattle after sowing seeds reduced the cover of sown species compared to grazing with sheep. One replicated, randomized, controlled study in New Zealand found that grazing with sheep continuously after sowing seeds increased the cover of four of eight sown species compared to grazing on rotation. Native/non-target species abundance (1 study): One replicated, controlled study in the USA found that grazing with cattle after sowing seeds reduced the cover of native plant species compared to sowing without grazing. VEGETATION STRUCTURE (0 STUDIES) OTHER (1 STUDY) Survival (1 study): One replicated, randomized, controlled study in the UK found that grazing in the winter after sowing seeds resulted in higher survival of cut-leaved cranesbill seedlings. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3423https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3423Mon, 28 Jun 2021 09:32:18 +0100Collected Evidence: Collected Evidence: Freeze sperm or eggs for future use We found no studies that evaluated the effects of freezing sperm or eggs for future use on reptile 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%2F3760https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3760Tue, 14 Dec 2021 16:06:26 +0000Collected Evidence: Collected Evidence: Grow native trees within perennial crop plantations One study evaluated the effects on butterflies and moths of growing native trees within perennial crop plantations. This study was in Costa Rica. COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): One replicated, site comparison study in Costa Rica found that coffee farms with a native and a non-native tree species growing within them had a higher diversity of butterflies than coffee farms with a single non-native tree species, but a similar diversity to coffee farms with two non-native tree species. The same study found a similar species richness of butterflies on all farms. POPULATION RESPONSE (1 STUDY) Abundance (1 study): One replicated, site comparison study in Costa Rica found that coffee farms with a native and a non-native tree species growing within them had a similar abundance of butterflies to coffee farms with one or two non-native tree species. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3920https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3920Thu, 11 Aug 2022 11:25:19 +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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