Collected Evidence: Collected Evidence: Legally protect habitats Four studies (two replicated) from Europe found population increases following habitat protection, more positive population trends in protected habitats, compared with outside, or with increases amounts of protected habitats. A literature review reported that a large number of cranes (Gruidae) of seven species used nature reserves in China, whilst a replicated, randomised and controlled study from Argentina found that some guilds of birds were found at higher species richnesses in protected forests, some at higher densities, and that some showed no differences. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F158https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F158Tue, 15 May 2012 13:48:22 +0100Collected Evidence: Collected Evidence: Mark or tint windows to reduce collision mortality Two randomised, replicated and controlled studies (one ex situ) found that marking windows did not appear to reduce bird collisions. However, when windows were largely covered with white cloth, fewer birds flew towards them. A randomised, replicated and controlled study found that fewer birds collided with tinted windows than with un-tinted ones, although the authors noted that the poor reflective quality of the glass could have influenced the results. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F167https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F167Sat, 19 May 2012 20:22:28 +0100Collected Evidence: Collected Evidence: Pay farmers to cover the costs of bird conservation measures Three reviews from the UK of three studies captured reported population increases of three species after the introduction of specially-designed agri-environment schemes. These species were cirl buntings, corncrakes and Eurasian thick-knees. One of these found that many other species continued to decline. Twenty-two of 25 studies all from Europe, including a systematic review,  examining local population levels or densities found that at least some birds studied were at higher densities, had higher population levels or more positive population trends on sites with agri-environment schemes, compared to non-agri-environment scheme sites. Some studies found that differences were present in all seasons, others in either summer or winter. Fifteen studies from Europe, including a systematic review, found that some or all species were not found at higher densities, had similar or lower population levels, showed similar population trends on sites with agri-environment schemes, compared with non-agri-environment scheme sites, or showed negative population trends. A study from the Netherlands found that many agri-environment scheme farms were sited in areas where they were unlikely to be effective. One small study from the UK found no differences between winter densities of seed-eating birds on UK Higher Levels Stewardship sites, compared with those under Entry Level Stewardship. A replicated study from the UK found that grey partridge survival was higher on agri-environment scheme sites than non-scheme sites. This difference was not significant every year. Two of three studies investigating reproductive productivity, including one replicated study, found that productivity was higher on farms under agri-environment schemes. One replicated study from the UK found no effect of agri-environment schemes on productivity. A review (Vickery et al. 2010) found that the amount of land entering an agri-environment scheme was on target, but that some options were not being used at high enough rates to help many species. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F172https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F172Sun, 20 May 2012 14:06:41 +0100Collected Evidence: Collected Evidence: Manage hedges to benefit birds The one study of six that investigated species richness found no difference in species richness between a UK site with wildlife-friendly hedge management and three control sites. Seven studies from the UK and Switzerland, five replicated, found that some species studied increased in relation to managed hedges or were more likely to be found in managed hedges, compared to other habitats. Two investigated several interventions at once. One replicated study found that species that showed positive responses to hedge management in some regions showed weak or negative responses in other parts of the UK. Four studies from the UK found that some species declined or showed no response to wildlife-friendly management of hedges. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F177https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F177Wed, 30 May 2012 13:46:53 +0100Collected Evidence: Collected Evidence: Plant wild bird seed or cover mixture All seven studies (based on five replicated experiments and a review) that investigated species richness or diversity were from the UK and found that fields or farms with wild bird cover had higher bird diversity than those without, or that more species were found in wild bird cover than in surrounding habitats. Thirty-two studies out of 33 from the UK and North America that examined abundance and population data, found that bird densities, abundances, nesting densities or use of wild bird cover was higher than in other habitats or management regimes, or that sites with wild bird cover had higher populations than those without. These studies included a systematic review and seven randomised, replicated and controlled studies. Some studies found that this was the case across all species or all species studied, while others found that only a subset showed a preference. Four studies investigated other interventions at the same time. Thirteen of the 33 studies (all replicated and from Europe and the USA), found that bird populations or densities were similar on wild bird cover and other habitats, that some species were not associated with wild bird cover or that birds rarely used wild bird cover. Three studies from the UK and Canada, two replicated, found higher productivities for some or all species monitored on wild bird cover, compared to other habitats. Two replicated and controlled studies from Canada and France found no differences in reproductive success between wild bird cover and other habitats for some or all species studied. Three studies from Europe and the USA investigated survival, with two finding higher survival of grey partridge Perdix perdix released on wild bird cover or of artificial nests in some cover crops. The third found that survival of grey partridge was lower on farms with wild bird cover, possibly due to high predation. Five studies from the UK, three replicated, found that some wild bird cover crops were preferred to others. A randomised, replicated and controlled study and a review from the UK found that the landscape surrounding wild bird cover and their configuration within it affected use by birds.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F187https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F187Sun, 10 Jun 2012 13:10:33 +0100Collected Evidence: Collected Evidence: Create beetle banks A small UK study found that a site with beetle banks had increasing populations of rare or declining species, although several other interventions were used on this site. A literature review from the UK found that grey partridge Perdix perdix populations were far larger on sites with beetle banks and other interventions than on other farms. Two replicated studies from the UK also investigated population-level effects: one found that no bird species were strongly associated with beetle banks; the second found no relationship between beetle banks and grey partridge population density trends. A UK literature review found that two bird species nested in beetle banks and that some species were more likely to forage in them than others. A study in the UK found that one of two species used beetle banks more than expected. The other used them less than other agri-environment options.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F217https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F217Tue, 17 Jul 2012 12:04:26 +0100Collected Evidence: Collected Evidence: Control avian predators on islands Out of 10 studies, six before-and-after studies from North America, Australia and Europe found that controlling avian predators led to increased population sizes, reduced mortality or increased reproductive success in seabirds on islands. The North American studies had several interventions, so increases could not be linked directly to predator control, and one found that increases were only at one of two sites studied. Two controlled studies in Europe found little evidence that crow control led to increased reproductive success in gamebirds or raptors on islands. A North American study found that, despite higher reproductive success, very few birds returned to the study site after predator removal. A study from North America found that an Atlantic puffin Fratercula arctica translocation programme, combined with the culling of predatory gulls, appeared to be successful. A study from the UK found that the number of common terns Sterna hirundo and black-headed gulls Larus ridibundus declined on gravel islands despite the attempted control of large gulls.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F372https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F372Tue, 07 Aug 2012 14:43:03 +0100Collected Evidence: Collected Evidence: Control mammalian predators on islands for pigeonsTwo before-and-after trials on Mauritius found that fewer pink pigeon Columba mayeri nests were predated and more chicks were fledged following systematic and intensive rat control.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F380https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F380Wed, 08 Aug 2012 14:19:04 +0100Collected Evidence: Collected Evidence: Control mammalian predators on islands for songbirds Two before-and-after trials in the Seychelles and Cook Islands describe population increases in magpie robins and monarch flycatchers following cat and rat control. A before-and-after study from New Zealand found that the population of South Island robins Petroica australis australis was almost identical before and after rat control. Two studies found higher reproductive success in monarch flycatchers and shrikes in areas with rodent control, compared to areas without control. However, this was climate dependent in shrikes. A before-and-after study from Hawaii found lower predation on artificial nests after intensive rodent control.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F382https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F382Wed, 08 Aug 2012 14:43:04 +0100Collected Evidence: Collected Evidence: Control predators not on islands for gamebirds Four controlled studies in Europe found increased populations or productivity of grouse and partridges on sites with predator removal. One study tested multiple interventions simultaneously. A fifth replicated UK study found no increase in grouse densities or reproductive success on sites with gamekeepers, compared to those without.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F387https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F387Wed, 08 Aug 2012 17:25:00 +0100Collected Evidence: Collected Evidence: Control or remove habitat-altering mammals Four studies from the Azores and Australia found that seabird populations increased following the eradication of European rabbits Oryctolagus cuniculus or other species, although in three studies there were several other interventions used as well. Two studies from Australia and the Madeira archipelago, Portugal, found that seabird populations’ productivities increased following rabbit and house mouse Mus musculus eradications, with several other interventions used in the Australian study.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F431https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F431Wed, 22 Aug 2012 14:21:43 +0100Collected Evidence: Collected Evidence: Provide artificial nesting sites for burrow-nesting seabirds Four studies from across the world found evidence for population increases or new populations being established in petrel species following the provision of nest boxes. In two cases nest boxes were combined with the translocation of chicks or other interventions. Six studies from across the world found high occupancy rates for artificial burrows by seabirds, with three finding that occupancy increased over time, taking years to build up. Three studies from across the world found very low occupancy rates for artificial burrows used by petrel species. Eight studies from across the world found that the productivity of birds using artificial burrows was high, in many cases as high or higher than in natural burrows. One replicated study from the USA and a small study from the Galapagos found low productivity of petrels using artificial burrows.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F481https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F481Thu, 30 Aug 2012 16:21:23 +0100Collected Evidence: Collected Evidence: Provide artificial nesting sites for songbirds Only three studies out of 66 from across the world found low rates of nest box occupancy, although this may be partially the result of publishing biases. Thrushes, crows, swallows and New World warblers were the target species with low rates of use. Thrushes, crows, finches, swallows, wrens, tits, Old World and tyrant flycatchers, New World blackbirds, sparrows, waxbills, starlings and ovenbirds all used nest boxes. One study from the USA found that wrens used nest boxes more frequently than natural cavities. Five studies from across the world found higher population densities or population growth rates in areas with nest boxes, whilst one study from the USA found higher species richness in areas with nest boxes. One study from Chile found that breeding populations (but not non-breeding populations) were higher for two species when next boxes were provided. Twelve studies from across the world found that productivity of birds in nest boxes was higher or similar to those in natural nests. One study found there were more nesting attempts in areas with more nest boxes, although a study from Canada found no differences in behaviour or productivity between areas with high or low densities of nest boxes. Two studies from Europe found lower predation of some species using nest boxes. However, three studies from the USA found low production in nest boxes, either in absolute terms or relative to natural nests. Thirteen studies from across the world founds that use, productivity or usurpation varied with nest box design, whilst seven found no difference in occupation rates or success with different designs. Similarly, fourteen studies found different occupation or success rates depending on the position or orientation of artificial nest sites. Two studies found no difference in success with different positions.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F498https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F498Tue, 04 Sep 2012 13:52:37 +0100Collected 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%2Fconservationevidencejournal.com%2Factions%2F507https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F507Thu, 06 Sep 2012 14:17:32 +0100Collected Evidence: Collected Evidence: Can supplementary feeding increase predation or parasitism? A replicated, controlled study in the USA found that providing seeds in predictable areas did not increase predation on seven species of songbird. A replicated and controlled trial in Spain found higher levels of potentially dangerous gut microflora when fed on livestock carrion, compared to those fed on wild rabbits. A replicated study in Spain found higher levels of predation on artificial nests close to carcasses provided for vultures.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F554https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F554Sat, 22 Sep 2012 20:37:07 +0100Collected Evidence: Collected Evidence: Artificially incubate and hand-rear seabirds in captivity Five studies from across the world found evidence for the success of hand-rearing seabirds. One small study in Spain found that one of five hand-reared Audouin’s gulls Larus audouinii successfully bred in the wild. Four studies found that various petrel species (Procellariiformes) successfully fledged after hand-rearing. One controlled study found that fledging rates of hand-reared birds was similar to parent-reared birds, although a study on a single bird found that the chick fledged at a lower weight and later than parent-reared chicks.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F604https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F604Sat, 13 Oct 2012 16:50:42 +0100Collected Evidence: Collected Evidence: Artificially incubate and hand-rear vultures in captivityA study in Peru found that hand-reared Andean condors Vultur gryphus had similar survival to parent-reared birds after release into the wild.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F613https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F613Sun, 14 Oct 2012 12:01:57 +0100Collected Evidence: Collected Evidence: Permanent presence of staff/manager One before-and-after study in Kenya found that numbers of Tana River red colobus and crested mangabeys decreased despite permanent presence of reserve staff, alongside other interventions. One study in Thailand found that a reintroduced population of lar gibbons declined over three years despite permanent presence of reserve staff alongside other interventions. One before-and-after study in Belize found that numbers of black howler monkeys increased by 138% over 13 years after introducing permanent presence of reserve staff, alongside other interventions. One before-and-after study in Congo found that most reintroduced central chimpanzees survived over five years after being accompanied by reserve staff, alongside other interventions. One before-and-after study in Gabon found that most reintroduced western lowland gorillas survived over nine months, after being accompanied by reserve staff, alongside other interventions. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1517https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1517Thu, 19 Oct 2017 09:22:48 +0100Collected Evidence: Collected Evidence: Ensure that researchers/tourists are up-to-date with vaccinations and healthy One controlled study in Malaysia found that a population of reintroduced orangutans decreased by 33% over 33 years despite staff and volunteers having received medical checks, alongside other interventions. One before-and-after study in Rwanda, Uganda and Congo found that mountain gorilla numbers increased by 168% over 41 years while sick/unwell researchers and visitors were not allowed to visit gorillas, alongside other interventions. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1546https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1546Thu, 19 Oct 2017 17:30:11 +0100Collected Evidence: Collected Evidence: Conduct veterinary screens of animals before reintroducing/translocating them One before-and-after study in Brazil found that most reintroduced golden lion tamarins did not survive over seven years, despite undergoing pre-release veterinary screens, alongside other interventions. One study in Brazil found that most reintroduced black lion tamarins that underwent veterinary screens, alongside other interventions, survived over four months. One before-and-after study in Malaysia found that 90% of reintroduced Müller's Bornean gibbons did not survive despite undergoing veterinary screens, alongside other interventions. One controlled study in Indonesia found that reintroduced Bornean agile gibbons that underwent veterinary screens, alongside other interventions, behaved similarly to wild gibbons. Two studies, including one controlled, in Malaysia and Indonesia found that most translocated orangutans that underwent veterinary screens, along with other interventions, survived translocation and the first three months post-translocation. Four studies, including three before-and-after studies, in Liberia, the Republilc of Congo and Guinea found that most reintroduced chimpanzees that underwent veterinary screens, alongside other interventions, survived over 1-5 years. One before and after study in Uganda found that a reintroduced chimpanzee repeatedly returned to human settlements after undergoing pre-release veterinary screens, alongside other interventions. Five studies, including four before-and-after studies, in Belize, French Guiana, Madagascar, Congo and Gabon found that most reintroduced or translocated primates that underwent veterinary screens, alongside other interventions, survived at least four months or increased in population size. Five studies, including four before-and-after studies, in French Guiana, Madagascar, South Africa and Vietnam found that most reintroduced or translocated primates were assumed to have died post-release despite undergoing pre-release veterinary screens, alongside other interventions. One controlled study in Kenya found that a population of translocated olive baboons were still surviving 16 years after translocation when veterinary screens were applied alongside other interventions. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1553https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1553Thu, 19 Oct 2017 20:15:52 +0100Collected Evidence: Collected Evidence: Captive breeding and reintroduction of primates into the wild: born and reared in cages One before-and-after study in Brazil found that most reintroduced golden lion tamarins that were born and reared in cages, alongside other interventions, did not survive over seven years or had a higher mortality than wild-born tamarins. One controlled study in French Guiana found that more squirrel monkeys which were born and reared in cages, alongside other interventions, died or were returned to captivity post-reintroduction compared to wild-born monkeys. One controlled study in Madagascar found that the diet of reintroduced black-and-white ruffed lemurs which were born and reared in cages, alongside other interventions, did not overlap with that of wild lemurs. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1594https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1594Fri, 20 Oct 2017 14:33:22 +0100Collected Evidence: Collected Evidence: Captive breeding and reintroduction of primates into the wild: limited free-ranging experience One controlled study in Madagascar found that the diet of reintroduced black-and-white ruffed lemurs with limited free-ranging experience, alongside other interventions, overlapped with that of wild lemurs. One before-and-after study in Madagascar found that most reintroduced black-and-white ruffed lemurs with limited free-ranging experience, alongside other interventions, died over five years. One before-and-after and site comparison and one before-and-after study in the Republic of Congo and Gabon found that most reintroduced western lowland gorillas with limited free-ranging experience, alongside other interventions, survived over a period of between nine months and four years. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1595https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1595Fri, 20 Oct 2017 14:36:52 +0100Collected Evidence: Collected Evidence: Captive breeding and reintroduction of primates into the wild: born and raised in a free-ranging environment One before-and-after study in Brazil found that only two out of three reintroduced black lion tamarins survived over four months, despite being raised in a free-ranging environment, alongside other interventions. One controlled study in Madagascar found that the diet of reintroduced black-and-white ruffed lemurs that were born and raised in a free-ranging environment alongside other interventions, overlapped with that of wild lemurs. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1596https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F1596Fri, 20 Oct 2017 14:44:59 +0100Collected Evidence: Collected Evidence: Plant crops to provide supplementary food for mammals Four studies evaluated the effects on mammals of planting crops to provide supplementary food. Two studies were in the USA, one was in the UK and one was in Spain. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (3 STUDIES) Abundance (3 studies): Two replicated, controlled studies (including one before-and-after study), in the UK and Spain, found that crops grown to provide food for wildlife resulted in a higher abundance of small mammals in winter, but not in summer and increased European rabbit abundance. A replicated, randomized, controlled study in the USA found that triticale (a cross between wheat and rye) held higher overwintering mule deer abundance relative to barley, annual ryegrass, winter wheat or rye. BEHAVIOUR (2 STUDIES) Use (2 studies): A replicated, randomized, controlled study in the USA found that mule deer consumed triticale (a cross between wheat and rye) more than they did barley, annual ryegrass, winter wheat or rye. A replicated, randomized, controlled study in the USA found that supplementary food provided for game species was also consumed by lagomorphs and rodents. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2394https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F2394Thu, 28 May 2020 10:07:10 +0100Collected Evidence: Collected Evidence: Create artificial burrows Six studies evaluated the effects of creating artificial burrows on reptile populations. Five studies were in Australia and one was in the USA. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Abundance (1 study): One controlled, before-and-after study in Australia found that areas with artificial burrows had more pygmy blue tongue lizards than areas with no artificial burrows Reproductive success (1 study): One replicated, controlled study in Australia found that female pygmy bluetongue lizards using artificial burrows produced larger offspring than those using natural burrows. Condition (1 study): One replicated, controlled study in Australia found that female pygmy bluetongue lizards using artificial burrows had better body condition than those using natural burrows. BEHAVIOUR (5 STUDIES) Use (4 studies): Three replicated studies (including one controlled study) in Australia found that artificial burrows were used by resident and translocated pygmy bluetongue lizards. One of the studies also found that pygmy bluetongue lizards preferred artificial burrows with a chamber than burrows with no chamber. One replicated study in the USA found that providing artificial burrows for translocated gopher tortoises resulted in more tortoises settling successfully in the release area. Behaviour change (1 study): One replicated, controlled, before-and-after study in Australia found that translocated pygmy blue tongue lizards used artificial burrows, and supplementary food affected the amount of time they spend in bare ground areasCollected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3721https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3721Mon, 13 Dec 2021 17:02:44 +0000
What Works 2021 cover

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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