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: Provide or retain set-aside areas in farmland Three replicated studies and a review of five studies from Europe and North America examining species richness or diversity found that more species were found on set-aside than on crops. One found fewer species on set-aside than other agricultural habitats. All 21 studies, including a systematic review, 12 replicated experiments and two reviews, from Europe and North America that investigated population trends or habitat associations found that some species were found at higher densities or used set-aside more than other habitats, or were found on set-aside. Four studies (three replicated) from the UK found that some species were found at lower densities on set-aside compared to other habitats. Three of four replicated studies from the UK found that waders and Eurasian skylarks had higher productivities on set-aside, compared to other habitats. One study found that skylarks nesting on set-aside had lower productivity compared to those on cereal crops, and similar productivities to those on other crops. One replicated paired study from the UK found that rotational set-aside was used more than non-rotational set-aside, a replicated paired study found no differences between rotational and non-rotational set-aside. A review from Europe and North America found that naturally regenerated set-aside held more birds and more species than sown set-aside. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F175https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F175Sun, 27 May 2012 15:10:59 +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: Use legislative regulation to protect wild populations Six out of seven before-and-after studies and two literature reviews/meta-analyses found evidence that legislation protects bird populations. Five studies in Europe, Indonesia and across the world found increased population levels of vultures, raptors, cranes and cockatoos following protective legislation (amongst other interventions). However, one found populations of raptors declined soon after. The literature review also found two cases of limited or no impact of legislation. Two before-and-after studies from Denmark and the USA and Canada and the meta-analysis found increased estimated survival of falcons, ducks and parrots with stricter protection, but not necessarily population-level responses. A meta-analysis found decreased harvest of parrots in areas with stricter protection regimes, but a before-and-after study found no evidence for reduced shearwater harvest with legislation.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F271https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F271Thu, 19 Jul 2012 16:57:57 +0100Collected Evidence: Collected Evidence: Use education programmes and local engagement to help reduce persecution or exploitation of species Five out of six studies from across the world found increases in bird populations or decreases in mortality following education programmes. In all but one case, education was one of several interventions employed. A replicated before-and-after study from Canada also found that there was a significant shift in local peoples’ attitudes to conservation and exploited species following educational programmes. One study from Venezuela found no evidence for decreases in yellow-shouldered parrot Amazona barbadensis poaching following an educational programme in local schools. The authors argue that the benefits would probably be seen later in the project.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F274https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F274Thu, 19 Jul 2012 18:28:35 +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: Reduce inter-specific competition for food by removing or controlling competitor species Two controlled before-and-after studies from the UK found that six species of wildfowl showed significant increases following the removal of fish from lakes. Three other species did not show increases. A study from France found that grey partridges Perdix perdix increased at a site with several interventions, including the control of competitor species. A before-and-after study from Spain found no change in the rate of kleptoparasitic attacks on herons after the culling of gulls at a colony.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F428https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F428Fri, 17 Aug 2012 17:54:16 +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: Reduce pesticide or herbicide use generally A single small study from the UK investigated population level effects of reduced chemical inputs, and found that the populations of some species increased when pesticide use was restricted alongside other interventions. Three studies, two replicated, one controlled, from the UK found that some or all species were found at higher densities on sites with reduced pesticide inputs, in one case with other interventions as well. Five studies from the UK, four replicated, four controlled, found that some or all species were not found at higher densities on fields or sites with reduced chemical inputs, or were not associated with reduced inputs. A controlled before-and-after study from the UK found that grey partridge Perdix perdix chicks had higher survival on sites with reduced pesticide applications. A replicated study from the UK found that reduced chemical inputs had a negative relationship with partridge brood size and no relationship with survival or the ratio of young to old birds.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F454https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F454Wed, 29 Aug 2012 14:08:01 +0100Collected Evidence: Collected Evidence: Restrict certain pesticides or other agricultural chemicals for birdsA small scale study found that Pyrazophos reduced chick food abundance more than other foliar fungicides. A before-and-after study from Spain found that the population of griffon vultures Gyps fulvus increased in the study area following multiple interventions including the banning of strychnine.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F455https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F455Wed, 29 Aug 2012 14:24:27 +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: Provide supplementary food for petrels to increase reproductive successA replicated controlled study in Australia found that Gould’s petrel Pterodroma leucoptera chicks provided with supplementary food had very similar fledging rates to both control and hand-reared birds, but were significantly heavier than other birds.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F522https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F522Sat, 08 Sep 2012 13:22:09 +0100Collected Evidence: Collected Evidence: Provide supplementary food for gannets and boobies to increase reproductive success A small controlled study in Australia found that Australasian gannet Morus serrator chicks were significantly heavier if they were supplied with supplementary food, but only in one of two years. Fledging success of fed nests was also higher, but not significantly so. A randomised replicated and controlled study in the Galapagos Islands found that fed female Nazca boobies Sula granti were more likely to produce two-egg clutches if they were fed, and that second eggs were significantly heavier.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F523https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F523Sat, 08 Sep 2012 13:25:20 +0100Collected Evidence: Collected Evidence: Provide supplementary food for auks to increase reproductive success Two replicated and controlled studies from the UK found that Atlantic puffin Fratercula arctica chicks provided with supplementary food were significantly heavier than control chicks. One study found differences between populations, suggesting some are more food-limited than others. The two UK studies found that fed chicks fledged at the same time as controls, whilst a randomised, replicated and controlled study from Canada found that tufted puffin Fratercula cirrhata chicks supplied with supplementary food fledged later than controls. The Canadian study found that fed chicks had faster growth by some, but not all, metrics.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F524https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F524Sat, 08 Sep 2012 13:32:31 +0100Collected Evidence: Collected Evidence: Provide supplementary food for wildfowl to increase reproductive successA small randomised and controlled ex situ study from Canada found faster growth and higher weights for fed greater snow goose Chen caerulescens atlantica chicks than unfed ones, but no differences in mortality rates.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F526https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F526Sun, 09 Sep 2012 17:16:26 +0100Collected Evidence: Collected Evidence: Provide supplementary food for gamebirds to increase reproductive successA controlled study in Tibet found that Tibetan eared pheasants Crossoptilon harmani that were fed supplementary food laid significantly larger eggs and clutches than control birds. Nesting success and laying dates were not affected.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F527https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F527Sun, 09 Sep 2012 17:34:24 +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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