Conservation Evidence: Evidence Data

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%2Fwww.conservationevidence.com%2Factions%2F158https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F158Tue, 15 May 2012 13:48:22 +0100Collected Evidence: Collected Evidence: Increase the proportion of natural/semi-natural vegetation in the farmed landscape Of four studies captured, one, a replicated and controlled paired sites study from Australia, found that farms with plantings of native vegetation held more species than those without. The effect was smaller than that explained by variation in the amount of natural habitat remaining on farms. A replicated study from Switzerland found more species in areas under the Ecological Compensation Area scheme than areas not under it. A before-and-after study from Switzerland found that the populations of three bird species increased after an increase in the amount of land under the Ecological Compensation Scheme. This study found that three species were more found more than expected on Ecological Compensation Scheme land. Another replicated study from Switzerland found that some habitats held more birds if they were close to ECA habitat but that the amount of Ecological Compensation Scheme in an area had no impact on population densities. A small study from the UK found no effect of habitat creation on grey partridge populations. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F171https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F171Sun, 20 May 2012 13:21:01 +0100Collected Evidence: Collected Evidence: Protect bird nests using electric fencing One before-and-after study from the UK found an increase in tern numbers after the erection of an electric fence, whilst a study from the USA found an increase in the number of nests. Five studies from the USA found higher survival or productivity at wader or seabird colonies with electric fencing, compared to areas without fencing, although one study found that hatching rates were no different, whilst nesting success was only higher in one of two years. One study from the USA found lower predation by mammalian predators inside electric fence exclosures, whilst predation by birds was higher. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F188https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F188Wed, 13 Jun 2012 16:59:40 +0100Collected Evidence: Collected Evidence: Undersow spring cereals, with clover for example Three studies from the UK, two replicated, found that there were higher densities of some study species on undersown fields or margins, compared with other fields, or that use of fields increased after they were undersown. One of these (reported in two places) found that not all species nested at higher densities. One replicated study from the UK found that various measures of grey partridge population health declined as the amount of undersown cereal on sites increased. A replicated study from the UK found no relationship between the amount of undersown cereals on a site and the productivity of grey partridge on that site. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F208https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F208Sun, 15 Jul 2012 17:28:25 +0100Collected Evidence: Collected Evidence: Revert arable land to permanent grassland All five studies looking at the effects of reverting arable land to grassland found no clear benefit to birds. The studies monitored birds or grey partridges in the UK and wading birds in Denmark (4). They included three replicated controlled trials. One of the studies, a controlled before-and-after study from the UK, showed that grey partridge numbers fell significantly following the reversion of arable fields to grassland. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F210https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F210Sun, 15 Jul 2012 18:00:36 +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%2Fwww.conservationevidence.com%2Factions%2F217https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F217Tue, 17 Jul 2012 12:04:26 +0100Collected Evidence: Collected Evidence: Delay haying/mowing Two reviews from the UK found that the population of corncrakes Crex crex increased following the implementation of two initiatives to encourage farmers to delay mowing (and provide cover and use corncrake-friendly techniques). A replicated and controlled paired sites study from the Netherlands found no evidence that waders and other birds were more abundant in fields with delayed mowing, compared to paired controls. A replicated and controlled before-and-after study from the Netherlands found that fields with delayed mowing held more birds than controls, but did so before the start of the scheme. Population trends did not differ between treatments. A replicated, controlled study from the USA found that destruction of nests by machinery was lower and late-season nesting higher in late-cut fields, compared with early-cut fields. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F223https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F223Tue, 17 Jul 2012 14:29:48 +0100Collected Evidence: Collected Evidence: Disturb birds at roosts One controlled study from the USA investigated the effects of harassment on fish predation, and found there were fewer double-crested cormorants Phalacrocorax auritus on, and fewer fish were taken from, fish ponds near roosts which were harassed, compared with undisturbed roosts. A review found that there was a reduction in the number of cormorants foraging near roosts after night-time disturbance. Four studies, two replicated, from the USA and Israel, found that cormorants moved away from roosts where they were disturbed at night. One study found that this effect was only temporary. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F245https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F245Wed, 18 Jul 2012 11:42:12 +0100Collected Evidence: Collected Evidence: Use netting to exclude fish-eating birds Two replicated studies from Germany and the USA found that netting or closely-spaced string barriers reduced losses of fish or deterred fish-eating birds from fish ponds. A review concluded that excluding birds was an effective way to reduce damage. A series of tests in the Netherlands found that netting or nylon lines over ponds did not prevent birds from landing, but did alter behaviour, whilst a before-and-after study from the USA found that fewer great blue herons Ardea Herodias landed at fish ponds with netting, but that they stayed longer. Two replicated studies from Germany and Israel found that some birds became entangled in netting or closely-spaced string barriers over fish ponds. The Israeli study found that dark, small meshed netting entangled fewer birds than other netting types. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F248https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F248Wed, 18 Jul 2012 12:00:45 +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%2Fwww.conservationevidence.com%2Factions%2F274https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F274Thu, 19 Jul 2012 18:28:35 +0100Collected Evidence: Collected Evidence: Set lines underwater to reduce seabird bycatch Four replicated and controlled studies and a literature review in Norway, South Africa and the North Pacific found reductions in northern fulmar Fulmarus glacialis, albatross and petrel bycatch rates when using an underwater setting funnel. Although one found a disproportionate number of albatross were caught during day line setting. A replicated and controlled study found that underwater setting increased attack rates of shearwaters Puffinus spp. on longlines and did not reduce bycatch. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F288https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F288Tue, 24 Jul 2012 16:38:44 +0100Collected Evidence: Collected Evidence: Use prescribed burning on savannas A replicated and controlled study from Kenya, of five studies captured, found that burned areas of savanna tended to have more birds and more species than control or grazed areas. However, the authors note that differences were not present during drought years and burned sites showed significant annual variation, unlike grazed sites. A replicated and controlled study from Australia found that the effects of burning on bird abundances depended on burn season, and habitat type. Two replicated studies in the USA found that some open country species were more common in burned areas than unburned, whilst other species were less so. A small study from the USA found that two eastern bluebird Sialia sialis successfully raised chicks after the habitat around their nest boxes was subject to a prescribed burn. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F320https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F320Thu, 26 Jul 2012 14:58:00 +0100Collected Evidence: Collected Evidence: Mow or cut natural grasslands Of six studies, two replicated and controlled studies from the USA found higher densities of birds or nests on mown grasslands, compared to unmanaged or burned areas. Two controlled studies from the USA, one replicated, found lower nesting or population densities of some species, on mown grasslands compared to unmown areas. Two replicated and controlled studies found no significant differences in nesting densities or community composition between mown and unmown areas. One study from the USA found that grasshopper sparrow nesting success was higher on mown areas than grazed areas of grassland. A replicated controlled study from the USA found that ducks had similar nesting success on cut and uncut areas. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F338https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F338Sat, 28 Jul 2012 15:41:22 +0100Collected Evidence: Collected Evidence: Use ring-barking (girdling), cutting or silvicides to produce snags Of five studies found, one replicated and controlled study from the USA found that forest plots provided with snags had higher bird diversity and abundance than plots without snags added. Three studies from the USA and UK found that woodpeckers and other species used artificially-created snags for nesting and foraging. One study from the USA found that use increased with how long a snag had been dead. A UK study found that no crested tits used snags created for them, possibly because they were not rotted enough, or because they were too close to the ground. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F343https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F343Sat, 28 Jul 2012 20:29:12 +0100Collected Evidence: Collected Evidence: Manage water level in wetlands Of six studies, one replicated, controlled study from the USA found that bird diversity was affected by maintaining water levels at different levels. A study from the USA found that ducks were more abundant when high water levels were maintained on a wetland site. Geese were more abundant when lower levels were maintained. Three studies from the USA and Canada, two replicated, found that different species showed preferences for different water levels in wetlands. A replicated study from the UK found that great bitterns established territories earlier when deep water levels were maintained, but this had no effect on productivity. A review from Spain found that management successfully maintained water near a greater flamingo nesting area, but the effects of this were not measured. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F355https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F355Sun, 29 Jul 2012 16:49:45 +0100Collected Evidence: Collected Evidence: Create scrapes and pools in wetlands and wet grasslands Of six studies captured, four before-and after studies from the UK and North America found that the use of sites, or the breeding population of birds on sites, increased following the creation of ponds and scrapes or was higher in areas with ditch-fed ponds. A study from the USA found that dabbling ducks used newly-created ponds in large numbers, although other species preferred older ponds. Songbirds did not appear to be affected by pond-creation. A replicated site from the UK found that northern lapwing chicks foraged in newly created wet features and that chick condition was higher in sites with a large number of footdrains. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F359https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F359Sun, 29 Jul 2012 17:26:31 +0100Collected Evidence: Collected Evidence: Restore or create coastal and intertidal wetlands All six studies found, from the USA and UK, found that target bird species used restored or created wetlands. Two found that numbers and/or diversity were at least as high as in natural wetlands, one that numbers were higher than in unrestored sites. Three found that bird numbers on wetlands increased over time. Two studies from the UK found that songbirds and waders decreased following wetland restoration, whilst a study from the USA found that songbirds were more common on unrestored sites than restored wetlands. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F367https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F367Tue, 07 Aug 2012 13:15:07 +0100Collected Evidence: Collected Evidence: Remove vegetation to create nesting areas Two out of six studies found that the number of waders and terns nesting in an area increased following the removal of vegetation, and another found that a tern colony moved to an area prepared by removing vegetation. Two of these studies used multiple interventions at once. One study found a decrease in colony size after several interventions, including vegetation control. A study from the UK found that gulls and terns nested in an area cleared of vegetation and a controlled study from Puerto Rico found that although no terns nested in plots cleared completely of vegetation, more nested in partially-cleared plots than in uncleared plots. A before-and-after study from Canada found that tern nesting success was higher after plots were cleared of vegetation and other interventions were used. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F505https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F505Thu, 06 Sep 2012 14:00:49 +0100Collected Evidence: Collected Evidence: Provide supplementary food for gulls, terns and skuas to increase reproductive success Four studies of three experiments from Europe and Alaska found that providing supplementary food increased fledging success or chick survival in two gull species, although a study from the UK found that this was only true for one island, with abnormally low breeding success. A second island with higher success was not affected by feeding. Two of the experiments fed parent birds and one fed the chicks directly. One study from the Antarctic found no effect of feeding parent skuas on productivity. One study from Alaska found increased chick growth when parents were fed; one study from the Antarctic found no increase in chick growth. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F525https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F525Sat, 08 Sep 2012 13:37:48 +0100Collected Evidence: Collected Evidence: Provide supplementary food for gamebirds to increase adult survival Two European studies found increased numbers of grey partridge Perdix perdix in fed areas, compared to unfed areas. In one study there was no change in the overall population in the study area, in the second there was an increase. One cross-over study from the USA found that northern bobwhites Colinus virginianus had higher overwinter survival in fed areas, one found lower survival and a literature review found no overall effect of feeding. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F544https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F544Sun, 16 Sep 2012 09:01:06 +0100Collected Evidence: Collected Evidence: Provide supplementary food for nectar-feeding songbirds to increase adult survival Two studies from Australia and New Zealand found that ten species of honeyeaters and stitchbirds Notiomystis cincta readily used feeders supplying sugar solutions, with seasonal variations varying between species and stitchbirds spending more time foraging for insects when food was supplied. A series of ex situ trials using southern African birds found that most species tested showed a preference for sucrose solutions over glucose or fructose. One study found that sunbirds and sugarbirds only showed such a preference at low (equimolar) concentrations. Two more studies found that two species showed preferences for sucrose when comparing 20% (by weight) solutions, although a third species did not show this preference. All species rejected solutions with xylose (a natural sugar in nectar) added. A final study found that sucrose preferences only became apparent at equicalorific concentrations high enough for birds to subsist on. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F553https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F553Sat, 22 Sep 2012 20:11:36 +0100Collected Evidence: Collected Evidence: Translocate parrots Three studies of two translocation programmes from the Pacific and New Zealand found that populations of parrots were successfully established on islands following translocations, including the colonisation of other islands in the New Zealand study. Survival of translocated birds was monitored in five studies of four programmes from across the world and ranged from 41% over 60 days for red-fronted parakeets Cyanoramphus novaezelandiae in New Zealand to 98% for kakapos Strigops habroptila in New Zealand. Survival for translocated thick-billed parrots Rhynchopsitta pachyrhyncha in the USA was higher than for captive-bred birds. Despite very high survival, kakapos that were translocated had very low reproductive output in New Zealand. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F578https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F578Sun, 30 Sep 2012 14:41:44 +0100Collected Evidence: Collected Evidence: Release captive-bred individuals into the wild to restore or augment wild populations of cranes Four studies of five release programmes from the USA and Russia, from a total of eight programmes, found that released cranes had high survival or bred in the wild. Two studies from two release programmes in the USA found low survival of captive-bred eggs fostered to wild birds, compared with wild eggs, or a failure to increase the wild flock size. A worldwide review found that releases of migratory species only tended to be successful if birds were released into existing flocks, with higher success for non-migratory populations. One study from the USA found that birds released as sub-adults had higher survival than birds cross-fostered to wild birds. One study from the USA found that 73% of all mortalities occurred in the first year after release. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F621https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F621Sun, 14 Oct 2012 14:04:41 +0100Collected Evidence: Collected Evidence: Release captive-bred individuals into the wild to restore or augment wild populations of songbirds A before-and-after study in Mauritius describes the establishment of a population of Mauritius fody Foudia rubra following the release of captive-bred individuals. Four studies of three release programmes on Hawaii found high survival of all three species released (Hawaiian crows Corvus hawaiiensis and two thrushes: omao Myadestes obscurus and puaiohi M. palmeri), with the two thrushes successfully breeding. The authors in one note that many of the released puaiohi dispersed from the release site, meaning that repopulating specific areas may require multiple releases. A replicated, controlled study from the USA found that San Clemente loggerhead shrike Lanius ludovicianus mearnsi pairs with captive-bred females had lower reproductive success than pairs where both parents were wild-bred. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F630https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F630Sun, 14 Oct 2012 23:05:39 +0100Collected Evidence: Collected Evidence: Use holding pens at release sites Three replicated and one small study from three release programmes in Saudi Arabia, the USA and Canada found that released birds had higher survival or were more likely to pair up if kept at release sites in holding pens before release. A replicated study in the USA found lower survival for thick-billed parrots Rhynchopsitta pachyrhyncha released in holding pens, compared to birds released without preparation. A review of northern bald ibis Geronticus eremita conservation found that holding pens successfully prevented most birds from migrating (which resulted in 100% mortality), although some 200 birds ‘escaped’ over 25 years. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F632https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F632Sun, 14 Oct 2012 23:22:45 +0100