Collected Evidence: Collected Evidence: Rehabilitation of injured and treated birds Two replicated studies from the USA and UK found that 40% and 25% of raptors were released following rehabilitation. The USA study also found that 32% of owls were released. Three replicated studies from the USA all found relatively high survival of released raptors, with only 2.4% of birds being recovered (i.e. found dead, 1) and 66–68% survival over two weeks and six weeks. One study found that mortality rates were higher for owls than raptors.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F476https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F476Thu, 30 Aug 2012 13:15:35 +0100Collected Evidence: Collected Evidence: Remove eggs from wild nests to increase reproductive output A replicated study from Mauritius found that harvesting entire clutches appeared to increase Mauritius kestrels Falco punctatus productivity more effectively than removing individual eggs as they were laid. A replicated study over 30 years in Canada (Kuyt 1996) found that wild whooping cranes Grus americana reproductive success was higher for nests with one or two eggs removed than for control nests. A single study from the USA found that removing bald eagle Haliaeetus leucocephalus eggs from wild nests for hand-rearing did not appear to greatly affect the wild population.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F477https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F477Thu, 30 Aug 2012 13:27:46 +0100Collected Evidence: Collected Evidence: Provide artificial nesting sites for divers/loons A replicated before-and-after study from the UK found that there was a very large increase in loon productivity on lakes provided with nesting rafts, with a corresponding increase in productivity across the whole country. Two studies from the USA found higher nesting success on lakes with floating  nesting rafts, compared to sites without rafts, but no new territories were established on lakes without loons but with rafts. A replicated study from the UK found that loons used nesting rafts and artificial islands in some areas of the UK, but not others.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F478https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F478Thu, 30 Aug 2012 14:13:43 +0100Collected Evidence: Collected Evidence: Provide artificial nesting sites for wildfowl using artificial/floating islands Two studies from North America found that a variety of wildfowl used artificial islands and floating rafts, and had high (70–80%) nesting success. A replicated study from across the UK found that wildfowl preferentially nested on well vegetated islands, compared to bare ones.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F483https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F483Sat, 01 Sep 2012 16:49:16 +0100Collected Evidence: Collected Evidence: Provide artificial nesting sites for waders Two replicated studies from the UK and the USA found that waders used artificial islands and nesting sites. The UK study found that sparsely vegetated islands at coastal sites were used more than well vegetated and inland sites.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F486https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F486Mon, 03 Sep 2012 12:00:21 +0100Collected Evidence: Collected Evidence: Provide artificial nesting sites for ibises and flamingos A study in Turkey found that northern bald ibises Geronticus eremite moved to a site with artificial breeding ledges. A before-and-after study from France and Spain found that large numbers of greater flamingos Phoenicopterus roseus used artificial nesting islands.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F487https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F487Mon, 03 Sep 2012 12:03:36 +0100Collected Evidence: Collected Evidence: Provide nesting habitat for birds that is safe from extreme weather A small from New Zealand found Chatham Island oystercatchers Haematopus chathamensis used raised nest platforms made from car tyres (designed to raise nests above the level of storm surges). The success of these nests is not reported. Two replicated, controlled studies from the USA found that the nesting success of terns and waders was no higher on specially raised areas of nesting substrate, compared to unraised areas, with one study finding that a similar proportion of nests were lost to flooding in raised and unraised areas.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F504https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F504Thu, 06 Sep 2012 13:55:55 +0100Collected Evidence: Collected Evidence: Guard nests to increase nest success A before-and-after study from Costa Rica found an increase in scarlet macaw Ara macau population following the monitoring of nests, along with several other interventions. Two studies from Puerto Rico and New Zealand found that parrot nest success was higher or mortality reduced or nest success higher with intensive monitoring of nests, ompared to periods without monitoring. A study from New Zealand also found high overall nest success when nests were monitored.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F506https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F506Thu, 06 Sep 2012 14:12:26 +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 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: 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%2Fwww.conservationevidence.com%2Factions%2F524https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F524Sat, 08 Sep 2012 13:32:31 +0100Collected Evidence: Collected Evidence: Provide supplementary food for rails and coots to increase reproductive success A small randomised and controlled trial in the USA found that fed American coots Fulica americana laid heavier eggs, but not larger clutches than controls. However, a randomised, replicated and controlled study in Canada found that clutch size, but not egg size was larger in fed American coot territories. There was also less variation in clutch size between fed territories. The Canadian study also found that coots laid earlier when fed, whilst a replicated cross-over trial from the UK found three was a shorter interval between  common moorhens Gallinula chloropus clutches in fed territories, but that fed birds were no more likely to produce second broods.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F528https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F528Sun, 09 Sep 2012 17:37:36 +0100Collected Evidence: Collected Evidence: Provide supplementary food for vultures to increase reproductive success Two before-and-after studies from the USA and Greece found that there were population increases in local populations of two vultures (one New World, one Old World) following the provision of food in the area. A study from Israel found that a small, regularly supplied feeding station could provide sufficient food for breeding Egyptian vultures Neophron percnopterus. A before-and-after study from Italy found that a small population of Egyptian vultures Neophron percnopterus declined following the provision of food at a feeding station, and only a single vulture was seen at the feeding station.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F531https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F531Sun, 09 Sep 2012 18:08:42 +0100Collected Evidence: Collected Evidence: Provide supplementary food for parrots to increase reproductive success Two studies from New Zealand found some evidence that providing supplementary food for kakapos Strigopus habroptilus increased the number of breeding attempts made, whilst a third study found that birds provided with specially-formulated pellets appeared to have larger clutches than those fed on nuts. One study found no evidence that providing food increased the number of nesting attempts.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F536https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F536Sun, 09 Sep 2012 19:43:26 +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 vultures to increase adult survival A before-and-after study from Spain found a large increase in griffon vulture Gyps fulvus population in the study area following multiple interventions including supplementary feeding. Two studies from the USA and Israel found that Californian condors Gymnogyps californianus and Egyptian vultures Neophron percnopterus fed on many of the carcasses provided for them. The Egyptian vultures were sometimes dominated by larger species at a feeding station supplied twice a month, but not at one supplied every day.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F545https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F545Sun, 16 Sep 2012 09:10:04 +0100Collected Evidence: Collected Evidence: Provide supplementary food for woodpeckers to increase adult survival One replicated, controlled study from the USA found that 12 female downy woodpeckers Picoides pubescens supplied with supplementary food had higher nutritional statuses than unfed birds. However, two analyses of a replicated, controlled study of 378 downy woodpeckers from the USA found that they did not have higher survival rates or nutritional statuses than unfed birds.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F551https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F551Sun, 16 Sep 2012 09:42:41 +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: 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%2Fwww.conservationevidence.com%2Factions%2F554https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F554Sat, 22 Sep 2012 20:37:07 +0100Collected Evidence: Collected Evidence: Provide supplementary food through the establishment of food populations One pre-1950 study in the USA found that waterfowl fed on specially-planted rye grass. Three studies from North America and Sweden found that attempts to support populations by establishing prey did not succeed. Whooping cranes Grus americana in the USA preferentially fed on scattered grains, over planted crops; attempts in Sweden to boost macroinvertebrate numbers were not successful and great horned owls Bubo virginianus in Canada did not respond to induced increases in prey populations.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F555https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F555Sat, 22 Sep 2012 20:40:45 +0100Collected Evidence: Collected Evidence: Use perches to increase foraging success Two studies from the USA found that raptors and other birds used perches provided, whilst a replicated and controlled study in Sweden found that raptors used clearcuts with perches significantly more than those without. However, a controlled study from the USA found that overall bird abundances were not higher in areas provided with perches and a small controlled cross-over trial on an island in the USA found that San Clemente loggerhead shrikes Lanius ludovicianus mearnsi did not alter their hunting patterns or increase their success rates following the installation of perches in their territories.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F556https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F556Sun, 23 Sep 2012 15:05:36 +0100Collected Evidence: Collected Evidence: Translocate petrels and shearwatersTwo studies from Australia and one from New Zealand found that colonies of burrow-nesting Procellariiformes were successfully established on two islands, and in uninhabited areas of another following the translocation and hand-rearing of chicks.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F568https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F568Sun, 30 Sep 2012 12:54:24 +0100Collected Evidence: Collected Evidence: Translocate wildfowl Three studies of two duck translocation programmes in New Zealand and Hawaii found high post-release survival, breeding and the successful establishment of new populations. A replicated study in USA found that none of 391 blue-winged teal Querquedula discors stayed in the release site and that there was high mortality after release. A replicated, controlled study in the USA found that wing-clipping female wood ducks Aix sponsa during translocation prevented them from abandoning their ducklings.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F571https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F571Sun, 30 Sep 2012 13:18:26 +0100Collected Evidence: Collected Evidence: Translocate rails Three reviews of two translocation programmes in the Seychelles and New Zealand found high survival amongst translocated rails. All studies found that translocated birds bred successfully, although one found that translocated takahe Porphyrio hochstetteri had lower reproductive success than birds in the source population. The other New Zealand study found no differences in breeding success between recently and formerly translocated takahe.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F573https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F573Sun, 30 Sep 2012 13:58:55 +0100Collected Evidence: Collected Evidence: Translocate nests to avoid disturbance Four small trials from the USA and a replicated study from Chatham Island, New Zealand found some success in relocating nests whilst they were in use. However, one study from the USA found that only 40% of burrowing owls Athene cunicularia were moved successfully, another found that American kestrels Falco sparverius tolerated movement of their nest, but not repeated disturbance and another found that barn swallow Hirundo rustica may follow their nest as it is slowly moved on a car, but may not stay at the new site.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F584https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F584Sat, 06 Oct 2012 21:27:21 +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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