Collected 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%2Fconservationevidencejournal.com%2Factions%2F478https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F478Thu, 30 Aug 2012 14:13:43 +0100Collected Evidence: Collected Evidence: Provide artificial nesting sites for grebesA single study from the UK found that grebes used nesting rafts in some areas of the UK but not others, and that the characteristics of used rafts differed geographically.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F479https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F479Thu, 30 Aug 2012 14:36:41 +0100Collected Evidence: Collected Evidence: Provide artificial nesting sites for ground and tree-nesting seabirds Three studies from the UK and the Azores found increases in gull and tern populations following the provision of rafts/islands or providing nest boxes alongside other interventions. A controlled, replicated study from the USA found that terns had higher nesting success on nesting rafts in one of two years monitored and a before-and-after study from Japan found that nesting success increased after the provision of nesting substrate. Five studies from Canada and Europe found that terns used re-profiled or artificial islands or nesting rafts, but pelicans did not. A small study from Hawaii found that red-footed boobies Sula sula preferentially nested in an artificial ‘tree-style’ nesting structure, compared to other designs.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F480https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F480Thu, 30 Aug 2012 14:40:27 +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 wildfowl Six studies from North America and Europe found that wildfowl populations increased with the provision of artificial nests, although one study from Finland found that there was no increase in the number of broods or chicks in areas with nest boxes. Twelve studies from North America investigated the success of nests in artificial nests with nine finding that success and productivity was high, sometimes higher than or similar to natural nests. Two studies found that success for some species in nest boxes was lower than for natural nests. Two studies investigated the impact of nest box location, finding that hidden nests had higher success and that nests over water were more successful than those in trees over land. Nineteen studies from across the world investigated occupancy rates of artificial nests, finding that rates varied from no use of 25 nest boxes in a single site in Indonesia to 100% occupancy across 20 sites in the USA with one study finding that nest boxes were used more than natural cavities. Two studies found that occupancy rates increased over time, whilst four studies found that occupancy rates appeared to be affected by design or positioning. Three studies from North America found that nest boxes could have other impacts on reproduction and behaviour, with common starlings Sturna vulgaris (a nest site competitor) avoiding some nest box designs; hidden nest boxes having lower intra-specific nest parasitism than easily visible boxes and female common eiders Somateria mollissima losing less weight over incubation if they were nesting in shelters, compared to birds nesting in the open, although they lost weight quicker after nesting.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F482https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F482Sat, 01 Sep 2012 14:23:12 +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%2Fconservationevidencejournal.com%2Factions%2F483https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F483Sat, 01 Sep 2012 16:49:16 +0100Collected Evidence: Collected Evidence: Provide artificial nesting sites for gamebirdsA replicated study in China found that an estimated 36–41% of the local population of Cabot’s tragopans Tragopan caboti used nesting platforms.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F484https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F484Sat, 01 Sep 2012 17:06:42 +0100Collected Evidence: Collected Evidence: Provide artificial nesting sites for railsA replicated study from across the UK found that common moorhens Gallinula chloropus and common coot Fulica atra readily used artificial islands for nesting.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F485https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F485Sat, 01 Sep 2012 17:10:02 +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%2Fconservationevidencejournal.com%2Factions%2F486https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F487https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F487Mon, 03 Sep 2012 12:03:36 +0100Collected Evidence: Collected Evidence: Provide artificial nesting sites for raptors Nine studies from North America and Spain found that raptors used artificial nesting platforms, although one describes low levels of use and another describes use increasing over time. Two studies from the USA describe increases in populations or population densities of raptors following the installation of artificial nesting platforms. Three studies describe successful use of platforms, whilst three describe lower productivity or failed nesting attempts, although these studies only describe a single nesting attempt each.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F488https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F488Mon, 03 Sep 2012 13:23:17 +0100Collected Evidence: Collected Evidence: Provide artificial nesting sites for falcons Four studies from the USA and Europe found that local populations of falcons increased following the installation of artificial nesting sites, with one reporting that there was no decline in natural nest use following the installation and use of nest boxes. A replicated study from Canada found that the local population of American kestrels Falco sparverius did not increase following the erection of nest boxes. Eight studies from across the world found that the success and productivity of falcons in nest boxes was high and equal to, or higher than those in natural nests. Four studies from across the world found that productivities in nest boxes were lower than in natural nests or in previously published results, or that some falcons were evicted from their nests by barn owls Tyto alba. Four studies from across the world found no differences in productivity between nest box designs or positions, whilst two, from Spain and Israel found that productivity in boxes varied between designs and habitats. Twenty-one studies from across the world found nest boxes were used by falcons, with one in the UK finding that nest boxes were not used at all. One study from Canada found that falcons preferentially nested in nest boxes over natural nest sites; a study from Mauritius found that most breeding attempts were in nest boxes Four studies found that use increased over time. Seven studies found that position or design affected use, whilst three found no differences between design or positioning.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F489https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F489Mon, 03 Sep 2012 14:01:21 +0100Collected Evidence: Collected Evidence: Provide artificial nesting sites for owls Three studies from the UK appeared to show increases in local populations of owls following the installation of artificial nests, although the authors from one note that they could not rule out birds merely switching from natural nest sites. Another UK study found that providing nesting sites when renovating buildings maintained barn owl Tyto alba populations, whilst they declined at sites without nests. Four studies from the USA and the UK found high levels of breeding success in artificial nests, three finding equal or higher productivity than natural nests. A replicated, controlled study from the USA found lower productivity from artificial nests, whilst a replicated, controlled study from Finland found that artificial nests were only successful in the absence of larger owls and a replicated, controlled study from Hungary found that fledglings from artificial nests were less likely to be found alive after one year. Four studies from the USA and Europe found that artificial nests were used at least as frequently as natural nesting sites. Five studies from across the world found that owls used artificial nests, with one finding that use increased over time, although only for one of two species. Three studies found that owls differentiated between nests in different positions, whilst five studies found that different designs of nests differed in occupancy or productivity. Three studies found occupancy did not differ between designs and two found no differences in productivity for different designs.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F490https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F490Mon, 03 Sep 2012 15:06:04 +0100Collected Evidence: Collected Evidence: Provide artificial nesting sites for oilbirdsA before-and after-study in Trinidad and Tobago found an increase in size of an oilbird colony following the creation of artificial nesting ledges.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F491https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F491Mon, 03 Sep 2012 16:25:31 +0100Collected Evidence: Collected Evidence: Provide artificial nesting sites for pigeonsTwo replicated studies from the USA and the Netherlands found high use rates and high nesting success of pigeons and doves using artificial nests.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F492https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F492Mon, 03 Sep 2012 16:47:27 +0100Collected Evidence: Collected Evidence: Provide artificial nesting sites for trogonsA small study from Guatemala found that at least one resplendent quetzal Pharomachrus mocinno nested in nest boxes provided.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F493https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F493Mon, 03 Sep 2012 16:55:55 +0100Collected Evidence: Collected Evidence: Provide artificial nesting sites for rollers A before-and-after study from Spain found that the use of nest boxes by European rollers Coracias garrulous increased over time and that use varied between habitats. A replicated controlled trial from Spain found no difference in success rates between new and old nest boxes, although birds in old boxes began nesting earlier.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F494https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F494Mon, 03 Sep 2012 17:06:54 +0100Collected Evidence: Collected Evidence: Provide artificial nesting sites for swiftsA study from the USA found that Vaux’s swifts Chaetura vauxi successfully used nest boxes provided.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F495https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F495Tue, 04 Sep 2012 12:42:04 +0100Collected Evidence: Collected Evidence: Provide artificial nesting sites for woodpeckers Four studies from the USA found local increases in red-cockaded woodpecker Picoides borealis populations or the successful colonisation of new areas following the installation of ‘cavity inserts’ (described above). One study also found that the productivity of birds using the inserts was significantly higher than the regional average. Two studies from the USA found that red-cockaded woodpeckers Picoides borealis used cavity inserts, in one case more frequently than making their own holes or using natural cavities. One study from the USA found that woodpeckers roosted, but did not nest, frequently in nest boxes. Five studies from the USA found that some woodpeckers excavated holes in artificial snags but only ever roosted in excavated holes or in nest boxes provided. A small study in the USA found that modifying artificial nests to allow easy access did not alter the behaviour of birds using them.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F496https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F496Tue, 04 Sep 2012 12:45:28 +0100Collected Evidence: Collected Evidence: Provide artificial nesting sites for parrots A before-and-after study from Costa Rica found that the local population of scarlet macaws Ara macao increased following the installation of nest boxes along with several other interventions. Five studies from South and Central America and Mauritius that nest boxes were used by several species of parrots, with one finding an increase in use over time until the majority of the population used them. One replicated study from Peru found that blue-and-yellow macaws Ara ararauna only used modified palms, not ‘boxes’, whilst another replicated study found that scarlet macaws Ara macao used both PVC and wooden boxes, but that PVC lasted much longer. Four studies from Venezuela and Columbia found that several species very rarely, if ever, used nest boxes. Six studies from Central and South America found that parrots nested successfully in nest boxes, with two species showing higher levels of recruitment into the population following nest box erection and another finding that success rates for artificial nests were similar to natural nests. Three studies from South America found that artificial nests had low success rates, in two cases due to poaching.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F497https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F497Tue, 04 Sep 2012 13:10:55 +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: Clean nest boxes to increase occupancy or reproductive success Five studies from Spain and North America found that various songbirds preferentially nested in cleaned nest boxes, compared to used ones. One study from the USA found that eastern bluebirds showed this preference, but most did not switch from a soiled to a cleaned nest box. One study from the USA found that birds showed an avoidance of heavily-soiled boxes and one from Canada found that tree swallows Tachycineta bicolor preferentially selected nests which were sterilised by microwaving. Two studies from the USA found that eastern bluebirds Sialia sialis and house wrens Troglodytes aedon preferentially nested in uncleaned nest boxes, and one study found that prothonotary warblers Protonotaria citrea showed no preference for cleaned or uncleaned boxes. None of the five studies that investigated it found any difference in success or parasitism levels between cleaned and uncleaned nest boxes.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F499https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F499Tue, 04 Sep 2012 16:10:03 +0100Collected Evidence: Collected Evidence: Artificially incubate eggs or warm nests A replicated, controlled trial in the UK found that great tits Parus major were less likely to interrupt their laying sequence if their nest box was heated, although there was no effect on egg or clutch size. A small study in New Zealand found that no kakapo Strigopus habroptilus eggs or chicks died from chilling following the use of nest warmers. Before this a nest had been lost to chilling.  Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F503https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F503Tue, 04 Sep 2012 16:34:31 +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%2Fconservationevidencejournal.com%2Factions%2F504https%3A%2F%2Fconservationevidencejournal.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%2Fconservationevidencejournal.com%2Factions%2F506https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F506Thu, 06 Sep 2012 14:12:26 +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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