Collected 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%2Fwww.conservationevidence.com%2Factions%2F480https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F480Thu, 30 Aug 2012 14:40:27 +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%2Fwww.conservationevidence.com%2Factions%2F482https%3A%2F%2Fwww.conservationevidence.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%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 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%2Fwww.conservationevidence.com%2Factions%2F485https%3A%2F%2Fwww.conservationevidence.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%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 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%2Fwww.conservationevidence.com%2Factions%2F488https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F488Mon, 03 Sep 2012 13:23:17 +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%2Fwww.conservationevidence.com%2Factions%2F490https%3A%2F%2Fwww.conservationevidence.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%2Fwww.conservationevidence.com%2Factions%2F491https%3A%2F%2Fwww.conservationevidence.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%2Fwww.conservationevidence.com%2Factions%2F492https%3A%2F%2Fwww.conservationevidence.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%2Fwww.conservationevidence.com%2Factions%2F493https%3A%2F%2Fwww.conservationevidence.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%2Fwww.conservationevidence.com%2Factions%2F494https%3A%2F%2Fwww.conservationevidence.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%2Fwww.conservationevidence.com%2Factions%2F495https%3A%2F%2Fwww.conservationevidence.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%2Fwww.conservationevidence.com%2Factions%2F496https%3A%2F%2Fwww.conservationevidence.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%2Fwww.conservationevidence.com%2Factions%2F497https%3A%2F%2Fwww.conservationevidence.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%2Fwww.conservationevidence.com%2Factions%2F498https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F498Tue, 04 Sep 2012 13:52:37 +0100Collected Evidence: Collected Evidence: Provide artificial subterranean bat roosts to replace roosts in reclaimed mines We found no studies that evaluated the effects of providing artificial subterranean bat roosts to replace roosts in reclaimed mines on bat populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F974https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F974Fri, 20 Dec 2013 12:43:16 +0000Collected Evidence: Collected Evidence: Provide artificial subterranean bat roosts to replace roosts in disturbed caves We found no studies that evaluated the effects of providing artificial subterranean bat roosts to replace roosts in disturbed caves on bat populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1005https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1005Fri, 20 Dec 2013 17:19:47 +0000Collected Evidence: Collected Evidence: Provide artificial water sources One before-and-after trial in Brazil found that a minority of reintroduced golden lion tamarins survived over seven years when provided with supplementary water, alongside other interventions. One before-and-after study in Madagascar found that a minority of reintroduced black-and-white ruffed lemurs survived for five years despite being provided with supplementary water, alongside other interventions. A before-and-after study in South Africa found that a minority of vervet monkeys had survived for 10 months when provided with supplementary water, alongside other interventions. A before-and-after study in Gabon found that a majority of western lowland gorillas survived for at least nine months while being provided with supplementary water, alongside other interventions. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1531https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1531Thu, 19 Oct 2017 10:26:56 +0100Collected Evidence: Collected Evidence: Provide artificial shelters Five studies examined the effects of providing artificial shelters on subtidal benthic invertebrates. Three studies were in the Caribbean Sea (Mexico); one in Florida Bay and one in the Florida Keys (USA).   COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Lobster abundance (2 studies): Two replicated, controlled, before-and-after studies in the Caribbean Sea found that abundance of lobsters either increased in plots with artificial shelters but not in plots without, or increased in all plots but more so in plots with artificial shelters than those without. Lobster condition (1 study): One replicated, controlled, before-and-after study in the Caribbean Sea found that lobsters in plots with artificial shelters were bigger than in plots without. BEHAVIOUR (3 STUDIES) Use (3 studies): Three replicated studies (two controlled) in Florida Bay, the Florida Keys, and the Caribbean Sea, found that artificial shelters were occupied by lobsters and molluscs, that occupancy by lobsters varied with artificial shelter designs, that lobsters occupied artificial shelters more than natural ones (crevices), and that lobsters occupying artificial shelters were larger, had greater nutritional condition, and had similar sex ratio and survival rate, compared to lobsters occupying natural shelters. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2257https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2257Wed, 23 Oct 2019 10:13:10 +0100Collected Evidence: Collected Evidence: Provide artificial shelters following release We found no studies that evaluated the effects of providing artificial shelters following the release of species on their populations.   ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2272https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2272Wed, 23 Oct 2019 12:48:42 +0100Collected Evidence: Collected Evidence: Provide artificial refuges for prey to evade/escape non-native predators We found no studies that evaluated the effects on mammals of providing artificial refuges for prey to evade/escape non-native predators. 'We found no studies' means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore, we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2533https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2533Mon, 08 Jun 2020 16:24:27 +0100Collected Evidence: Collected Evidence: Provide artificial refuges/breeding sites Eight studies evaluated the effects on mammals of providing artificial refuges/breeding sites. Two studies were in each of the USA, Spain and Portugal and one was in each of Argentina and Australia. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (4 STUDIES) Abundance (3 studies): Two studies (one controlled), in Spain and Portugal, found that artificial warrens increased European rabbit abundance. A replicated, randomized, controlled, before-and-after study in Argentina found that artificial refuges did not increase abundances of small vesper mice or Azara's grass mice. Survival (1 study): A study in USA found that artificial escape dens increased swift fox survival rates. BEHAVIOUR (4 STUDIES) Use (4 studies): Four studies (two replicated), in Australia, Spain, Portugal and the USA, found that artificial refuges, warrens or nest structures were used by fat-tailed dunnarts, European rabbits, and Key Largo woodrats and Key Largo cotton mice. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2583https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2583Wed, 10 Jun 2020 15:06:41 +0100Collected Evidence: Collected Evidence: Provide artificial shade for individuals Two studies evaluated the effects of providing artificial shade for individuals on reptile populations. One study was in Australia and one was in Canada. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (2 STUDIES) Use (2 studies): One replicated, randomized study in Australia found that shaded, artificial rocky outcrops were used less often than unshaded ones by velvet geckos. One study in Canada found that coverboards were used by northern pacific rattlesnakes in the year they were installed, but not a decade later. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3641https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3641Thu, 09 Dec 2021 15:17:20 +0000Collected Evidence: Collected Evidence: Provide artificial shade for nests or nesting sites Four studies evaluated the effects of providing artificial shade for nests or nesting sites on reptile populations. Two studies were in the USA and one was in each of Panama, and Australia. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (3 STUDIES) Reproductive success (3 studies): One of two controlled studies (including one replicated study) in Panama and Australia found that shaded leatherback turtles nests had higher hatching success than unshaded nests. The other study found that shaded and unshaded loggerhead turtle nests had similar hatching success. One replicated, controlled study in the USA found that relocating diamondback terrapin nests to artificial nest mounds and providing shade had mixed effects on hatchling success. Condition (2 studies): One of two controlled studies (including one replicated study) in Panama and Australia found that greater shade cover resulted in smaller hatchlings for leatherback turtles. The other study found that shading loggerhead turtle nests had mixed effects on hatchling size and crawl speed. BEHAVIOUR (0 STUDIES) OTHER (2 STUDIES) Offspring sex ratio (2 studies): One of two controlled studies (including one before-and-after study) in Panama and the USA found that shading leatherback turtle nests resulted in fewer female hatchlings compared to unshaded nests. The other study found that shaded and unshaded Agassiz’s desert tortoise nests produced a similar sex ratio of hatchlings. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3643https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3643Thu, 09 Dec 2021 15:28:57 +0000
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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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