Collected Evidence: Collected Evidence: Can nest protection increase nest abandonment? A replicated before-and-after study from the USA found that nest abandonment increased after nest exclosures were installed. Two replicated studies in Sweden and the USA found small levels of abandonment, or non-significant increases in abandonment following nest exclosure installation. A meta-analysis from the USA found that some designs of nest exclosures were more likely to lead to abandonment than others.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F401https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F401Thu, 16 Aug 2012 13:41:47 +0100Collected Evidence: Collected Evidence: Can nest protection increase predation of adults and chicks? Three replicated and controlled studies from North America and Sweden found higher levels of predation on adult birds with nest exclosures, one study from Sweden found that predation was no higher. A replicated and controlled study from Alaska found that long-tailed jaegers Stercorarius longicaudus learned to associate exclosures with birds, targeting adult western sandpipers Calidris mauri and quickly predating chicks when exclosures were removed.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F403https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F403Thu, 16 Aug 2012 14:45:33 +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: Can captive breeding have deleterious effects on individual fitness? Three studies of wild populations, wild and captive populations and museum specimens, one replicated, found evidence for  potentially deleterious physiological or genetic changes due to captive breeding. These studies did not investigate fitness. A study of a wild Mauritius kestrel, Falco punctatus, population derived totally from captive individuals found high inbreeding and a loss of genetic diversity, but this was caused more by the very low population size (four wild birds) than by captivity per se. The museum-based study found reduced relative brain volume in captive wildfowl, compared with wild birds, whilst a comparison of wild and captive populations of white-headed ducks Oxyura leucocephala found lower genetic diversity in captive populations.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F599https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F599Sat, 13 Oct 2012 16:00:16 +0100Collected Evidence: Collected Evidence: Captive breeding frogs Thirty-three studies investigated the success of breeding frogs in captivity. Twenty-three of 33 studies, three of which were reviews and 30 replicated studies, across the world found that amphibians produced egg in captivity, in four cases by captive-bred females. Seven found mixed results, with some species of frogs or 17–50% of captive populations  reproducing successfully in captivity, but with other species difficult to maintain or raise to adults. One found that frogs did not breed successfully in captivity and another that all breeding frogs died. Seventeen of the studies found that captive-bred frogs were raised successfully to hatching, tadpoles, froglets or adults in captivity. One found that froglet survival was low and another that three species were not successfully raised to adulthood. Four replicated studies (including one small study) in,Canada, Fiji, Hong Kong and Italy found that 30–88% of eggs hatched or survival to metamorphosis was 75%, as froglets was 17–51% or to adults was 50–90% in captivity. One review and four replicated studies (including two small studies) in Germany, Italy and the USA found that reproductive success of frogs in captivity depended on temperature or a simulated wet and dry season, but not on whether frogs were housed in high or low maintenance facilities. Three replicated studies (including one small study) in Germany, Australia and Canada found that egg or tadpole development in captivity was affected by parental care, density or temperature.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F835https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F835Thu, 29 Aug 2013 09:25:18 +0100Collected Evidence: Collected Evidence: Captive breeding harlequin toads (Atelopus species) One review and three of five replicated studies (including one small study) in Colombia, Ecuador, Germany and the USA found that harlequin toads reproduced in captivity. One found that eggs were only produced in captivity by simulating a dry and wet season and one found that successful breeding was difficult. One found that captive-bred harlequin toads were raised successfully to metamorphosis in captivity. Two found that most toads died before or after hatching.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F836https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F836Thu, 29 Aug 2013 13:54:34 +0100Collected Evidence: Collected Evidence: Captive breeding Mallorcan midwife toads Two replicated studies in the UK found that Mallorcan midwife toads produced eggs that were raised to metamorphs or toadlets successfully in captivity. One found that clutches dropped by males were not successfully maintained artificially. One replicated study in the UK found that survival to metamorphosis was 85%. One randomized, replicated, controlled study in the UK found that toads bred in captivity for nine or more generations had slower tadpole development, reduction in one predator defence trait and decreased genetic diversity.      Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F837https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F837Thu, 29 Aug 2013 14:21:37 +0100Collected Evidence: Collected Evidence: Captive breeding salamanders (including newts) Four of six replicated studies (including four small studies) in Japan, Germany, the UK and USA found that eggs were produced successfully in captivity, in one case by one captive-bred female. Two found that production of eggs depended on tank habitat or was more successful in semi-natural compared to laboratory conditions. Captive-bred salamanders were raised to yearlings or a small number of larvae or adults in captivity. One review found that four salamander species bred successfully in captivity, but slimy salamanders produced eggs that did not hatch. One replicated study in Japan found that 60% of Japanese giant salamander eggs survived to hatching in captivity. Two replicated studies (including one small study) in Mexico and the USA found that larval development, body condition and survival of captive-bred amphibians were affected by water temperature, density and whether they were raised under laboratory or semi-natural conditions.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F838https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F838Thu, 29 Aug 2013 14:43:51 +0100Collected Evidence: Collected Evidence: Captive breeding toads Ten replicated studies (including three small studies) in Germany, Italy, Spain, the UK and USA found that toads produced eggs in captivity, in one case by second generation captive females. Eight found that captive-bred toads were raised successfully to tadpoles, toadlets or adults in captivity. Two found that most toads died after hatching or after metamorphosis. Two reviews found mixed results with four species of toad or 21% of captive populations of Puerto Rican crested toad breeding successfully in captivity. Four replicated studies in Germany, Spain and the USA found that reproductive success of captive toads was affected by tank humidity or was higher in outdoor enclosures than indoor tanks. One replicated study in Germany found that survival of European red-bellied toad eggs, tadpoles and juveniles was higher in captivity than the wild.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F848https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F848Thu, 05 Sep 2013 12:44:56 +0100Collected Evidence: Collected Evidence: Captive breeding and reintroduction of primates into the wild: born and reared in cages One before-and-after study in Brazil found that most reintroduced golden lion tamarins that were born and reared in cages, alongside other interventions, did not survive over seven years or had a higher mortality than wild-born tamarins. One controlled study in French Guiana found that more squirrel monkeys which were born and reared in cages, alongside other interventions, died or were returned to captivity post-reintroduction compared to wild-born monkeys. One controlled study in Madagascar found that the diet of reintroduced black-and-white ruffed lemurs which were born and reared in cages, alongside other interventions, did not overlap with that of wild lemurs. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1594https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1594Fri, 20 Oct 2017 14:33:22 +0100Collected Evidence: Collected Evidence: Captive breeding and reintroduction of primates into the wild: limited free-ranging experience One controlled study in Madagascar found that the diet of reintroduced black-and-white ruffed lemurs with limited free-ranging experience, alongside other interventions, overlapped with that of wild lemurs. One before-and-after study in Madagascar found that most reintroduced black-and-white ruffed lemurs with limited free-ranging experience, alongside other interventions, died over five years. One before-and-after and site comparison and one before-and-after study in the Republic of Congo and Gabon found that most reintroduced western lowland gorillas with limited free-ranging experience, alongside other interventions, survived over a period of between nine months and four years. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1595https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1595Fri, 20 Oct 2017 14:36:52 +0100Collected Evidence: Collected Evidence: Captive breeding and reintroduction of primates into the wild: born and raised in a free-ranging environment One before-and-after study in Brazil found that only two out of three reintroduced black lion tamarins survived over four months, despite being raised in a free-ranging environment, alongside other interventions. One controlled study in Madagascar found that the diet of reintroduced black-and-white ruffed lemurs that were born and raised in a free-ranging environment alongside other interventions, overlapped with that of wild lemurs. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1596https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1596Fri, 20 Oct 2017 14:44:59 +0100Collected Evidence: Collected Evidence: Bury upper layer of peat/soil (without planting) We found no studies that evaluated the effects, on peatland vegetation, of burying the upper layer of peat or soil (without planting afterwards). ‘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%2F1810https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1810Tue, 28 Nov 2017 08:31:22 +0000Collected Evidence: Collected Evidence: Carnivores: Feed commercially prepared diets One replicated, before-and-after study in the USA found that providing a commercial diet to maned wolves led to similar dry matter intake and digestibility despite having a lower protein content. One replicated, randomized study of African wildcats in the USA found that feeding a commercial diet decreased crude protein digestibility and increased food intake and faecal output compared to raw meat. One controlled study of African wildcats in the USA found lower organic matter digestibility compared to a ground-chicken diet. One replicated, controlled study in South Africa found that cheetahs fed a commercial diet had a similar likelihood of developing gastritis as those fed horse meat, lower levels of blood protein urea but higher levels of creatine. One study in USA found that cheetahs fed a commercial meat diet or whole chicken carcasses had plasma a-tocopherol, retinol and taurine concentrations within the ranges recommended for domestic cats. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1900https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1900Wed, 24 Jan 2018 09:26:14 +0000Collected Evidence: Collected Evidence: Carnivores: Feed whole carcasses (with or without organs/gastrointestinal tract) Two replicated, before-and-after studies in the USA found that feeding whole carcasses reduced pacing levels in lions, leopards, snow leopards and cougars. However, it increased pacing in tigers. One replicated, randomized, controlled study in Denmark found that when fed whole rabbit, cheetahs had lower blood protein urea, zinc and vitamin A levels compared to supplemented beef. One replicated before-and-after study in Denmark found that feeding whole rabbit showed lower levels of inflammatory bowel indicators in cheetahs. One replicated, randomized study and one controlled study in the USA found that when fed whole 1 to 3 day old chickens, ocelots had lower digestible energy and fat compared to a commercial diet and African wildcats had had lower organic matter digestibility compared to a ground-chicken diet. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1901https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1901Wed, 24 Jan 2018 09:52:15 +0000Collected Evidence: Collected Evidence: Carnivores: Feed a plant-derived protein diet One replicated, randomized, controlled study and one replicated, controlled study in the USA found that a plant-derived protein diet increased digestible energy and dry matter digestibility but decreased mineral retention and plasma taurine levels in maned wolves compared to a (supplemented) animal-based protein diet. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1903https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1903Wed, 24 Jan 2018 10:15:58 +0000Collected Evidence: Collected Evidence: Carnivores: Allocate fast days One replicated, before-and-after study in the UK found that large felids fed once every three days paced more frequently on non-feeding days. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1906https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1906Wed, 24 Jan 2018 10:38:37 +0000Collected Evidence: Collected Evidence: Carnivores: Alter food abundance or type seasonally No evidence was captured for the effects of altering food abundance or type seasonally on captive carnivores. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested 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%2F1910https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1910Wed, 24 Jan 2018 10:42:25 +0000Collected Evidence: Collected Evidence: Carnivores: Alter feeding schedule according to visitor activity No evidence was captured for the effects of altering feeding schedule to visitor activity on captive carnivores. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested 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%2F1914https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1914Wed, 24 Jan 2018 10:46:41 +0000Collected Evidence: Collected Evidence: Carnivores: Hide food around enclosure Four replicated, before-and-after studies in the USA, UK and Germany and one before-and-after study of a black bear, leopard cats, bush dogs, maned wolves and Malayan sun bears found that hiding food increased exploring and foraging behaviours. One replicated, before-and-after study and one before-and-after study in the USA found a decrease in stereotypical pacing in leopard cats and black bear. One before-and-after study in the USA found that hiding food reduced the time Canadian lynx spent sleeping during the day. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1915https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1915Wed, 24 Jan 2018 10:47:53 +0000Collected Evidence: Collected Evidence: Carnivores: Feed individuals separately No evidence was captured for the effects of feeding individuals separately on captive carnivores. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested 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%2F1917https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1917Wed, 24 Jan 2018 10:50:39 +0000Collected Evidence: Collected Evidence: Carnivores: Change location of food around enclosure One replicated, before-and-after study in Ireland found that altering the location of food decreased pacing behaviours in cheetahs. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1918https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1918Wed, 24 Jan 2018 10:51:27 +0000Collected Evidence: Collected Evidence: Carnivores: Feed individuals within a social group No evidence was captured for the effects of feeding individuals within a social group. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested 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%2F1919https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1919Wed, 24 Jan 2018 10:53:13 +0000Collected Evidence: Collected Evidence: Carnivores: Hand-feed No evidence was captured for the effects of hand-feeding on captive carnivores. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested 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%2F1920https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1920Wed, 24 Jan 2018 10:54:17 +0000Collected Evidence: Collected Evidence: Captive rear in large enclosures prior to release Four studies evaluated the effects of captive rearing mammals in large enclosures prior to release. Two studies were in the USA, one was in Mexico and one was in Australia. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (3 STUDIES) Reproductive success (1 study): A study in Mexico found that peninsular pronghorn taken from the wild and kept in a large enclosure bred successfully and the population increased, providing stock suitable for reintroductions. Survival (2 studies): A replicated, controlled study in USA found that black-footed ferrets reared in outdoor pens had higher post-release survival rates than did ferrets raised indoors. A controlled study in Australia found that Tasmanian devils reared free-range in large enclosures did not have greater post-release survival rates than animals from intensively managed captive-rearing facilities. Condition (1 study): A controlled study in Australia found that Tasmanian devils reared free-range in large enclosures did not gain more body weight post-release compared to animals from intensively managed captive-rearing facilities. BEHAVIOUR (1 STUDY) Behaviour change (1 study): A controlled study in USA found that captive-bred black-footed ferrets raised in large enclosures dispersed shorter distances post-release than did ferrets raised in small enclosures. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2507https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2507Thu, 04 Jun 2020 16:36:49 +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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