Collected Evidence: Collected Evidence: Release captive-bred individuals into the wild to restore or augment wild populations of wildfowl Two studies of reintroduction programmes of ducks in New Zealand found high survival of released birds and population establishment, with one describing successful breeding. One study describes higher success in the second year of the release programme, potentially because there was then a population present in the wild and more intensive predator control. A before-and-after study from Alaska found low survival of released cackling geese Branta hutchinsii, but that the population recovered from 1,000 to 6,000 birds after releases and the control of mammalian predators. A review of a reintroduction programme from Hawaii found that the release of 2,150 Hawaiian geese (nene) Branta sandvicensis had not resulted in the establishment of a self-sustaining population, although some birds bred. Two studies from Canada found very low return rates for released ducks with one finding no evidence for survival of released birds over two years, although there was some evidence that breeding success was higher for released birds than wild ones. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F618https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F618Sun, 14 Oct 2012 13:05:11 +0100Collected Evidence: Collected Evidence: Release captive-bred individuals into the wild to restore or augment wild populations of gamebirds One of five studies from across the world found that releasing gamebirds established a population or bolstered an existing population, although the authors argued that the population of 30–40 western capercaillie Tetrao urogallus (from nearly 400 released) was unlikely to be self-sustaining. A review of a reintroduction programme in Pakistan found some breeding success in released cheer pheasants Catreus wallichii, but that habitat change at the release site then excluded released birds. Three studies from Europe and the USA found that released birds had low survival, low reproductive success and had no impact on the wild population.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F619https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F619Sun, 14 Oct 2012 13:38:41 +0100Collected Evidence: Collected Evidence: Release captive-bred individuals into the wild to restore or augment wild populations of rails One replicated study from Australia found that released Lord Howe Island woodhens Tricholimnas sylvestris successfully bred in the wild, re-establishing a wild population. A replicated study from the UK found high survival of released corncrake Crex crex in the first summer (although no data were available on overwinter survival or breeding). A replicated study in New Zealand found very low survival of North Island weka Gallirallus australis greyi following release, mainly due to predation by invasive mammals.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F620https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F620Sun, 14 Oct 2012 13:58:52 +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 bustards Three reviews of a release programme for houbara bustard Chlamydotis undulata macqueenii in Saudi Arabia and a replicated trial as part of the same programme found low initial survival of released birds, but the establishment of a breeding population and an overall success rate of 41%. The programme tested many different release techniques, discussed elsewhere, with releases being most successful if sub-adults were released, able to fly, into a large exclosure.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F622https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F622Sun, 14 Oct 2012 14:23:17 +0100Collected Evidence: Collected Evidence: Release captive-bred individuals into the wild to restore or augment wild populations of wadersA review of black stilt Himantopus novaezelandiae releases in New Zealand found that birds had low survival (13–20%) and many moved away from their release sites so, in consequence, that they could not be managed and were unlikely to interact with stilt populations in the wild.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F623https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F623Sun, 14 Oct 2012 14:32:46 +0100Collected Evidence: Collected Evidence: Release captive-bred individuals into the wild to restore or augment wild populations of storks and ibisesA replicated study and a review of northern bald ibis Geronticus eremita release programmes in Europe and the Middle East found that only one of four had resulted in a wild population being established or supported, with many birds dying or dispersing, rather than forming stable colonies.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F624https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F624Sun, 14 Oct 2012 14:38:18 +0100Collected Evidence: Collected Evidence: Release captive-bred individuals into the wild to restore or augment wild populations of vultures Four studies of two release programmes found that release programmes led to large population increases in Andean condors Vultur gryphus in Colombia and griffon vultures Gyps fulvus in France. A small study in Peru found high survival of released Andean condors Vultur gryphus over 18 months, with all fatalities occurring in the first six months after release.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F625https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F625Sun, 14 Oct 2012 14:40:59 +0100Collected Evidence: Collected Evidence: Release captive-bred individuals into the wild to restore or augment wild populations of raptors Five studies of three release programmes from across the world found the establishment or increase of wild populations of falcons Falco spp. Five studies from the USA found high survival of released raptors (with between one and 204 birds released), whilst two found that released birds behaved normally and hunted successfully. One study from Australia found that a wedge-tailed eagle Aquila audax had to be taken back into captivity after acting aggressively towards humans, whilst another Australian study found that only one of 15 brown goshawks Accipiter fasciatus released was recovered, although the authors do not draw conclusions about survival rates from this.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F626https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F626Sun, 14 Oct 2012 14:54:39 +0100Collected Evidence: Collected Evidence: Release captive-bred individuals into the wild to restore or augment wild populations of owls A study in the USA found that a barn owl Tyto alba population was established following the release of 157 birds in the area over three years. A replicated, controlled study in Canada found that released burrowing owls Athene cunicularia had similar reproductive output, but higher mortality than wild birds, and no released birds returned after migration, although return rates for released birds’ offspring were no different from wild birds.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F627https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F627Sun, 14 Oct 2012 22:47:34 +0100Collected Evidence: Collected Evidence: Release captive-bred individuals into the wild to restore or augment wild populations of pigeonsA single review of a captive-release programme in Mauritius found that that released pink pigeons Nesoenas mayeri had a first year survival of 36%.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F628https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F628Sun, 14 Oct 2012 22:54:33 +0100Collected Evidence: Collected Evidence: Release captive-bred individuals into the wild to restore or augment wild populations of parrots A before-and-after study from Venezuela found that the local population of yellow-shouldered amazons Amazona barbadensis increased significantly following the release of captive-bred birds, along with other interventions. A replicated study in Costa Rica and Peru found high survival and some breeding of scarlet macaw Ara macao after release. Three replicated studies in the USA, Dominican Republic and Puerto Rico found low survival in released birds (4–41% in the first year after release), although the Puerto Rican study also found that released birds bred successfully.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F629https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F629Sun, 14 Oct 2012 22:56:19 +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: Release captive-bred green and golden bell frogs One review and two before-and-after studies in Australia found that captive-bred green and golden bell frogs released mainly as tadpoles did not established breeding populations, or only established stable breeding populations following one of four release programmes. One study in Australia found that a small proportion of captive-bred green and golden bell frog released as tadpoles survived at least 13 months after release.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F872https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F872Wed, 11 Sep 2013 16:03:45 +0100Collected Evidence: Collected Evidence: Release captive-bred Mallorcan midwife toads Three studies (including one replicated study and one review) in Mallorca found that captive-bred midwife toads released as tadpoles, toadlets or adults established breeding populations at 38%, 80% or 100% of sites. One randomized, replicated, controlled study in the UK found that predator defences were maintained, but genetic diversity reduced in a captive-bred reintroduced population.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F873https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F873Thu, 12 Sep 2013 10:43:06 +0100Collected Evidence: Collected Evidence: Release captive-bred salamanders (including newts) One before-and-after study in Germany found that captive-bred great crested newts and smooth newts released as larvae, juveniles and adults established stable breeding populations.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F874https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F874Thu, 12 Sep 2013 10:48:40 +0100Collected Evidence: Collected Evidence: Release captive-bred individuals to re-establish or boost populations in native range Thirty-one studies evaluated the effects of releasing captive-bred mammals to establish or boost populations in their native range. Seven studies were in the USA, three were in Australia and Italy, two studies were in each of Canada, Sweden, Saudi Arabia, the UK, the Netherlands and South Africa and one study was in each of France, Africa, Europe, and North America, Estonia, the USA and Mexico, Poland and China. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (30 STUDIES) Abundance (7 studies): Five of five studies (one replicated) and two reviews in Saudi Arabia, Australia, the USA, South Africa, France, the Netherlands and China found that following release of captive-bred (or in one case captive-reared, or including translocated) animals, populations of mountain gazelles, Corsican red deer, Père David's deer, Eurasian otters and swift foxes increased. The two reviews found that following release of mainly translocated but some captive-bred large carnivores, populations of four of six species increased, and over half of mammal release programmes were considered successful. Reproductive success (5 studies): Four studies (one replicated) in Saudi Arabia, the UK and the Netherlands found that released captive-bred (and in some cases some wild-born translocated) mountain gazelles, dormice and some Eurasian otters reproduced successfully and female Arabian oryx reproduced successfully regardless of prior breeding experience. A controlled study in Italy found that released captive-born Apennine chamois reproduced in similar numbers to wild-caught translocated chamois. Survival (24 studies): Four of three controlled studies (two replicated) and two reviews in Canada, Canada and the USA, Sweden, Italy and across the world found that released captive-bred swift foxes, European otters and mammals from a review of 49 studies had lower post-release survival rates than did wild-born translocated animals. The other study found that released captive-born Apennine chamois survived in similar numbers to wild-caught translocated chamois. Three studies (one replicated) in the USA and Canada found that released captive-born Key Largo woodrats, Vancouver Island marmots and swift fox pups had lower survival rates than wild-born, wild-living animals. One of the studies also found that Vancouver Island marmots released at two years old were more likely to survive than those released as yearlings. Eleven studies (three replicated) in Italy, Sweden, the UK, Estonia, Poland, Saudi Arabia, Australia and the USA found that following the release of captive-bred (and in some cases some wild-born translocated) animals, Arabian oryx, populations of European otters, European mink and mountain gazelle survived for 2-11 years, roe deer and over a third of brush-tailed rock-wallabies, black-footed ferrets and brown hares survived for 0.5-24 months and dormice populations survived three months to over seven years. A review in Australia found that release programmes for macropod species resulted in successful establishment of populations in 61% of cases and that 40% survived over five years, and another review in Australia found that over half of programmes were considered successful. Two studies and a review in the USA, USA and Mexico and South Africa found that over 40% of released captive-bred American black bears were killed or had to be removed, only one of 10 oribi survived over two years and that most black-footed ferret releases were unsuccessful at maintaining a population. BEHAVIOUR (3 STUDIES) Use (3 studies): Two studies in the USA and Australia found that following release, most captive-bred and translocated mountain lions that had been held in captivity prior to release and most released captive-bred brush-tailed rock-wallabies established stable home ranges. A controlled study in Italy found that released captive-born Apennine chamois remained closer to the release site than released wild-caught translocated chamois. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2476https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2476Thu, 04 Jun 2020 10:11:11 +0100Collected Evidence: Collected Evidence: Release captive-bred mammals into fenced areas Fourteen studies evaluated the effects of releasing captive-bred mammals into fenced areas. Nine studies were in Australia and one each was in Jordan, South Africa, the USA, Saudi Arabia and Senegal. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (14 STUDIES) Abundance (5 studies): Four studies (one replicated) and a review in Australia, Jordan and Senegal found that after releasing captive-bred animals into fenced areas, a population of burrowing bettongs increased, a population of Arabian oryx increased six-fold in 12 years, a population of dorcas gazelle almost doubled over four years, three populations of eastern barred bandicoot initially increased and abundance of eastern barred bandicoots increased. Reproductive success (6 studies): Four studies and a review in South Africa, Australia, Saudi Arabia and Senegal found that following release of captive-bred animals into fenced areas (in some cases with other associated management), African wild dogs, three populations of eastern barred bandicoot, dorcas gazelle and most female black-footed rock-wallabies reproduced, and Arabian gazelles started breeding in the year following the first releases. A study in Australia found that four of five mammal populations released into a predator-free enclosure and one released into a predator-reduced enclosure reproduced, whereas two populations released into an unfenced area with ongoing predator management did not survive to reproduce. Survival (10 studies): A study in Australia found that four of five mammal populations released into a predator-free enclosure and one population released into a predator-reduced enclosure survived, whereas two populations released into an unfenced area with ongoing predator management did not. Six studies (one controlled before-and-after study and two replicated studies) in Australia and the USA found that following release of captive-bred animals into fenced areas (in some cases with other associated management), a burrowing bettong population, three eastern barred bandicoot populations and over half of black-footed rock-wallabies survived between one and eight years, most captive-bred hare-wallabies survived at least two months, at least half of black-footed ferrets survived more than two weeks, and bandicoots survived at five of seven sites up to three years after the last release. One study in Australia found that following release into fenced areas, a captive-bred population of red-tailed phascogales survived for less than a year. A study in South Africa found that captive-bred African wild dogs released into fenced reserves in family groups had high survival rates. A randomized, controlled study in Australia found that captive-bred eastern barred bandicoots released into a fenced reserve after time in holding pens had similar post-release survival compared to bandicoots released directly from captivity. Condition (1 study): A randomized, controlled study in Australia found that captive-bred eastern barred bandicoots released into a fenced reserve after time in holding pens had similar post-release body weight compared to those released directly from captivity. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2521https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2521Mon, 08 Jun 2020 09:55:37 +0100Collected Evidence: Collected Evidence: Release captive-bred marine and freshwater mammals to re-establish or boost native populations Two studies evaluated the effects of releasing captive-bred marine and freshwater mammals to re-establish or boost native populations. One study was in the Porto de Pedras estuary (Brazil) and one in water bodies in Florida (USA). COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Survival (2 studies): Two studies in the Porto de Pedras estuary and water bodies in Florida found that two of three Antillean manatees and two of 14 Florida manatees born in captivity and released into the wild survived for at least one year without further intervention. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2933https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2933Tue, 09 Feb 2021 11:36:19 +0000Collected Evidence: Collected Evidence: Release captive-bred reptiles into the wild: Sea turtles Three studies evaluated the effects of releasing captive-bred sea turtles into the wild. Two studies were in the Gulf of Mexico and one was in the Caribbean. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (3 STUDIES) Reproductive success (1 study): One replicated study in the Caribbean found that eight of over 30,000 captive-bred green turtles released into the wild (around 15,000 reared to one year or more in captivity) were observed nesting and two produced clutches of >100 eggs with hatching success of 63% and 88%. Survival (3 studies): Three replicated studies in the Gulf of Mexico and the Caribbean reported that following releases of captive-bred Kemp's ridley turtles and green turtles into the wild, 120–606 of 22,000–30,000 turtles survived for 1–19 years after release. Condition (1 study): One replicated study in the Gulf of Mexico found that captive-bred Kemp's ridley turtles released into the wild grew by 19–59 cm over 1–9 years. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3768https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3768Tue, 14 Dec 2021 17:46:32 +0000Collected Evidence: Collected Evidence: Release captive-bred reptiles into the wild: Tortoises, terrapins, side-necked & softshell turtles Fourteen studies evaluated the effects of releasing captive-bred tortoises terrapins, side-necked & softshell turtles into the wild. Five studies were in the USA, three were in Italy, two were in the Seychelles, and one was in each of Madagascar, Australia and Spain and Minorca and one was global. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (13 STUDIES) Abundance (1 study): One global review found that when using recruitment to the adult population as a measure of success, 32% of reptile translocations/releases (releases of captive individuals were 7% of total projects) were successful. Occupancy/range (1 study): One review in Australia found that two of three releases of captive-bred Western swamp tortoises were classified as successful. Reproductive success (2 studies): Two studies (including one replicated study) in Italy reported evidence of a gravid female and successful reproduction following release of captive-bred European pond turtles. Survival (11 studies): Six of nine studies (including two replicated, controlled studies) in Madagascar, the Seychelles, the USA and Italy reported that 66–100% of 5–80 captive-bred tortoises and turtles released into the wild survived over monitoring periods of six months to two years. Two studies reported that 16–20% of 5 and 246 individuals survived over two years. The other study reported that some of over 250 individuals (number not given) were recaptured over a year of monitoring. One study also found captive-bred alligator snapping turtles that were older at their time of release had higher survival than younger turtles. One replicated study in Italy found that annual survival of released captive-bred European pond turtles was 67–91%. One replicated study in Spain and Minorca found that survival of captive-bred Hermann’s tortoises was higher after three years after release into the wild compared to 1–2 years after release. The study also found that after three years, survival of released tortoises was similar to that of wild tortoises in one population, but lower in a second population. Condition (2 studies): One of two controlled studies (including one replicated study) in the USA found that released captive-bred juvenile alligator snapping turtles grew at a similar rate and achieved higher body condition than juveniles that remained in captivity. The other study found that released alligator snapping turtles had similar body conditions compared to individuals that remained in captivity. BEHAVIOUR (1 STUDY) Behaviour change (1 study): One randomized study in the USA found that captive-bred Blanding’s turtles released into open water habitat had larger home ranges than those released into places dominated by cattail or willows. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3770https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3770Wed, 15 Dec 2021 11:07:11 +0000Collected Evidence: Collected Evidence: Release captive-bred reptiles into the wild: Snakes & lizards Ten studies evaluated the effects on reptile populations of releasing captive-bred snakes and lizards into the wild. Three studies were in New Zealand, two were in the USA and one was in each of the Galápagos, Spain, Australia and Canada and one was global. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (10 STUDIES) Abundance (2 studies): One global review found that when using recruitment to the adult population as a measure of success, 32% of reptile releases (releases of captive individuals were 7% of total projects) were successful. One review in New Zealand found that 13% of lizard releases (some involving captive-bred animals) found evidence of populations growth Reproductive success (3 studies): Three studies (including two reviews) in the USA and New Zealand found evidence of breeding following release in one of two captive-bred populations of cornsnakes, one captive-bred population of Otago skinks and in at least 16 lizard mitigation translocations, some of which involved captive-bred animals. Survival (9 studies): One replicated, controlled study in Spain found that released large psammodromus lizards had similar annual survival compared to resident lizards. Two of six studies (including one replicated study and two reviews) in the USA, Australia, New Zealand and Canada reported that 13% of 40 indigo snakes were re-sighted at least once during 5–8 years following release or that 58% of 12 Otago skinks survived at least 18 months. Two studies found that zero of nine and 27 individuals survived more than 143 days or beyond their first hibernation. The other two studies found that one of two and five of 53 releases (only some of which involved captive-bred animals) failed completely (no individuals survived). One study in New Zealand found that survival of captive-bred Otago skinks released into an enclosure was higher when mice had been eradicated compared to when skinks were released in the presence of mice. One replicated study in the Galápagos found that while releases were ongoing over a decade (183 released in total), 17–32 Galápagos land iguanas were recaptured each year. Condition (1 study): One controlled study in New Zealand found that body condition of captive-reared Otago skinks was higher than wild skinks, but sprint speed was lower. BEHAVIOUR (1 STUDY) Behaviour change (1 study): One replicated, controlled study in Spain found that released large psammodromus lizards moved between habitat fragments more frequently than resident lizards but showed similar behaviour in three other measures. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3771https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3771Wed, 15 Dec 2021 11:29:15 +0000Collected Evidence: Collected Evidence: Release captive-bred reptiles into the wild: Crocodilians Four studies evaluated the effects of releasing captive-bred crocodilians into the wild. Two studies were in China, one was in South Africa and one was a global review. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (4 STUDIES) Abundance (2 studies): One global review found that when using recruitment to the adult population as a measure of success, 32% of reptile translocations/releases (releases of captive individuals were 7% of total projects) were successful. One study in South Africa reported that following releases of captive-bred Nile crocodiles, wild populations increased in size over 30 years, but then declined in the subsequent 15 years. Reproduction (2 studies): Two studies (one replicated) in China reported that breeding or nesting was observed within four years of releasing captive-bred Chinese alligators. Survival (1 study): One study in China reported that of nine captive-bred Chinese alligators, three survived for nine years and six survived for at least one year following release. BEHAVIOUR (1 STUDY) Use (1 study): One replicated study in China reported that after 10 years of releases of captive bred Chinese alligators to an area that had historically been occupied, 56% of constructed ponds were occupied. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3772https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3772Wed, 15 Dec 2021 11:53:57 +0000Collected Evidence: Collected Evidence: Release captive-bred reptiles into the wild: Tuatara Two studies evaluated the effects of releasing captive-bred tuatara into the wild. One study was in New Zealand and one was a global review. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Abundance (1 study): One global review found that when using recruitment to the adult population as a measure of success, 32% of reptile translocations/releases (releases of captive individuals were 7% of total projects) were successful. Condition (1 study): One study in New Zealand found that tuatara reared close to the release site had higher growth, but similar body condition compared to individuals reared in a warmer climate. BEHAVIOUR (1 STUDY) Behaviour change (1 studies): One study in New Zealand found that tuatara reared close to the release site had similar home range sizes and post-release dispersal compared to individuals reared in a warmer climate. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3773https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3773Wed, 15 Dec 2021 12:02:09 +0000Collected Evidence: Collected Evidence: Release captive-bred individuals to the wild Thirteen studies evaluated the effects of releasing captive-bred butterflies and moths into the wild. Nine studies were in the UK and one was in each of the UK and Ireland, the UK and the Netherlands, the USA and Poland and Slovakia. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (12 STUDIES) Abundance (10 studies): Six studies (including one before-and-after study) in the UK, the USA and Poland and Slovakia reported that captive-bred butterfly populations released as eggs, caterpillars, pupae and adults (sometimes into managed habitat or alongside translocated individuals) persisted for 2–28 years and increased in abundance (sometimes with continued captive-rearing of wild-laid caterpillars or supplemented by further releases). Two studies (including one review) in the UK reported that captive-bred large copper and belted beauty moth populations released as caterpillars (sometimes into managed habitat) died out one, two or 12 years after release, or required further releases to survive. One replicated study in the UK reported that three of 10 captive-bred barberry carpet moth populations released as caterpillars (and in one case as adults) established, and at least one persisted for five years. One review across the UK and Ireland found that 25% of captive-bred and translocated butterfly populations survived for >3 years, but 38% died out in that time, and only 8% were known to have survived for >10 years. Reproductive success (2 studies): One study in the UK reported that after the release of a captive-bred population of large copper, the number of eggs laid/female increased over the first three years. One before-and-after study in the UK reported captive-bred adult pearl-bordered fritillaries released into coppiced woodland successfully bred at least once. Survival (3 studies): Three studies (including two replicated, site comparison studies and one review) in the UK and the UK and the Netherlands found that released, captive-bred large copper caterpillars had a lower survival rate than captive, wild or translocated caterpillars. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3914https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3914Wed, 10 Aug 2022 15:06:58 +0100
What Works 2021 cover

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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The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust
For a full list of, and information about, our champions:
All Evidence Champions
About our champions, why and how to become one:
Become an Evidence Champion

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