Conservation Evidence: Evidence Data

Collected 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: 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 +0100Collected Evidence: Collected Evidence: Use holding pens at release site prior to release of captive-bred mammals Thirty-one studies evaluated the effects of using holding pens at the release site prior to release of captive-bred mammals. Seven studies were in Australia, and in the USA, four were in the UK, three in Argentina, two in each of Israel, Saudi Arabia and China and one in each of Canada, Namibia, South Africa and Germany. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (30 STUDIES) Abundance (2 studies): A study in Saudi Arabia found that a population of captive-bred Arabian sand gazelles kept in holding pens prior to release nearly doubled in size over four years. A before-and-after study in China found that following release of captive-bred animals from a pre-release enclosure into the semi-wild (free-roaming in summer, enclosed in winter and provided with food), Przewalski’s horses increased in number. Reproductive success (10 studies): Eight studies (one replicated) and one review in the UK, Saudi Arabia, the USA, Israel and Australia found that following the use of holding pens prior to release (and in some cases provision of supplementary food), captive-bred Eurasian otters, Arabian sand gazelles, eastern-barred bandicoots, some swift foxes, some red wolves and over 33% of Persian fallow deer reproduced, Arabian gazelles started breeding in the first year and the reproductive success of female Asiatic wild ass increased over 10 years. A study in Australia found that after being kept in a holding pen, all four mammal populations released into an invasive-species-free fenced enclosure reproduced. Survival (23 studies): One of three studies (two controlled, one replicated) in the UK, Canada and Australia found that using holding pens prior to release of captive-bred (and some translocated) animals resulted in greater post-release survival for water voles compared to animals released directly into the wild. The other two studies found similar survival rates for eastern barred bandicoots and swift foxes compared to animals released directly into the wild. A replicated study in the USA found that captive-bred Allegheny woodrats kept in holding pens prior to release, had higher early survival rates than those not kept in holding pens, but overall survival rates tended to be lower than wild resident woodrats. Three studies in South Africa, USA and Argentina found that released captive-bred (and some translocated) African wild dogs, riparian brush rabbits and guanacos that spent longer in, and in one case in larger, holding pens had a higher survival rate. Three studies (one controlled) in Australia and the USA found that captive-bred animals kept in holding pens prior to release had similar (bridled nailtail wallabies) or lower (black-footed ferret kits) annual survival rate after release to that of wild-born translocated animals and lower (black-footed ferrets) survival rates than resident animals. Ten studies (including one controlled, before-and-after study) and one review in Saudi Arabia, the USA, Argentina, China, Israel, Australia and Germany found that following the use of holding pens prior to release of captive-bred animals (or in some cases captive-reared/rehabilitated, or with provision of supplementary food), four of four mammal populations, 19% of red wolves, Asiatic wild ass, Persian fallow deer, most Arabian sand gazelles, most swift foxes, eastern-barred bandicoots and European mink survived at least 1-10 years, over half of giant anteaters, hare-wallabies and Père David’s deer survived for at least 1.5-6 months. Three studies in Namibia, the USA and Australia found that that following the use of holding pens prior to release of captive-bred or reared animals (some provided with nest boxes and/or supplementary food), red-tailed phascogales, most Mexican wolves and African wild dogs survived less than 6-12 months. Condition (4 studies): A randomized, controlled study in Australia found that eastern barred bandicoots released after time in holding pens lost a similar proportion of body weight and recovered to a similar weight compared to bandicoots released directly. A controlled study in the UK found that common dormice lost weight after being put into holding pens whereas wild translocated dormice gained weight. A controlled, before-and-after study in Australia found that captive-bred rufous hare-wallabies placed in holding pens prior to release lost body condition in holding pens. A before-and-after study in Australia found that captive-bred brush-tailed rock-wallabies placed in a holding pen prior to release maintained good health. BEHAVIOUR (1 STUDY) Behaviour change (1 study): A controlled study in Argentina found that after being kept in holding pens and provided with supplementary food, released captive-bred giant anteaters were less nocturnal in their activity patterns than released wild-born rehabilitated individuals. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2510https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2510Fri, 05 Jun 2020 09:17:56 +0100Collected Evidence: Collected Evidence: Provide live natural prey to captive mammals to foster hunting behaviour before release Three studies evaluated the effects of providing live natural prey to captive mammals to foster hunting behaviour before release. One study was in Spain, one was in the USA and one was in Botswana. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (2 STUDIES) Survival (2 studies): Two studies in Spain and Botswana found that a rehabilitated Iberian lynx and wild-born but captive-reared orphaned cheetahs and leopards that were provided with live natural prey in captivity survived for between at least three months and 19 months after release. BEHAVIOUR (1 STUDY) Behaviour change (1 study): A controlled study in the USA found that captive-bred black-footed ferrets fed on live prairie dogs took longer to disperse after release but showed greater subsequent movements than did ferrets not fed with live prairie dogs. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2518https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2518Mon, 08 Jun 2020 09:14:03 +0100Collected Evidence: Collected Evidence: Train captive-bred mammals to avoid predators Two studies evaluated the effects of training captive-bred mammals to avoid predators. One study was in Australia and one was in the USA. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Survival (1 study): A randomized, controlled study in the USA found that training captive-born juvenile black-tailed prairie dogs, by exposing them to predators, increased post-release survival. BEHAVIOUR (1 STUDY) Behaviour change (1 study): A before-and-after study in Australia found that rufous hare-wallabies could be conditioned to become wary of potential predators. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2520https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2520Mon, 08 Jun 2020 09:30:41 +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: Provide supplementary food during/after release of captive-bred mammals Fifteen studies evaluated the effects of providing supplementary food during/after release of captive-bred mammals. Four studies were in Australia, two were in each of the USA, China and Argentina, and one was in each of Poland, the UK, Oman and Saudi Arabia. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (14 STUDIES) Abundance (5 studies): Four studies (one replicated, one before-and-after study) and one review in Poland, Oman, China and Australia found that following provision of supplementary food (and in one case water) to released captive-bred animals, populations of European bison increased more than six-fold over 20 years, Arabian oryx increased over 14 years, eastern-barred bandicoots increased for the first five years before declining, Père David's deer increased more than six-fold over 12 years and Przewalski’s horses (enclosed in winter) increased over 11 years. Reproductive success (9 studies): Eight studies (including two replicated and one before-and-after study) and one review in Poland, the UK, China, the USA, Australia and Saudi Arabia found that following the provision of supplementary food (and in one case water or artificial nests) after release of captive-bred animals, some from holding pens, European bison, European otters, Père David's deer, eastern-barred bandicoots, Przewalski’s horses and some captive-bred red wolves successfully reproduced, Arabian gazelles started breeding in the year following releases and sugar gliders established a breeding population. Survival (6 studies): Four of six studies (one controlled, before-and-after study) in the UK, USA, Argentina and Australia found that following the provision of supplementary food (and in one case water or nest boxes) after release of captive-bred animals, many from holding pens, 19% of red wolves survived for at least seven years, Eurasian otters survived for at least two years, over half the giant anteaters (some rehabilitated) survived for at least six months and hare-wallabies survived at least two months. Two of the studies found that red-tailed phascogales survived for less than a year and most Mexican wolves survived less than eight months. BEHAVIOUR (1 STUDY) Behaviour change (1 study): A controlled study in Argentina found that after being provided with supplementary food and kept in holding pens, released captive-bred giant anteaters were less nocturnal in their activity patterns than released wild-born rehabilitated individuals. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2527https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2527Mon, 08 Jun 2020 14:23:58 +0100