Use of wild–caught individuals as a key factor for success in vertebrate translocations (original) (raw)
Related papers
Limited contributions of released animals from zoos to North American conservation translocations
Conservation Biology
With the loss of biodiversity accelerating, conservation translocations such as reintroductions are becoming an increasingly common conservation tool. Conservation translocations must source individuals for release from either wild or captive-bred populations. We asked what proportion of North American conservation translocations rely on captive breeding and to what extent zoos and aquaria (hereafter zoos) fulfill captive breeding needs. We searched for mention of captive breeding and zoo involvement in all 1863 articles included in the North American Conservation Translocations database, which comprises journal articles and grey literature published before 2014 on conservation translocations in Canada, the United States, Mexico, the Caribbean, and Central America before 2014 as identified by a comprehensive literature review. Conservation translocations involved captive breeding for 162 (58%) of the 279 animal species translocated. Fifty-four zoos contributed animals for release. The 40 species of animals bred for release by zoos represented only 14% of all animal species for which conservation translocations were published and only 25% of all animal species that were bred for releases occurring in North America. Zoo contributions varied by taxon, ranging from zoo-bred animals released in 42% of amphibian conservation translocations to zero contributions for marine invertebrates. Proportional involvement of zoos in captive-breeding programs for release has increased from 1974 to 2014 (r = 0.325, p = 0.0313) as has the proportion of translocationfocused scientific papers coauthored by zoo professionals (from 0% in 1974 to 42% in 2013). Although zoos also contribute to conservation translocations through education, funding, and professional expertise, increasing the contribution of animals for release in responsible conservation translocation programs presents a future conservation need and opportunity. We especially encourage increased dialogue and planning between the zoo community, academic institutions, and governments to optimize the direct contribution zoos can make to wildlife conservation through conservation translocations.
The fitness consequences of wildlife conservation translocations: A meta-analysis
bioRxiv (Cold Spring Harbor Laboratory), 2023
Conservation translocation is a common strategy to offset mounting rates of population declines through the transfer of captive-reared or relocated organisms to imperiled populations. However, these programs have been criticized for low success rates and husbandry practices that produce individuals with genetic and performance deficits. We assessed the disparity in post-release performance of translocated organisms relative to wild-resident conspecifics through a metaanalysis of 826 performance comparisons from 172 studies representing nine animal classes (101 species). We found that translocated organisms have 70% decreased odds of out-performing their wild-resident counterparts, supporting published claims of systemic issues hampering conservation translocation. Pre-release animal enrichment significantly reduced performance disparities, whereas our results suggest no overall effects of captive generation time or the type. CC-BY-NC-ND 4.0 International license available under a (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made The copyright holder for this preprint this version posted January 17, 2023. ;
2004
Captive breeding of animals is widely used to manage endangered species, frequently with the ambition of future reintroduction into the wild. Because this conservation measure is very expensive, we need to optimize decisions, such as when to capture wild animals or release captive-bred individuals into the wild. It is unlikely that one particular strategy will always work best; instead, we expect the best decision to depend on the number of individuals in the wild and in captivity. We constructed a first-order Markov-chain population model for two populations, one captive and one wild, and we used stochastic dynamic programming to identify optimal state-dependent strategies. The model recommends unique sequences of optimal management actions over several years. A robust rule of thumb for species that can increase faster in captivity than in the wild is to capture the entire wild population whenever the wild population is below a threshold size of 20 females. This rule applies even if the wild population is growing and under a broad range of different parameter values. Once a captive population is established, it should be maintained as a safety net and animals should be released only if the captive population is close to its carrying capacity. We illustrate the utility of this model by applying it to the Arabian oryx (Oryx leucoryx). The threshold for capturing the entire Arabian oryx population in the wild is 36 females, and captive-bred individuals should not be released before the captive facilities are at least 85% full.
Biological Conservation, 1998
We use the phylogenetically based statistical method of independent contrasts to reanalyze the Wolf, C.M., Grith, B., Reed, C., Avian and mammalian translocations: update and reanalysis of 1987 survey data. Conservation Biology 10, 1142±1154). translocation data set for 181 programs involving 17 mammalian and 28 avian species. Although still novel in conservation and wildlife biology, the incorporation of phylogenetic information into analyses of interspeci®c comparative data is widely accepted and routinely used in several ®elds. To facilitate application of independent contrasts, we converted the dichotomous (success/failure) dependent variable ., Scott, J.M. Carpenter, J.W., Reed, C., 1989. Translocations as a species conservation tool: status and strategy. Science 245, 477±480) into a more descriptive, continuous variable with the incorporation of persistence of the translocated population beyond the last release year, relative to the species' longevity. For comparison, we present three models: nonphylogenetic multiple logistic regression with the dichotomous dependent variable (the method used by , nonphylogenetic multiple regression with the continuous dependent variable, and multiple regression using phylogenetically independent contrasts with the continuous dependent variable. Results of the phylogenetically based multiple regression analysis indicate statistical signi®cance of three independent variables: habitat quality of the release area, range of the release site relative to the historical distribution of the translocated species, and number of individuals released. Evidence that omnivorous species are more successful than either herbivores or carnivores is also presented. The results of our reanalysis support several of the more important conclusions of the studies and increase our con®dence that the foregoing variables should be considered carefully when designing a translocation program. However, the phylogenetically based analysis does not support either the ®ndings with respect to the statistical signi®cance of taxonomic class (bird vs mammal) and status (game vs threatened, endangered, or sensitive), or the ®ndings with respect to the signi®cance of reproductive potential of the species and program length. #
2018
Wildlife management balances conservation goals with meeting societal objectives. It incorporates scientific disciplines such as ecology, animal behaviour, geography, and sociology to determine management practices and make policy recommendations. Two major areas of contemporary management are conservation (protecting animals in at risk environments) and conflict management (mitigating human-animal conflict). Translocation, the targeted movement of animals to a new location, is a method that can be used for conservation or conflict management. When dealing with conflict animals, translocation offers several advantages over culling. It can allow for the survival of the animal, a particular concern with threatened species, and has relatively low impact on its non-problem conspecifics. However, there is ambivalent evidence regarding the effectiveness of translocations. We conducted a series of categorical and continuous model meta-analyses to assess the effect of translocation on the s...
Biological Conservation, 2018
Translocations to restore populations of endangered species are an important conservation tool, but a reliable diagnosis is needed to assess their success. We used capture-recapture modeling to analyze the adult apparent survival of released and resident tortoises in two translocation projects in Spain monitored for 14 and 29 years. We tested if long-term survival rates differ between released and resident individuals, if survival was lower during the phase of establishment (i.e. release cost), how long acclimation lasts and if increased density due to releases affects survival. We found lower survival of released tortoises during the phase of establishment (1 to 3 years) when residents were already present. After establishment, survival was very high and unaffected by density-dependence. Body condition before release was similar between recaptured and dead/missing tortoises, and did not predict establishment survival. Stochastic population viability analysis showed that success when releasing small numbers of individuals strongly depends upon adult long-term survival. Release of small second batches of tortoises was not sensitive to a growing population, regardless of its release timing. Our results highlight long-term survival as crucial in translocation projects of long-lived species, invalidating short-term (first year) survival assessment, when survival release cost does not match long-term survival. A release cost of different duration should be included in model estimation before modeling predictions. Releasing tortoises (for welfare of captive individuals or for mitigating human negative impacts) in an already established population is not recommended under most circumstances. Acclimation cost is followed by survival approaching wild counterparts. If this milestone is not achieved, the project needs to be carefully assessed to adopt other management options or should be stopped altogether.
Restoration Ecology, 2015
Translocation to areas free of exotic predators, habitat degradation, or disease may be the most viable restoration option for many endangered species. We report on a successful translocation of the critically endangered St. Croix ground lizard, Ameiva polops, extirpated from St. Croix, U.S. Virgin Islands, Caribbean, by predation from introduced mongooses (Herpestes auropunctatus). We translocated 57 adult A. polops from Green Cay to Buck Island in May 2008. We placed 4 females and 3 males each in eight, 100 m 2 , enclosures on Buck Island for 71 days, then the enclosures were opened. During the enclosure period, 20 individuals were identified and 32 others were seen. The average number sighted per survey was only 5.28 (range = 2-10). One hatchling was sighted in an enclosure, indicating a translocated female successfully nested. Body condition of the translocated individuals increased significantly by the end of the enclosure period. Population monitoring surveys at 61 sites across Buck Island showed that 5 years after the initial translocation in June 2013, the new population had grown to an estimated 1,473 individuals and occupied 58.9% of the island. We attribute eradication of mongoose, life history of the species, large propagule size, condition of habitat, soft-release, use of adults, interagency collaboration, and systematic assessment as primary factors that facilitated this successful translocation. Our findings provide meaningful insights on factors that enhance the potential for successful translocations, and point to new strategies aimed at restoring populations of endangered reptiles in their native ranges.
Translocation and Post-Release Monitoring of Captive-Raised Blue-fronted AmazonsAmazona aestiva
Acta Ornithologica, 2018
Translocation is a useful tool for the conservation of endangered species, because it enables individuals to be moved between wild populations and between captivity and the wild. The use of captive-raised animals in these processes is sometimes the only option to recover a declining population, but captive-raised parrots are commonly seen as the worst candidates for release because they lose their ability to recognize predators, to find food in the wild and to socialize with conspecifics. The Blue-fronted Amazon Amazona aestiva is one of the most popular parrot species in captivity. Thirty-one parrots were soft released and monitored during 13 continuous months in a Cerrado area (savannahlike vegetation) of Minas Gerais State, southeastern Brazil. Three released parrots (10%) were confirmed to die and five (16%) disappeared soon after release and no behavioral recordings or data about their destinations were available. Ten parrots (32%) showed behaviors that suggest adaptation to the wild and 13 individuals (42%) expressed behaviors more typical of captivity. Difficulties in settling were observed for the parrots after release. One released pair, and one female paired with a wild male, reproduced. There was a tendency to decrease in all captive-related behaviors and to increase in wild-related behaviors since time after release. Supplementary food use diminished as the parrots explored natural food resources. This study indicates that confiscated captive-raised parrots can be good candidates for translocation if a training program could be applied prior to their release to reduce undesirable behaviors and the chance of recapturing by humans. Furthermore, the use of non-endangered species in conservation programs can be useful to create protocols for the conservation programs of rare and endangered species.