Abstract
Owing to climate change and other anthropogenic environmental changes, the suitability of locations is changing for many biota that consequently have to adapt in situ or to move to other areas. To mitigate the effects of such pressures, assisted colonization is a conservation tool developed to reduce extinction risks by intentionally moving and releasing an organism outside its native range, and thus, to facilitate tracking changing environmental conditions. This conservation tool has been proposed for threatened animals or plants that presumably cannot adapt in situ or follow environmental changes by dispersal or migration. However, there have been contentious debates about the shortcomings and risks of implementing assisted colonization. For this reason, we evaluated the specific opinions of global experts for assisted colonization on potential risks and opportunities that this approach offers. For this purpose, we used an online survey targeted at authors of scientific publications on assisted colonization. The majority (82%) of the 48 respondents were in favor of applying assisted colonization for species that are at risk of global extinction due to anthropogenic environmental change. Most respondents agreed that assisted colonization should be considered only when other conservation tools are not available and that certain preconditions must be met. Some of these were already highlighted in the IUCN guidelines for assisted colonization and include a completed risk assessment, clearly defined management plans and secured political as well as financial support. The advocacy of assisted colonization in response to anthropogenic global environmental changes was only weakly dependent on the geographic origin of the experts and their working background. Regarding possible risks, most of the respondents were concerned about consequences like failure of the long-term establishment of the translocated species and the transmission of diseases and invasiveness potentially endangering native biota. To keep these risks as low as possible most of the experts agreed that a target area must have a reasonable carrying capacity to sustain a minimum viable population and that adaptive management should be implemented. Careful evaluation of assisted colonization projects is required to generate further evidence that needs to be considered for further developing conservation tools for the Anthropocene.
Highlights
Climate change is rapidly becoming an increasingly pervasive pressure on species distributions (Dawson et al 2011; Urban 2015)
Given the diversity of aspects to be considered and the diversity of opinions appearing in the published literature, we evaluated in this study the views of conservation experts on assisted colonization via an online survey
Impact of origin on the perception of usefulness and risks of assisted colonization We found a statistically significant difference among the answers from respondents of different continents on the usefulness of assisted colonization for (i) the prevention of global species extinction caused by anthropogenic pressures other than climate change (Kruskal-Wallis test: n = 48; df = 4; Cohen’s d = 0.78; p = 0.046), and (ii) for the prevention of regional species extinction caused by climate change (Kruskal-Wallis test: n = 48; df = 4; Cohen’s d = 0.85; p = 0.032)
Summary
Climate change is rapidly becoming an increasingly pervasive pressure on species distributions (Dawson et al 2011; Urban 2015). This novel pressure acts on top of other anthropogenic impacts such as habitat loss, water extraction, toxic pollutants, and invasive alien species (Grimm et al 2013), which are already threatening the survival of roughly a quarter of extant species (Ma et al 2018; Díaz et al 2019). Climate change and other anthropogenic pressures create a huge challenge for species conservation and call for the identification of novel tools for ensuring species survival in the Anthropocene (Loss et al 2011; Wessely et al 2017; Genovesi and Simberloff 2020). In situations where in situ adaptation is unlikely, translocation of organisms by assisted colonization may represent an option – at least for some species – (Hällfors et al 2017; Lloyd et al 2019) and has been proposed as a novel conservation tool to complement current conservation strategies (Hällfors et al 2014)
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call