Genetic guidelines for translocations: Maintaining intraspecific diversity in the lion (Panthera leo)

Abstract

Conservation translocations have become an important management tool, particularly for large wildlife species such as the lion (Panthera leo). When planning translocations, the genetic background of populations needs to be taken into account; failure to do so risks disrupting existing patterns of genetic variation, ultimately leading to genetic homogenization, and thereby reducing resilience and adaptability of the species. We urge wildlife managers to include knowledge of the genetic background of source/target populations, as well as species‐wide patterns, in any management intervention. We present a hierarchical decision‐making tool in which we list 132 lion populations/lion conservation units and provide information on genetic assignment, uncertainty and suitability for translocation for each source/target combination. By including four levels of suitability, from ‘first choice’ to ‘no option’, we provide managers with a range of options. To illustrate the extent of international trade of lions, and the potential disruption of natural patterns of intraspecific diversity, we mined the CITES Trade Database for estimated trade quantities of live individuals imported into lion range states during the past 4 decades. We identified 1056 recorded individuals with a potential risk of interbreeding with wild lions, 772 being captive‐sourced. Scoring each of the records with our decision‐making tool illustrates that only 7% of the translocated individuals were ‘first choice’ and 73% were ‘no option’. We acknowledge that other, nongenetic factors are important in the decision‐making process, and hence a pragmatic approach is needed. A framework in which source/target populations are scored based on suitability is not only relevant to lion, but also to other species of wildlife that are frequently translocated. We hope that the presented overview supports managers to include genetics in future management decisions and contributes towards conservation of the lion in its full diversity.

Guidelines for evaluating the conservation value of African lion (Panthera leo) translocations

“…However, it could be argued that genetic suitability should be a consideration only after the rationale for a translocation is clearly established. The wide array of lion translocation rationales (Table 1) and subsequent outcomes stemming from poorly conceived or unsuitable translocations warrants additional standardized evaluation and guidance beyond genetic considerations (Bertola et al, 2022).…”

“…Indeed, lion translocations sometimes occur across multiple countries or regions and are becoming increasingly common throughout Africa (Wolf and Ripple, 2018;Bertola et al, 2022). There are a variety of motivations for translocations, including restoration of locally extirpated populations or augmentation of existing populations, human-lion conflict mitigation, reestablishing populations for tourism purposes, and for a range of other commercial, personal, ethical, and financially motivated reasons (Table 1; Stander, 1990;Funston et al, 2001;Hunter et al, 2007;Trinkel et al, 2008;Miller and Funston, 2014;Morapedi et al, 2021).…”

“…It must be intended to yield a measurable conservation benefit at the level of a population, species or ecosystem, and not only provide benefit to translocated individuals" (IUCN/SSC, 2013). However, many lion translocations have not considered or followed the IUCN best practice guidelines for conserving species and habitats (Bauer et al, 2018;Bertola et al, 2022). Reasons for this are variable; often decision-making is required urgently, leading to suboptimal decisions; international collaboration is usually insufficient; suboptimal source animals are readily available versus suitable wild individuals; and translocations are often driven by a need to remove lions from a source population (e.g.…”

“…problem animals, metapopulation surpluses) rather than the needs of the recipient area and population. This is a concern because it undermines the potential conservation value of such endeavors, by devaluing translocation benefits, producing adverse welfare outcomes for lions and people at release sites, and posing a risk of introducing animals of inappropriate genetic composition (Slotow and Hunter, 2009;Bertola et al, 2022).…”

“…A recent study evaluating CITES permit data for lions translocated between countries from 1988-2019 found that 848 out of 1056 individuals (80%) were listed as 'captive-sourced' on the permit, referring mostly to intensively managed lion populations, not to be confused with captive-bred lions for body parts or canned hunting purposes (Williams and 't Sas-Rolfes, 2019), for which the origin could be traced for only 76 individuals (7%). Since the genetic background of the remaining individuals was unknown, these translocations (73%) were categorized as 'unsuitable', where preserving genetic integrity within naturally occurring clades of wild lions was the primary criterion (Bertola et al, 2022). Given that genetic diversity is directly related to persistence and resilience of populations, and that the local adaptations of lion populations evolved over millennia and are not fully understood, genetic considerations are important.…”