here is a list to help manage lion populations
Biodiversity exists at three different levels: diversity between ecosystems, between species and within species. The genetic diversity that exists within a species is what allows the species to evolve and adapt. Numerous studies have shown that genetic diversity provides resilience against extinction.
Conserving biodiversity therefore means more than preventing the extinction of a species. It also means preventing the loss of genetic diversity within that species.
One way to lose genetic diversity is when populations disappear in a particular location and genetic lines come to an end. Another way is when individuals in small, isolated populations become more strongly bonded to each other. It can lead to inbreeding depression – when the offspring are less fertile and less likely to survive. This has been described for many species, including lions.
Conservation managers can intervene to support the genetic diversity of a species. For example, to expand and restore a species’ natural range, managers can release individual animals into an area where they have previously disappeared. Or if a population has become so small and isolated that its genetic health is in jeopardy, managers can bring in new unrelated individuals to mimic natural migration between populations.
In practice, however, these initiatives usually focus on population or number of individuals. They don’t always take genetic information into account. It’s dangerous. When managers fail to choose genetically suitable animals, moving them to another population can fail. It can even have a negative influence on global biodiversity.
In African wildlife management, individual animals for translocations often come from South Africa. The country has many intensively managed parks, which regularly show surpluses of certain species. But shipping South African animals across the continent and reintroducing them away from their original population could have adverse effects on biodiversity. If they integrate into the resident populations of the target site, they can spread their genes there, influencing the genetic makeup of the local population. It could even lead to the loss of genetic adaptation to local environments. And if this happens on a large scale, in multiple localities, all populations could become similar.
When planning a translocation, the genetic makeup of the source and target populations must be considered. Preferably, the two populations should come from the same genetic line. In this way, the translocation resembles a natural migration between populations.
We recently published a scientific article in which we evaluate the available genetic data and their implications for translocations in Lion.
The lion has been a popular subject for studying diversity on the genetic level. Lions are a species that many people know and care about, with a wide range across sub-Saharan Africa and as far as India. Genetic data shows that lion diversity is spread across four different evolutionary lineages: East Africa, Southern Africa, West/Central Africa and India. The first two lineages are grouped into southern subspecies, while the latter two are grouped into northern subspecies. To conserve the lion for the long term, we must conserve its genetic diversity.
In our study, we listed 132 lion populations or conservation units and provided information on genetic attribution, uncertainty, and translocation fitness for each source and target combination.
To get a better idea of the extent and directions of lions moved across the continent, we also extracted trade data from the CITES Trade Database. This registers all import and export permits for cross-border trade. There is additional information about the origin of the individuals and the purpose of the transport. Data shows that in less than 40 years, more than 1,000 live lions have been moved from country to country and to countries where wild lions live.
We then assessed whether, based on all currently available genetic information, these transports occur within or between genetic lineages. We identified three levels of fitness, based on genetic differentiation between populations. We noted translocation between subspecies as ‘inappropriate’, as well as translocation of ‘captive’ individuals, with unknown genetic background.
We concluded that the vast majority of transferred lions would be classified as “unfit”. In other words, they could constitute a risk for the genetic diversity of lions and for biodiversity in general.
Integrating genetics into decision making
Although genetic data may not be available for some populations, based on our understanding of diversity of lions and known locations of boundaries between different lineages, we can often infer which genetic group they belong to. Thus, genetics can be taken into account, even when genetic data for a particular population is missing.
We hope that the three different skill levels we have provided will help conservation managers explore different options when making their decisions. We encourage them to follow the natural distribution of genetic diversity in the lion when looking for suitable source populations.
In management interventions, many other factors must also be considered – ecological, behavioral and even political. Although these factors are not considered here, we hope that our work will provide guidance and support for incorporating genetics into future management decisions.
It is in the interest of the lion, as a species, to focus not only on the persistence of populations, but also on the underlying genetic diversity. This will increase its resilience and adaptability, necessary for the long-term survival of the species.