Tanzanian Black Rhinoceros
A common strategy for conservation of small populations of endangered species that have experienced high levels of inbreeding is "genetic rescue" from genetically distinct populations. However, there is a potential trade-off between the fitness benefits of increasing genetic variation and reducing inbreeding and the potential costs of introducing negative mutations that were not previously present in the population. Using the eastern black rhinoceros (Diceros bicornis michaeli), here we demonstrate the power of assessing the genomic impacts of past management strategies to inform such conservation decisions. Focusing on cohorts of individuals whose parents had come from different sources, we find that allowing natural dispersal between populations with a long history of inbreeding could be more effective than more expensive long-distance translocations.