Analysing pedigree to identify undesirable losses of genetic diversity and to prioritize management decisions in captive breeding: a case study

Abstract When the priority is preventing species extinction, captive breeding is a key component in conservation programmes, allowing recording pedigree information in studbooks. Genealogical information registered in the Cuvier’s gazelle (Gazella cuvieri) studbook between 1975 and 2023 was analysed to: a) assess if the implemented mating policy was successful in preserving the genetic background of the founders (1 male : 3 females) in the present population; and b) improve future management and breeding decisions. Although the maternal contribution of one founder female was lost and the mean inbreeding of the total alive population was high (0.305 ± 0.095), the breeding policy was successful in keeping the individual increase in inbreeding relatively low (ΔFi = 0.047 ± 0.021). Notably, ΔFi per year of birth tended to decrease during the last three decades of the breeding programme, ensuring the viability of that small, highly inbred population. Historical dissemination of individuals among zoos of Europe and North America caused population structuring and genetic differentiation of the alive North America population. However, it does not risk the viability of the species captive population. Analyses allowed to identify individuals with underrepresented genotypes in the population and advised the implementation of management decisions aiming at promoting their reproduction to keep the founders' representation balanced in the next generations. These results show the importance of keeping long-term pedigree information to monitor changes in the genetic diversity of a captive population, which are crucial to implement optimal mating decisions assuring its long-term viability within an ex situ conservation programme.