Influence of the rate of introduction on the fitness of restored populations

• Published in: Conservation genetics Vol. 5; no. 5; pp. 673 - 682
• Main Authors: Robert, Alexandre, Denis Couvet, Fran ois Sarrazin
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Nature B.V 01.10.2004
• Subjects: Carrying capacity; Conservation biology; Genetics; Population number; Simulation; Wildlife conservation; Wildlife management
• ISSN: 1566-0621; 1572-9737
• DOI: 10.1007/s10592-004-1855-z

Most studies using demographic PVA models in a context of species restoration have concluded that rather than the rate of introduction, the total number of individuals released had the most important significant influence on the chance of success. In this article we use a genetic simulation model including deleterious and adaptive alleles to assess the impact of the method of release on the change in population mean fitness. We systematically compare a strategy that consists in releasing all individuals at the same time with a strategy that consists in staggering releases over a long period of time. Our results show that the former strategy is more beneficial for long-term fitness when considering advantageous genes only, while the latter is better when considering deleterious genes only. If deleterious and adaptive alleles are considered together, the best strategy depends then essentially on which of these types of alleles has the stronger influence on the change in total fitness. Although the relative contributions of the variance in total fitness due to adaptive and deleterious alleles may vary with the initial frequencies and the selective and dominance effects of these alleles, our results show that the optimal rate of release is mostly dependant on the expected long-term population size. Thus from a genetic view-point, the temporal release strategy of reintroduced populations should be considered with respect to their environment's carrying capacity.[PUBLICATION ABSTRACT]