Assessing the genetic diversity of captive populations of endangered species is key to the successful management of conservation-breeding programs. In this study, we sequenced a 393-bp fragment of the mitochondrial DNA (mtDNA) control region of 23 captive individuals of the Endangered François’ langur (Trachypithecus francoisi) to assess the mtDNA diversity of the European captive population and to identify the possible geographical origins of the population founders. Combined with 42 sequences previously published from 29 wild François’ langurs, we identified a total of 40 haplotypes in T. francoisi, including 12 haplotypes in the 23 samples from the European captive population. Only one of the haplotypes from captive animals has previously been reported from wild populations; the remaining 11 haplotypes are newly reported here. Our results suggest that the captive T. francoisi population currently holds a relatively good genetic diversity compared with many other captive populations, that this diversity originates from a fairly broad range across the species’ distribution in the wild, and that the captive population could play a significant role in increasing genetic diversity of isolated wild populations. However, the European captive population is currently quite small, and genetic diversity could be lost rapidly, which has been demonstrated in other captive populations. We recommend further investigation of the genetic diversity of captive and wild T. francoisi populations, as well as the effective conservation of this diversity.

Ruffed lemurs (Varecia variegata and Varecia rubra) are categorized as Critically Endangered on the IUCN Red List, and genetic studies are needed for assessing the conservation value of captive populations. Using 280 mitochondrial DNA (mtDNA) D-loop sequences, we studied the genetic diversity and structure of captive ruffed lemurs in Madagascar, Europe and North America. We found 10 new haplotypes: one from the European captive V. rubra population, three from captive V. variegata subcincta (one from Europe and two from Madagascar) and six from other captive V. variegata in Madagascar. We found low mtDNA genetic diversity in the European and North American captive populations of V. variegata. Several founder individuals shared the same mtDNA haplotype and therefore should not be assumed to be unrelated founders when making breeding recommendations. The captive population in Madagascar has high genetic diversity, including haplotypes not yet identified in wild populations. We determined the probable geographical provenance of founders of captive populations by comparison with previous studies; all reported haplotypes from captive ruffed lemurs were identical to or clustered with haplotypes from wild populations located north of the Mangoro River in Madagascar. Effective conservation strategies for wild populations, with potentially unidentified genetic diversity, should still be considered the priority for conserving ruffed lemurs. However, our results illustrate that the captive population in Madagascar has conservation value as a source of potential release stock for reintroduction or reinforcement projects and that cross-regional transfers within the global captive population could increase the genetic diversity and therefore the conservation value of each regional population.