In situpopulation structure andex siturepresentation of the endangered Amur tiger

Abstract

The Amur tiger (Panthera tigris altaica) is a critically endangered felid that suffered a severe demographic contraction in the 1940s. In this study, we sampled 95 individuals collected throughout their native range to investigate questions relative to population genetic structure and demographic history. Additionally, we sampled targeted individuals from the North American ex situ population to assess the genetic representation found in captivity. Population genetic and Bayesian structure analyses clearly identified two populations separated by a development corridor in Russia. Despite their well-documented 20th century decline, we failed to find evidence of a recent population bottleneck, although genetic signatures of a historical contraction were detected. This disparity in signal may be due to several reasons, including historical paucity in population genetic variation associated with postglacial colonization and potential gene flow from a now extirpated Chinese population. Despite conflicting signatures of a bottleneck, our estimates of effective population size (N(e) = 27-35) and N(e)/N ratio (0.07-0.054) were substantially lower than the only other values reported for a wild tiger population. Lastly, the extent and distribution of genetic variation in captive and wild populations were similar, yet gene variants persisted ex situ that were lost in situ. Overall, our results indicate the need to secure ecological connectivity between the two Russian populations to minimize loss of genetic diversity and overall susceptibility to stochastic events, and support a previous study suggesting that the captive population may be a reservoir of gene variants lost in situ.

Genetic evidence of hybridization between the critically endangered Cuban crocodile and the American crocodile: implications for population history and in situ/ex situ conservation

“…In the present study, we found slightly higher levels of observed heterozygosity and average number of alleles per locus in captivity relative to the wild C. rhombifer population (Table 1), including a large number of private alleles. These differences in the extent and distribution of in situ and ex situ genetic variation could be indicative of gene variants retained in the captive population that are now extirpated in the wild, as has been found in other critically endangered species (Henry et al, 2009). Alternatively, this pattern may have been influenced by long-term introgression with C. acutus in captivity dating back to the early years of the breeding program.…”

Camera-trap monitoring of Amur Tiger (Panthera tigris altaica) in southwest Primorsky Krai, 2013–2016: preliminary results

“…Tigers in Southwest Primorye are separated from the main tiger population in the Sikhote-Alin Mountains by a development corridor between the two major cities of Vladivostok and Ussuriysk (Darman & Williams, 2003;Miquelle et al, 2015). This anthropogenic barrier has limited dispersal of large carnivores and resulted in a genetically distinct tiger population in southwest Primorye (Henry et al, 2009;Sorokin et al, 2015). Although a few migrants from southern SikhoteAlin have been identified in southwest Primorsky Krai, it is still unknown whether these occasional migrants have successfully contributed to the gene pool of the southwestern sub-population (Henry et al, 2009).…”

“…This anthropogenic barrier has limited dispersal of large carnivores and resulted in a genetically distinct tiger population in southwest Primorye (Henry et al, 2009;Sorokin et al, 2015). Although a few migrants from southern SikhoteAlin have been identified in southwest Primorsky Krai, it is still unknown whether these occasional migrants have successfully contributed to the gene pool of the southwestern sub-population (Henry et al, 2009). Further disruption of tiger movements between two landscapes may have serious consequences for genetic health of the smaller group of tigers, and limits the potential for expansion of the leopard population.…”

Helminths of Rare Feline Species (Felidae) in Siberia and the Russian Far East

“…Comparison of the helminths presence in the Amur tiger excrements collected in the south, center and north of its range suggests that helminth fauna has certain particularities in different parts of the tiger habitat, with about the same proportion of samples with eggs of helminths found. So, in the Amur tiger population in the Southwest of Primorskii Kray that is considered isolated 11,38 , two specific parasites were discovered (nematoda Aelurostrongylus abstrusus and cestoda Spirometra erinacei). Nematoda Toxocara cati, found in virtually all excrement samples, is the most common species in all parts of the Amur tiger habitat.…”