Effect of landscape features on genetic structure of the goitered gazelle (Gazella subgutturosa) in Central Iran

An evaluation of isolation by distance and isolation by resistance on genetic structure of the Persian squirrel (Sciurus anomalus) in the Zagros forests of Iran

For the conservation of wild species, it is important to understand how landscape change and land management can affect gene flow and movement. Landscape genetic analyses provide a powerful approach to infer effects of various landscape factors on gene flow, thereby informing conservation actions. The Persian squirrel is a keystone species in the woodlands and oak forests of Western Asia, where it has experienced recent habitat loss and fragmentation. We conducted landscape genetic analyses of individuals sampled in the northern Zagros Mountains of Iran (provinces of Kurdistan, Kermanshah, and Ilam), focusing on the evaluation of isolation by distance (IBD) and isolation by resistance (IBR), using 16 microsatellite markers. The roles of geographical distance and landscape features including roads, rivers, developed areas, farming and agriculture, forests, lakes, plantation forests, rangelands, shrublands, and rocky areas of varying canopy cover, and swamp margins on genetic structure were quantified using individual-based approaches and resistance surface modeling. We found a significant pattern of IBD but only weak support for an effect of forest cover on genetic structure and gene flow. It seems that geographical distance is an important factor limiting the dispersal of the Persian squirrel in this region. The results of the current study inform ongoing conservation programs for the Persian squirrel in the Zagros oak forest.

Genetic diversity of the endangered Mongolian saiga antelope Saiga tatarica mongolica (Artiodactyla: Bovidae) provides insights into conservation

The Saiga antelope (Saiga tatarica) is one of the few megafauna species from the mammoth steppe still living today. Currently, saiga are classified as critically endangered, persisting only in small areas of Central Asian steppe and desert ecosystems. The species is divided into two subspecies: Saiga tatarica mongolica and Saiga tatarica tatarica. In this study, we have for the first time characterized the genetic diversity of the Mongolian saiga (S. t. mongolica) using both mitochondrial DNA and microsatellite markers. We also analysed S. t. tatarica specimens in order to genetically compare both subspecies. The mitochondrial control region was sequenced for a total of 89 individuals: 20 skin, 53 umbilical cord, three placentae and a muscle sample from S. t. mongolica, and a total of 12 hair samples from S. t. tatarica. Additionally, 19 microsatellites developed for saiga antelope were also screened. Our results revealed that the Mongolian saiga presents very low genetic diversity at the mitochondrial level, with no shared mitochondrial haplotype between the two subspecies. Low genetic diversity is also present at the autosomal level, with most loci having low heterozygosity (Ho/He) and a low number of alleles per locus. Despite the low genetic diversity, we found no separation between the subpopulations in Mongolia, indicating that conservation corridors are actually promoting contact between different herds. Our results validate current conservation efforts and inform the implementation of new measures to increase the viability of the S. t. mongolica subspecies.

Ancient DNA from a 2700-year-old goitered gazelle (Gazella subgutturosa) supports gazelle hunting in Iron Age Central Asia

Central Asia has been an important region connecting the different parts of Eurasia throughout history and prehistory, with large states developing in this region during the Iron Age. Archaeogenomics is a powerful addition to the zooarchaeological toolkit for understanding the relation of these societies to animals. Here, we present the genetic identification of a goitered gazelle specimen (Gazella subgutturosa) at the site Gazimulla-Tepa, in modern-day Uzbekistan, supporting hunting of the species in the region during the Iron Age. The sample was directly radiocarbon dated to 2724-2439 calBP. A phylogenetic analysis of the mitochondrial genome places the individual into the modern variation of G. subgutturosa. Our data do represent both the first ancient DNA and the first nuclear DNA sequences of this species. The lack of genomic resources available for this gazelle and related species prevented us from performing a more in-depth analysis of the nuclear sequences generated. Therefore, we are making our sequence data available to the research community to facilitate other research of this nowadays threatened species which has been subject to human hunting for several millennia across its entire range on the Asian continent.

Assessing the origin, genetic structure and demographic history of the common pheasant (Phasianus colchicus) in the introduced European range

The common pheasant, a game species widely introduced throughout the world, can be considered as an ideal model to study the effects of introduction events on local adaptations, biogeographic patterns, and genetic divergence processes. We aimed to assess the origin, spatial patterns of genetic variation, and demographic history of the introduced populations in the contact zone of Central and Southeast Europe, using mitochondrial DNA control region sequences and microsatellite loci. Both types of molecular markers indicated relatively low to moderate levels of genetic variation. The mtDNA analyses revealed that common pheasants across the study area are divided into two distinct clades: B (mongolicus group) and F (colchicus group). Analyses of the microsatellite data consistently suggested a differentiation between Hungary and Serbia, with the pheasant population in Hungary being much more genetically homogeneous, while that of Serbia has much more genetic mixture and admixture. This cryptic differentiation was not detected using a non-spatial Bayesian clustering model. The analyses also provided strong evidence for a recent population expansion. This fundamental information is essential for adequate and effective conservation management of populations of a game species of great economic and ecological importance in the studied geographical region.

Habitat Connectivity for the Conservation of Small Ungulates in A Human-Dominated Landscape

Conserving landscape connections among favorable habitats is a widely used strategy to maintain populations in an increasingly fragmented world. A species can then exist as a metapopulation consisting of several subpopulations connected by dispersal. Our study focuses on the importance of human–wildlife coexistence areas in maintaining connectivity among primary habitats of small ungulates within and outside protected areas in a large landscape in central India. We used geospatial information and species presence data to model the suitable habitats, core habitats, and connectivity corridors for four antelope species in an ~89,000 km2 landscape. We found that about 63% of the core habitats, integrated across the four species, lie outside the protected areas. We then measured connectivity in two scenarios: the present setting, and a hypothetical future setting—where habitats outside protected areas are lost. We also modelled the areas with a high risk of human-influenced antelope mortality using eco-geographical variables and wildlife mortality records. Overall, we found that the habitats in multiple-use forests play a central role in maintaining the connectivity network for antelopes. Sizable expanses of privately held farmlands and plantations also contribute to the essential movement corridors. Some perilous patches with greater mortality risk for species require mitigation measures such as underpasses, overpasses, and fences. Greater conservation efforts are needed in the spaces of human–wildlife coexistence to conserve the habitat network of small ungulates.

Repeated hybridization of two closely related gazelle species (Gazella bennettii and Gazella subgutturosa) in central Iran

Interspecific hybridization increasingly occurs in the course of anthropogenic actions, such as species translocations and introductions, and habitat modifications or occurs in sympatric species due to the shortage of conspecific mates. Compared with anthropogenically caused hybridization, natural hybridization is more difficult to prove, but both play an important role in conservation. In this study, we detected hybridization of two gazelle sister species, Gazella bennettii (adapted to dry areas) and Gazella subgutturosa (adapted to open plains), in five habitat areas, where G. bennettii naturally occur in central Iran. The hybrids have a nuclear genomic identity (based on two introns), habitat preference, and phenotype of G. bennettii, but the mitochondrial identity (based on cyt b) of G. subgutturosa. We suggest that natural hybridization of female G. subgutturosa and male G. bennettii happened twice in central Iran in prehistoric times, based on the haplotype pattern that we found. However, we found indications of recent hybridization between both species under special circumstances, for example, in breeding centers, due to translocations, or in areas of sympatry due to the shortage of conspecific mates. Therefore, these two species must be kept separately in the breeding centers, and introduction of one of them into the habitat of the other must be strictly avoided.

Diversification and subspecies patterning of the goitered gazelle (Gazella subgutturosa) in Iran

Goitered gazelles, Gazella subgutturosa, exist in arid and semiarid regions of Asia from the Middle to the Far East. Although large populations were present over a vast area until recently, a decline of the population as a result of hunting, poaching, and habitat loss led to the IUCN classification of G. subgutturosa as "vulnerable." We examined genetic diversity, structure, and phylogeny of G. subgutturosa using mitochondrial cytochrome b sequences from 18 geographically distant populations in Iran. The median-joining network of cyt b haplotypes indicated that three clades of goitered gazelles can be distinguished: a Middle Eastern clade west of the Zagros Mountains (and connected to populations in Turkey and Iraq), a Central Iranian clade (with connection to Azerbaijan), and an Asiatic clade in northeastern Iran (with connection to Turkmenistan, Uzbekistan, and other Asian countries as far as northeastern China and Mongolia). Based on our results, we argue that Iran is the center of diversification of goitered gazelles, due to the presence of large mountain ranges and deserts that lead to the separation of populations. In accordance with previous morphological studies, we identified the Asiatic clade as the subspecies G. s. yarkandensis, and the other two clades as the nominate form G. s. subgutturosa. The new genetic information for goitered gazelles in Iran provides the basis for future national conservation programs of this species.