Parturition in the wild camel (Camelus ferus): the first in situ recorded observation

Polymorphic markers on the male-specific part of the Y chromosome (MSY) provide useful information for tracking male genealogies. While maternal lineages are well studied in Old World camelids using mitochondrial DNA, the lack of a Y-chromosomal reference sequence hampers the analysis of male-driven demographics. Recently, a shotgun assembly of the horse MSY was generated based on short read next generation sequencing data. The haplotype network resulting from single copy MSY variants using the assembly as a reference revealed sufficient resolution to trace individual male lines in this species. In a similar approach we generated a 3.8 Mbp sized assembly of the MSY of Camelus bactrianus. The camel MSY assembly was used as a reference for variant calling using short read data from eight Old World camelid individuals. Based on 596 single nucleotide variants we revealed a Y-phylogenetic network with seven haplotypes. Wild and domestic Bactrian camels were clearly separated into two different haplogroups with an estimated divergence time of 26,999 ± 2,268 years. Unexpectedly, one wild camel clustered into the domestic Bactrian camels’ haplogroup. The observation of a domestic paternal lineage within the wild camel population is concerning in view of the importance to conserve the genetic integrity of these highly endangered species in their natural habitat.

This study aimed to reveal the microbial diversity in the fecal samples of bactrian camels using the 16S rRNA sequencing analysis on the Illumina MiSeq platform. Three fecal samples were collected from two geographical regions in China. Operational taxonomic unit (OTU) clustering was performed by identifying an OTU at 97% sequence identity. The alpha and beta diversities were applied to estimate the differences in microbial diversity among the three fecal samples. Totally, 4409, 3151 and 4075 OTUs in the fecal samples were identified in the Lop Nor wild camel (Camelus ferus), the domestic camel (C. bactrianus) and Dunhuang wild camel (C. ferus), respectively. The majority of bactreria were affiliated with phylum Firmicutes and Bacteroidetes in the three samples. The wild camels had higher gastrointestinal tract microbial diversity than the domestic one, while the microbial composition of the Lop Nor wild camel shared higher similarity with domestic camel at the genus and family levels than that of the Dunhuang wild camel did. Our results may provide a theoretical basis for assessing their health conditions and may thus be useful for protecting the critically endangered species of C. ferus.

Hybridization between wild species and their domestic congeners often threatens the gene pool of the wild species. The last wild Bactrian camel (Camelus ferus) populations in Mongolia and China are examples of populations facing such a hybridization threat. To address this key issue in the conservation of wild camels, we analysed wild, hybrid and domestic Bactrian camels (Camelus bactrianus) originating from Mongolia, China and Austria. Through screening of an 804-base-pair mitochondrial fragment, we identified eight mitochondrial haplotypes and found high sequence divergence (1.9%) between C. ferus and C. bactrianus. On the basis of a mitochondrial DNA sequence fixed difference, we developed a diagnostic PCR restriction fragment length polymorphism (PCR-RFLP) assay to differentiate between wild and domestic camel samples. We applied the assay to 81 individuals and confirmed the origin of all samples including five hybrids with known maternal ancestry. The PCR-RFLP system was effective for both traditional (blood, skin) and non-invasive samples (faeces, hair), as well as for museum specimens. Our results demonstrate high levels of mitochondrial differentiation between wild and domestic Bactrian camels and that maternal hybridization can be detected by a rapid and reliable PCR-RFLP system.

The wild Bactrian camel is one of the world’s rarest and most endangered animals and is facing hybridization threat due to human encroachment. Although captive breeding programs of the wild camel have been undertaken to save it from extinction, to succeed, we need to take into account many factors, e.g., maintain genetic diversity of captive populations similar to that found in wild populations. We applied restriction-site associated DNA sequencing (RAD-Seq) on a captive population in the most important wild camel conservation center in China—Gansu endangered animal conservation center—to investigate the genetic diversity, potential hybridization and inbreeding threats, and thus further guide population management. We sequenced a total of 44 Bactrian camels including 13 wild camels and 31 domestic camels and generated a genome-wide polymorphism dataset with 679,195 high-quality SNPs. This enabled us to detect wild camel individuals with recent genetic introgression from domestic camels. In addition, it revealed that the studied captive population suffers from inbreeding. We therefore suggest practical measures to improve the management of the wild camel and to protect its natural gene pool.

Wild camel is the endangered native species of Central Asia that are found only in the western north of China, and Trans Altai Gobi of Mongolia. In this article was written that the reproductivity of captive wild bactrian camels based on the result and analysis developed at the research center for “Captive Wild camel breeding center”located near administration of Great Gobi Strictly Protected Area “A” part, between 1992 -2015. A gestation age, birth repetition and birth time of female captive wild camels at the breeding center under semi-captive condition have been observed and analysed. According to the research, captive wild camel birth time is started from the last 10 days of March and it finished at the last 10 days of May. Most extensive birth time is April. Captive male wild camel at the breeding center starting to mate at the beginning of January, and finished at the end of February. Therefore, an average gestation period of captive female camels is 400-440 days. However, sometimes, it can fluctuated due to age, fattening, and climate condition. But also birth date of female camels may different because of sex of calf.

The wild camel (Camelus ferus) is the only surviving species of the genus Camelus. Fewer than 1,000 of these two-humped wild camels survive today in one of the most hostile regions on earth. The wild camel is classified as critically endangered (CR) in the IUCN Redlist and it is one of the top 100 Evolutionarily Distinct and Globally Endangered (EDGE) species identified by the Zoological Society of London. Two centuries ago, over 10,000 wild camels were once distributed throughout the arid area of Central Asia. Due to human activity and environmental change in the last century, the distributing range of wild camels has been reduced and wild camel populations have decreased rapidly. Lop Nur and its adjacent areas became the last refuge for wild camels. A field survey estimated there were 340–420 wild camels in the Lop Nur area in 1997. A quarter of a century later, we used the line transect method to investigate the whereabouts of wild camels along 14 line transects in the Lop Nur Wild Camel National Nature Reserve (LNWCNNR) during the spring months from 2010 to 2013. According to this four-year observation, the wild camel's density in the Lop Nur area was estimated to be 0.068±0.025/km2 (density ± standard error) and the population size was 638 ± 251, calculated with Distance®. LNWCNNR carried out patrolling and a public education programme, controlled poaching and unauthorised field expeditions in the reserve. LNWCNNR also channeled water from the valley of Arjin mountains to the Gobi for the use of the wild camel. Therefore, the wild camel population in Lop Nur is slowly recovering after more than a decade of protection by the authorities of the LNWCNNR.

The wild camel (Camelus ferus) in China: Current status and conservation implications

Wild Bactrian camels (Camela ferus) are listed as Critically Endangered by the International Union for Conservation of Nature (IUCN) and only persist in some of the most remote locations in northern China and southern Mongolia. Although the species has been recognized as an umbrella species for the fragile central Asian desert ecosystem and has been high on the conservation agenda, little is known about the species’ habitat requirements, with most information coming from anecdotal sightings and descriptive studies. We compiled the only available telemetry data from wild camels worldwide. Seven wild camels, which were followed for 11–378 monitoring days, covered a total range of 28,410km2, with individual annual ranges being >12,000km2 for three animals followed over a year. Camels reacted strongly to capture events, moving up to 64km from the capture site within a day, whereas normal average daily straight line distances were 3.0–6.4km/day. Camels showed a preference for intermediate productivity values (NDVI, habitat type) and landscape parameters (distance to water, elevation) and an avoidance of steep slopes. Our telemetry results suggest that wild camels still range throughout the entire Great Gobi A Strictly Protected Area (SPA), are highly mobile, and very sensitive to human disturbance. Their habitat preference may be a trade-off between dietary and safety requirements. Small sample size did not allow the development of a full habitat model testing all variables simultaneously and we urgently call for more data from additional wild camels as a foundation for evidence driven conservation actions.

Common names allow species diversity to be acknowledged by experts and non-specialists alike; they are descriptors with both scientific and cultural implications. However, a lack of clarity when using a common name could risk altering perceptions of threatened species. This is the case for the Critically Endangered wild camel Camelus ferus, which, despite extensive evidence of its species status, is frequently referred to in English as wild Bactrian camel. However, the wild camel (Mongolian: хавтгай, khavtgai; Chinese: 野骆驼, ye luo tuo) is not a wild version of the domestic Bactrian camel Camelus bactrianus but a separate species near extinction, with an estimated population of c. 950. Failure to clearly separate Bactrian and wild camels in name risks masking the plight of the few remaining wild camels with the visible abundance of the domesticated species. Here we advocate the use of the accurate English common name wild camel for C. ferus ideally alongside its Indigenous names to correctly represent its cultural and conservation importance.

The wild camel (Camelus ferus) is a critically endangered large ungulate, surviving in just three distinct populations located in the Taklamakan Desert, China; deserts near Lop Nuur, China; and in China and Mongolia within and adjacent to Mongolia’s Great Gobi Strictly Protected Area (GGSPA). The population surviving in Mongolia remains poorly researched, but as few as 500 individuals may survive, although its distribution has remained relatively constant over the past 30 - 50 years. This study aimed at identifying potentially important environmental factors that influence the distribution of wild camels in Mongolia and predicting seasonal movement. We predicted distribution by season using presence only data and selected environmental predictors, including land surface temperature, normalized difference vegetation indices (NDVI), water sources, vegetation and soil. Model predictions revealed that land surface temperature in summer correlated significantly with wild camel distribution, with camels occurring in cooler areas. Abundance of biomass did not significantly correlate with camel distribution. Camels occurred in areas with intermediate levels of NDVI in most seasons, implying that they may base foraging decisions on forage quantity, not quality. Positive correlations of camel distribution with higher NDVI in summer (P = 0.03) suggests that they may prefer herbaceous species that appear after rainfall. Models indicate distance to water sources may be critical for camel distribution in all seasons. Camel occurrence correlated with areas containing shallow mountain soils in summer. Camels displayed no significant habitat correlations in other seasons, yet ranges differed among all seasons. Camels used a common region in spring, summer and autumn that we believe represents the core of the species’ annual range. Wild camel distribution during winter varied significantly from other seasons. Our modelling led to a predicted distribution range that was consistent with ranges described by previous research, indicating consistency between survey data and satellite tracking data.

Current genetic diversity of 5 local breeds of Mongolian camels and 2 samples of Camelus ferus was studied and compared their levels of variability. DNA was extracted using Qiaamp® DNA kit (Qiagen) and amplified mtDNA D-loop control region from 36 blood samples of Mongolian Bactrian camels and 2 from Mongolian Camelus ferus. Three common haplotypes (H1, H2, H6) and 4 unique haplotypes (H3, H4, H5, H8) revealed in the population of domestic camels based on the mitochondrial DNA region. For the further study we carried out best result 26 sequences. We did not find high inbreeding levels in the different breeds. The phylogenetic analysis suggested that domestic and wild camels have two distinct lineages.

The endangered Wild Camel (Camelus ferus Mongolian: хавтгай, khavtgai; Chinese: , ye luo tuo) is the only extant wild species of the Camelini tribe. Surviving only in remote areas of the Gobi deserts of Mongolia and China, this species is threatened with extinction through climate change, associated habitat disruptions and small population impacts. The Wild Camel can hybridize with domestic Bactrian Camel (Camelus bactrianus), and although this introgression has been considered a threat to species survival, the extent to which it has occurred is unknown. DNA was extracted from 257 individuals, from predominantly non-invasive samples, collected across the insitu and ex situ Wild Camel populations in Mongolia. Genotyping with nuclear markers combined with mitochondrial DNA sequencing was used to gain a greater understanding of the extent and source of introgression and levels of genetic diversity in these populations. Results show evidence of nuclear, mitochondrial, and historic introgression of Bactrian Camel genes in the Wild Camel population insitu, and in some Wild Camel individuals within the ex situ herd. Nuclear introgression was detected between 10% and 22% of the insitu population in Mongolia. Mitochondrial and nuclear DNA analysis have allowed for the sources of introgression to be understood, with paternal introgression being the major source in both insitu and ex situ populations. Results have also shown reduced heterozygosity and elevated inbreeding in the insitu population and reveal similar characteristics in the ex situ herd. Although hybridization is often considered a threat, it may also be an opportunity for species' population viability, and this dilemma creates challenges in conservation management. Whilst the global conservation community currently adopts largely arbitrary thresholds for what is an acceptable level of introgression, a detailed genetic perspective is crucial in understanding hybridization and its effect on conservation.

The genus Camelus is an interesting model to study adaptive evolution in the mitochondrial genome, as the three extant Old World camel species inhabit hot and low-altitude as well as cold and high-altitude deserts. We sequenced 24 camel mitogenomes and combined them with three previously published sequences to study the role of natural selection under different environmental pressure, and to advance our understanding of the evolutionary history of the genus Camelus. We confirmed the heterogeneity of divergence across different components of the electron transport system. Lineage-specific analysis of mitochondrial protein evolution revealed a significant effect of purifying selection in the concatenated protein-coding genes in domestic Bactrian camels. The estimated dN/dS < 1 in the concatenated protein-coding genes suggested purifying selection as driving force for shaping mitogenome diversity in camels. Additional analyses of the functional divergence in amino acid changes between species-specific lineages indicated fixed substitutions in various genes, with radical effects on the physicochemical properties of the protein products. The evolutionary time estimates revealed a divergence between domestic and wild Bactrian camels around 1.1 [0.58–1.8] million years ago (mya). This has major implications for the conservation and management of the critically endangered wild species, Camelus ferus.

Molecular diversity and phylogenetic analysis of domestic and wild Bactrian camel populations based on the mitochondrial ATP8 and ATP6 genes

The evolutionary relationship between the domestic bactrian camel and the extant wild two-humped camel and the factual origin of the domestic bactrian camel remain elusive. We determined the sequence of mitochondrial cytb gene from 21 camel samples, including 18 domestic camels (three Camelus bactrianus xinjiang, three Camelus bactrianus sunite, three Camelus bactrianus alashan, three Camelus bactrianus red, three Camelus bactrianus brown and three Camelus bactrianus normal) and three wild camels (Camelus bactrianus ferus). Our phylogenetic analyses revealed that the extant wild two-humped camel may not share a common ancestor with the domestic bactrian camel and they are not the same subspecies at least in their maternal origins. Molecular clock analysis based on complete mitochondrial genome sequences indicated that the sub-speciation of the two lineages had begun in the early Pleistocene, about 0.7 million years ago. According to the archaeological dating of the earliest known two-humped camel domestication (5000–6000 years ago), we could conclude that the extant wild camel is a separate lineage but not the direct progenitor of the domestic bactrian camel. Further phylogenetic analysis suggested that the bactrian camel appeared monophyletic in evolutionary origin and that the domestic bactrian camel could originate from a single wild population. The data presented here show how conservation strategies should be implemented to protect the critically endangered wild camel, as it is the last extant form of the wild tribe Camelina.