This review summarizes studies on Przewalski’s horse since its extinction in the wild in the 1960s, with a focus on the reintroduction projects in Mongolia and China, with current population status. Historical and present distribution, population trends, ecology and habitats, genetics, behaviors, conservation measures, actual and potential threats are also reviewed. Captive breeding and reintroduction projects have already been implemented, but many others are still under considerations. The review may help to understand the complexity of problem and show the directions for effective practice in the future.

Recent technological innovations have led to an upsurge in the availability of unmanned aerial vehicles (also known as drones and hereafter referred to as UAVs)aircraft remotely operated from the groundwhich are increasingly popular tools for ecological research, and the question of this study concerns the extent to which wildlife responses might allow aerial wildlife monitoring (AWM) by UAVs. Our experiment tests the hypothesis that the wildlife-UAVs interaction depends strongly on flight altitude that there may be a lowest altitude range for which the ungulates are not exceedingly disturbed, dictating a practically achievable level of discernibility in flight observation, for this question might influence the future viability of the UAVs in the study and protection of the other wildlife in Chinas semiarid ecosystem. We examined the behavioral responses of a group of enclosed Przewalskis horses (Equus ferus przewalskii) to the presence of different in-flight UAVs models by conducting flights at altitudes ranging from 1 to 52 meters and recorded the heights at which each horse reacted to (noticed and fled) the UAVs. All horses exhibited a stress response to UAVs flights as evidenced by running away. The results suggest strong correlations between flight altitude and response across the different subjects that adults generally noticed the UAVs at the larger heights (20.58±10.46m) than the immature (4.67±0.87m). Meanwhile, reaction heights of females (15.85±6.01m) are smaller than that of males (26.85±18.52m). Supported by their biological roles in herds (e.g., males must give protection to his entire herd while females are purely responsible for their offspring), our results also show that age, closely followed by gender, are the two most significant elements that determine a horses level of alertness to the UAVs. This research will help future scientists to better gauge the appropriate height to use a drone for animal observation in order to minimize disturbance and best preserve their natural behavior.

Due to the influence of bio-geographical and environmental factors, as well as anthropogenic landscape features, organisms show different reproductive strategies among different populations. There is a lack of detailed information on the reproductive biology of Kentish plover Charadrius alexandrinus in arid lands in Central Asia. In this study, we summarized the characteristics of the reproductive biology of three geographically distinct plover populations in Aibi Lake in northwestern Xinjiang, Taitema Lake in southern Xinjiang and artificial reservoirs around Urumqi City in northern Xinjiang, based on 440 eggs from 158 nests observed and analyzed from April to July of 2019 and 2020. We found that there was no significant difference in clutch size among the three populations. However, the egg size of the Taitema Lake population was significantly larger than those of the other two populations, whilst the egg volume and clutch volume of the artificial reservoirs’ populations were significantly larger than that of Aibi Lake. With the postponement of laying dates, the northern and northwestern populations showed the characteristics of a small clutch size and a relatively small egg size, respectively, and a decrease in reproductive output. The heavier female plovers in Taitema Lake laid eggs earlier, and there was a significantly positive correlation between female body mass and clutch size and egg size. The tarsometatarsus length of the female plovers was significantly positively correlated with the reproductive output in all three populations. The model selection results show that female body size and ambient temperature restrict the egg size and reproductive output of Kentish plovers, which is consistent with the upper limit hypothesis of the maternal condition and maternal constraint. Our data support the hypothesis that Kentish plovers show distinct flexibility in their breeding strategies to cope with the harsh natural environment in the arid lands of Xinjiang, China. The results of a relatively high average clutch size and average egg size imply that the saline wetlands of Western China are important breeding habitats for Kentish plovers.

Changes in the palaeoenvironment and paleoclimate expedite the process of evolutionary divergence in animals. The evolutionary events of some small mammals distributed in Xinjiang Arid Region remain ambiguous. Thus, it is necessary to predict their evolutionary histories based on divergence estimates. Some museum specimens were involved in this analysis because of sampling limitation for threatened species in the arid region. A related problem is that some mutilated specimens without complete taxonomic data made it difficult to directly analyze species divergence. Here, sequences of cytochrome c oxydase I were used to identify museum specimens and combined with cytochrome b to estimate the recent divergence of extant small mammals constrained with eight fossil calibrations. The results showed that the massive species differentiation emerged during the Middle and Late Miocene periods. We inferred that differentiation of these small mammals might be associated with the retreat of the Tethys Sea from the Tarim Basin around the Eocene-Oligocene boundary and the global climate fluctuations during the Miocene period. Furthermore, the aridification and changes in the Taklimakan and Gurbantunggut Deserts might have driven the diversification of intraspecies and the emergence of cryptic species since the Late Pleistocene.

Due to the influence of bio-geographical and environmental factors, as well as anthropogenic landscape features, organism shows different reproductive strategies among different populations. There is lack of detailed information on the reproductive biology of Kentish plover Charadrius al-exandrinus in arid lands in Central Asia. In this study, we summarized the characteristics of the reproductive biology of three geographically distinct plover populations in Aibi Lake in the Northwestern Xinjiang, Taitema Lake in the Southern Xinjiang and artificial reservoirs around Urumqi City in Northern Xinjiang respectively, based on 440 eggs of 158 nests observed and ana-lyzed from April to July of 2019 and 2020. We find that there is no significant difference in clutch size among the three populations. However, the egg size of Taitema Lake population is signifi-cantly larger than those of the other two populations, whilst egg volume and clutch volume of ar-tificial reservoirs population are significantly larger than that of Aibi Lake. With the postpone-ment of laying date, the northern and northwestern populations respectively show the character-istics of small clutch size and relatively small egg size, and decrease of reproductive outputs. The heavier female plovers in Taitema Lake lays eggs earlier, and there was significantly positive cor-relation between the female body mass and the clutch size and egg size. The tarsometatarsus length of the female plovers was significantly positively correlated with the reproductive output in all three populations. The model selection results show that female body size and ambient tem-perature restrict the egg size and reproductive output of Kentish plovers, which is consistent with the upper limit hypothesis of the maternal condition and the maternal constraint. Our data sup-port that Kentish plover show distinct flexibility in breeding strategies to cope with the harsh nat-ural environment in arid lands of Xinjiang, China. The results of relatively high average clutch size and average egg size imply that saline wetlands in Western China are important breeding habitats for Kentish plover.

In this paper, we update the status of Black-necked cranes (Grus nigricollis) in Xinjiang Uyghur Autonomous Region, China where it has hardly been recorded. We report on research in Southern Xinjiang，mainly in Altun (Arjin in Chinese) and Kunlun Mountain ranges and their adjacent areas, including part of Pamir Plateau and the southern edge of Lop Nur Basin. Black-necked cranes were observed in seven counties, by direct observation in 2010 to 2017, and we deduced that 180-220 individuals of the species inhabited Kunlun and Altun Mountains and the surrounding areas. 137 cranes, the largest population, were recorded in the autumn migration season in the Altun Mountain Nature Reserve in 2013. The most recent record of Black-necked cranes in the Lop Nur Basin ( N 40°19', E 91°58', alt. 790 m) was observed on May 2010 would be the northernmost distribution location with the lowest latitude and extreme arid environment．