The pikas of China: a review of current research priorities and challenges for conservation

Of the approximately 30 extant species of pika (Ochotona; Ochotonidae; Lagomorpha), at least 23 occur in China. Of these, 8 are endemic, and 3 are classified as Endangered by the IUCN. Research into most Chinese species is scarce, and there is much to learn about basic aspects of their ecology. We reviewed the literature on the 23 Chinese Ochotona species, with the aim of highlighting knowledge gaps and biases in research allocation. Specifically, we identify (1) which pika species receive the most attention from researchers, (2) which topics are the most frequently studied, and (3) how well research satisfies conservation priorities. We covered a total of 879 articles, most of which were written in English or Chinese. Around 75% of all publications focused on the plateau pika Ochotona curzoniae. Seven species were represented by 10 or fewer publications each. Endangered and endemic species were particularly poorly represented. 204 papers treated pikas as a pest, while 13 studied conservation issues. Nine species were considered possible targets for pest control, including some poorly known endemics. We make some recommendations on how research into Chinese Ochotona could be improved, including: (1) recognizing that the current species-level taxonomy may be an ineffective way to prioritize conservation research in Ochotona, (2) directing more research toward threatened and endemic species, subspecies, and populations, (3) researching the ecosystem engineering effects of pikas, (4) collecting basic data on natural history of the many understudied species, and (5) researching threats, including climate change and pest control campaigns.     

Assurance of the existence of a trans‐boundary population of the snow leopard (Panthera uncia) at Tsagaanshuvuut – Tsagan‐Shibetu SPA at the Mongolia–Russia border

The existence of a trans‐boundary population of the snow leopard (Panthera uncia) that inhabits the massifs of Tsagaanshuvuut (Mongolia) – Tsagan‐Shibetu (Russia) was determined through non‐invasive genetic analysis of scat samples and by studying the structure of territory use by a collared female individual. The genetic analysis included species identification of samples through sequencing of a fragment of the cytochrome b gene and individual identification using a panel of 8 microsatellites. The home range of a female snow leopard marked with a satellite Global Positioning System (GPS) collar was represented by the minimum convex polygon method (MCP) 100, the MCP 95 method and the fixed kernel 95 method. The results revealed insignificant genetic differentiation between snow leopards that inhabit both massifs (minimal fixation index [F_ST]), and the data testify to the unity of the cross‐border group. Moreover, 5 common individuals were identified from Mongolian and Russian territories. This finding clearly shows that their home range includes territories of both countries. In addition, regular movement of a collared snow leopard in Mongolia and Russia confirmed the existence of a cross‐border snow leopard group. These data support that trans‐boundary conservation is important for snow leopards in both countries. We conclude that it is crucial for Russia to study the northern range of snow leopards in Asia.     

Elusive cats in our backyards: persistence of the North Chinese leopard (Panthera pardus japonensis) in a human-dominated landscape in central China

The North Chinese leopard (Panthera pardus japonensis), the least-known big cat, disappeared in most historical range for decades, following the development of modern civilization. Unfortunately, we have scarce knowledge about the status of this big cat so far, apart from anecdotal reports. In this study, we investigated density, distribution, and habitat use of the leopard, the apex predator, in a complex forest landscape in the Loess Plateau. We used a camera-trapping network to obtain population estimates for leopards over 2 years through spatially explicit capture–recapture models. Our results, based on maximum likelihood and Bayesian/MCMC methods, reveal that the largest wild population of the leopard was found widely distributed in remnant forests in central Loess plateau. The population is increasing in our study area, and the density of leopards (1.70 (SE = 0.48) − 2.40 (SE = 0.67)/100 km²) is higher than other areas of China. According to the analysis of 2 seasonal occupancy models, prey species drive partially the leopard habitat use, predicting that the big cat thrives from the recovery of prey community. However, human disturbances, especially oil wells, seem to have negative impacts on the habitat use of leopards. Specifically, it is necessary to have joint efforts by the government and researchers to improve human disturbances management and prey species population density, as well as strengthen the investment in research on the North Chinese leopard, which could all further strengthen protection ability and ensure the long-term survival of this species.     

Density and carrying capacity in the forgotten tigerland: Tigers in the understudied Nepalese Churia

While there are numerous wildlife ecology studies in lowland areas of Nepal, there are no in‐depth studies of the hilly Churia habitat even though it comprises 7642 km² of potential wildlife habitat across the Terai Arc. We investigated tiger, leopard and prey densities across this understudied habitat. Our camera trapping survey covered 536 km² of Churia and surrounding areas within Chitwan National Park (CNP). We used 161 trapping locations and accumulated 2097 trap‐nights in a 60‐day survey period during the winter season of 2010–2011. In addition, we walked 136 km over 81 different line transects using distance sampling to estimate prey density. We photographed 31 individual tigers, 28 individual leopards and 25 other mammalian species. Spatial capture–recapture methods resulted in lower density estimates for tigers, ranging from 2.3 to 2.9 tigers per 100 km², than for leopards, which ranged from 3.3 to 5.1 leopards per 100 km². In addition, leopard densities were higher in the core of the Churia compared to surrounding areas. We estimated 62.7 prey animals per 100 km² with forest ungulate prey (sambar, chital, barking deer and wild pig), accounting for 47% of the total. Based on prey availability, Churia habitat within CNP could potentially support 5.86 tigers per 100 km² but our density estimates were lower, perhaps indicating that the tiger population is below carrying capacity. Our results demonstrate that Churia habitat should not be ignored in conservation initiatives, but rather management efforts should focus on reducing human disturbance to support higher predator numbers.     

Free-ranging livestock altered the spatiotemporal behavior of the endangered North Chinese leopard (Panthera pardus japonensis) and its prey and intensified human–leopard conflicts

Widespread distribution of livestock in the natural habitats of large carnivores may negatively impact carnivore populations by reducing wild prey availability and increasing human–carnivore conflicts. In this study, we used camera-trapping data collected in the temperate forests of the Taihang Mountains in North China during 2016–2019 to examine whether and how free-ranging cattle affected habitat use and Diel activity patterns of the endangered North Chinese leopard (Panthera pardus japonensis) and its 2 wild prey species, Siberian roe deer (Capreolus pygargus), and wild boar (Sus scrofa). Residents were also interviewed to record livestock depredation events by leopards during 2015–2019. We found that roe deer spatially avoided sites frequented by cattle, but wild boar did not. In the growing seasons, leopards shared habitats with cattle and tended to increase their diurnal activities where cattle were present. All 3 study species exhibited fine-scale spatial-temporal segregation to cattle. Leopards selectively preyed on calves over adult cattle and livestock depredation frequency was positively correlated with the detection rates of cattle and wild prey, but not that of leopard. These findings not only show that through behavioral adaption large carnivores and their ungulate prey may persist under livestock disturbance, but also highlight how important proper livestock management is for conserving North Chinese leopards in this region. To enhance livestock management and mitigate human–leopard conflicts, we recommend specific actions, such as better guarding of free-ranging cattle or adoption of a captive farming system.     

Blue sheep in the Annapurna Conservation Area,Nepal: habitat use,population biomass and their contribution to the carrying capacity of snow leopards

The Himalaya region of Nepal provides a habitat for the endangered snow leopard (Panthera uncia) and its principal prey species, the blue sheep (Pseudois nayaur). The aim of this study was to describe the habitat, the distribution and the population structure of blue sheep, and to estimate their contribution to the carrying capacity of snow leopard in the upper Mustang region of Nepal. Blue sheep were recorded at altitudes from 3209–5498 m on slopes with gradients of 16–60° and aspects of 40°NE to 140°SE. A total of 939 blue sheep were counted in the upper Mustang region, and 98 were counted in the Yak Kharka region of Manang district; however, upper Mustang had the lowest population density of blue sheep recorded within their distribution range in Nepal (0.86 blue sheep/km²). The results of the study show that a higher density of blue sheep is associated with greater plant species diversity. The most important species present in the blue sheep habitat were Kobresia pygmaea, Artemesia spp., Lonicera spp., Lancea tibetica, Poa spp., Astragalus spp. and Ephedra gerardiana. It is estimated that the existing blue sheep population biomass of approximately 38 925 kg in the upper Mustang region could support approximately 19 snow leopards (1.6 snow leopards/100 km²).     

Presence–absence surveys of prey and their use in predicting leopard (Panthera pardus) densities: a case study from Armenia

It is important to predict how many individuals of a predator species can survive in a given area on the basis of prey sufficiency and to compare predictive estimates with actual numbers to understand whether or not key threats are related to prey availability. Rugged terrain and low detection probabilities do not allow for the use of traditional prey count techniques in mountain areas. We used presence–absence occupancy modeling and camera‐trapping to estimate the abundance and densities of prey species and regression analysis to predict leopard (Panthera pardus) densities from estimated prey biomass in the mountains of the Nuvadi area, Meghri Ridge, southern Armenia. The prey densities were 12.94 ± 2.18 individuals km^?2 for the bezoar goat (Capra aegagrus), 6.88 ± 1.56 for the wild boar (Sus scrofa) and 0.44 ± 0.20 for the roe deer (Capreolus capreolus). The detection probability of the prey was a strong function of the activity patterns, and was highest in diurnal bezoar goats (0.59 ± 0.09). Based on robust regression, the estimated total ungulate prey biomass (720.37 ± 142.72 kg km^?2) can support a leopard density of 7. 18 ± 3.06 individuals 100 km^?2. The actual leopard density is only 0.34 individuals 100 km^?2 (i.e. one subadult male recorded over the 296.9 km²), estimated from tracking and camera‐trapping. The most plausible explanation for this discrepancy between predicted and actual leopard density is that poaching and disturbance caused by livestock breeding, plant gathering, deforestation and human‐induced wild fires are affecting the leopard population in Armenia.     

Spatial density estimate of the snow leopard,Panthera uncia,in the Central Tibetan Plateau,China

Knowledge of large carnivore population abundance is essential for wildlife management and conservation, but these data are often difficult to obtain in inherently low-density species. In particular, the snow leopard, Panthera uncia, an enigmatic cat occupying remote mountains in Central Asia, has received insufficient assessments of its population abundance because of logistical and methodological challenges. Here, we aimed to develop a robust density estimation of snow leopards based on 81 days of camera trapping within a contiguous and previously unsurveyed 1950 km² area of habitat on the Tibetan Plateau (Mayue Township, Shenzha County, Tibet Autonomous Region, China). By applying spatially explicit capture–recapture models, we produced an estimate of 1.40 (95%CI: 1.06–1.84) individuals per 100 km². Results also suggested sex-specific variation in the range of movement around activity centers, with male (N = 10, σ = 4.02) movement considerably greater than female (N = 8, σ = 1.84) movement. The findings can serve as a reliable baseline reference for assessing the population trends of this endangered felid species with future estimates. This study will provide context to contribute toward a better understanding of ecological factors shaping the distribution and abundance of snow leopards and the related conservation measures needed to sustain their long-term survival on the Tibetan Plateau.     

牧区积雪光学与微波遥感研究进展

在总结国内外积雪监测常用卫星资料甚高分辨率扫描辐射仪(AVHRR)、多光谱扫描仪(MSS)、专题绘图仪(TM)、中分辨率成像光谱仪(MODIS)、多通道微波辐射计(SMMR)、微波成像专用传感器(SSM/I)、改进型微波辐射扫描仪(AMSR/AMSR-E)、合成孔径雷达(SAR)和FY系列传感器优缺点的基础上,系统研究了牧区积雪可见光遥感研究进展以及微波积雪深度反演、积雪分类决策树遥感研究进展,提出了积雪监测中存在的一些问题及未来发展趋势和研究重点,为进一步做好牧区积雪监测提供科学依据。     

Non-invasive assessment of adrenocortical activity as a measure of stress in leopards Panthera pardus

Leopards Panthera pardus are classified in the IUCN Red List as Vulnerable, primarily due to habitat loss, natural prey base depletion and exploitation caused by various anthropogenic activities. Although protected areas are important for leopard conservation, the majority of suitable leopard habitat lies beyond protected area boundaries exposing individuals to different environmental, physiological and psychosocial stressors. This study aimed to examine the suitability of five different enzyme immunoassays (EIAs) for monitoring adrenocortical function in the leopard based on faecal glucocorticoid metabolite (fGCM) analysis. After performing an adrenocorticotrophic hormone (ACTH) stimulation test and investigating the stability of fGCM post-defaecation, faeces from free-ranging leopards in a peri-urban and a conservation area were collected to investigate the potential impact of habitat variability on glucocorticoid output. An EIA measuring fGCM with a 5α-3β-11β-diol structure performed best, demonstrating a ～200%–330% increase in fGCM concentrations approximately 40 h post-ACTH administration. Concentrations of fGCM remained quite stable for up to six days post-defaecation and showed a maximum increase of 8% and a maximum decrease of 9%. Although not significantly different, overall median fGCM concentrations were 68% higher in individuals utilising the peri-urban area compared with leopards utilising the conservation area. The ranges of fGCM concentrations between sites, however, were similar. Individual median fGCM concentrations differed distinctly between free-ranging males and females, possibly linked to female reproductive status. The established method can now assist in addressing some of the issues facing local wildlife managers, conservationists and researchers tackling various aspects related to leopard conservation and management under different land-use practices.     

东北豹保护对策研究

通过概述世界上东北豹的种群数量特征和分布状况,分析了东北豹保护面临的各种威胁和问题,如人类过度干扰、乱砍滥伐、乱捕滥猎、近亲繁殖以及人类的开发建设等活动对栖息地造成的严重破坏,使栖息地呈片段化、破碎化发展趋势,直接威胁东北豹种群的生存和繁衍。中国对东北豹的保护没有足够的重视,还没有建立专门的东北豹自然保护区,而俄罗斯对于东北豹的保护非常重视,不但建立了专门的东北豹自然保护区,还完善了东北豹的各项保护措施。最后,针对上述情况,提出了东北豹栖息地保护、猎物种群恢复、东北豹的重引入、建立东北豹跨界保护区等相应的保护对策。     

What explains tourists’ support for snow leopard conservation in the Annapurna Conservation Area,Nepal?

Wildlife tourism is increasingly important for the conservation of threatened species such as snow leopards. However, what tourists know or value about snow leopards, and to what extent they support the conservation of this species, has received limited empirical attention. This paper investigates tourist knowledge about snow leopards, beliefs and values toward the species, and support for its conservation in the Annapurna Conservation Area of Nepal. Survey data were collected from 406 foreign tourists between March and May 2014. Although knowledge about snow leopards varied among respondents, there was widespread support for their conservation. Knowledge about snow leopards was best explained by education level and environmental organization membership. Improved knowledge about the species, and a variety of intrinsic conservation values, were found to increase tourist support for snow leopard conservation. These results provide important insights to help tailor tourism initiatives to support the conservation of snow leopards.     

An initial coprological survey of parasitic fauna in the wild Amur leopard (Panthera pardus orientalis)

The Amur leopard, one of nine recently recognized subspecies of leopard, is still the most threatened by a stochastic procession of extinction. Evaluation of the potential danger to the conservation of the Amur leopard originating from disease urgently needs to be studied. Unfortunately, research on the potential risk to Amur leopards caused by disease is rare. In terms of parasitic diseases that affect this species, even basic data for parasitic fauna are absent. The aim of this study is to acquire this knowledge to improve the general understanding of Amur leopard parasites. Seven parasite species, including 3 nematodes (Toxocara cati, a capillarid‐type parasite, and a Metastrongyloidea‐type parasite), 2 cestodes (Spirometra sp. and Taenia sp.), 1 trematode (Paragonimus sp.), and 1 protozoan (Cystoisospora felis), were found in this research. Toxocara cati occurred most frequently, followed by Spirometra sp.     

The effects of prey depletion on dietary niches of sympatric apex predators in Southeast Asia

Resource depletion exerts opposing pressures on co-occurring consumers to expand diets while limiting overlap with competitors. Using foraging theory as a framework, we tested the effects of prey availability on diet specialization and overlap among competing Asian predators: dhole, leopard, and tiger. We used scat analysis from a prey-poor site, combined with a quantitative synthesis of 40 other diet studies, to determine biomass of different prey types consumed by each predator. We then assessed diet composition in relation to prey density, and compared diet breadth and overlap between prey-poor and prey-rich sites. In prey rich areas, all three predators specialized on energetically profitable medium and large ungulates (>30 kg), resulting in narrow, overlapping niches. Each predator shifted toward less profitable small-bodied prey (≤30 kg) as preferred ungulates declined, whereas consumption of preferred ungulates was unrelated to small prey abundance, as predicted by foraging theory. Diet breadths doubled under prey depletion (except leopard), but overlap declined as diets diverged via species-specific traits that facilitated capture of different types of alternative prey. Asia's apex predators adapt similarly to depletion of mutually preferred ungulates by switching to more numerous but less profitable small prey. Yet they can also partition a depleted prey base through intrinsic niche differences, thereby avoiding competitive exclusion. Our findings illuminate the stabilizing properties of adaptive foraging and niche differences in ecological communities, and provide insights into the behavior and resilience of Asia's endangered apex predators in response to prey depletion in the heavily poached forests of this region.     

卧龙自然保护区雪豹的生境选择偏好与食源结构特征

近年来,人类活动范围不断扩大,对雪豹(Panthera uncia)所处高海拔生态系统侵入不断增加,对雪豹生存已造成威胁。准确掌握雪豹生境选择偏好与食源结构特征,可以完善雪豹基础研究,提高雪豹保护管理效率。因此于2019年7月对卧龙自然保护区内雪豹集中分布区域进行野外调查,研究雪豹对各生境因子的选择偏好情况;分析粪便组成,明确雪豹食源结构。结果显示:雪豹偏好于海拔3500—4500 m、坡度31°—45°且地形较为崎岖的无家畜活动区域,在坡位的选择上,雪豹偏好于山脊与上坡位,避开中、下坡位与山谷。在植被类型选择上,雪豹偏好草甸与高山流石滩,同时也会选择稀疏且基径较小的灌丛。雪豹倾向于选择草本植物稀疏,低矮的区域。雪豹动物性食源以岩羊(59.26%)为主,家畜(25.93%)与啮齿目(22.22%)次之,鸟类(7.41%)占比最少。植物性食源以禾本科(59.26%)、苔藓植物(44.44%)与莎草科(33.33%)为主,灌木及其他植物占比较少。本文丰富了雪豹的基础研究内容,为卧龙及其他保护区雪豹保护管理工作中相关政策的制定提供参考依据。     

马来熊的研究现状及保护对策探析

马来熊是国家Ⅰ级保护动物,其生物学信息缺乏,也缺乏科学的保护和管理对策。本文通过回顾关于马来熊的研究文献,对其研究现状进行总结归纳,并针对种群分布现状提出科学保护和管理对策。关于马来熊的研究主要见于野生种群现状、野外生态及圈养种群的饲养管理等,其中野外生态主要集中于生境选择利用、家域特征、行为节律、食性等,需要进一步深入研究其个体生态学或种群生态学规律。针对马来熊的保护和研究现状,应采取加强立法、推行宣教、提高公众保护意识;加强基础科学研究;建立保护区、缓冲区及森林廊道等以恢复其栖息地等措施来有效保护其野生种群。     

高山兀鹫（Gyps himalayensis）的繁殖行为研究

大型猛禽行为研究难度大,方法落后,国内尚处在摸索阶段.高山兀鹫（Gyps himalayensis）是中亚及青藏高原特有物种,对其繁殖行为研究几乎空白.2012 ～ 2014年,在新疆天山中段采用路线调查法和行为扫描法,结合访问,探寻高山兀鹫的繁殖巢区及观察育雏过程.同时通过实地观测、迷你自动相机拍摄等方法,开展了栖息地调查、巢数统计、巢结构分析、孵化过程及雏鸟生长发育观察、繁殖周期及食物组成分析等.对天山7个地点的14个巢区及上百个巢穴统计,结果发现高山兀鹫喜欢在朝南的崖壁上集群营巢（约占78.6％）,窝卵数为1枚（n=21）,最长的一个繁殖区（A区）绵延7.3 km,相距另外一个较近的巢区（B区）约47 km.其巢的结构特殊,均以细禾草铺垫.随着幼鸟长大,亲鸟的护幼强度逐渐减弱.为了错开产卵时间,其种群的整个繁殖周期长达8 ～10个月（1～10月）,超出其他大型猛禽平均繁殖周期1倍的时间.因为食物缺乏,其育雏期可能被迫延迟.对高山兀鹫的主要威胁来自人类的过度放牧、采矿、药物滥用、捡蛋与捉幼鸟等.加强猛禽保护,迫在眉睫.还讨论了兀鹫与狼、雪豹及天葬的关系.     

Evaluation of β‐carotene assimilation in leopard geckos (Eublepharis macularius)

Although leopard geckos (Eublepharis macularius) are commonly kept under human care, their vitamin requirements are largely unknown. Many invertebrate preys display a low vitamin A concentration; thus, gut‐loading insects with vitamin A or carotenoids is a common practice. The objective of this prospective experimental study was to investigate whether dietary supplementation with β‐carotene, including prey gut‐loading, leads to sufficient vitamin A hepatic storage and prevents epithelial squamous metaplasia development in leopard geckos. Ten clinically healthy female leopard geckos were randomly divided in two groups with various supplementations: a group receiving vitamin A supplementation and a group receiving β‐carotene. Insects were gut‐loaded continuously with a supplement containing vitamin A or β‐carotene, depending on the group. Oral supplementation with cod liver oil or carrot juice was administered weekly to each lizard from “vitamin A group” and “carotenoid group” respectively. After 10 weeks of supplementation, surgical hepatic biopsies were obtained in three geckos of each group while the two remaining geckos were euthanized to undergo complete necropsy. Hepatic vitamin A concentration was determined for each lizard (n = 10) by ultra‐performance liquid chromatography. Histopathology revealed hepatocellular vacuolization and vitellogenic follicles in five females. Epithelial squamous metaplasia was not observed in any of the geckos. Hepatic vitamin A concentration was significantly higher in the carotenoid‐supplemented group than in the vitamin A‐supplemented group (p = 0.03). Our results suggest that in leopard geckos, dietary supplementation with β‐carotene allows sufficient vitamin A hepatic storage.     

Management Tools to Reduce Carnivore-Livestock Conflicts: Current Gap and Future Challenges

Predation on domestic animals by carnivores is a persistent problem wherever carnivores and livestock co-occur. A wide range of management tools to reduce predation has been invoked. However, the evidence of their effectiveness is still limited for a broader range of species and conditions. Using a global analysis of domestic animal predation by native carnivores under a “before-after/control-impact” framework, we assessed the effectiveness of management techniques used to reduce domestic animal predation identifying knowledge gaps and research needs. We reviewed 291 predation cases in 149 studies published between 1990 and 2017 involving 47 carnivores. Lethal control is the most common method to reduce predation in comparison with nonlethal techniques. Yet the effectiveness of both approaches remains poorly evaluated (30.1% of study cases) and largely based on producers’ perceptions (70% of cases where effectiveness was evaluated). Lethal control and night confinement of domestic animals would have no effect on reducing predation, whereas the use of livestock-guarding dogs, fencing, or herdsmen may significantly reduce domestic animal losses. When the effectiveness of each technique to reduce predation was assessed by large and mesocarnivores, fencing significantly reduced predation of domestic animals by the former. Despite little scientifically published material, our findings indicate lethal control would have no effect in reducing animal predation by native carnivores when compared with nonlethal techniques. Our study also indicates the effectiveness may vary depending on the type of carnivore involved in the conflict with livestock activity. The use of an evidence-based framework to measure and assess the differential effectiveness of nonlethal techniques and the use of complementary tools at different spatial and temporal scales must be research priorities to prevent livestock predation while promoting the conservation of carnivores in production-oriented lands as encouraged by the Convention of Biological Diversity.     

基于文献计量的国际草地农业生态学研究发展态势分析

草地农业生态学研究体现出生物学、农学和地理学交叉的特点。近年来,全球许多国家及相关研究机构对草地农业生态学的研究力度不断加大。本研究以SCIE论文数据库作为数据源,利用Thomson Data Anlyzer(TDA)和UCINET软件对1996-2015年草地农业生态学研究论文进行数据挖掘和定量分析,探究了近20年来国际草地农业生态学研究的变化趋势、研究力量分布、重点领域、研究热点及国际合作。结果表明,近20年来,国际草地农业生态学研究论文以平均8%的速度增长;草地农业生态学研究所涉及的学科较多,主要有农业、环境科学与生态学、植物科学、生物多样性与保护、地质学等;除了对草地、农业关注外,草地农业生态学研究也对物种及生态环境保护较为重视;美国、英国等发达国家的草地农业生态学研究论文的综合影响力较高,美国在国际间合作中表现最为突出,与各主要国家间均具有很强的合作关系;中国科学院在草地农业生态学研究方面非常活跃,其论文量遥遥领先于法国农业科学研究院、加拿大萨斯喀彻温大学等其他机构,但研究水平、影响力以及国际合作能力仍有待提升。