The post-fledging period, extending from fledging to independence, is a crucial life stage characterized by high mortality due to fledglings' limited mobility and inexperience. During this stage, fledglings gradually increase their mobility, leave their parents, disperse from their natal site, and respond to the challenges of new environments. Characterizing these post-fledging movements and space use is essential for understanding juvenile survival strategies and devising targeted conservation measures. The Crested Ibis (Nipponia nippon), an endangered species and a highly protected animals at the national level in China, has seen limited research on its post-fledging movements and space use. From 2015 to 2023, we utilized biologgers, combined with field surveys, to study the movement and space use characteristics of 37 fledglings in Hanzhong City, Shaanxi Province, China, over a two-month post-fledging period. We quantified changes in activity levels (based on overall dynamic body acceleration), independence timing, onset of post-fledging dispersal, habitat selection, and daily activity rhythms after independence. Our results revealed individuals began independent living 26.23 ± 2.34 days post-fledging and onset of dispersal at 25.58 ± 2.33 days, with a range area at the natal of 2.08 ± 0.56 km2. The initial 30 days post-fledging are characterized as an ontogenetic phase marked by a rapid increase in body activity level. Fledglings preferred paddy fields during the independent period rather than the forests they relied on before independence. Interestingly, the daily activity rhythm, particularly foraging behavior, peaked at noon—contrasting with the expected morning and evening activity peaks—likely as an adaptation to avoid periods of peak human activity. Additionally, drowning, collisions, and predation in paddy fields are noteworthy causes of fledgling mortality. Consequently, we recommend protecting a 2-km2 area around the nest site for at least two-month post-fledging, implementing safety measures around power lines and cesspools. Additionally, reducing human disturbances near foraging habitats and expanding space within paddy fields would help mitigate survival pressures on fledglings.

The risk-benefit trade-off theory is a fundamental concept in the study of animal behavior strategies and remains a prominent topic in animal ecology. Cattle Egrets (Bubulcus ibis) foraging alongside ungulates has garnered considerable attention. Previous research has highlighted the impact of ungulates on disturbing grassland insects, leading to increased foraging success for Cattle Egrets. However, the risk-benefit relationship from an anti-predator perspective remains underexplored. This study, conducted in Yang County, Shaanxi Province, China, focused on Cattle Egrets and compared the foraging efficiency and flight initiation distance (FID) when foraging alongside cattle (Bos spp.) versus foraging alone. Additionally, our study analyzed the impact of increasing cattle numbers on the FID to assess whether foraging with cattle enhances the perceived safety. We hypothesized that, with more cattle, Cattle Egrets would be less vigilant if they can gain vigilance advantages from cattle. The results indicated significantly higher foraging efficiency and lower FID for Cattle Egrets when foraging with cattle compared to foraging alone, suggests that the presence of cattle enables Cattle Egrets to better tolerate potential predation risks. However, more cattle did not significantly affect the FID, indicating that the perceived predation risk of Cattle Egrets did not reduce with more cattle. The lower FID of Cattle Egrets when foraging with cattle is more likely attributed to higher foraging efficiency rather than lower perceived predation risk in their risk-benefit trade-off. This study explores the mechanism of Cattle Egrets foraging with cattle from an anti-predation perspective, enhancing understanding of this phenomenon and contributing to the risk-benefit trade-off hypothesis.

An adult Crested Ibis (Nipponia nippon) was found moribund in the Qinling area of China. Postmortem examination and histopathological analysis revealed lung inflammation and multi-organ hemorrhage. Bacterial isolation and whole-genome sequencing confirmed Edwardsiella tarda infection.

Numerous studies have examined the correlation between offspring quantity and quality, and many have found that the most common brood size is often smaller than broods with the highest offspring quality or production. However, the reasons why these small broods with lower offspring quality are produced are still poorly explained. Using data spanning 29 years, we investigated the effects of brood size on nestlings’ body mass and the lifetime fitness for those offspring as adults (as proxies of offspring quality) in the Crested Ibis ( Nipponia nippon ). We also examined the temporal variation of brood size. We found that overall offspring quality increases with brood size and that individuals from broods of three had the highest quality, as quantified by larger body mass, higher adult survival, and lifetime reproductive success. Furthermore, the brood size of an individual pair significantly varied across years, and the proportion of broods containing two offspring increased while broods of three decreased after 2000 when the population dispersed to low-quality habitat. These findings indicate that spatiotemporal variation in resources may impact variation in brood size and subsequent fitness consequences, and that small broods are more common in resource-poor years or low-quality habitats. In contrast, parents with access to high-quality resources produce larger broods of nestlings that achieve higher body mass and subsequently experience higher adult survival and lifetime fitness. This study highlights how variation in life history traits can be influenced by resource condition and provides an insight into particular habitats that need conservation for Crested Ibis. Significance statement Although life history theory predicts a trade-off between offspring quantity and quality, and that fewer, high-quality offspring are expected to be more common to prolong one’s own survival prospect in long-lived species, birds, mammals, and humans often show a positive correlation for these traits. Why do parents produce small broods with lower offspring quality? Here, we found that offspring quality—such as nestlings’ body mass, survival, and the lifetime reproductive success of offspring as adults—increased overall with brood size, up to broods of three of Crested Ibis. Brood size varied across years; in particular, pairs appear to produce smaller broods of nestlings that have lower body mass and lifetime fitness in resource-poor years or lower-quality habitats. This long-term study helps to advance our understanding of the fitness consequences and ecological mechanisms that impact offspring quantity and quality in long-lived animals.

为分析陕西某地夜鹭死亡原因,对死亡夜鹭进行了剖检,并对存在明显病理变化的组织脏器进行了病理组织学检查、细菌分离培养、形态学观察、生化鉴定、动物致病性试验、药物敏感性试验,应用细菌16SrRNA基因通用引物进行基因扩增测序,选取同源性高的14株细菌序列进行同源性分析构建系统进化树.结果显示:从脏器中分离得到1株革兰阴性杆菌;16SrRNA序列与布氏柠檬酸杆菌同源性高达99％;生化试验鉴定为布氏柠檬酸杆菌;分离菌株对青霉素、苯唑西林、氨苄西林、哌拉西林、头孢氨苄、头孢唑林、头孢呋辛、头孢曲松、头孢哌酮、丁胺卡那、庆大霉素、卡那霉素、新霉素、红霉素、麦迪霉素、诺氟沙星、氧氟沙星、环丙沙星、复方新诺明、氯霉素等20种抗菌药敏感,对头孢他啶苯唑西林、万古霉素、克林霉素等3种抗菌药耐药;该菌株对雏鸡具有较强致病性,可以从死亡雏鸡体内重新分离到该菌株,表明该夜鹭受到布氏柠檬酸杆菌的感染.本研究为夜鹭布氏柠檬酸杆菌相关疾病的防治提供了科学依据.

Although dispersal is a key driver of population dynamics and species distributions, we still know little about how it affects the dynamics of endangered and restricted-range species. Density-dependent effects on dispersal in particular may be critical for the range expansion of recovering populations. After 1981, when the last 7 wild individuals of Crested Ibis (Nipponia nippon) were discovered in China, the species remained confined to a single location ("original nesting area") until 2000 (< 24 breeding pairs). Then, the breeding population began a significant spatial and numerical expansion toward new breeding sites ("secondary nesting areas"). Our analyses of long-term (1993-2017) individual resighting data (n = 193) found that natal dispersal was common (similar to 77.2%), whereas breeding dispersal was rare (similar to 2.1%). Breeding density was negatively related to productivity, and natal dispersal was more likely toward low-density areas. The Weibull distribution provided the best fit to the observed dispersal distances, indicating the presence of long-distance natal dispersers. Although we cannot rule out the effect of dispersal mechanisms inherent in the species regardless of density, our findings suggest that the probability of natal dispersal is density-dependent, implying a role for intraspecific competition in the Crested Ibis spreading in the region. We expect the Crested Ibis to spread throughout the region if conservation programs can identify and protect potential reintroduction areas at a large spatial scale to allow dispersing Crested Ibis to settle into new and low-density breeding areas.

2017年7月—2020年6月,在陕南地区进行调查监测过程中,共收集到朱鹮(Nip-ponia nippon)死亡个体273只,其中包括雏鸟15只、幼鸟153只、成鸟105只.对其死亡时间、地域分布和原因进行分析.结果表明:朱鹮的死亡时间主要集中在5—8月和1—2月;洋县境内死亡朱鹮数量占死亡总数的70％以上;朱鹮死亡原因包括疾病、机械性损伤、天敌捕食、坠巢、溺水、电击、盗猎、中毒、先天残疾,自然灾害以及其他未知死因共11类.

朱鹮(Nipponia nippon)野生种群目前仅分布在陕西省洋县及邻近的城固、西乡、南郑、汉台、勉县、宁强、留坝、汉阴等9个县区,数量达到2 500余只,但对其野外伤病和收容救治状况报道较少.陕西汉中朱鹮国家级自然保护区在2016至2019年的巡护和监测过程中,共发现并收容救治野生朱鹮伤病个体362只.本文利用双因素方差方法分析了伤病朱鹮的来源、年龄结构、季节性差异、收治时间、伤病情况、救治效果和放归后监测情况.结果发现,野生朱鹮幼鸟收容救助数量显著高于成鸟,夏季主要救助幼鸟,冬季为成鸟;朱鹮救助的主要伤病类型为饥饿、外伤、骨折、疾病、坠巢和残疾.饥饿、坠巢和外伤个体救治后痊愈放归比例较高,而疾病和骨折的死亡率较高.本文探讨了野生朱鹮收容救助数量逐年增多、救助个体主要为幼鸟、存在季节性差异等特点.建议急需增强救助中心收容救助能力,建立朱鹮收容救治网络,完善野外救助工作.

河流是朱鹮重要栖息地之一,在朱鹮逐渐转移至低海拔区域生存的趋势下,提高河流栖息地生境质量是当前朱鹮保护的重要内容之一.利用数据收集、现场调研、ArcGIS等分析方法对近年来河流栖息地生态变化过程进行分析,分别从栖息地适宜性、景观格局指数及生境质量3个方面探讨朱鹮河流栖息地质量的状况,从中找出朱鹮河流栖息地生境的具体问题.从不同河流生境尺度,探讨朱鹮河流栖息地的修复方法.

2020年12月下旬,陕西省洋县清凉水库周边陆续出现多只野生朱鹮死亡.剖检死亡朱鹮发现肺部淤血,肝脏肿胀,胰脏点状出血,胃内充满鱼类组织,消化道弥散性出血等.为了研究致朱鹮死亡的原因,采集2只死亡朱鹮的肝脏和脾脏组织进行细菌分离培养,成功分离到2株细菌.对分离菌进行微生物学和生化特性鉴定以及细菌16 S rDNA检测,结果显示,分离到的2株菌是同一菌株,为气单胞菌属简达气单胞菌.该菌致病性较强,1.0×1010 CFU/只剂量腹腔接种小鼠24 h致死率为75％.药敏试验表明,分离菌对丁胺卡那霉素、氟哌酸、氯霉素和复方新诺明4种药物高度敏感.

Summary Understanding how birds select breeding sites plays an important role in habitat protection, especially for the conservation of endangered species. With the increase in population size of the endangered Crested Ibis Nipponia nippon, its distribution range has expanded from mountain areas to plains located outside protected areas, representing a new challenge for conservation of the species. Identifying the current nesting habitat requirements is thus needed and can provide valuable information for the planning of new nature reserves. In this research, we surveyed a total of 117 nests across the whole distribution range from 2015 to 2019. We used generalized linear mixed-effects models to assess nesting preferences of the Crested Ibis in the wild. Results showed that in mountain areas, Masson pines Pinus massoniana were preferred (64.6%), whereas elms Ulmus pumila (44.9%) and aspens Populus davidiana (40.6%) were used more frequently lower down, probably because of their higher availability. In both mountain areas and plains the ibises selected tall nesting trees with larger diameter at breast height and preferred nesting rather high above ground, especially in plains where taller trees provided higher suitable nesting positions. The ibises also preferred nesting close to tree trunks, especially in mountain areas, probably for more safety from collapsing. Furthermore, in mountain areas, slope and distance to path had positive effects on nesting occurrence, and understorey coverage was avoided by nesting ibises, while these variables had little impact in plains. Our results indicate that, despite their range expansion, Crested Ibises rely on very specific habitat characteristics for nesting. We suggest relatively tall trees like elms and aspens should be preserved in plains. In addition, we highlight how selection patterns of Crested Ibises may vary, and that such variation should be addressed in conservation planning, especially in future reintroduction.

The concept of foraging niche provides an insight into habitat use and dietary information of animals. Knowing intraspecific variation in foraging niche and trophic level is critical to the understanding of the species response to environmental changes during the process of range expansion, as well as the habitat management for conservation of threatened species. Using stable isotopic values of eggshell membranes (δ13C and δ15N), we examined whether there are differences in habitat use, trophic level, foraging niche width between the new and old breeding habitats (plains vs. mountains) of wild Crested Ibis (Nipponia nippon) in the early breeding season. Crested Ibis exhibited high variability in both δ13C and δ15N values, δ13C and δ15N varied as a function of habitat types. Birds breeding in plains had significantly higher δ13C but lower δ15N values compared to the birds breeding in mountains. Higher δ15N suggested that individuals in mountains consumed a great proportion of higher trophic level prey species in the early breeding season. Moreover, the isotopic niches were distinctly different in positions and showed small overlap between the two habitat types. The niche width was wider in old habitat than in the expanded new habitat. Our results demonstrated that the wild Crested Ibis had a high intraspecific variation in habitat uses and trophic levels in the early breeding season, and they could be divided into mountain and plain groups based on their different foraging niches. The difference in δ15N and niche width revealed that high trophic level food resources might be insufficient in plains. These findings stressed the importance of protecting foraging grounds in mountains and the necessity of improving foraging grounds in plains during winter and spring. Our study highlights the feasibility of investigating intraspecific variation in foraging ecology of birds through non-invasive isotopes of eggshell membranes. Understanding foraging niche variation gives us an insight into the food resource diversity in local areas and provides important information regarding particular foraging habitats that require protection.

In order to better design conservation programs to conserve threatened species, social, economic and political factors must be carefully considered. The wild population of the endangered Crested Ibis (Nipponia nippon) is currently only distributed in Yangxian County, Shaanxi province of China, and as the gradual dispersal of its population from the mountains to the plains, the possibility of human-wildlife interaction has increased, which poses certain challenges for conservation and management. Here, we used a questionnaire to investigate public attitudes and willingness to pay (WTP) toward Crested Ibis conservation, and to evaluate relevant influencing factors, with a view to providing recommendations for its management. The results showed that local residents strongly support the conservation of ibis and factors like education level, income, residential area, perception for ibis and prior experiences significantly affected their support for conservation. Results also indicated that the annual WTP was US$18.28 per household, and the potential value of donations is about US$2.45 million per year for Crested Ibis conservation. Regression analysis indicated that income, perception for ibis, prior experience, support for conservation and environmental attitudes had a significant effect on WTP. The comparison between the original research value of the ibis and the predicted value from the Meta-regression analysis function indicated that the benefit transfer values are able to inform policy decisions. Our results can be applied not only to the design of tailored outreach programs and management policies for the Crested Ibis, but also to facilitate conservation and management of other endangered species by encouraging decision makers to use benefit transfer models for the rapid valuation in the absence of species economic information.

朱鹮Nipponia nippon属国家一级重点保护野生动物,被世界自然保护联盟濒危物种红色名录列为濒危(EN).目前野生朱鹮主要分布于陕西省洋县及其周边区域.本调查以陕西汉中朱鹮国家级自然保护区为研究区域,运用ENVI 4.0和ArcGIS 10.2通过支持向量机法制成农田分布图,随机抽取12条样线以1.8 km·h-1的步行速度用10×42双筒望远镜统计朱鹮的数量.本研究将样线上的农田分为未翻犁蓄水稻田、翻犁蓄水稻田、翻犁未蓄水稻田、未翻犁未蓄水稻田、旱地和撂荒地6种类型,利用选择系数和选择指数衡量朱鹮对觅食地的选择.在7条朱鹮活动频繁的样线上随机抽取28个1 m×1 m的样方,统计样方内底栖动物的丰富度.结果表明,越冬期朱鹮偏好选择未翻犁蓄水稻田,选择指数为0.49±0.11,且偏好在水深3～6 cm的水田上觅食,选择指数为0.16±0.21.水田中底栖动物以昆虫为主,占总生物数量的64.02％.未翻犁蓄水田和翻犁蓄水田底栖动物的密度均没有显著差异.上述结果表明,冬季朱鹮更倾向于在未翻犁、蓄水深度为3～6 cm的水田中觅食.

陕西汉中朱鹮国家级自然保护区收容饲养的一只朱鹮发生头颈部羽毛脱落、头部裸露皮肤表面生有黄白色痂片,怀疑为真菌感染.用75％ 酒精消毒患处皮肤后刮取痂皮,置载玻片上,加10％ 的K O H溶液溶解皮屑,观察发现较长分枝状菌丝和短菌丝碎片.将痂皮接种于沙堡氏培养基27℃培养,11 d时长出大量直径约0.3 m m的平绒样白色湿润的菌落,继续培养,白色菌落逐渐转变为淡粉色、橘黄色,橘红色.挑取橘红色菌落镜下观察,可见菌丝上大量梨型小分子和有棘状凸起6～8个分隔的大分子孢子.诊断为禽小孢子菌感染引起的冠癣.在进行实验室诊断的同时,根据发病朱鹮症状给予制霉菌素、复合维生素B口服用药并使用黑癣王药膏外敷给药,5d后基本临床症状消失,10 d后再次取样培养未发现菌体.

通过对一例下颌肿胀、颈部肿块野生朱鹮的救治,以及死亡后尸体的剖检,结合事发地环境,诊断为疑似毒蛇咬伤.为朱鹮此类疾病的诊断救治积累了经验.

文章利用景观生态学分析方法,先从宏观尺度上分析朱鹮栖息地整体生境构成问题,并对朱鹮3个活动周期范围内的生境因子进行分析,找出相关生境因子问题;然后以陕西洋县傥水河下游生境修复为例,通过现场调研,在局地尺度上找出重要节点存在的具体生境问题,尝试在不同空间尺度下运用风景园林学科的设计方法,对重要节点——河流生境因子进行生境修复,设计适宜度较高的朱鹮栖息地.

2020年4月陕西汉中朱鹮国家级自然保护区管理局救助一只左翅下垂的雄性成年朱鹮,次日该鸟死亡,剖检发现胸部和腹部皮下黄白色沙粒样物质,取样在显微镜下观察为长椭圆形有4对足的虫体,经形态学和分子生物学鉴定为禽囊螨.

We report the measurements and analysis of weak antilocalization (WAL) in Pb1-xSnxSe topological quantum wells in a new regime where the elastic scattering length is larger than the magnetic length. We achieve this regime through the development of high-quality epitaxy and doping of topological crystalline insulator (TCI) quantum wells. We obtain elastic scattering lengths that exceeds 100nm and become comparable to the magnetic length. In this transport regime, the Hikami-Larkin-Nagaoka model is no longer valid. We employ the model of Wittmann and Schmid to extract the coherence time from the magnetoresistance. We find that despite our improved transport characteristics, the coherence time may be limited by scattering channels that are not strongly carrier dependent, such as electron-phonon or defect scattering.

2018年11月,繁育中心在对朱鹮进行驱虫后,多数个体出现精神沉郁、羽轴开裂和飞羽脱落等临床症状.经分析,初步断定为驱虫药中毒,通过解毒保肝、促进机体恢复治疗,效果明显.