The Crested Ibises expanding to plain areas exhibit a higher tolerance of human proximity

Animals must strike a balance between anti-predation behavior and other essential behaviors,such as foraging.Within the same species,strategies may vary on individuals’risk-taking preferences,and in this process the environment is a determinant,in addition to predator regime.The Crested Ibis(Nipponia nippon)exhibits such tendency.This is an endangered species,once inhabiting exclusively in China’s Qinling Mountain.This used to be the sole remaining wild population.However,over recent decades,this population has expanded.A portion has relocated to breed in the lower plain area,which is characterized by elevated level of human activities and landscape complexity.We used flight initiation distance(FID)as an indicator of the ibises’risk-taking preference,particularly their response to human proximity.Additionally,we examined the environmental factors influencing their foraging site selection,including altitude,terrain openness,human activity intensity and human construction.Our findings revealed a significantly shorter FID among individuals relocating to plain habitats,indicating a higher tolerance of human proximity.The results showed that FID decreased with distance to the nearest human settlement.Another finding is that FID was independent of instant human activity intensity and environmental factors(altitude and terrain openness).These different may arise from various combinations of human activity,predation risk,and food abundance within the two habitats.These results provide insights into the in situ conservation of the threatened species within the context of global urbanization.

Using stable isotope to compare the habitat use and trophie level between the new and old breeding range of wild Crested Ibis in the early breeding season

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(δ;C andδ;N),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 bothδ;C andδ;N values,δ;C andδ;N varied as a function of habitat types.Birds breeding in plains had significantly higherδ;C but lowerδ;N values compared to the birds breeding in mountains.Higherδ;N 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 inδ;N 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.

Transcriptional analysis and histochemistry reveal that hypersensitive cell death and H2O2 have crucial roles in the resistance of tea plant (Camellia sinensis (L.) O. Kuntze) to anthracnose

Anthracnose causes severe losses of tea production in China.Although genes and biological processes involved in anthracnose resistance have been reported in other plants,the molecular response to anthracnose in tea plant is unknown.We used the susceptible tea cultivar Longjing 43 and the resistant cultivar Zhongcha 108 as materials and compared transcriptome changes in the leaves of both cultivars following Colletotrichum fructicola inoculation.In all,9015 and 8624 genes were differentially expressed between the resistant and susceptible cultivars and their controls(0 h),respectively.In both cultivars,the differentially expressed genes(DEGs)were enriched in 215 pathways,including responses to sugar metabolism,phytohormones,reactive oxygen species(ROS),biotic stimuli and signalling,transmembrane transporter activity,protease activity and signalling receptor activity,but DEG expression levels were higher in Zhongcha 108 than in Longjing 43.Moreover,functional enrichment analysis of the DEGs showed that hydrogen peroxide(H2O2)metabolism,cell death,secondary metabolism,and carbohydrate metabolism are involved in the defence of Zhongcha 108,and 88 key genes were identified.Protein–protein interaction(PPI)network demonstrated that putative mitogen-activated protein kinase(MAPK)cascades are activated by resistance(R)genes and mediate downstream defence responses.Histochemical analysis subsequently validated the strong hypersensitive response(HR)and H2O2 accumulation that occurred around the hyphal infection sites in Zhongcha 108.Overall,our results indicate that the HR and H2O2 are critical mechanisms in tea plant defence against anthracnose and may be activated by R genes via MAPK cascades.

Species distribution modeling in regions of high need and limited data： waterfowl of China

Background: A number of conservation and societal issues require understanding how species are distributed on the landscape, yet ecologists are often faced with a lack of data to develop models at the resolution and extent desired, resulting in inefficient use of conservation resources.Such a situation presented itself in our attempt to develop waterfowl distribution models as part of a multi-disciplinary team targeting the control of the highly pathogenic H5N1 avian influenza virus in China.Methods: Faced with limited data, we built species distribution models using a habitat suitability approach for China's breeding and non-breeding(hereafter, wintering) waterfowl.An extensive review of the literature was used to determine model parameters for habitat modeling.Habitat relationships were implemented in GIS using land cover covariates.Wintering models were validated using waterfowl census data, while breeding models, though developed for many species, were only validated for the one species with sufficient telemetry data available.Results: We developed suitability models for 42 waterfowl species(30 breeding and 39 wintering) at 1 km resolution for the extent of China, along with cumulative and genus level species richness maps.Breeding season models showed highest waterfowl suitability in wetlands of the high-elevation west-central plateau and northeastern China.Wintering waterfowl suitability was highest in the lowland regions of southeastern China.Validation measures indicated strong performance in predicting species presence.Comparing our model outputs to China's protected areas indicated that breeding habitat was generally better covered than wintering habitat, and identified locations for which additional research and protection should be prioritized.Conclusions: These suitability models are the first available for many of China's waterfowl species, and have direct utility to conservation and habitat planning and prioritizing management of critically important areas, providing an example of how this approach may aid others faced with the challenge of addressing conservation issues with little data to inform decision making.

Three-dimensional niche partitioning between two colonially nesting ardeid species in central China

Background:Interspecific competition is known to be strongest between those species that are both closely related and sympatric.Egrets are colonially nesting wetland birds that often overlap and can therefore be expected to compete in roosting and nesting habitat as well as in diet.According to the niche partitioning hypothesis,it is to be expected that these similar species would show differentiation in at least one of the main niche dimensions to reduce competition.We tested niche partitioning between the colonially nesting Little Egret(Egretta garzetta)and Cattle Egret(Bubulcus ibis)in temporal,spatial and trophic dimensions.Methods:Field study was conducted in three mixed egret colonies in Yangxian County,southwest Shaanxi Prov-ince,central China.For each nest colony we recorded its spatial location,the height of nesting trees and of nests,the height of roosting trees and of roosting individuals within the trees.We determined the first egg-laying and first hatching dates of the two species.Craw dissection of storm-killed egret nestlings was used to measure the diet.Six transects were surveyed to study foraging habitat selection.Results:We found that hatching time of Little Egrets peaked earlier(by about 1 month)than that of Cattle Egrets.Cattle Egrets nested and roosted higher than Little Egrets.The foraging habitats used by Little Egrets were dominated by river banks(73.49%),followed by paddy fields(13.25%)and reservoirs(10.84%),whereas Cattle Egret foraging sites were characterized by grasslands(44.44%),paddy fields(33.33%)and river banks(22.22%).Little Egrets consumed more fishes(65.66%)and Odonata larvae(13.69%)than Cattle Egrets,while Cattle Egrets were found feeding mainly on Coleoptera(29.69%)and Orthoptera(23.29%).Little Egrets preyed on larger mean biomasses of food items than Cattle Egrets.Conclusions:Our results confirm the niche partitioning hypothesis as a mechanism for coexistence among ecologi-cally similar species.In two coexisting egret species,niche partitioning is multidimensional,such that the two coexist-ent species occupy differing ecological space based on all three temporal,spatial and trophic niche dimensions.

iTRAQ-based quantitative proteomic analysis of tea plant(Camellia sinensis(L.)O.Kuntze)during cold acclimation and de-acclimation procedures

To gain a better understanding on the mechanism of cold acclimation in tea plant[Camellia sinensis(L.)O.Kuntze]at the proteome level,an iTRAQ based quantitative proteome analysis was carried out to identify differentially accumulated proteins in the mature leaves which were collected at non-acclimated(NA),fully acclimated(CA)and de-acclimated(DA)stages.407 and 477 proteins identified from CA and DA showed significant abundance changes(at 95%confidence)compared with NA,respectively.Moreover,251 protein species changed their abundance in DA compared with CA.Those differential abundance protein species were mainly involved in metabolism,cell wall,photosynthesis,energy,protein synthesis,antioxidation,carbohydrate metabolic process and binding,and mapped to the pathways of biosynthesis of secondary metabolites,microbial metabolism in diverse environment,ribosome,metabolic pathway,sugar metabolism,protein processing,photosynthesis,and plant-pathogen interaction pathway.However,no significant correlation was detected between the identified proteins and cognate gene transcript levels by correlation analysis and qRT-PCR analysis.This study presents a comprehensive proteome in mature leaves at different cold acclimation status and provides new insights into cold acclimation mechanisms in tea plants.

Integrating Wintering Waterbird Movements with Earth Observation Data of Wetland Dynamics

Wetlands are among the most productive and essential ecosystems on earth,but they are also highly sensitive and vulnerable to climate change and human disturbance.One of the current scientific challenges is to integrate high-resolution remote sensing data of wetlands with wildlife movements,a task we achieve here for dynamic waterbird movements.We demonstrate that the White-naped cranes Antigone vipio wintering at Poyang Lake wetlands,southeast of China,mainly used the habitats created by the dramatic hydrological variations,i.e.seasonal water level fluctuation.Our data suggest that White-naped cranes tend to follow the water level recession process,keeping close to the boundary of water patches at most of the time.We also highlight the benefits of interdisciplinary approaches to gain a better understanding of wetland ecosystem complexity.

加入《迁徙物种公约》,促进全球迁徙动物保护

自然界中,一些野生动物为了觅食或繁殖,会随着季节沿固定或非固定路线从一处栖息地转换到另一处栖息地。这些野生动物常常跨越国界进行长距离的迁徙或洄游,其生存容易受到迁徙或洄游路线阻断、过度捕猎/捕捞、气候变化以及觅食或繁殖栖息地丧失和退化的威胁(Wilcove&Wikelski,2008)。

Linking the past and present to predict the distribution of Asian crested ibis(Nipponia nippon)under global changes

Understanding how species’ecological niches adapt to environmental changes through time is critical for predicting the effect of future global change on endangered species.Yet few studies have incorporated knowledge of past niche shifting into the assessment of species’future fate in a changing world.In this study,we integrated the ecological niche dynamics into the species distribution modeling of the Asian crested ibis(Nipponia nippon)in East Asia.Specifically,we compared historical and present ecological niches of crested ibis in four-dimensional environmental space based on species occurrence and environmental data.We then employed a multi-temporal ecological niche model to estimate the potential geographical distribution of crested ibis under future climate and land-use changes.Our results show that crested ibis retained similar though not identical ecological niches over time.Compared to the historical baseline range,the current suitable habitat for crested ibis has been reduced by 39.6%.The effects of human activity outweigh those of climate change regarding the distribution of crested ibis.We conclude that the ecological niche of crested ibis was tended to be conservative,and future potentially suitable habitat may encounter northeastward and northwestward shift,and possibly expand by 18.7%referred to the historical range.Thefindings of our study are of clear importance for the conservation and successful reintroduction of crested ibis in East Asia.