Impacts of Ecological Restoration and Human Activities on Habitat of Overwintering Migratory Birds in the Wetland of Poyang Lake, Jiangxi Province, China

Increasing human activities have contributed to global climate change, and thus resulted in a downward trend in the number of species and population sizes of migratory birds. This trend is closely related to a reduction in habitat size and lower habitat quality. The Poyang Lake wetland in China constitutes one of Asia's largest overwintering habitats for migratory birds. Over the past 10 years, restoration projects have improved the habitat ecology of these wetlands. In this study, we assessed the changes in habitat quality for overwintering migratory birds from 2000 to 2012 near two villages in the Poyang Lake wetland using the In VEST model. Average habitat quality for migratory birds has been improved by 18.8% and47.7%. Differences in the degrees of habitat improvement can be attributed to differences in the change of habitat size and in the impact of threat sources that resulted from the combined effects of restoration and human activities in these two villages.

Influences of the Weather and Climate on Wintering Migratory Bird in Dongting Lake

[Objective] The research aimed to study influences of the weather and climate on wintering migratory bird in Dongting Lake. [Method] Bird analysis data provided by East Dongting Lake National Nature Reserve and wintering migratory bird monitoring data in big and small west lakes in recent 5 years were used. By combing water level data and various meteorological factors in Chenglingji, wintering migratory bird in Dongting Lake was analyzed. [Result] Abnormal precipitation led to drought or flood in Dongting Lake, causing significant adverse effect on the birds. Abnormal climate was important reason for that wintering migratory bird greatly reduced, such as high temperature and later going south of the strong cold air. Extreme weather and climate events led that some birds in Dongting Lake significantly reduced. Meteorological element had certain influence to bird survey. We should select a reasonable investigation time based on weather and climate. In Birding Festival, weather had little effect on bird species observation. In the migratory season of bird, we could see many birds in fine cold weather after a strong cold air, which suitable for observing bird. When it was low temperature or less rain in autumn, and was high temperature or more rain and sunshine in early winter, it was suitable for migratory birds wintering in Dongting Lake. Ardea cinerea, Anser fabalis and Anser erythropus were more in sunny days while Phalacrocorax carbo was more in rainy weather. Grus grus was more in heavy wind weather while Recurvirostra avosetta was more in small wind weather. [Conclusion] The research provided scientific basis for studying migratory bird in east Dongting Lake.

Dynamic analysis and bifurcation control of a delayed fractional-order eco-epidemiological migratory bird model with fear effect

In this paper,a new delayed fractional-order model including susceptible migratory birds,infected migratory birds and predators is proposed to discuss the spread of diseases among migratory birds.Fear of predators is considered in the model,as fear can reduce the reproduction rate and disease transmission rate among prey.First,some basic mathematical results of the proposed model are discussed.Then,time delay is regarded as a bifurcation parameter,and the delay-induced bifurcation conditions for such an uncontrolled system are established.A novel periodic pulse feedback controller is proposed to suppress the bifurcation phenomenon.It is found that the control scheme can successfully suppress the bifurcation behavior of the system,and the pulse width can be arbitrarily selected on the premise of ensuring the control effect.Compared with the traditional time-delay feedback controller,the control scheme proposed in this paper has more advantages in practical application,which not only embodies the advantages of low control cost and easy operation but also caters to the periodic changes of the environment.The proposed control scheme,in particular,remains effective even after the system has been disrupted by a constant.Numerical simulation verifies the correctness of the theoretical results.

Highly pathogenic avian influenza H5N1 Clade 2.3.2.1c virus in migratory birds,2014–2015

A novel Clade 2.3.2.1c H5N1 reassortant virus caused several outbreaks in wild birds in some regions of China from late 2014 to 2015.Based on the genetic and phylogenetic analyses,the viruses possess a stable gene constellation with a Clade 2.3.2.1c HA,a H9N2-derived PB2 gene and the other six genes of Asian H5N1-origin.The Clade 2.3.2.1c H5N1 reassortants displayed a high genetic relationship to a human H5N1 strain(A/Alberta/01/2014).Further analysis showed that similar viruses have been circulating in wild birds in China,Russia,Dubai(Western Asia),Bulgaria and Romania(Europe),as well as domestic poultry in some regions of Africa.The affected areas include the Central Asian,East Asian-Australasian,West Asian-East African,and Black Sea/Mediterranean flyways.These results show that the novel Clade 2.3.2.1c reassortant viruses are circulating worldwide and may have gained a selective advantage in migratory birds,thus posing a serious threat to wild birds and potentially humans.

The potential function of post-fledging dispersal behavior in first breeding territory selection for males of a migratory bird

One possible hypothesis for the function of post-fledging dispersal is to locate a suitable future breeding area.This post-fledging period may be particularly important in migratory species because they have a limited period to gather information prior to autumn migration,and in protandrous species,males must quickly acquire a territory after returning from spring migration to maximize their fitness.Here we use color-ring resightings to investigate how the post-fledging dispersal movements of the Cyprus wheatear Oenanthe cypriaca,a small migratory passerine,relate to their first breeding territory the following year when they return from migration.We found that males established first breeding territories that were significantly closer to their post-fledging location than to their natal sites or to post-fledging locations of other conspecifics,but these patterns were not apparent in females.Our findings suggest that familiarity with potential breeding sites may be important for juveniles of migratory species,particularly for the sex that acquires and advertises breeding territories.Exploratory dispersal prior to a migrant’s first autumn migration may contribute toward its breeding success the following year,further highlighting the importance of early seasonal breeding on fitness and population dynamics more generally.

Ecology of avian influenza viruses in migratory birds wintering within the Yangtze River wetlands

Migratory birds are considered natural reservoirs of avian influenza A viruses(AIVs).To further our viral ecology knowledge and understand the subsequent risk posed by wild birds,we conducted a 4-year surveillance study of AIVs in the bird wintering wetlands of the Yangtze River,China.We collected over8000 samples and isolated 122 AIV strains.Analyses were then carried out with 108 novel sequenced genomes and data were deposited in GISAID and other public databases.The results showed that the Yangtze River wintering wetlands functioned as a mixing ground,where various subtypes of AIVs were detected harboring a high diversity of nucleotide sequences;moreover,a portion of AIV gene segments were persistent inter-seasonally.Phylogenetic incongruence presented complex reassortment events and distinct patterns among various subtypes.In addition,we observed that viral gene segments in wintering wetlands were closely related to known North American isolates,indicating that intercontinental gene flow occurred.Notably,highly pathogenic H5 and low pathogenic H9 viruses,which usually circulate in poultry,were found to have crossed the poultry/wild bird interface,with the viruses introduced to wintering birds.Overall,this study represented the largest AIV surveillance effort of wild birds within the Yangtze River wintering wetlands.Surveillance data highlighted the important role of wintering wild birds in the ecology of AIVs and may enable future early warnings of novel AIV emergence.

Influence of land use change on the waterbird community of Sihwa Lake,Republic of Korea

Background:Land use and development alter mudflat and wetland habitat availability,although mudflats and wetlands provide important stopover habitats for shorebirds during the spring and autumn migrations and support communities of ducks and geese during the winter months in the Republic of Korea.This study investigated land use changes around Sihwa Lake(Republic of Korea)and evaluated the effect of these changes on waterbird community characteristics.Methods:We conducted a land-use-change analysis at the medium-resolution level using land cover maps for 2001,2007,2009,and 2014.Also,a tidal stream survey was conducted in Sihwa Lake and the surrounding reclaimed mudflats every season for 10 years(2003-2012)to identify the seasonal and interannual variations in waterbird species composition.To determine the total annual waterbird species and population counts,species diversity index,and interspecies variations,a TRIM(trends and indices for monitoring data)analysis was used.Results:Wetland area decreased more than 10%while agricultural land,barren land,and grassland area increased more than 10%due to continuous reclamation activities around Sihwa Lake.Barren land later turned into agricultural land or other land use.Sixty-three species and 566,623 individuals were recorded.The number of species,population size,and species diversity index by year and by species showed decreasing trends that were more marked in spring and summer.Furthermore,seasonal and annual variations in waterbird species composition showed decreasing trends in dabbling ducks,herons,grebes,and shorebirds but diving ducks displayed increasing trends.In particular,shorebirds were reduced to a greater extent than other waterbird species because of the reduction and simplification of the intertidal zone,and shallow waters caused by reclamation and road construction.Conclusions:Increased development and construction around Sihwa Lake has altered migratory shorebird populations with a general decline in species diversity and population size.The greatest decline was observed in wading birds,while diving duck populations showed increasing trends.

Nickel concentration in two bird species from Hara Biosphere Reserve of southern Iran

We investigated the levels of nickel in the feathers of the Western Reef Heron (Egretta gularis) and Siberian Gull (Larus heuglini) from the Hara Biosphere Reserve in southern Iran from November to December 2010. Analysis of variance shows that no significant differences in nickel levels were found between gender and age groups in either species, but it should be pointed out that the number of samples was small. Student t tests show that the amount of nickel in the feathers of the Siberian Gull was higher than in the Western Reef Heron. The level of nickel concentration in the Western Reef Heron was higher in females than in males; on the other hand, this level of concentration in the Siberian Gull was higher in males.

Do migrant and resident species differ in the timing of increases in reproductive and thyroid hormone secretion and body mass? A case study in the comparison of pre-breeding physiological rhythms in the Eurasian Skylark and Asian Short-toed Lark

Background:Physiological preparation for reproduction in small passerines involves the increased secretion of reproductive hormones, elevation of the metabolic rate and energy storage, all of which are essential for reproduction. However, it is unclear whether the timing of the physiological processes involved is the same in resident and migrant species that breed in the same area. To answer this question, we compared temporal variation in the plasma concentration of luteinizing hormone(LH), testosterone(T), estradiol(E_2), triiothyronine(T_3) and body mass, between a migrant species, the Eurasian Skylark(Alauda arvensis) and a resident species, the Asian Short-toed Lark(Calandrella cheleensis), both of which breed in northeastern Inner Mongolia, China, during the 2014 and 2015 breeding seasons.Methods:Twenty adult Eurasian Skylarks and twenty Asian Short-toed Larks were captured on March 15, 2014 and 2015 and housed in out-door aviaries. Plasma LH, T(males), E_2(females), T_3 and the body mass of each bird were measured every six days from March 25 to May 6.Results:With the exception of T, which peaked earlier in the Asian Short-toed Lark in 2014, plasma concentrations of LH, T, E_2 and T_3 of both species peaked at almost the same time. However, Asian Short-toed Larks attained peak body mass earlier than Eurasian Skylarks. Plasma T_3 concentrations peaked 12 days earlier than plasma LH in both species. Generally, plasma LH, T, E_2, T_3 and body mass, peaked earlier in both species in 2014 than 2015.Conclusions:The timing of pre-reproductive changes in the endocrine system and energy metabolism can be the same in migrant and resident species; however, residents may accumulate energy reserves faster than migrants. Although migration does not affect the timing of pre-breeding reproductive and metabolic changes, migrant species may need more time to increase their body mass. T levels in resident species may be accelerated by higher spring temperatures that may also advance the pre-breeding preparation of both migrants and residents.

Characteristics of cross transmission of gut fungal pathogens between wintering Hooded Cranes and sympatric Domestic Geese

Migratory birds travel long distance and link various pathogens.Due to habitat degradation,wintering waterfowls forage together with poultry,increasing the risk of pathogen transmission between hosts.We investigated the fungal communities between wintering Hooded Cranes and Domestic Geese by high-throughput sequencing,and inferred the potential gut pathogens for both hosts at different wintering stages.The fungal community compositions were significantly different between seasons and between the hosts.The negative correlation was found between fungal diversity and pathogenic diversity,with higher fungal diversity and less pathogenic diversity in early stage and less fungal diversity and higher pathogenic diversity in late stage for both hosts.The dissimilarity of pathogenic community compositions decreased from early to late stage,with the quantity of overlapping potential pathogenic OTUs increasing along wintering periods between the two hosts,demonstrating the existence of pathogen cross transmission between the two hosts.Furthermore,the transmission pathway of avian pathogens was mainly from Hooded Cranes to Domestic Geese while the transmission direction of human pathogens was primarily from Domestic Geese to wild cranes.Based on above results,we argued that pathogen cross transmission and underlying outbreak risk of disease should be closely monitored in migratory birds and domestic poultry.

Epizootic, Endemic and Pandemic Zoonotic Viral Infections

More than 60% human infectious diseases have zoonotic origin. Cross species transmission of pathogens is a continuous, dynamic process that occurs throughout the world, giving rise to epizootic (temporary, limited infection), endemic (on-going infection limited to a defined geographic region) and pandemic viral infections (infection spreading to every part of the world) like the current COVID-19 pandemic, which depends on the existing conditions on the ground. In Nov 2021, sudden mortality of numerous migrating demoiselle cranes was reported from their resting site near Jodhpur, Rajasthan. The symptomatic cranes became gradually weak and were unable to fly. They eventually fell dead which caused concern locally, given the current prevailing SARS-CoV-2 pandemic situation the world over. By the end of Dec 2021, the number of cranes with mortality and morbidity reduced, making it a temporary “epizootic infection”. Molecular diagnosis carried out at a specialized laboratory identified the etiological agent to be the highly pathogenic Avian Influenza Virus H5N1 (HPAIV), which has been responsible for morbidity of avian species from different parts of the world. There was no report of spreading the H5N1 AIV infection from the infected migratory cranes to nearby chicken farms or pig farms for now. In the absence of vaccines against the highly pathogenic H5N1 AIVs, and the inherent ability of influenza viruses, both avian AIV and human IAVs to constantly mutate its envelope gene or the surface antigens, resulting from the error-prone nature of the viral RNA Polymerase enzyme are the roadblocks for development of a universal, broad-spectrum influenza vaccine. Even when such a universal vaccine against H5N1 is available, vaccinating a large number of wild migratory cranes would be difficult. However, it is possible and indeed necessary to vaccinate chickens in poultry farms and pigs in farms that raise pigs for human consumption.

ROLE OF DISEASE PROPAGATION IN MIGRATORY BIRD POPULATION

Chatterjee considered a predator prey model with avian migration in the migration prey population IS. Chatterjee, Alternative prey source coupled with prey recovery enhance stability between migratory prey and their predator in the presence of disease, Nonlinear Anal. Real World Appl. 11 （2010） 4415-4430]. In this paper, we modify and analyze the model by taking time dependent parameters and the general flmctional response into consideration. The conditions for the persistence of the system and the extinction of the disease are obtained. The global attractivity of the system is also studied. By numerical simulations, we find that the qualitative behavior of the system independent on the choice of the functional response. Moreover, it is observed that the infection rate, recruitment rate and the predation rate play a vital role in predicting the behavior of the dynamics.

Bird habitat preferences drive hemoparasite infection in the Neotropical region

The role that the environment plays in vector-borne parasite infection is one of the central factors for understanding disease dynamics.We assessed how Neotropical bird foraging strata and habitat preferences determine infection by parasites of the genera Haemoproteus,Plasmodium,Leucocytozoon,and Trypanosoma and filarioids,and tested for phylogenetic signal in these host-parasite associations.We performed extensive searches of the scientific literature and created a database of hemoparasite surveys.We collected data on host body mass,foraging strata,habitat preference,and migratory status,and tested if host ecological traits predict each hemoparasite occurrence and prevalence using a phylogenetic Bayesian framework.Species of Plasmodium tend to infect birds from tropical forests while birds from altitudinal environments are likely to be infected by species of Leucocytozoon.The probability of a bird being infected by filarioid or Trypanosoma is higher in lowland forests.Bird species that occur in anthropic environments and dry habitats of tropical latitudes are more susceptible to infection by species of Haemoproteus.Host foraging strata is also influential and bird species that forage in the mid-high and canopy strata are more prone to infection by species of Haemoproteus and filarioids.We also identified phylogenetic signal for host-parasite associations with the probability of infection of Neotropical birds by any hemoparasite being more similar among more closely related species.We provided a useful framework to identify environments that correlate with hemoparasite infection,which is also helpful for detecting areas with potential suitability for hemoparasite infection due to land conversion and climate change.

Consideration of climate change impacts will improve the efficiency of protected areas on the Qinghai-Tibet Plateau

The protection of migratory birds and their habitats is important to the ecological stability of the Qinghai-Tibet Plateau(QTP).Currently protected areas(PAs)were designed in accordance with species distribution patterns under current climatic conditions,thus ignoring climate change will lead to a decrease in the protection efficiency of PAs.In this study,using the flagship species Grus nigricollis,as an example,we used the maximum entropy(MaxEnt)model to simulate the distributions and conservation status of G.nigricollis and optimized the existing PA boundaries.The results showed that(1)suitable habitat-for G.nigricollis accounts for 12.48%of the QTP area,and the PAs established under current climatic conditions cover 17.84%of this suitable habitat area;(2)future climate changes will influence the distribution and quality of G.nigricollis habitats,and the average protection efficiency of the current PAs in four climatic scenarios will decrease from 17.84%to 15.31%;and(3)through optimization,the efficiency of existing PAs can be increased by 0.75 times and reach 28.37%,indicating PA planning must consider not only current climate conditions but also the effects of climate changes.Our results aim to address shortcomings in the conservation efficiency of PAs and provide an example for resolving mismatched PA boundaries and habitat changes for species.

Tigecycline resistance tet(X3)gene is going wild

The emergence of mobile Tigecycline-resistant tet(X3)and tet(X4)is believed to be a global threat to public health.Here,we investigated the prevalence of tet(X3)and tet(X4)in our metagenomic data of migratory birds.While tet(X4)was not identified in our samples,tet(X3)was found in two gut microbiomes of bird fecal samples,with 100%amino acid identity of sites 150–387.These results suggest that tet(X3)has been spreading into the environment for a long period of time and that there is an urgent need to control its further transmission.

Gastrointestinal helminthes of houbara bustard(Chlamydotis undulata)from north of Iran

The parasitic infection of houbara bustard(Chlamydotis undulate)in north of Iran,Golestan Province was reported in this study.The carcass of a male houbara bustard about 2 years old with 2.5 kg body weight,was forfeited from impermissible hunters by the Department of Environment in Gorgan,Golestan Province during January 2015.The gastrointestinal tracts was dissected and examined for helminth infection.Species of Nematoda,Cestoda and Acanthocephala were found which were as following:Hartertia obesa,Idiogenes otidis,Mediorhynchus taeniatus,respectively from small intestine.Based on the results obtained from the present study,it can be concluded that Chlamydotis undulata may play an important role in the transmission of the mentioned parasites.In addition,this is the first report of Hartertia obesa,Idiogenes otidis,Mediorhynchus taeniatus in Iran.