Protection effect of overwintering water bird habitat and defining the conservation priority area in Poyang Lake wetland, China

Biodiversity conservation is one of the most important objectives of protected areas. Most biodiversity assessment-related studies use the change in species abundance data to measure the level of biodiversity conservation. Yet for many areas, long-term species data are not available and thus it is necessary to use biodiversity indices to monitor the effect of land use (LU) changes or the impact of protected area establishment. Poyang Lake wetland is one of the most important wintering sites for migratory water birds on the East Asian–Australasian flyway. To protect this habitat, 14 nature reserves were created in the region between 1997 and 2003. This paper aims to assess the effect of nature reserve creation on the status of habitat for overwintering water birds in Poyang Lake wetland by analysing LU and land cover data from 1995, 2005 and 2015. We developed a composite biodiversity index to search for current biodiversity hotspots (conservation priority) in the study area. An integrated approach consisting of the Integrated Valuation of Ecosystem Services and Trade-offs model, GIS, fragment analysis and hotspot analysis was used to realize our objective. Our results showed that the creation of the nature reserve had positive effects on overwintering water bird habitat. However, tremendous changes (such as change of habitat area, quality and fragmentation) within and outside the nature reserve showed that the role of protected area still needs to be further discussed. Moreover, regional synthesis LU management plans such as ecological restoration should be carried out. The results of the habitat assessment also indicate that a comprehensive biodiversity index framework based on net primary productivity, habitat connectivity and habitat quality could be more efficient in assessing biodiversity and defining a reasonable protected area, from data obtain in large scale perspective.Program for BINGWEI Excellent Young Talents of Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of SciencesNatural Sciences Foundation of ChinaPeer Reviewe

The Socioeconomic and Ecological Drivers of Avian Influenza Risks in China and at the International Level

abstract: Avian influenzas are zoonoses, or pathogens borne by wildlife and livestock that can also infect people. In recent decades, and especially since the emergence of highly pathogenic avian influenza (HPAI) H5N1 in 1996, these diseases have become a significant threat to animal and public health across the world. HPAI H5N1 has caused severe damage to poultry populations, killing, or prompting the culling of, millions of birds in Asia, Africa, and Europe. It has also infected hundreds of people, with a mortality rate of approximately 50%. This dissertation focuses on the ecological and socioeconomic drivers of avian influenza risk, particularly in China, the most populous country to be infected. Among the most significant ecological risk factors are landscapes that serve as “mixing zones” for wild waterfowl and poultry, such as rice paddy, and nearby lakes and wetlands that are important breeding and wintering habitats for wild birds. Poultry outbreaks often involve cross infections between wild and domesticated birds. At the international level, trade in live poultry can spread the disease, especially if the imports are from countries not party to trade agreements with well-developed biosecurity standards. However, these risks can be mitigated in a number of ways. Protected habitats, such as Ramsar wetlands, can segregate wild bird and poultry populations, thereby lowering the chance of interspecies transmission. The industrialization of poultry production, while not without ethical and public health problems, can also be risk-reducing by causing wild-domestic segregation and allowing for the more efficient application of surveillance, vaccination, and other biosecurity measures. Disease surveillance is effective at preventing the spread of avian influenza, including across international borders. Economic modernization in general, as reflected in rising per-capita GDP, appears to mitigate avian influenza risks at both the national and sub-national levels. Poultry vaccination has been effective in many cases, but is an incomplete solution because of the practical difficulties of sustained and widespread implementation. The other popular approach to avian influenza control is culling, which can be highly expensive and raise ethical concerns about large-scale animal slaughter. Therefore, it is more economically efficient, and may even be more ethical, to target the socio-ecological drivers of avian influenza risks, including by implementing the policies discussed here.Dissertation/ThesisDoctoral Dissertation Biology 201

Water level affects availability of optimal feeding habitats for threatened migratory waterbirds

Extensive ephemeral wetlands at Poyang Lake, created by dramatic seasonal changes in water level, constitute the main wintering site for migratory Anatidae in China. Reductions in wetland area during the last 15 years have led to proposals to build a Poyang Dam to retain high winter water levels within the lake. Changing the natural hydrological system will affect waterbirds dependent on water level changes for food availability and accessibility. We tracked two goose species with different feeding behaviors (greater white‐fronted geese Anser albifrons [grazing species] and swan geese Anser cygnoides [tuber‐feeding species]) during two winters with contrasting water levels (continuous recession in 2015; sustained high water in 2016, similar to those predicted post‐Poyang Dam), investigating the effects of water level change on their habitat selection based on vegetation and elevation. In 2015, white‐fronted geese extensively exploited sequentially created mudflats, feeding on short nutritious graminoid swards, while swan geese excavated substrates along the water edge for tubers. This critical dynamic ecotone successively exposes subaquatic food and supports early‐stage graminoid growth during water level recession. During sustained high water levels in 2016, both species selected mudflats, but also to a greater degree of habitats with longer established seasonal graminoid swards because access to tubers and new graminoid growth was restricted under high‐water conditions. Longer established graminoid swards offer less energetically profitable forage for both species. Substantial reduction in suitable habitat and confinement to less profitable forage by higher water levels is likely to reduce the ability of geese to accumulate sufficient fat stores for migration, with potential carryover effects on subsequent survival and reproduction. Our results suggest that high water levels in Poyang Lake should be retained during summer, but permitted to gradually recede, exposing new areas throughout winter to provide access for waterbirds from all feeding guilds

The impacts of water level fluctuations from paddy fields and aquaculture ponds on wetland habitats for wintering waterbirds: Implications for wetland management

The distribution and composition of wetland habitats for wintering waterbirds are heavily influenced by water level fluctuations. Through polder construction and aquaculture activities, paddy fields and aquaculture ponds have decreased the lateral connectivity of water level fluctuations in the lake. However, the impacts of water level fluctuations on habitat suitability, which can be seen using high-resolution images analysis, often cannot separate disturbances caused by the paddy fields and aquaculture ponds, and it is difficult to capture the actual impact of water level fluctuations on wetland habitats. Based on remote sensing image data and hydrological data, we selected Caizi Lake as a study site and comparatively analyzed the changes in wintering waterbird habitats in a water level sequence under the two scenarios. Our work showed that paddy fields and aquaculture ponds should be considered as potential options for creating more suitable habitats for migratory waterbirds if combined with reasonable and effective management of the water level within the paddy fields and aquaculture ponds. The present study results could facilitate the management and sustainable utilization of Caizi Lake wetlands and provide support for creating small habitats by managing the water levels of paddy fields and aquaculture ponds.This research was funded by the National Natural Science Foundation of China (Grant No. U2040210), the Scientific and Technology Project of the Anhui Provincial Group Limited for Yangtze-to-Huaihe Water Diversion (Grant No. YJJH-ZT-ZX-20180404062)

Breeding and migration ecology of bar-headed goose Anser indicus and swan goose Anser cygnoides in Asia

Most waterfowl that breed in Mongolia, part of the semiarid northern region of East Asia, are long distant migrants. They depend on availability of lake, river, and wetland habitats on their breeding and wintering grounds and need suitable staging and stopover sites along their flight routes to complete their migration. Waterfowl in this region have developed important adaptations and strategies to ensure their survival and reproductive fitness across generations. I studied the ecology of two goose species endemic to this semiarid region, the bar-headed goose (Anser indicus) and swan goose (Anser cygnoides), to examine their use of highly-variable, wetland habitats. I studied the breeding biology of bar-headed geese across three summers (2009-2011) while conducting the first systematic nesting study in the semiarid Khangai Mountains region of west-central Mongolia. Bar-headed geese were found nesting on both islands and cliffs, but their daily nest survival was higher at cliff nests and ranged from 0.94 to 0.98 with average nest survival of 42.6% during the incubation period. Information-theoretic models indicated that nest survival decreased with nest age and varied annually. Waterfowl in this region may be limited by available nest sites, but disturbance and depredation also may play a critical role in their population dynamics. I also tracked the migration of both species via satellite telemetry from their breeding grounds to wintering grounds. Satellite tracking data revealed that swan geese migrated through the Yalu River Delta to a wintering area primarily restricted to Eastern China. In contrast, bar-headed geese had a much greater wintering area ranging from southern China to the southern tip of India. Recently, wintering grounds of both species have had significant land cover and land use changes related to global warming and human activities. For the first time, I was able to document unique and narrow migration corridors for both species that were related to landscape features. The migration corridor of bar-headed geese on the Qinghai-Tibetan Plateau was restricted to one biogeographic biome, while swan geese moved across biomes in a loop migration, preferred stopover sites in natural landscapes, avoided areas of eastern China with large scale developments and high human densities, and wintered in the Yangtze River Basin. Migration of bar-headed geese was associated with vegetation green-up as indicated by the Normalized Difference Vegetation Index (NDVI), and geese strategically moved between areas with peak NDVI values extending from their wintering grounds in India, migration stopover areas on the Qinghai-Tibetan Plateau, and breeding grounds in Mongolia. The arrival of bar-headed geese at staging areas during the spring migration was correlated with a decline of green vegetation biomass on their wintering grounds in India and advancement of vegetation green-up in northern latitudes. During the autumn migration, snow cover and land surface temperature corresponded well with their southward movement. These results will have important implications to improve understanding of wild bird biology in this region as well as disease ecology -- waterfowl may contribute to gene flow of avian influenza viruses among different geographical populations of wild and domestic birds through their long distance migration. Species distributions are expected to shift in response to climate change, and swan and bar-headed geese likely will alter their distribution and migratory behavior in response but constrained by both natural habitat availability and human effects limiting their habitats

HABITAT SUITABILITY SPATIAL MODEL OF NEAR THREATENED SUNDA TEAL ANAS GIBBERIFRONS (MULLER, 1842) (ANSERIFORMES: ANATIDAE) IN MUARA ANGKE WETLANDS, JAKARTA, INDONESIA

Wetland ecosystems are important habitats for many waterbird species, including the IUCN nearthreatened Sunda Teal Anas gibberifrons, a species that inhabit wetlands in Indonesia. Muara Angke is one of few remaining wetlands located in Jakarta and has potential as an important habitat for Sunda Teal. This study aims to assess and model suitable habitat for near-threatened Sunda Teal in remaining wetlands in Muara Angke in Jakarta, Indonesia. The study areas include an ecotourism park, the western and eastern parts of the Angke protected forest, and the wildlife reserve. Remote sensing data and geographic information system (GIS) analysis were employed to assess Sunda Teal’s habitat suitability. Some environmental variables negatively influencing habitat suitability for the species include the presence of fishponds and settlements, and represent anthropogenic disturbance. In contrast, variables that may positively influence the species include the occurrence of gastropod and crustacea, both groups being known as food resources, and mangrove cover. The highly and moderately suitable habitats were estimated to form 32.36% and 23.48% of the total wetlands, respectively. In contrast, 12.17% was considered unsuitable for Sunda Teal. The ecotourism park had the most unsuitable habitats. In contrast to the ecotourism park, the protected forest, followed by the wildlife reserve, had more moderately and highly suitable habitats

Numerical evaluation of flow regime changes induced by the Three Gorges Dam in the Middle Yangtze

The full operation of the Three Gorges Dam (TGD) has altered the downstream natural flow regime. Flow regime changes have resulted in profound influences on the utility of water resources and hence a large area with a riparian ecosystem including China's two largest freshwater lakes in the Middle Yangtze. Because of complicated flow regimes in this large-scale river–lake system, the TGD's impacts on flow regimes are highly heterogeneous and require to be carefully addressed. To better understand them, we estimated water level and discharge changes solely induced by the TGD from 2006 to 2011 using a hydrodynamic model that facilitates the separation of the TGD's contribution to flow regimes. Results indicated that water regulation of the TGD caused profound impacts on the flow regimes of the Middle Yangtze. In the impoundment period from mid-September to October, rapid and significant decline of the water discharge downstream the TGD produced a prolonged dry season that occurred around 10 days earlier than before. Our analysis elucidated a pattern of recent changes in the flow regimes caused by the TGD. The findings are useful for addressing the TGD-induced environmental issues, optimizing the TGD's operation, and generating adaptive management strategy for the complex river–lake ecosystem

WILD BIRDS AND EMERGING DISEASES: MODELING AVIAN INFLUENZA TRANSMISSION RISK BETWEEN DOMESTIC AND WILD BIRDS IN CHINA

Emerging infectious diseases in wildlife have become a growing concern to human health and biological systems with more than 75 percent of known emerging pathogens being transmissible from animals to humans. Highly pathogenic avian influenza (HPAI) H5N1 has caused major global concern over a potential pandemic and since its emergence in 1996 has become the longest persisting HPAI virus in history. HPAI viruses are generally restricted to domestic poultry populations, however, their origins are found in wild bird reservoirs (Anatidae waterfowl) in a low-pathogenic or non-lethal form. Understanding the spatial and temporal interface between wild and domestic populations is fundamental to taking action against the virus, yet this information is lacking. My dissertation takes two approaches to increase our understanding of wild bird and H5N1 transmission. The first includes a field component to track the migratory patterns of bar-headed geese (Anser indicus) and ruddy shelduck (Tadorna ferruginea) from the large H5N1 outbreak at Qinghai Lake, China. The satellite telemetry study revealed a new migratory connection between Qinghai Lake and outbreak regions in Mongolia, and provided ecological data that supplements phylogenetic analyses of virus movement. The second component of my dissertation research took a modeling approach to identify areas of high transmission risk between domestic poultry and wild waterfowl in China, the epicenter of H5N1. This effort required the development of spatial models for both the poultry and wild waterfowl species of China. Using multivariate regression and AIC to determine statistical relationships between poultry census data and remotely-sensed environmental predictors, I generated spatially explicit distribution models for China's three main poultry species: chickens, ducks, and geese. I then developed spatially explicit breeding and wintering season models of presence-absence, abundance, and H5N1 prevalence for each of China's 42 Anatidae waterfowl species. The poultry and waterfowl datasets were used as the main inputs for the transmission risk models. Distinct patterns in both the spatial and temporal distributions of H5N1 risk was observed in the model predictions. All models included estimates of uncertainty, and sensitivity analyses were performed for the risk models

Plant Diet Selectivity and Some Environmental Parameters at Foraging Sites of Wattled Crane (Bugeranus carunculatus) in Malagarasi Wetlands, Tanzania

Wattled Crane Bugeranus carunculatus is a threatened wetland-dependent bird species of sub-Saharan Africa with a declining population throughout its range due to habitat degradation. Ecological studies on this species have come from large populations in Botswana and Zambia. Little is known of the isolated small populations, especially those in Tanzania where about 200 individuals survive. This study reports observations made on vegetation height, water depth and consumption of plant tubers at foraging locations of the Wattled Crane in Malagarasi-Muyovozi Ramsar Site. Foraging birds preferred wet habitats with short vegetation. Birds fed mainly on Pycreus nitidus and Cyperus articulatus plant tubers but not those of Eleocharis, a chief food plant in southern Africa, which in this study was restricted to deep water levels along lakeshores. As water gradually recedes, the swamp provides good foraging environment for the Wattled Crane. Moreover, it is during the same period when human activities especially livestock grazing and burning increase in the swamp. These human activities are likely to interfere with water level balance and change wetland vegetation structure. Furthermore, if such activities are not controlled could affect productivity, availability and accessibility of the plant tubers, the predominant food of the globally threatened Wattled CraneKeywords: Eleocharis; Pycreus nitidus; tuber selectivity; wetland-dependent bird

Waterbird counts on large water bodies: comparing ground and aerial methods during different ice conditions

The aerial and ground methods of counting birds in a coastal area during different ice conditions were compared. Ice coverage of water was an important factor affecting the results of the two methods. When the water was ice-free, more birds were counted from the ground, whereas during ice conditions, higher numbers were obtained from the air. The first group of waterbirds with the smallest difference between the two methods (average 6%) contained seven species: Mute Swan Cygnus olor, Whooper Swan Cygnus cygnus, Greater Scaup Aythya marila, Tufted Duck Aythya fuligula, Common Goldeneye Bucephala clangula, Smew Mergellus albellus and Goosander Mergus merganser; these were treated as the core group. The second group with a moderate difference (average 20%) included another six species: Mallard Anas platyrhynchos, Eurasian Wigeon Mareca penelope, Common Pochard Aythya ferina, Great Crested Grebe Podiceps cristatus and Eurasian Coot Fulica atra. The third group with a large difference (average 85%) included five species, all of the Anatini tribe: Gadwall Mareca strepera, Northern Pintail Anas acuta, Northern Shoveler Spatula clypeata, Eurasian Teal Anas crecca and Garganey Spatula querquedula. During ice conditions, smaller numbers of most species were counted from the ground. The exception here was Mallard, more of which were counted from the ground, but the difference between two methods was relatively small in this species (7.5%). Under ice-free conditions, both methods can be used interchangeably for the most numerous birds occupying open water (core group) without any significant impact on the results. When water areas are frozen over, air counts are preferable as the results are more reliable. The cost analysis shows that a survey carried out by volunteer observers (reimbursement of travel expenses only) from the land is 58% cheaper, but if the observers are paid, then an aerial survey is 40% more economical