Waterbird Monitoring Research Articles

Ecological values of Ourkiss wetland (Oum El Bouaghi province - Algeria), an overview of waterbirds diversity and richness

The monitoring of waterbirds’ abundance and richness serves as the primary method for scientists to characterize the ecological values and diversity profile of wetlands. This survey was specifically conducted in Ourkiss wetland, situated in the Oum El Bouaghi province of East Algeria, spanning from January to May 2013. The study aimed to elucidate the ecological significance of Ourkiss wetland by analyzing various parameters, including the abundance, richness, diversity profile, and conservation status of its waterbird population. A total of 23 species, representing 11 families, were documented during the survey period, with Anatidae and Rallidae emerging as the most prevalent taxa. Notably, Ourkiss wetland exhibited two distinct populations: the “wintering population” and the “breeding population,” with significant waterbird activity observed during migration between the northern and southern regions. The presence of the endangered species Oxyura leucocephala further underscores the ecological importance of this wetland. Noteworthy peaks in waterbird diversity were particularly observed in April, as indicated by richness and Shannon indices. To safeguard the ecological integrity of Ourkiss wetland, it is strongly recommended to intensify conservation efforts and implement effective management plans.

Assessment of Ground and Drone Surveys of Large Waterbird Breeding Rookeries: A Comparative Study

Assessing nesting metrics in large waterbird breeding rookeries is challenging due to their size and accessibility. Drones offer a promising solution, but their comparability with ground surveys remains debated. In our study, we directly compared ground and drone data collected simultaneously over the same breeding areas. Drones excel in accessing remote terrain, enhancing coverage, mapping colony extent and reducing sampling bias. However, flying at the low altitudes required to capture young chicks in nests within densely populated rookeries poses challenges, often requiring observer presence and diminishing the distance advantage. Drones enable rapid data collection and facilitate accurate ibis chick counts, particularly at the “runner” stage when chicks are very mobile, and our surveys found significant differences in the counts between drone and ground surveys at this nesting stage. Ground surveys, on the other hand, provide valuable contextual observations, including water variables and sensory cues concerning the health of the colony. Both methods offer unique insights, with drones providing high-resolution aerial data and ground surveys complementing with human observations. Integrating both methods is ideal for comprehensive waterbird monitoring and conservation.

Effects of Habitat Change on the Wintering Waterbird Community in China’s Largest Freshwater Lake

Poyang Lake wetland in the middle and lower Yangtze River floodplain provides important wintering sites for migratory waterbirds. Extreme climatic events and human activities have resulted in the degradation and redistribution of habitat over the last few decades. However, the effects of habitat changes on the abundance of waterbirds remain unclear. We used long-term waterbird monitoring data and Landsat remote-sensing data to characterize changes in abundance and the relationship between habitat variation and abundance. A total of 113 waterbird species were recorded in the wintering period between 1999 and 2021, including 23 globally threatened species. Greater White-fronted Goose (Anser albifrons), Swan Goose (Anser cygnoides), Bean Goose (Anser fabalis), and Tundra Swan (Cygnus columbianus) were the dominant species. A total of 46 species with more than 6 annual surveys and average abundance >100 were recorded between 1999 and 2021. For most species, the mean abundance across all sub-lakes was higher in the first year than in the last year, and no obvious changes were observed over the last 20 years. The mean abundances of the vulnerable species Hooded Crane (Grus monacha) and White-naped Crane (Grus vipio) significantly declined between 1999 and 2021. No significant changes in the mean abundance of all foraging groups were observed. The area of water bodies increased, and the area of mudflats decreased. For most species with significant changes in abundance, habitat change did not greatly contribute to variation in mean abundance. The reduction in the area of mudflats greatly contributed to declines in the mean abundance of the gray heron (Ardea cinerea) and gadwall (Anas strepera).

Identifying the wetlands of international importance in Beibu Gulf along the East Asian – Australasian Flyway, based on multiple citizen science datasets

The Beibu Gulf (Gulf of Tonkin, Vinh Bac Bo in Vietnamese), located midway along the East Asian-Australasian Flyway (EAAF), is a critical stopover and wintering region for migratory waterbirds. This transboundary coastal region, spanning between China and Vietnam, harbors diverse wetland habitats that provide refuge to waterbird species, including highly threatened species such as the spoon-billed sandpiper (CR) and the black-faced spoonbill (EN). However, the scarcity of comprehensive assessments regarding waterbird abundances, distribution, key wetland habitats, and regional threats hinders our understanding of its conservation significance at the flyway level. Further research is needed to address these knowledge gaps and facilitate effective conservation efforts in the Beibu Gulf. By synthesizing accessible citizen science datasets and published records from wetland sites in south China and northeast Vietnam, we concluded that at least 97 waterbird species used the Gulf’s wetlands during their annual cycle. Among surveys conducted from 2014 to 2022, 5 and 11 waterbird species were considered as first and second class protected species under the National Key Protected Wild Animal List in China; 2 species were listed as Critically Endangered on the IUCN Red List, 4 as Endangered and 2 as Vulnerable, underlying the critical importance of the Beibu Gulf for the survival of these species. Our study identified 25 sites in the Beibu Gulf that met the criteria for designation as internationally important wetlands. Alarmingly, less than a quarter (n = 5, or 20%) of these sites benefit from national or international protection. Localized threats, including aquatic resource harvesting, hunting, and aquaculture/fisheries, were widespread in the region. This study provides a crucial scientific baseline for continued waterbird monitoring, site prioritization, and the development of effective habitat management plans to conserve vital coastal wetland habitats in the Beibu Gulf in China and Vietnam.

Faster and Better: Comparison between Traditional and Drone Monitoring in a Cryptic Species, the Purple Heron Ardea purpurea

Monitoring waterbirds is fundamental to understand the health status of wetland habitats. However, this monitoring has to be conducted by means of reliable data collection that can provide accurate information on population trends. Usually, waterbird monitoring is difficult, as nesting grounds are usually located in inaccessible reedbed, and by eye detection of cryptic species is hard. Drones have the capacity to overcome most of these problems, as they can provide with an aerial view of places otherwise unreachable, while reducing the disturbance and time spent in the field. The present study aims to compare the accuracy, disturbance levels, and managerial efficiency between ground (traditional) and drone counts of a cryptic species, the Purple Heron Ardea purpurea. Traditional monitoring methods were only capable of detecting 35% of the nesting pairs detected by the drone surveys (8.0 ± 11.8 versus 22.9 ± 38.2 nesting pairs in ground and drone surveys, respectively). Consequently, colony size estimates between methods showed poor agreement, to the point that traditional methods missed colonies otherwise detected by the drone. No apparent negative effects on nesting pairs where found when flying the drone. In addition, mean time spent to survey breeding sites with a drone was far less than with the traditional approach, down to a six-fold time reduction. This reduction, together with a lack of disturbance observed when conducting the drone monitoring, and an increasing monitoring precision and accuracy, supports the use of drones as the least invasive option for studies on population monitoring on hardly accessible sites.

Optimized Small Waterbird Detection Method Using Surveillance Videos Based on YOLOv7

Waterbird monitoring is the foundation of conservation and management strategies in almost all types of wetland ecosystems. China’s improved wetland protection infrastructure, which includes remote devices for the collection of larger quantities of acoustic and visual data on wildlife species, increased the need for data filtration and analysis techniques. Object detection based on deep learning has emerged as a basic solution for big data analysis that has been tested in several application fields. However, these deep learning techniques have not yet been tested for small waterbird detection from real-time surveillance videos, which can address the challenge of waterbird monitoring in real time. We propose an improved detection method by adding an extra prediction head, SimAM attention module, and sequential frame to YOLOv7, termed as YOLOv7-waterbird, for real-time video surveillance devices to identify attention regions and perform waterbird monitoring tasks. With the Waterbird Dataset, the mean average precision (mAP) value of YOLOv7-waterbird was 67.3%, which was approximately 5% higher than that of the baseline model. Furthermore, the improved method achieved a recall of 87.9% (precision = 85%) and 79.1% for small waterbirds (defined as pixels less than 40 × 40), suggesting a better performance for small object detection than the original method. This algorithm could be used by the administration of protected areas or other groups to monitor waterbirds with higher accuracy using existing surveillance cameras and can aid in wildlife conservation to some extent.

Remote and local threats are associated with population change in Taiwanese migratory waterbirds

Although several countries along the East Asian-Australasian Flyway have recently begun reporting population trends and identifying threats to migratory waterbirds, there remains rather sparse geographical coverage of systematic waterbird monitoring, impeding our understanding of the flyway-wide status of waterbird populations. To fill this gap, we used the data from a nationwide citizen science project, the “Taiwan New Year Bird Count'' to examine recent population trends of 31 migratory waterbird species across Taiwan, and within three of its waterbird hotspot regions, between 2014 and 2021. Island-wide, the abundance of two species declined significantly while five species increased. However, there was substantial heterogeneity in population trends among regions, with nine species declining significantly in Yi-Lan, four species in Chang-Hua and one species in Chia-Nan. Conversely, 11 species increased significantly in Chia-Nan, one species in Chang-Hua, but no species increased in Yi-Lan. This suggests that a combination of local and remote factors is driving population change in Taiwanese migratory waterbirds. Moreover, species that use local rice paddies or are dependent on tidal flats around the Yellow Sea were more likely to show population declines, and those able to use aquacultural wetlands showed growth. These results suggest that recent rice paddy loss and habitat loss in the Yellow Sea have been contributing to migratory waterbird declines in Taiwanese wetlands. Our findings suggest that local land use planning policies within Taiwan as well as mitigation of Yellow Sea tidal flat loss are likely to be complementary in safeguarding the future of migratory waterbirds in Taiwan.

Abundance and diversity of waterbirds around the Begnas Lake of Pokhara Valley, Nepal

We studied the seasonal abundance and diversity of waterbirds around the Begnas lake of Pokhara Valley. The status of waterbirds in Begnas wetland is not documented so; we monitored the waterbirds using the point count method in 12 different plots around the lake and compared the seasonal abundance and diversity during the 2019 Summer and 2020 winter with 24 hours of observation in each plot. A total of 585 individuals of 25 waterbird species from 10 families were recorded during the study period. Among the recorded species two species were globally threatened and the remaining were the least concerned categories. The greater abundance of waterbirds was recorded during winter (t = -5.98, p < 0.001). The abundance of all feeding guilds was found higher during winter. Cattle egret was recorded with the greatest abundance (N = 85) and Relative abundance (RA = 14.52), it was followed by great cormorant (N = 57, RA = 9.74) and common pochard was the least abundant (N = 2, RA = 0.34). There was no seasonal variation in the Shannon Wiener index (H’) and species evenness however, the species richness was higher during winter (W = 16.5, p < 0.01). Distance to the forest, road, and settlement did not affect the abundance and diversity of waterbirds however, the abundance of insectivore birds was increased with the decrease of distance to croplands (t = -3.13, p < 0.05). The Begnas wetland was found with a lower abundance and diversity of waterbirds in comparison to the Phewa and other wetlands of the Terai region of Nepal. The lake water pollution, infrastructural development, anthropogenic activities, recreational activities, and infestation of invasive plants like water hyacinth were the main threats to the waterbirds around Begnas lake. An awareness program about the conservation of waterbirds and regular monitoring of waterbirds in Begnas was recommended.

Unlocking the Potential of Deep Learning for Migratory Waterbirds Monitoring Using Surveillance Video

Estimates of migratory waterbirds population provide the essential scientific basis to guide the conservation of coastal wetlands, which are heavily modified and threatened by economic development. New equipment and technology have been increasingly introduced in protected areas to expand the monitoring efforts, among which video surveillance and other unmanned devices are widely used in coastal wetlands. However, the massive amount of video records brings the dual challenge of storage and analysis. Manual analysis methods are time-consuming and error-prone, representing a significant bottleneck to rapid data processing and dissemination and application of results. Recently, video processing with deep learning has emerged as a solution, but its ability to accurately identify and count waterbirds across habitat types (e.g., mudflat, saltmarsh, and open water) is untested in coastal environments. In this study, we developed a two-step automatic waterbird monitoring framework. The first step involves automatic video segmentation, selection, processing, and mosaicking video footages into panorama images covering the entire monitoring area, which are subjected to the second step of counting and density estimation using a depth density estimation network (DDE). We tested the effectiveness and performance of the framework in Tiaozini, Jiangsu Province, China, which is a restored wetland, providing key high-tide roosting ground for migratory waterbirds in the East Asian–Australasian flyway. The results showed that our approach achieved an accuracy of 85.59%, outperforming many other popular deep learning algorithms. Furthermore, the standard error of our model was very small (se = 0.0004), suggesting the high stability of the method. The framework is computing effective—it takes about one minute to process a theme covering the entire site using a high-performance desktop computer. These results demonstrate that our framework can extract ecologically meaningful data and information from video surveillance footages accurately to assist biodiversity monitoring, fulfilling the gap in the efficient use of existing monitoring equipment deployed in protected areas.

Wintering waterbirds diversity and their impact factors in coastal lake wetlands of the Yangtze River in Jiangsu Province

长江及其中下游湖泊湿地组成了独特的江-河复合型生态系统，孕育了极高的生物多样性，是全球生物多样性研究的热点区域之一.该区域是东亚-澳大利西亚迁徙通道上最重要的水鸟越冬地之一，每年冬季有超过百万只水鸟在此越冬，因此，分析相关因素对越冬水鸟多样性的影响对维持其越冬安全具有重要意义.然而，目前相关研究多集中在如鄱阳湖、洞庭湖、升金湖等部分国家级保护区内，对经济较发达的江苏省沿江区域湖泊湿地水鸟多样性的研究仍不多见.本研究选择江苏长江沿江10处代表性湖泊湿地，于2018—2020年冬开展越冬水鸟调查，同时结合环境和人为因素，分析其对区域越冬水鸟多样性的影响.3次调查共记录到越冬水鸟42种109998只，隶属于6目9科.按地理区系划分，古北界16种，广布种15种，古北界-东洋界9种，东洋界2种；按生态类群划分，有游禽22种，涉禽20种.在10处湖泊湿地中，石臼湖水鸟物种数和数量均最多，金牛湖水鸟物种数和数量均为最低；Shannon-Wiener和Inverse-Simpson多样性指数最高的为石臼湖，最低分别为长荡湖和昆承湖.β多样性结果表明石臼湖水鸟群落与其它湿地相似性最低，长荡湖次之.β多样性分解分析结果显示，区域β多样性主要形成机制为物种替换.石臼湖对区域β多样性的相对贡献显著高于其它湖泊湿地，其次是长荡湖，相对贡献最低的是尚湖.线性模型结果表明：越冬水鸟丰富度与湿地总面积呈正相关，与缓冲区植被和水体面积呈负相关.人均GDP与越冬水鸟丰富度呈显著负相关.越冬水鸟物种数与湖泊湿地面积呈正相关，与人均GDP呈负相关.水鸟多样性指数受面积和人均GDP影响均不显著.江苏沿江地区是我国经济最发达的区域之一，对其越冬水鸟多样性及其影响因素开展研究进而提出相关保护建议，如持续开展越冬水鸟监测，及时发现保护空缺，提高对湿地周边区域土地利用状况的关注度等.本研究结果不仅为本地区越冬水鸟保护工作提供依据，同时也为上游经济相对薄弱但发展较快的地区开展相关保护工作提供参照.;The Yangtze River and its floodplain are unique for the extensive wetlands, recharged by summer monsoonal precipitation, laden with nutrients and sediment. It's the largest amount of shallow and seasonal flooded wetlands in the world, providing ecosystem services to tens of millions of people. The wetlands also support globally significant numbers of wintering waterbirds. Every year, more than 1 million waterbirds spend winter here. It is critical to understand the effects of different variables on wintering waterbirds diversity. So far, most of the research were focused on some National Nature Reserves, e.g. Lake Poyang, Lake Dongting and Lake Shengjin. The researches concerning wintering waterbirds diversity on lake wetlands located in the Lower Yangtze River floodplain in Jiangsu Province are still limited, where the economic is relatively developed. In this study, we systematically surveyed 10 representative wetlands along the Yangtze River in Jiangsu Province from 2018 to 2020 and then analyzed the effect of ecological and anthropogenic factors on waterbird abundance, species richness and diversities. In total, 109998 waterbird of 42 species were recorded, belonging to 6 orders and 9 families. Of them, 22 species are Natatores and the others are all Waders. In terms of the biogeographic distribution, 16 species belong to Paleartics, 15 species are wide distributive species, 9 species belong to Paleartics-Oriental, and 2 species belong to Oriental. Among the 10 lake wetlands, Lake Shijiu has the highest Shannon-Wiener and Inverse-Simpson diversity index, and the lowest are Lake Changdang and Lake Kuncheng respectively. In addition, the community composition dissimilarity (β diversity) between Lake Shijiu and the other lakes are the highest, following by Lake Changdang. Results of the decomposition of β diversity suggested that species replacement was the main process influencing regional β diversity. Lake Shijiu had a significant higher relative contribution to regional β diversity, followed by Lake Changdang, while Lake Shanghu had the lowest relative contribution. Wintering waterbird abundance positively correlated with total area of wetlands but negatively affected by vegetation area and water area in the buffer area, as well as the effect of per capita GDP. Number of wintering bird species positively correlated with total area of lake wetlands but negatively affected by per capita GDP. Area had no effects on both Shannon-Wiener and Inverse-Simpson indices. As one of the most developed areas in China, unveiling the effects of different variables on wintering waterbirds diversity may not only offer practical conservation measures for this area, for example, carrying out continuous waterbird monitoring projects, detecting conservation gaps and playing close attention on landscape changes of surrounding area, but also provide a good sample for the conservation work in up-stream areas of the Yangtze River where the economic is ongoing developing.

The Okavango Delta’s waterbirds – Trends and threatening processes

The Okavango Delta is renowned as an extraordinary ecosystem of high biodiversity, listed as both a Ramsar and World Heritage Site, with part protected in the Moremi Game Reserve. This extensive floodplain ecosystem has 444 recorded bird species, with just under a quarter of these waterbirds, including at least 16 breeding and 4 threatened (1 endangered, 3 vulnerable) species. Despite the global importance of this ecosystem, and its transboundary nature, there are surprisingly few long-term assessments of status of the ecosystem or waterbird communities, a key indicator of ecosystem health, with threats such as upstream water extraction, and climate change threatening its outstanding biodiversity. We compiled a comprehensive 53-year dataset comprised of citizen science and other datasets (1970–2019), on 36 waterbird species (Anhingidae, Ardeidae, Ciconiidae, Gruidae, Pelecanidae, Phalacrocoracidae, and Phoenicopteridae), including eight waterbird breeding colonies in the Okavango Delta. We investigated trends in waterbird biodiversity as well as responses to temperature, flow, flooding, and local rainfall. Waterbird breeding colonies were associated with relatively high areas of riparian woodland, and experienced moderate flooding frequencies (> 1 in 5 years). Total abundance of all 36 waterbird species was positively related to river flows. Despite increased citizen science effort over time, total abundance within the Okavango Delta significantly declined with declining average inundation. Four species led these declines (African darter Anhinga rufa, green-backed heron Butorides striata, slaty egret Egretta vinaceigula, squacco heron Ardeola ralloides) and one marabou stork Leptoptilos crumenifer, increasing (only sufficient data to analyse 15 species individually). Decreased inundation within the Delta and other internal factors (urbanisation, tourism, vegetation change) as well as external factors (habitat loss elsewhere) are likely driving these declines. Rigorous monitoring of waterbirds, including the eight breeding colonies across the Delta, is needed to explore these changes closely, providing baselines in the case of water resource developments on the rivers supplying the Okavango Delta. Long-term conservation of the magnificent Okavango Delta and its dependent biodiversity, including its waterbirds, is highly reliant on protection of river flows in three countries to ensure natural flooding regimes, alongside the conservation of neighbouring wetlands.

Waterbird Composition and Changes With Wetland Park Construction at Lake Dianchi, Yunnan–Guizhou Plateau

Establishing effectively protected and managed ecosystems with high biodiversity is the broad aim of the Aichi initiative. Assessing the biodiversity of a specific ecosystem is the first step in estimating its conservation value. Most lakes on the Yunnan–Guizhou Plateau are formed by mountain faulting and are surrounded by human settlements. Lake ecosystems are fragile and frequently disturbed by pollution, agricultural activities, and tourism. The current lakeside wetland parks are intended to abate pollution and promote tourism. However, the composition of the monthly and yearly waterbird population and the impacts of the parks on waterbirds are unclear. Using direct observation and spot map census methods, we conducted 104 field surveys across 4 consecutive years at Lake Dianchi to fill the gaps in current knowledge. The results showed that Dianchi could provide habitats for more than 60,000 individual birds of 105 species, including residents, summer visitors, migrants, and winter visitors. The current oxidation ponds in wetland parks, created for water purification and tourism, were not suitable for most shorebirds. Consequently, we suggest that plans for the construction of artificial wetlands or wetland parks in this region should consider the habitat requirements of different waterbirds in different seasons. Particular attention should be given to protecting the marshlands and mudflats that wading birds require. We also suggest that increased waterbird monitoring in different seasons across different years is needed around Lake Dianchi and other wetlands on the Yunnan–Guizhou Plateau for effective conservation.

Assessment of the Suitability of Wintering Anatidae Habitats before and after Impoundment in the Three Gorges Reservoir Region

In this study, we aimed to understand the distribution of and changes in the habitats suitable for Anatidae wintering in the Three Gorges Reservoir Region (TGRR), China, and to explore the impact of the impoundment during different impoundment periods. Based on species occurrence data for four dominant species of Anatidae and environmental factors, a maximum entropy (MaxEnt) model was used to analyze the suitability of habitats during five impoundment periods. The results show that the main factors affecting Anatidae distribution were temperature and roads before the Three Gorges Project (TGP) and elevation after the TGP. After the TGP, the area of the suitable habitat declined rapidly and then gradually increased with increasing water level. After impoundment, the primary area of increased habitat suitability was the main stream of the Yangtze River from Changshou District to Yunyang County and its tributary in the Kaizhou area. Among the habitats, the central water regions were more suitable than the marginal shoal areas. Anatidae habitats in the TGRR were distributed mainly within the Yangtze River main stream and the surrounding areas before the TGP, and the surrounding areas largely disappeared after the TGP, particularly in Chongqing City and Jiangjin District. In this context, it is challenging to create new protected areas within the habitat suitable for Anatidae in the main stream of the Yangtze River; we propose adding the Anatidae as conservation targets within the existing conservation agencies and implementing a waterbird monitoring program for scientific waterbird conservation and the sustainable development of the reservoir.

Improving waterbird monitoring and conservation in the Sahel using remote sensing: a case study with the International Waterbird Census in Sudan

In several regions of the world, the remoteness of potential bird hotspots and lack of trained observers have often prevented countries from effectively designing proper monitoring schemes at a national scale. For many countries, it is not known whether certain bird strongholds have been missed that should be included for more complete censuses. Such gaps at national scales, sometimes large, may be detrimental for global monitoring schemes. To address this, we used the irregular participation of Sudan to the International Waterbird Census (IWC) as a case study. We designed and tested a method based on remote‐sensing data of the country’s lowlands to detect open water bodies in order to develop predictive models of the potential distribution of waterbird abundance and diversity. To identify open water bodies and their flooding duration, we used a Modified Normalized Difference Water Index (MNDWI) derived from Landsat 8 data. Field ornithological surveys were then used as ground‐truth data to estimate the method’s accuracy. The statistical results (overall accuracy = 0.972; Kappa index = 0.93) confirmed its effectiveness. Remotely sensed water bodies and additional environmental covariates were then used to build simple habitat models of the distribution of waterbird abundance and diversity based on IWC field survey data. Of the 3119 remotely sensed clusters of open water bodies, three were predicted to host more than 10 000 waterbirds, 89 more than 1000 waterbirds and five more than 30 waterbird species. Located mainly in the southern agricultural floodplains along the main rivers, these predicted waterbird strongholds are therefore recommended for inclusion in the next IWC survey in Sudan. Our findings indicate that using remote sensing to identify open water bodies combined with simple statistical modelling is likely to be a cost‐effective solution to improve IWC sampling and to enhance both waterbird and wetland monitoring in vast under‐surveyed regions.

Citizen science networks for waterbird monitoring: Case study of the Asian Waterbird Census in Indonesia

Citizen science is a public participation research involving citizen participation, whose outcomes are often advancements in scientific research and increase the public’s understanding. This study is aimed to identify the characteristics of volunteers who joined the Asian Waterbird Census (AWC), a part of the long-term global annual monitoring initiative by Wetlands International. Data were gathered through analysis of documentations (year 2015-2019), observation, and deep interview. The number of participants has increased, with the highest was 379 persons in 2019 (an average of 233 persons/year), with half comprised of university graduates (Bachelor or above). There were 5 types of groups involved in AWC: student/universities (34%), NGOs (27%), individuals (19%), government employees (16%), and private sectors (3%). Females’ participation was quite high (43%). About 18% of participants and 44% of the groups, have been joining AWC at least twice, indicating that AWC was an interesting activity. Reasons to join were identified as: increasing personal values, personal scientific development, strengthening social relationships/networks, recreational, and develop a career. Information on AWC schedules was obtained mostly through social media Whatsapp (35%) and Facebook (32%), the organizer (i.e. Wetlands International Indonesia; 37%) and participants’ networks (37%). About 73% of the participants were able to observe less than 100 bird species. Participants’ constraints during the AWC were ability of bird identification, limitation of proper equipment, and low accessibility to potential observation sites. Our study indicated that understanding the characteristics of participants might help to improve the citizen science program, as well as to recruit and retain volunteers.

Survey frequency affects the estimates and conclusions of long-term changes in waterbird populations: a case study from a South African wetland

Accurately detecting the magnitude and direction of population trends provides essential information for conservation management. There are numerous local and international long-term waterbird monitoring programmes with substantial variation in how frequently surveys are conducted. We aimed to assess how temporal frequency of waterbird surveys influence three aspects of population trends: (1) level of uncertainty around estimates of long-term trends; (2) frequency, duration and overlap of significant short-term increases or declines in trend trajectory; and (3) differences between estimated change in population size measured over four different time periods. Data from 28 years of surveys at a waste water treatment facility in South Africa were used to model the population trend of 41 waterbird species. We used generalised additive mixed-models to compare significance and magnitude of population change trends between monthly and biannual surveys. Direction and shape of species trends were similar between protocols although uncertainty around trends was generally lower when monthly data were used. The number of significant trend trajectories, the majority of which were declines, was higher in monthly models. Temporal overlap of periods of significant change of trends of the two protocols averaged 30%. However, both sampling protocols offered similar conclusions about long-term change in population size of species. General patterns differed conspicuously among species, although groups of species showed similar trajectories of population change. We conclude that biannual surveys are appropriate if the goal is to assess general patterns of population change. However, if management action relies on understanding the significance of population trajectories, surveys at a finer temporal scale are required, especially for species showing a pattern of unpredictable movement. Trade-offs between logistical constraints and statistical rigour as well as species identity need to be carefully considered for the design of long-term monitoring programmes of waterbirds.

Seasonal Monitoring of Waterbirds of Chhari Dhandh wetland in Kachchh District, Gujarat, India

Seasonal Monitoring of Waterbirds of Chhari Dhandh wetland in Kachchh District, Gujarat, India

A Video Surveillance System to Monitor Breeding Colonies of Common Terns (<em>Sterna Hirundo</em>)

Many waterbird populations have faced declines over the last century, including the common tern (Sterna hirundo), a waterbird species with a widespread breeding distribution, that has been recently listed as endangered in some habitats of its range. Waterbird monitoring programs exist to track populations through time; however, some of the more intensive approaches require entering colonies and can be disruptive to nesting populations. This paper describes a protocol that utilizes a minimally invasive surveillance system to continuously monitor common tern nesting behavior in typical ground-nesting colonies. The video monitoring system utilizes wireless cameras focused on individual nests as well as over the colony as a whole, and allows for observation without entering the colony. The video system is powered with several 12 V car batteries that are continuously recharged using solar panels. Footage is recorded using a digital video recorder (DVR) connected to a hard drive, which can be replaced when full. The DVR may be placed outside of the colony to reduce disturbance. In this study, 3,624 h of footage recorded over 63 days in weather conditions ranging from 12.8 °C to 35.0 °C produced 3,006 h (83%) of usable behavioral data. The types of data retrieved from the recorded video can vary; we used it to detect external disturbances and measure nesting behavior during incubation. Although the protocol detailed here was designed for ground-nesting waterbirds, the principal system could easily be modified to accommodate alternative scenarios, such as colonial arboreal nesting species, making it widely applicable to a variety of research needs.

<b>Spatial and temporal patterns of stork sightings (Aves: Ciconiidae) in National Chambal Sanctuary of Gangetic River system</b>

During 1984–86 and 1995–2016 winter surveys five stork species were observed in 12 study zones of the river Chambal in the Ganga tributary system. Comparative temporal and spatial analyses of stork distribution are presented from two broad stretches of the river, 205km of Pali-Rajghat in the upstream and 230km of Rajghat-Pachhnada in the downstream. Different species show different distribution patterns. Study zones IV+V comprising 113km in the upstream and XI+XII comprising 75km in the downstream accounted for 66% of total stork sightings. About 56% of total sightings were recorded downstream of Rajghat. The Painted Storks Mycteria leucocephala comprised 52% of total stork sightings. Eleven districts adjoining river Chambal recorded low rainfall prior to 2008 when sighting of storks abruptly increased, particularly in the downstream. It is important to continue the monitoring of water birds in the National Chambal Sanctuary as it could lead to initiating conservation interventions in habitats in the region which experience extreme ecological conditions and fluctuations in populations.

Distribution and Long-Term Population Trends of Wintering Waterbirds in Poyang Lake, China

Although total wintering waterbirds have increased in Poyang Lake, some groups or species might have declined. Identifying declining groups and species will help to optimize conservation strategies. In addition, knowledge of waterbird distribution is required to identify priority areas for protection. In this study, we aimed to explore long-term population trends of waterbird groups and species and to investigate waterbird distribution in Poyang Lake by integrating survey data from 1996/1997 to 2014/2015. Poyang Lake Nature Reserve, Duchang and Nanji Wetland Nature Reserve had high waterbird richness and abundance and high proportion of IUCN endangered species, thus they are important areas for waterbird protection. An important limitation to waterbird protection in the three areas is lack of management rights of most sub-lakes. Most waterbird groups in Poyang Lake have grown, but ducks have declined. Hunting and the decline of aquatic vegetation might be driving the duck declines. In addition, White-naped Crane (Grus vipio), Spot-billed Duck (Anas poecilorhyncha) and Northern Lapwing (Vanellus vanellus) have declined. While we believe the data presented here indicate general trends in groups and species, the analyses suffered from variation in methods used in different surveys. We advocate long-term waterbird monitoring using standardized methods to better understand waterbirds’ population dynamics.