Waterbird Populations Research Articles

Scale-dependent population drivers inform avian management in a declining saline lake ecosystem.

Shrinking saline lakes provide irreplaceable habitat for waterbird species globally. Disentangling the effects of wetland habitat loss from other drivers of waterbird population dynamics is critical for protecting these species in the face of unprecedented changes to saline lake ecosystems, ideally through decision-making frameworks that identify effective management options and their potential outcomes. Here, we develop a framework to assess the effects of hypothesized population drivers and identify potential future outcomes of plausible management scenarios on a saline lake-reliant waterbird species. We use 36 years of monitoring data to quantify the effects of environmental conditions on the population size of a regionally important breeding colony of American white pelicans (Pelecanus erythrorhynchos) at Great Salt Lake, Utah, US, then forecast colony abundance under various management scenarios. We found that low lake levels, which allow terrestrial predators access to the colony, are probable drivers of recent colony declines. Without local management efforts, we predicted colony abundance could likely decline approximately 37.3% by 2040, although recent colony observations suggest population declines may be more extreme than predicted. Results from our population projection scenarios suggested that proactive approaches to preventing predator colony access and reversing saline lake declines are crucial for the persistence of the Great Salt Lake pelican colony. Increasing wetland habitat and preventing predator access to the colony together provided the most effective protection, increasing abundance 145.4% above projections where no management actions are taken, according to our population projection scenarios. Given the importance of water levels to the persistence of island-nesting colonial species, proactive approaches to reversing saline lake declines could likely benefit pelicans as well as other avian species reliant on these unique ecosystems.

Predicting avian diversity based on land use and cover on a national scale

This study explores the relationship between landscape features and avian diversity in South Korea, examining both taxonomic and functional diversity. The Korean Peninsula serves as a pivotal habitat for resident bird species and a migratory pathway in the East Asia-Pacific flyway. Using a national dataset with block sizes ranging from 3.5 to 4.5 kilometers per side, we found that less urbanized open plains exhibit higher taxonomic diversity, while coastal regions with diverse water bird populations show higher functional diversity. These findings underscore the significance of conserving the existing land types and qualities in specific regions to substantially impact bird distribution and regional biodiversity. Remarkably, closed forests display diversity patterns akin to urban/built-up areas, despite their disparate land use characteristics. The stability of bird diversity indices across different land use types enables us to predict bird diversity indices based on the particular land use and land cover configurations. This study emphasizes the complementary nature of functional biodiversity indices in comprehending bird distribution patterns alongside taxonomic diversity indices.

Human-Made 1,000 Hectare Archipelago “Marker Wadden” Has Positive Impact on Regional and Flyway Populations of Waterbirds of Dynamic Freshwater Ecosystems

Human-Made 1,000 Hectare Archipelago “Marker Wadden” Has Positive Impact on Regional and Flyway Populations of Waterbirds of Dynamic Freshwater Ecosystems

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.

Deteriorating habitat suitability and connectivity of waterbirds in the Bohai Sea Rim: Consequences of land use transformation

Wetlands in the Bohai Sea Rim play an indispensable role in maintaining the stability of waterbird populations on the East Asian-Australian flyway. However, motivated by economic development and urban expansion, coastal wetlands in this region have been extensively reclaimed, leading to a decline in the area and degradation of natural wetlands over the past two decades. We analyzed the temporal and spatial changes of suitable habitats of different groups of waterbirds and quantified habitat connectivity changes and the importance of different patches by using the Probability of Connectivity. The results show that the suitable habitat area of all the different groups of waterbirds decreased sharply from 2000 to 2020. In addition, the utilization ratio by waterbirds of artificial habitats increased. Land use is the primary environmental variable determining the distribution of suitable habitats. Meanwhile, the connectivity of habitats of different groups of waterbirds has also been declining. However, the patches of Tianjin and Hebei in Bohai Bay still have high importance for waterbirds, particularly shorebirds. Expanding existing protection areas to cover the above-mentioned patches is recommended. We also advocate stricter protection measures and necessary ecological restoration activities on both the natural and artificial wetlands.

Diet of the raccoon dog, an invasive mesopredator, during the breeding season of declining waterbird populations

Invasive predators are one of the leading causes of global biodiversity loss, threatening local ecosystems through predation and spreading diseases. In Europe, the most common and widespread invasive mesopredator is the raccoon dog (Nyctereutes procyonoides). Raccoon dog is an opportunistic omnivore listed as a species of European Union concern, as they are suspected of harming ground-nesting waterbird populations. However, the actual extent of risks caused by raccoon dog predation has been disputed, partly due to methodological constraints in detecting all prey in the diet. Here, we studied the animal components of raccoon dog diet using DNA metabarcoding, a powerful tool to detect even the smallest traces of ingested food items. We sequenced genes 12S rRNA and COI from raccoon dog scat samples collected during the breeding season of birds close to water bodies in southern Finland. We also examined whether the occurrence of different dietary items would depend on the habitat around the latrine. We found that frogs were the most common vertebrate food item in raccoon dog diet during spring. The proportion of detected bird material was not higher compared to earlier studies, despite the potential to detect DNA originating from eggs. The proportion of fish in the diet increased with increasing water area around the latrine, but no other relationships between diet and habitat were found. We conclude that even though raccoon dogs predate on waterbirds’ and other ground nesting birds’ nests, they do not seem to be specialized on it in our study areas. However, declining waterbird populations and, in particular, local amphibian populations could be negatively impacted by raccoon dog predation.

Anthropogenic bottom-up and top-down impacts on boreal breeding waterbirds.

Wetland habitats are changing under multiple anthropogenic pressures. Nutrient leakage and pollution modify physico-chemical state of wetlands and affect the ecosystem through bottom-up processes, while alien predators affect the ecosystems in a top-down manner. Boreal wetlands are important breeding areas for several waterbird species, the abundances of which potentially reflect both bottom-up and top-down ecosystem processes. Here, we use long-term national monitoring data gathered from c. 130 waterbird breeding sites in Finland from the 1980s to the 2020s. We hypothesised that the physico-chemical state of the waters and increasing alien predator abundance both play a role in steering the waterbird population trends. We set out to test this hypothesis by relating population changes of 17 waterbird species to changes in water chemistry and to regional alien predator indices while allowing species-specific effects to vary with foraging niche (dabblers, invertivore divers, piscivorous divers, herbivores), nesting site, female mass and habitat (oligotrophic, eutrophic). We found niche and nesting site-specific, habitat-dependent changes in waterbird numbers. While the associations with higher phosphorus levels and browning water were in overall positive at the oligotrophic lakes, the numbers of invertivore and piscivore diving ducks were most strongly negatively associated with higher phosphorus levels and browning water at the eutrophic lakes. Furthermore, increased pH levels benefitted piscivores. Invertivore diving duck species nesting on the wetlands had declined most on sites with high alien predator indices. Large herbivorous species and species preferring oligotrophic lakes seem to be successful. We conclude that the large-scale breeding waterbird decline in Finland is closely connected to both bottom-up and top-down processes, where negative associations are emphasised especially at eutrophic lakes. Niche-, nest site- and habitat-specific management actions are required to conserve declining waterbird populations. Managing wetlands on catchments level together with alien predator control may provide important approaches to future wetland management.

Suspended sediment dynamics and the related environmental risk assessment in a sensitive water area

Suspended sediment (SS) is a natural component of aquatic environments. It is characterized by the adsorption of pollutants, and its physical properties can affect water volume quality. In this study, SS dynamics were simulated using a 2D hydrodynamic model in the Nanji Mountain Nature Reserve (NNR), and the fluxes of pollutants caused by SS were calculated to assess the biological risks during the wet (May–August) and dry (November–March) seasons. High spatial and temporal variability in SS load within the NNR was found in this study. The average SS load in the reserve increased and then decreased during the year, and the SS input from Ganjiang significantly affected the SS load in the NNR (p < 0.01). The SS load uptrend in the NNR occurred later than that of Ganjiang during the wet season because of the SS sedimentation in the NNR. And the suspension of SS in the NNR during the dry season resulted in a later SS load downtrend compared to Ganjiang. High SS load from Ganjiang during the wet season was responsible for the high nutrient and microplastic fluxes in the NNR, which were 8.38 and 10.61 times higher than those in the dry season, respectively. And the pollutant fluxes during the wet season were almost all from Ganjiang. In contrast, higher waterbird diversity and population during the dry season is the main reason for the increased biological risk of contaminants. Therefore, monitoring and managing SS and its contamination concentrations in rivers entering the lake is helpful for the protection of ecologically sensitive areas and key species in the lake.

Interactions Between Heavy Metal Exposure and Blood Biochemistry in an Urban Population of the Black Swan (Cygnus atratus) in Australia

There is growing recognition of the threat posed to wildlife by pollutants. Waterbirds are robust bioindicators of ecosystem health, and metal toxicity is a threat to these species in waterways worldwide. Urban waterbirds are likely to be at the highest risk of heavy metal exposure, but this issue has not been widely explored in Australia. Our aim was to estimate contemporary heavy metal exposure in a sedentary urban waterbird population: black swans (Cygnus atratus) inhabiting an inner-city wetland in one of Australia’s largest cities, Melbourne. To investigate the physiological implications of legacy heavy metal exposure in these birds, we quantified blood biochemistry profiles and examined their relationships with metal concentrations in feathers. We caught 15 swans in 2021 and took feather samples to measure the concentration of eight heavy metals (chromium (Cr), manganese (Mn), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), lead (Pb), and mercury (Hg)), and blood samples to measure the concentration of 13 plasma analytes. Multivariate regression analysis revealed few associations between heavy metals and biochemistry markers, and no differences between sexes or age classes. This study presents a baseline dataset of these contaminants and blood biochemical profiles of swans at this wetland that can be used for future monitoring and is an important step toward a better understanding of the threat posed by heavy metals to Australian urban waterbirds.

The drying of Lake Urmia and its consequences for waterbird assemblages

Summary The hypersaline Lake Urmia, located in Iran, has undergone a significant reduction in size and is currently facing the risk of desiccation. The decrease in water levels, coupled with elevated salinity levels, has initiated ecological degradation, leading to a substantial decline in the region’s waterbird population. This study employs breakpoint analysis to determine the year when the drought event affecting the lake commenced. Additionally, canonical correspondence analysis (CCA) is utilised to elucidate the interaction between environmental parameters and the waterbird assemblages in Lake Urmia over the period 1970–2018. Our investigation identifies the year 2000 as the initiation of the water crisis in Lake Urmia, synchronously coinciding with the decline in the waterbird populations. This finding highlights a significant connection between the majority of waterbird species and the axes of CCA, intricately linked with water availability within Lake Urmia. This revelation underscores the pivotal role of fluctuations in water levels in shaping the dynamics of the lake’s waterbird assemblages. Furthermore, our observations emphasise the importance of even minor improvements in hydrological conditions of the lake, resulting in substantial positive impacts on waterbird populations.

Spatiotemporal variations in migratory bird diversity and abundance along the coast of Gochang getbol.

Tidal flats provide critical habitat for migratory waterbird species; however, populations of migratory waterbirds have significantly declined due to tidal flat loss and degradation caused by human activities, particularly in Asia. Gochang getbol is one of tidal flats located on the southwest coast of South Korea and a center of clam production. Using bird monitoring data collected at five zones (zone1 to zone5) established across Gochang getbol and near coastal area, we examined distribution patterns of migratory bird diversity and conservation-related species along the coast of Gochang getbol. The intensity of human activity ‒ mudflat culture (mostly bivalve) and aquaculture was relatively high at zone2 and zone3, occupying > 30% of 2km circular area surrounding most sample points of these zones. Zone1 and particularly zone4 contained more natural/semi-natural habitats (less disturbed mudflats and wetlands) and zone5 had smallest mudflat than others. Shannon diversity, species richness, and abundance of migratory birds differed between zones (Anova test, P ≤ 0.02) except Shannon diversity in winter. In fall, all values were higher at zone4 than zone3 and zone5. In winter, zone1 showed greatest species richness and higher abundance than zone2, zone3, and zone5. In spring, while most differences were found between zone4 and zone5, abundance at zone4 was somewhat higher than zone2. The results from the fourth corner analysis indicated that abundance of species foraging at mudflat level was positively associated with zone1 (winter) but negatively with zone3 (fall). Sandpipers were positively associated with zone4. Abundance distribution maps of conservation-related species, created by inverse distance-weighted interpolation modeling, also showed high abundance of most conservation-related species at zone4 and 1. The findings of our study suggest the importance of natural/semi-natural habitat, and the possible link between human activity and distribution patterns of migratory birds in Gochang getbol. While we need further investigation on direct response of migratory birds to human activity, areas with low human activity with more natural/semi-natural habitat, e.g., zone4 and zone1 may be crucial for the conservation of migratory birds.

Shallow sub-lakes are essential for sustaining the successful wintering of waterbirds in Poyang Lake, China

For migratory waterbirds, the quality of wintering habitat is related to spring migration and successful breeding in the next year. The availability of food resources in the habitat is critical and varies within water levels. Although the water-level fluctuations in Poyang Lake have been extremely variable interannually in recent years, the wintering waterbird populations have remained relatively stable. Hence, the mechanism of maintaining the stability is worth exploring. This study aimed to compare the distribution of vegetation and herbivorous waterbirds in 2015–2016 and 2016–2017, focusing on three shallow sub-lakes and one main lake are. The results showed that the emergence of tubers and the growth of Carex spp. provided a continuous food supply and habitat for wintering waterbirds with a gradual decline in the water level. Shallow sub-lakes supported almost all of the tuber-eating waterbirds (1.42–1.62 × 105) and most geese (1.34–1.53 × 106). However, the main lake area, covered with Persicaria hydropiper, did not provide adequate and accessible food. This resulted in almost no distribution of tuber-eating waterbirds, with only a few geese congregating in early winter. Our results demonstrated that the shallow sub-lakes under human control provided a different environment from the main lake and are key to sustaining the successful wintering of hundreds of thousands of migratory waterbirds in Poyang Lake. Therefore, we recommend refining the anthropogenic management of the shallow sub-lakes to regulate the water level to ensure the carrying capacity of Poyang Lake.

Predation of the endangered Ae'o (Hawaiian Stilt) by a native raptor, the Pueo (Hawaiian Short-eared Owl) on the island of O'ahu, Hawai'i, USA.

While the impact of introduced predators is a widely acknowledged issue and key component of conservation considerations for endemic waterbird populations in the Hawaiian Islands, the impact of native predators on endemic, endangered waterbirds is not as frequently discussed or factored into recovery models. The Pueo (Hawaiian Short-eared Owl; Asio flammeus sandwichensis) is a subspecies of Short-eared Owl endemic to the Hawaiian Islands and is State-listed as Endangered on the island of O'ahu. The Ae'o (Hawaiian Stilt; Himantopus mexicanus knudensi) is a subspecies of the Black-necked Stilt endemic to Hawai'i and is federally listed as Endangered throughout its range. A variety of non-native predators are confirmed to consume Ae'o eggs, chicks, and adults, including invasive mammals (e.g., feral cats), birds (e.g., Barn Owls), and amphibians (e.g., bullfrogs). While predation by native predators was suspected, there are no cases documented in the literature to date describing Pueo preying upon Ae'o. Here, we describe four events that provide evidence of Pueo predating Ae'o during the 2019-2021 breeding seasons in a wetland area on the island of O'ahu: (1) confirmed Pueo predating an Ae'o chick, (2) a suspected predation attempt of a Pueo chasing adult Ae'o, and (3) two suspected predation events based on (a) 10 adult-sized Ae'o carcasses and remains found near an active Pueo nest and (b) game camera photos of Pueo visiting two Ae'o nests. To our knowledge, these novel observations are the first published accounts of predator-prey interactions between these two subspecies.

Vegetation and inundation characteristics of waterbird breeding sites in the Murray–Darling Basin, Australia

Context The Murray–Darling Basin serves as a crucial habitat for aggregating waterbirds; however, decades of large-scale regulation of rivers and water resources have adversely affected waterbird breeding in the Basin. Aims To understand the characteristics of wetlands that attract and support aggregating waterbirds, focusing on identifying environmental conditions conducive to waterbird breeding. Methods In total, 52 wetland sites across the Murray–Darling Basin, with high waterbird abundances, were identified, of which 26 supported waterbird breeding. Classification models were developed using temporally static and dynamic environmental datasets to discern wetland characteristics associated with waterbird breeding. Key results Analyses showed that wetlands supporting waterbird breeding contained a maximum inundated area of ‘other shrublands’ exceeding 3.635 km2 and variation in normalised difference vegetation index, possibly reflective of a ‘boom and bust’ ecological response. Conclusions Understanding the habitat requirements of wetlands to prompt waterbird breeding is critical for effective environmental water management and conservation strategies. Implications Targeted wetland management and environmental water allocation to support waterbird breeding populations in the Murray–Darling Basin is essential for continued waterbird breeding. There is a need for continued research to refine management strategies and ensure the long-term sustainability of waterbird populations in the face of ongoing environmental challenges.

Exploring NAO influence on waterbirds abundance through hydrological changes in a Mediterranean coastal wetland

Predicting how waterbird populations may respond to climate change is a major challenge for conservation, which could be addressed by understanding the effects of large-scale climate oscillations, such as the North Atlantic Oscillation (NAO), on breeding population size. Here, we explore the relationship between the NAO position and the abundance of waterbird breeding pairs in a protected Mediterranean coastal wetland (Mouth of the Guadalhorce River, Málaga, southern Iberian Peninsula). We found a significant and negative relationship between the winter NAO index and the abundance of grebes (r=-0.72, N=15, p&lt;0.01), rails (r=-0.74, N=15, p&lt;0.01), diving ducks (r=-0.56, N=15, p&lt;0.05) and dabbling ducks (r=-0.54, N=15, p&lt;0.05). Our results suggest that this relation is mediated by the NAO indirect effects on wetland flooded surface via changes in winter precipitation and Mediterranean sea level. These results should be considered to design appropriate environmental management strategies devoted to preventing or mitigating potential deleterious effects of the NAO variability on Mediterranean wetlands ecosystems and preserving their valuable waterbird communities.

Conservation and restoration efforts have promoted increases in shorebird populations and the area and quality of their habitat in the Yellow River Delta, China

ABSTRACTConservation policies have been formulated for coastal wetlands in China, and exploration of conservation effectiveness based on waterbirds and their habitat is important for guiding conservation actions. We characterized the effects of conservation efforts on shorebird diversity, habitat area and quality using long-term remote sensing data, and shorebird survey data in the Yellow River Delta. From 1997 to 2021, habitat area, quality and population number significantly declined by 49.8% (r = −0.72, p < 0.05), 13.6% (r = −0.72, p < 0.05) and 60.67% (R2 = 0.77, p < 0.05). Before 2012, habitat area (decreased by 38.2%, r = −0.62, p > 0.05, slope = −0.25), quality (decreased by 10.53%, r = −0.68, p > 0.05, slope = −0.008), and population size (significantly decreased by 94.5%, r = −0.95, p < 0.05, slope = −7874.3) declined, and the decline in habitat area significantly contributed to population reductions (r = 0.79, p < 0.05). Since 2012, habitat area (increased by 14.3%, r = 0.71, p > 0.05, slope = 0.12), quality (increased by 17.12%, r = 0.83, p > 0.05, slope = 0.01), and population size (increased by 8.34%, R2 = 0.29, p > 0.05) slightly increased. The coefficients of variation for habitat area and quality, and population size were smaller after 2012 than before 2012. These results suggest that conservation actions maintained the stability of waterbird populations and their habitat; additional actions are needed to mediate the conservation of other degraded habitats along coastal wetlands.

Rise and fall of an avian oasis: Tracking the impacts of land use change in a key coastal wetland in the world's largest megalopolis

Tropical estuaries support wetlands with high biodiversity value and provide essential ecosystem services. Many of these systems, however, are global hotspots for urbanization, particularly in Asia, where this process has resulted in rapid conversion, fragmentation, and degradation of 80 % of the wetlands along the East Asian-Australasian Flyway (EAAF) for migratory birds. However, the impact of such landscape scale changes on migratory birds at a key stopover site along the EAAF has not been evaluated. Here, we used long-term data (> 40 years) from Deep Bay (Hong Kong), a shallow embayment in the Pearl River estuary (PRE) in south China, to investigate the impact of urbanization on (1) catchment land use and water quality, and (2) its impact on the capacity of the wetland to support populations of migratory waterbirds. Deep Bay supports the largest remnants of mangrove forests and tidal mudflats in the PRE and is an important refueling ground along the EAAF. It is also part of the Greater Bay Area (GBA, population 86 million), the world's largest megalopolis. The principal component analysis highlighted the nutrient loading and cleansing effect from seasonal flushing as characterizing variation in water quality in Deep Bay over four decades. Major shifts in water quality during the study period were accompanied by contemporaneous changes in wintering waterbirds numbers. Prior to 2003, the main drivers of water quality were organic nutrients from animal husbandry. Following large-scale reclamation and increases in impervious surface cover post-2003, primarily due to the development of the megacity of Shenzhen (population 17.7 million), the hydrodynamics of Deep Bay have changed, with knock-on effects of sedimentation, input of pollutants, and changes in the macrobenthos. The wintering waterbirds community responded to these changes both in total numbers and the relative importance of feeding guilds. Where total bird counts are positively influenced by benthic biomass, and the benthic biomass is positively correlated to the water quality that is driven by the cleansing effect of tidal flushing. These anthropogenic drivers have negatively impacted migratory birds that use Deep Bay as a refueling station. This study highlights the need for policymakers to control these drivers and limit the level to which sensitive coastlines are urbanized.

Overwintering Cranes, Waders, and Shorebirds versus Ducks and Coots Showed Contrasting Long-Term Population Trends in Caohai Wetland in Guizhou Province, China

The Guizhou Caohai Wetland plays a crucial role as a wintering site for migratory birds in the Yunnan–Guizhou Plateau and ranks among the largest wintering spots globally for black-necked cranes (Grus nigricollis). To better understand the factors influencing waterbird populations and ecosystem changes, we conducted a comprehensive analysis of historical waterbird population variations over a 30-year period spanning from 1992 to 2022. The current investigation revealed a downward trend in the abundance index curve of the total number of waterbirds during this observation period. Among the five waterbird guilds examined, dabbling ducks, diving ducks, and coots (Fulica atra) experienced declines in their populations, while wading birds and shorebirds saw an increase. Moreover, we observed a rise in species richness within the community over time, accompanied by smaller compositional changes. Additionally, the findings indicated positive growth trends in wintering endangered species such as black-necked cranes and common cranes (Grus grus) in Caohai. Furthermore, we observed an increase in the occurrence and persistence of rare species, such as Eurasian spoonbills (Platalea leucorodia), black-faced spoonbills (Platalea minor), and black storks (Ciconia nigra) wintering in Caohai. These occurrences suggest that the wetland environment provides favorable conditions for a diverse range of species. Despite the rise in species richness, these trends in the abundance and species composition of wintering waterbirds over the past thirty years are still of concern. This study serves as fundamental scientific support for waterbird conservation and the restoration of ecological wetlands in the Guizhou Caohai Wetland.

Spatial Distribution of Malaysian Storks Determined Based on Citizen Science (eBird) Data

Waterbird populations are rapidly declining worldwide, including in many countries in Southeast Asia. Massive land use changes in Peninsular Malaysia are a major threat to biodiversity due to habitat loss and alteration, affecting the populations of many waterbird species. This study was conducted to determine the spatial distribution of three stork species, the Asian Openbill Anastomus oscitans, Painted Stork Mycteria leucocephala and Milky Stork Mycteria cinerea, in Peninsular Malaysia using the citizen science database, eBird. About 86,881 occurrences of the Asian Openbill, 2,391 occurrences of the Painted Stork and 242 occurrences of the Milky Stork were identified in the eBird database throughout Peninsular Malaysia between 2019 and 2021, suggesting major differences in occurrence size between the three species. Map generated from ArcGIS and a statistically significant difference in the population distribution of the three stork species across Peninsular Malaysia indicate habitat segregation. The populations of these stork species should be carefully monitored and managed to avoid imbalance with other waterbird populations.

Species composition and diversity of waterbird communities in Important Bird and Biodiversity Area (IBA) of South West Johor Coast, Malaysia

Abstract. Fauzi NA, Munian K, Shah AKMK, Norazlimi NA. 2023. Species composition and diversity of waterbird communities in Important Bird and Biodiversity Area (IBA) of South West Johor Coast, Malaysia. Biodiversitas 24: 3471-3480. Mangroves play a crucial role in supporting intertidal flats and providing habitats that enrich benthic communities, which in turn serve as feeding grounds for coastal waterbirds. However, the degradation of mangrove habitats caused by coastal reclamation activities indirectly impacts prey availability and, consequently, the populations of waterbirds. The coastline habitat along the Important Bird and Biodiversity Area (IBA) of the South West Johor Coast is currently under threat due to new and ongoing development projects involving large-scale reclamation activities. Therefore, this research was conducted to study the diversity and abundance of waterbirds and their relationship with prey availability. The study was conducted in three coastal mudflat sites along the South West Johor Coast, namely Tanjung Piai, Pontian Kechil, and Muar, from November 2020 to May 2021. The direct observation technique was used to determine the abundance of waterbirds, while the benthic core sampling method was employed to assess prey availability in all study sites. In total, 3,717 individual waterbirds, comprising 17 species, were counted across the three study sites. The study confirmed a significant positive relationship between the abundance of waterbirds and prey availability (R2=0.501). The results of this study serve as important baseline data and references for the conservation of waterbirds along the South West Johor Coast. Through the study, we believe that the relevant authorities are able to formulate sound conservation strategies to preserve the habitat for a vast diversity of waterbirds.