Platalea Minor Research Articles

DNA metabarcoding reveals the dietary composition in the endangered black-faced spoonbill

Extensive loss of natural wetlands caused by changes in land use largely diminishes the food resources essential for the survival of migratory waterbirds. Globally, the decline in waterbird populations in East Asia is the most serious, with 64% of these populations showing a decreasing trend. In this study, we applied DNA metabarcoding to examine the spatiotemporal variations and diversities in the dietary compositions of migratory waterbirds in a natural/artificial wetland complex in Asia. By investigating 110 fecal samples from the endangered black-faced spoonbill (Platalea minor) wintering in the wetland, our results show that P. minor had a broad dietary spectrum. The birds fed on at least 26 species in the classes Actinopterygii and Malacostraca, with Mugiliformes, Cichliformes, and Gobiiformes being the main taxa in their diets. Our results also demonstrated clear patterns of the spatiotemporal variations between the roosting groups and intraspecific variations between the individuals, which potentially reflect some of their feeding habits, and the probable usage of different habitat types in the wetland complex. Using high-throughput sequencing, we were able to elucidate the food resources that are critical to P. minor non-invasively, this method can also be used to provide invaluable information for the conservation of many other waterbird species.

Age-dependent shifts and spatial variation in the diet of endangered Black-faced Spoonbill (Platalea minor) chicks.

The endangered Black-faced Spoonbill (Platalea minor) strictly breeds in marine environments and is threatened by the rapid loss of coastal wetlands within its breeding range. Adults with chicks are thought to gradually switch feeding sites from freshwater wetlands to coastal mudflats as the chicks’ osmoregulatory system develops. We investigated age-dependent shifts in the diet of Black-faced Spoonbill chicks at four breeding colonies with varying freshwater habitat availability by examining stable isotopes (δ13C, δ15N) between the tip (grown at the age of 10 days) and middle (grown at the age of 22 days) portions of their primary feathers. The δ13C value of the middle portions was significantly higher than that of the tips, which suggested that the ratio of marine resources increased with the growth and development of chicks. A Bayesian isotope mixing model revealed that the diet proportion of marine prey in the early-chick rearing season was slightly higher than in the late-chick rearing season at three colonies in inshore areas, although this proportion was approximately 60% even in the early chick-rearing period. In contrast, isotopic values and reconstructed diet composition suggested that chicks in an offshore colony with limited freshwater wetlands relied more heavily on freshwater diets for both chick-rearing periods (>80%). Our results suggest that the shifts in feeding sites seen in previous studies might be related to the age-dependent dietary shift of chicks, highlighting the importance of freshwater wetlands for spoonbills on offshore islands without an inflow of freshwater in nearby intertidal mudflats. These findings emphasize the importance of freshwater prey and wetlands even for the endangered marine-breeding spoonbills, even though the negative impact of salt stress remains inconclusive.

Research on the Effectiveness of Black-Faced Spoonbill Bird Tourism and Conservation Strategy. A Case Study of Shifen Community at Chi-Gu District of Tainan City

In this study, the concept of ecotourism serves as the framework for the investigation of black-faced spoonbill tourism and conservation strategies implemented in Shifen, a community in the Chi-Gu District of Tainan City. It featured an examination of the formulation, planning, and implementation of the conservation strategies and conducted in-depth interviews on individuals from the public sector, local residents, tourists, and nongovernment organizations. Research results identified numerous problems: latent concerns regarding black-faced spoonbills as a tourism resource, poor awareness of ecotourism, difficulties in implementing black-faced spoonbill tourism and conservation strategies, and difficulty maintaining a balance between conservation and residents’ livelihoods. The government is advised to integrate the opinions and suggestions of local residents, promote community participation, and increase job opportunities for local residents to create a win-win model for the development of community-based ecotourism.

Risk Assessment of Coastal Flooding under Different Inundation Situations in Southwest of Taiwan (Tainan City)

The Pacific island countries are particularly vulnerable to the effects of global warming including more frequent and intense natural disasters. Seawater inundation, one of the most serious disasters, could damage human property and life. Regional sea level rise, highest astronomic tide, vertical land motions, and extreme sea level could result in episodic, recurrent, or permanent coastal inundation. Therefore, assessing potential flooding areas is a critical task for coastal management plans. In this study, a simulation of the static flooding situation in the southwest coast of Taiwan (Tainan city) at the end of this century was conducted by using a combination of the Taiwan Digital Elevation Model (DEM), regional sea level changes reconstructed by tide gauge and altimetry data, vertical land deformation derived from leveling and GPS data, and ocean tide models. In addition, the extreme sea level situation, which typically results from high water on a spring tide and a storm surge, was also evaluated by the joint probability method using tide gauge records. To analyze the possible static flood risk and avoid overestimation of inundation areas, a region-based image segmentation method was employed in the estimated future topographic data to generate the flood risk map. In addition, an extreme sea level situation, which typically results from high water on a spring tide and a storm surge, was also evaluated by the joint probability method using tide gauge records. Results showed that the range of inundation depth around the Tainan area is 0–8 m with a mean value of 4 m. In addition, most of the inundation areas are agricultural land use (60% of total inundation area of Tainan), and two important international wetlands, 88.5% of Zengwun Estuary Wetlands and 99.5% of Sihcao Wetlands (the important Black-faced Spoonbills Refuge) will disappear under the combined situation. The risk assessment of flooding areas is potentially useful for coastal ocean and land management to develop appropriate adaptation policies for preventing disasters resulting from global climate change.

Black-Faced Spoonbill Platalea minor Population Trends, Breeding Success, and Nest Characteristics in the Chilsan Archipelago, South Korea

Long-term population monitoring is very important for the conservation of threatened and endangered species. The Black-faced Spoonbill Platalea minor is a globally endangered species and the majority of its population breed on uninhabited islands off the west coast of the Korean Peninsula. The Chilsan Archipelago in the southwest is the southernmost breeding site for this species in Korea and is expected to help buffer the potential dispersal of Black-faced Spoonbills from breeding populations currently concentrated in the Gyeonggi Bay area. As there has been a lack of information regarding the number of Black-faced Spoonbills, their characteristics, and their recent population trends, the present study investigated the population trends of Black-faced Spoonbills breeding in the Chilsan Archipelago. The study, from 2014 to 2018, examined breeding success in 2015 and 2018, and the size and location of nests in 2018. The number of nests ranged from 43 to 163 (2014, 43; 2015, 93; 2016, 84; 2017, 85; 2018, 163). The percentage of birds that attempted breeding between April and May was 84.9% in 2015 and 87.1% in 2018, while the breeding success rate was 69.9% in 2015 and 81.5% in 2018. The average nest size in 2018 was 55.06±6.09 cm long and 53.44±6.56 cm wide, while the average surface slope below the nest was 25.42±6.95°. In total, nine plant species were used as vegetation for nests. During the present study, the environmental conditions and the presence of anthropogenic disturbances seemed to affect breeding success. Therefore, strictly controlled access to breeding sites and effective management are needed to protect and conserve breeding populations of this endangered species.

Can Aquaculture Ponds Be Managed as Foraging Habitats for Overwintering Water Birds? An Experimental Approach

Coastal wetlands have been gradually developed by aquaculture and other anthropogenic infrastructure, reducing the habitat for water birds. The traditional operation of shallow-pond milkfish (Chanos chanos) aquaculture in Taiwan may provide a model for aquaculture production that operates in harmony with overwintering water birds. The goal of this study was to test whether experimental water drawdown of aquaculture ponds, following the seasonal, traditional milkfish aquaculture, can create resource pulses that attract water birds in Tainan City in southern Taiwan. This experiment tested four types of aquaculture with potential for application: wild fish, no-feed tilapia, milkfish, and tilapia with feed. Ponds were surveyed every other day for water depth and water birds at least 37 times in four winters after water drawdown. In general, drawdown ponds created resource pulses that attracted higher feeding bird densities and numbers of species than control ponds in all aquaculture types. Milkfish ponds often had higher water birds in each year. Deep waders were sometimes the most abundant guild in the control, whereas shorebirds, shallow and deep waders were often higher in the drawdown treatment. Bird densities and numbers of species were correlated with water level, benthic biomass and water Chl a, but not with tilapia biomass. Species, such as Black-faced Spoonbills (Platalea minor), responded to water levels with the exception of Little Egrets (Egretta garzetta). The operation of seasonal, traditional shallow-pond milkfish aquaculture is suitable for foraging of water birds during the winter migratory bird season.

Avian Surveys in the Korean Inner Border Area, Gimpo, Republic of Korea.

BackgroundBirds are useful environmental indicators as their presence reflects the health of the food web. Bird occurrence, rarity and abundance are reliable indicators of ecosystem health. Monitoring of avian populations in the Republic of Korea (ROK) is a primary requirement due to plummeting populations and the risks to threatened species. The Ministry of Environment of ROK started conducting winter bird censuses in 1999, including inland areas and coast areas, such as Cheorwon, Yeoncheon, Junam Reservoir and Han River. Cheolwon, Yeoncheon and some extent islands in the West Sea have been survey extensively due to iconic bird species, such as White-naped Crane (Grus vipio) or Red-Crowned Crane (Grus japonensis) wintering there. However, the winter bird census has not covered Yu Islet, Han River Estuary. Yu Islet is located within the Han River Estuary, a protected wetland in the Neutral Zone between the two Koreas and north of Gimpo in the ROK. The Islet currently supports a large, mixed breeding colony of waterbirds, such as one of the nation’s largest concentration of breeding Great Cormorants (Phalacrocorax carbo) and smaller numbers of breeding Black-faced Spoonbill (Platalea minor), Grey Heron (Ardea cinereal), Great Egret (Ardea alba) and Intermediate Egret (Ardea intermedia). Access to the area has long been restricted for military reasons, but recently, regular survey activity is possible supported by Gimpo City and the military base in Gimpo from November 2018.New informationHere, we provide data demonstrating that Yu Islet is important for breeding for waterbirds; and that the northern Gimpo part of Han River Estuary is also internationally important for waterbirds during the migratory bird season, as defined by the Ramsar Convention (Ramsar 1971, RRC-EA 2017). In particular, four waterbird species were found during the survey in the Main Survey Area: Swan Goose (Anser cygnoides), Taiga Bean Goose (Anser fabalis), Tundra Bean Goose (Anser serrirostris) and Greater White-fronted Goose (Anser frontalis). Once considered widespread in East Asia and abundant, the world population of Swan Goose is now estimated at only 60,000 - 78,000 individuals (Wetlands International 2020) and the species is assessed by BirdLife International as globally Vulnerable (BirdLife International 2020). The 1,010 Swan Goose (Anser cygnoides) counted on the vegetated mudflats at Jogang-Ri in the Main Survey Area on 27 November 2018 represents more than 1% of the total world population of this species. Notably, it is also the highest count of this species in the ROK for at least a decade. The count confirms the continuing international importance of the Han River Estuary for the survival of the Swan Goose. The number counted in November had fallen to 250 by 28 December 2018; and none was recorded in the Main Survey Area in January or February 2019. Although searched for in March, none was noted during the northward migration either. The surveys also found small numbers of nationally-scarce Grey-capped Pygmy Woodpecker (Yungipicus canicapillus) in several areas of woodland surrounded by the Han River Estuary. By selecting the most species-rich count within a given month in each of the two survey sectors, the number of species we recorded ranged from a minimum 29 in January to a maximum of 65 in April 2019. Based on the species recorded, the survey area is clearly important for avian conservation. Its importance derives from the combination of the extensive areas of high-quality wetland and its geographic location within one of the Korea Peninsula’s largest and most important remaining wetland ecosystems, the Han River Estuary. Our surveys resulted in the detection of a substantial number of bird species, especially in March and April when forest-breeding birds are more obviously vocal. The survey result is provided in the supplementary material (Suppl. material 1).

Colonial Nesting Birds of Peter the Great Bay, Sea of Japan (Pelecaniformes, Ciconiiformes)

This study reports recent data on the distribution and breeding abundance of seven species of colonial birds on the coast of Peter the Great Bay, Sea of Japan. Over the past 30 years, three species of cormorants (great, Japanese, and pelagic cormorants), as well as the black-faced spoonbill, have significantly increased their numbers. The number of breeding pairs of gray heron and Chinese egret decreased, while the numbers of the little egret did not change.

A Comparative Study of Nest Attendance Patterns of Chick-rearing Black-faced Spoonbills (Platalea minor) in Incheon, South Korea

A Comparative Study of Nest Attendance Patterns of Chick-rearing Black-faced Spoonbills (Platalea minor) in Incheon, South Korea

Nesting of the black-faced spoonbill (Platalea minor) (Pelecaniformes: Threskiornithidae) and the hybrid partner on the coasts of Khanka Lake (the Russian Federation)

At the east coast of Khanka Lake (Russian Federation) on May 15, 2020, an unusual pair of spoonbill was observed. One of the partners was a black-faced spoonbill; the second partner included features of both the black-faced spoonbill and the Eurasian spoonbill, which can be regarded as a hybrid. This pair had a nest with two eggs, which later hatched one chick with signs of a black-faced spoonbill.

Wetland destruction on migration routes threatens a breeding population of the endangered black-faced spoonbill (Platalea minor)

To further protect the breeding population of black-faced spoonbills (Platalea minor), it is important to understand the current conservation status of breeding distribution sites and migration routes, especially for important stopover and wintering sites of black-faced spoonbills. Six individuals were tagged with satellite transmitters at Zhuanghe, Liaoning Province, northeastern China, in July of 2017 and 2018 to identify important distribution sites during the breeding period and detailed migration routes. The results showed that Zhuanghe Bay, Qingduizi Bay and Dayang Estuary were important feeding and roosting sites for black-faced spoonbills from August to October. Jiaozhou Bay, Shandong Province, and Lianyungang and Yancheng, Jiangsu Province, were important stopover sites during fall migration, and the coastal areas of Yancheng, Jiangsu; Hangzhou Bay, Zhejiang Province; and Tainan, Taiwan of China; and the inland areas of Poyang Lake, Jiangxi Province, and Nanyi Lake, Anhui Province, were important wintering sites. This is the first study to report the inland migration routes of black-faced spoonbills in China. Our findings on the key breeding distribution sites, fall migration routes and current threats (such as aquaculture, mudflat reclamation and dam construction) have important implications for the conservation of and global action plan development for the endangered black-faced spoonbill.

A Comparative Study of Juvenile Black-faced Spoonbills Platalea Minor Home Range in Gujido and Chilsando Islets, South Korea

A Comparative Study of Juvenile Black-faced Spoonbills Platalea Minor Home Range in Gujido and Chilsando Islets, South Korea

Breeding and wintering home ranges of the black-faced spoonbill Platalea minor

It is important to the study sites for breeding, wintering, and stopovers of migratory birds to understand their habitat characteristics. Black-faced spoonbills Platalea minor are an internationally endangered migratory bird. The majority of the population breeds on uninhabited islets off the west coast of the Korean Peninsula. By using GPS wildlife tracker on five black-faced spoonbill individuals, this study compared the home ranges of black-faced spoonbills in the postfledging stage and investigated the home ranges of their wintering sites. In the postfledging stage, all five black-faced spoonbill individuals occupied home ranges in the coastal area before migrating to wintering sites. The home range sizes (mean ± SD) were estimated to be: 65.81±25.20 km2 using 100% minimum convex polygon, 43.44±11.97 km2 using 95% KDE and 8.09±2.98 km2 using 50% Kernel density estimation. At the wintering sites, the home ranges included the coastal areas and inland areas of China, Hong Kong, and Taiwan. This study could not directly compare the home ranges of postfledging stage individuals and the home ranges of wintering sites. It was evident, however, that efforts should be made to protect the habitats by minimizing human disturbances in the areas near the home ranges of the breeding and wintering sites described in this study.

Variation in Biparental Incubation Patterns of the Black-Faced Spoonbill (Platalea minor)

This study was conducted using wildlife cameras at nests in a colony of Black-faced Spoonbill (Platalea minor) on Mae-do Islet (37° 34′ 07.17″ N, 126° 35′ 08.10″ E), Incheon, South Korea to monitor and examine the variation in incubation patterns between males and females among four different stages of incubation (Egg-laying, Early-, Mid-, and Late-incubation stage). Mean egg-incubation bout length was longer for females (Egg-laying stage = 6.55 ± 0.44 hr SE; Early-incubation = 7.34 ± 0.48 hr; Mid-incubation = 7.22 ± 0.44 hr; Late-incubation = 7.89 ± 0.58 hr) than for males (Egg-Laying = 4.55 ± 0.39 hr; Early-incubation = 6.35 ± 0.46 hr; Mid-incubation = 6.94 ± 0.40 hr; Late-incubation = 7.07 ± 0.51 hr), but the differences in average incubation bout length between females and males decreased after the Egg-laying stage. Females incubated a greater proportion of time during nighttime (Females: 88.21 ± 3.73%; Males: 11.79 ± 3.73%), and males incubated a greater proportion of time during daytime (Female: 25.19 ± 3.48%, Male: 74.80 ± 3.48%) after the egg-laying stage. This study suggests that Black-faced Spoonbills divide their duties according to diel schedule and adjust the incubation duration throughout the entire incubation period.

Water Bird Communities in Nonoperational Cigu Salt Pan Wetland of Varying Land Elevation and Water Depth on the Southwest Taiwan Coast

The Black-faced Spoonbill (Platalea minor) is a critically endangered species. More than 50% of these spoonbills winter regularly on the southwestern coast of Taiwan. From 2007 to 2019, the rate of increase of the Black-faced Spoonbill population was only 10.5%, which is lower than the rate of 12.0% per year reported between 1991 and 2004. Black-faced Spoonbills have experienced several bottlenecks, and problems may exist in their breeding and/or in wintering habitats. Understanding the ecological environment of their habitats in Taiwan is an important issue, including the current use of water birds, the water depth of their habitats and even the aquatic plants. A total population of 93,614 birds of 88 species was recorded in a survey of the Cigu salt pan from October 2017 to October 2018. The biodiversity H' (loge) of the total birds was 2.67. Dunlin (Calidris alpina) was the most dominant species with a population of 21,053 (22.5%), followed by Kentish Plover (Charadrius alexandrinus) with a population of 20,350 (21.7%). The largest area of terrain elevation at -1.0 to -0.2 m was 685.4 ha (38.5%) and at -0.2 to -0.1 m was 320.4 ha (18.0%). Between 2017 and 2018, the similarity in water depth classification was 47.2%, reflecting climate change, a degree of water accumulation, and the wader utilization situation. A strategy for maintaining biodiversity in the Cigu salt pan wetland and conserving spoonbills is therefore proposed in this paper.

Detection of two Arctic birds in Greenland and an endangered bird in Korea using RGB and thermal cameras with an unmanned aerial vehicle (UAV).

Unmanned aerial vehicles (UAVs), so-called ‘drones’, have been widely used to monitor wild animals. Here, we tested a UAV with red, green, and blue (RGB) and thermal cameras to detect free-living birds in a high Arctic region in North Greenland and in a restricted area in the Republic of Korea. Small flocks of molting pink-footed geese (Anser brachyrhynchus) near sea ice and incubating common ringed plovers (Charadrius hiaticula) in the Arctic environment were chosen for the RGB and thermal image studies. From the acquired images, we built mosaicked RGB images and coregistered thermal images, and estimated the animal shapes. Our results showed that geese were discriminated in both RGB and thermal images with water and sea ice backgrounds. Incubating plover bodies were not distinguished in RGB images due to their cryptic coloration, but they were detected in thermal images with cold background areas in the Arctic environment. We further conducted a blind survey in a restricted area under military control in Korea near the breeding sites of black-faced spoonbill (Platalea minor), which is an endangered species. From UAV flights with RGB and thermal cameras operated out of the restricted area, we acquired images of white objects in the mudflats and verified that the objects were resting spoonbills by watching the birds. We suggest that thermal cameras and UAVs can be applied to monitor animals in extreme environments and in restricted areas and help researchers find cryptic wader nests.

New records of chewing lice (Phthiraptera: Amblycera, Ischnocera) from the black-faced spoonbill (Platalea minor).

Three species of chewing lice-Eucolpocephalum femorale (Piaget, 1880) (Amblycera: Menoponidae), Ibidoecus plataleae (Denny, 1842) (Ischnocera: Philopteridae) and Ardeicola plataleae (Linnaeus, 1758) (Ischnocera: Philopteridae)-are reported from the black-faced spoonbill (Platalea minor Temminck Schlegel, 1849) in Japan. These three louse species are new records for this host. The black-faced spoonbill is classified as a "Critically Endangered" species in the IUCN Red List; although its species of lice are known to infest other species of spoonbills, these lice are endangered at the population level.

Feeding Behavior of Black-faced Spoonbills <i>Platalea minor</i> on Rice Paddy in Gangwha Island, Korea

Feeding Behavior of Black-faced Spoonbills <i>Platalea minor</i> on Rice Paddy in Gangwha Island, Korea

Using choice experiments to inform management of black-faced spoonbill reserve in Taiwan

The evaluation of wildlife tourism benefits is one of the key considerations in planning proper management measures and promoting mutually beneficial coexistence of wildlife tourism and wildlife re...

Factors Affecting Incubation Rhythm of the Black-faced Spoonbill (Platalea minor) Breeding in Gyeonggi Bay, Korea

Factors Affecting Incubation Rhythm of the Black-faced Spoonbill (Platalea minor) Breeding in Gyeonggi Bay, Korea