Black-faced Spoonbill Platalea Research Articles

Conservation-oriented management benefits the Black-faced Spoonbill, an endangered migratory waterbird

Active conservation management is crucial for maintaining and recovering populations of threatened species. Yet, there are remarkably few studies quantifying the benefits of conservation management and comparing ecological and anthropogenic influences on populations. We investigate these issues using the Black-faced Spoonbill Platalea minor as a case study. This species is an endangered migratory waterbird that garnered significant conservation attention along the East Asian-Australasian Flyway. Its global population has shown an upward trend recently, yet the speed of recovery has varied spatially. Understanding the species’ occurrence across wintering sites and the factors driving the geographical variation in recovery is vital for examining the benefits of management. In winter 2021–2022, we surveyed the occurrence and abundance of Black-faced Spoonbills and gathered data on environmental conditions across six important wintering sites in Taiwan and the Chinese mainland. Our results indicated a preference for larger wetlands with water depths of 10–20 cm. Birds were more likely to be present in wetlands receiving conservation management interventions. Wetlands with vegetated bunds and fewer artificial materials tended to attract larger flocks. The contribution of wetland size and conservation management aimed at increasing spoonbill abundance varied across regions, with a more significant positive effect of conservation management observed in Taiwan. Our results serve as a valuable reference for regional conservation planning and wetland management in wintering areas, aiding their long-term conservation. In line with this, we recommend increased conservation management efforts informed by our findings, particularly in regions with relatively slow recovery rates.

Current water pollution status at an important wintering site of the black-faced spoonbill Platalea minor in Xinghua Bay, south China

Xinghua Bay is one of the largest wintering sites of the black-faced spoonbill Platalea minor in mainland China. The ecosystem of Xinghua Bay has shown a deteriorating trend with the increasing pressure of economic development in recent decades. To understand the current conservation status of the wintering spoonbills in Xinghua Bay, we collected water samples along the coast of Xinghua Bay and important spoonbill habitats during the wintering period to analyze the pollution degree of 7 target heavy metals and organics. The Nemerow pollution index (NPI), heavy metal pollution index (HPI) and contamination degree (CD) were used to assess the heavy metal pollution levels. The ecological risk index of a target heavy metal (Efi) and potential ecological risk index of all target heavy metals (RI) were used to assess the ecological risk of heavy metals levels in Xinghua Bay. Positive matrix factorization (PMF) was used to determine the sources of heavy metals in coastal waters with the EPA PMF5.0 model. The results showed that there was moderate to very heavy pollution by heavy metals and moderate associated ecological risks in Xinghua Bay, in which Hg and Cd were the major heavy metal pollution sources, and the level of organic pollution was of serious concern. The use of fertilizers for cultured shellfish and aquaculture in and around the bay were the major cause of the excessive nitrogen and phosphorus levels, and factories surrounding Xinghua Bay were the major sources of heavy metals and organic pollution. We propose conservation measures to increase black-faced spoonbill population and enhance its habitats.

Chromosomal-level genome assembly and single-nucleotide polymorphism sites of black-faced spoonbill Platalea minor.

Platalea minor, or black-faced spoonbill (Threskiornithidae), is a wading bird confined to coastal areas in East Asia. Due to habitat destruction, it was classified as globally endangered by the International Union for Conservation of Nature. However, the lack of genomic resources for this species hinders the understanding of its biology and diversity, and the development of conservation measures. Here, we report the first chromosomal-level genome assembly of P.minor using a combination of PacBio SMRT and Omni-C scaffolding technologies. The assembled genome (1.24Gb) contains 95.33% of the sequences anchored to 31 pseudomolecules. The genome assembly has high sequence continuity with scaffold length N50 = 53Mb. We predicted 18,780 protein-coding genes and measured high BUSCO score completeness (97.3%). Finally, we revealed 6,155,417 bi-allelic single nucleotide polymorphisms, accounting for ∼5% of the genome. This resource offers new opportunities for studying the black-faced spoonbill and developing conservation measures for this species.

Arboreal nesting in the Black-faced Spoonbill <i>Platalea minor</i>

Populations of the Black-faced Spoonbill Platalea minor declined significantly until the 1990’s, before a slow but consistent increase in population size in response to successful conservation efforts. Specific sites have been designed to be adequate breeding areas for the species, and these land-based locations are successfully used. We report on the arboreal nesting of Black-faced Spoonbill, a behaviour that is only rarely reported and is not generally present in the scientific literature for the species. A literature search however revealed that all other Platalea species are opportunistic arboreal breeders, and this rarely observed behaviour in Black-faced Spoonbill may be prevalent in specific contexts. Several pairs of P. minor were observed nesting on trees on Yu Islet (37.775°N, 126.534°E), in May 2020 and this behaviour may have consequences for the conservation of the species as it implies that nesting individuals can avoid competition with other ground breeding species, and avoid flooding, a stochastic event having a significant impact on nesting Black-faced Spoonbill.

Reversing the Decline in a Threatened Species: The Black-Faced Spoonbill Platalea minor

The black-faced spoonbill Platalea minor is a species endemic to the coastal fringes and archipelagos of East Asia. The global population was fewer than 300 individuals in the late 1980s. Since then, two international action plans (1995 and 2010–2020) have been implemented, and the global population has increased to more than 6000 individuals in 2021–2022; the species was downlisted from “Critically Endangered (CR)” to “Endangered (EN)” in 2000. To examine the basis for this success, we reviewed the implementation of the action plans in light of the IUCN Species Conservation Cycle (Assess–Plan–Act–Network–Communicate) framework, using publicly available information documenting the planned activity or policy outcome. Additionally, we used the IUCN Green Status of Species framework to assess the impact of this conservation effort on the black-faced spoonbill’s recovery to date and recovery potential. We found that the action plans for the black-faced spoonbill contain activities across all SCC framework components, though the number of activities implemented differed among countries. Our preliminary Green Status assessment indicates that the black-faced spoonbill is currently Largely Depleted, with a Species Recovery Score of 35%; however, without past conservation actions, we estimate that its score would be only 15% today (Critically Depleted), and that it is biologically possible for the species to fully recover (100%) in the next 100 years, if ambitious actions are taken. This provides further evidence that premeditated, evidence-based conservation interventions can reverse biodiversity loss.

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.

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.

Genetic diversity and population structure of the Black-faced Spoonbill (Platalea minor) among its breeding sites in South Korea: Implication for conservation

The endangered Black-faced Spoonbill Platalea minor has experienced drastic reductions in population size, geographic distribution, and habitat availability throughout East Asia. In the present study, we examined population genetic structure and genetic diversity of Black-faced Spoonbills inhabiting five sites off the west coast of South Korea encompassing a few of its major breeding sites. Ten microsatellite loci and the mitochondrial sequence were used to assess patterns of genetic variation based on 63 individuals. Three ND2 haplotypes were found among 61 individuals; the remaining two were identified as Eurasian Spoonbills, revealing an unexpected hybridization between these two species having different ecological niches in South Korea—the Eurasian Spoonbill overwinters in inland areas, whereas the Black-faced Spoonbill inhabits coastal areas during the summer. Analyses of microsatellite variation revealed no discrete population structure among the five breeding sites but very weak genetic differentiation among geographically distant regions. Assignment tests identified several possible migrants among sites. Our findings suggested that Black-faced Spoonbills from the five breeding sites could be managed as a single population and highlighted the importance of conserving the populations from Maedo, Suhaam, and Namdong reservoir, which are geographically close and have retained high levels of genetic diversity and large populations.

Population trends of the Black-faced Spoonbill Platalea minor: analysis of data from international synchronised censuses

SummaryLong-term population monitoring is crucial to evaluate the effectiveness of conservation efforts. Systematic surveys of the endangered Black-faced Spoonbill Platalea minor, the rarest spoonbill species globally, are not possible during the breeding season as the largest breeding grounds are inaccessible to surveyors. Instead, we have examined population trend in this species during the winter by utilising a dataset of synchronised surveys conducted annually across 42 sites between 1997 and 2014. We found that the global population has increased from 535 individuals in 1997 to 2,726 in 2014, an annual increase of 8.0%. Population increases were more pronounced in protected sites and sites with low levels of human disturbance, indicating that control of human disturbance is crucial for conservation in this species. It is of concern that the wintering populations are highly clumped and the two largest populations have ceased to increase since 2012; research to investigate the underlying causes is urgently needed. Synchronised surveys in all known wintering sites should be continued to provide up-to-date data on the global population of this endangered species.

Breeding status and nest site characteristics of Black-faced Spoonbills Platalea minor on Chilsando Islands, Korea1a

Breeding status and nest site characteristics of Black-faced Spoonbills Platalea minor on Chilsando Islands, Korea1a

New perspectives on habitat selection by the Black-faced Spoonbill Platalea minor based upon satellite telemetry

SummaryIn 2011 the Black-faced Spoonbill Platalea minor census recorded a 22% drop in numbers from 2010, particularly at the known large coastal wintering sites. During this period, we discovered two new inland wintering sites for the species using satellite telemetry data, one located in China, where the individual followed the Yangtze river as far as Wuhan (500 km inland), and the other across the Vietnam-Cambodia border (70–200 km inland). Long periods of concentrated use of various freshwater habitats were in evidence for these two tagged individuals (China: 79 days, Vietnam/Cambodia: 91 Days) and in the latter case visual confirmation indicated a larger group of at least five individuals. The importance and potential of inland freshwater environments is highlighted towards the further conservation of the recovering population.

The Influence of Constructing a Shinkansen Bridge on Black-Faced SpoonbillsPlatalea minorWintering In Kyushu, Japan

Black-faced Spoonbill Platalea minor is a globally endangered migratory species restricted to East Asia, with a population of only 2,041 birds recorded in 2009. A total of 215 Black-faced Spoonbills has been counted wintering in Japan, and the Yatsushiro Sea, in western Kyushu is one of their main wintering sites (outside Taiwan, where the bulk of the population winters). Construction of a new bridge for the expansion of the Shinkansen (bullet train) network into Kyushu, was planned very close to an important spoonbill loafing site in the Yatsushiro Sea. Changes in the wintering situation were examined during the construction of the Shinkansen bridge (2004–2009) in the Yatsushiro Sea. Moreover, conservation approaches, including the expansion of loafing sites and the use of decoy models, were also evaluated, by conducting habitat expansion and experiments both before and during the construction phase. Initially, the number of Black-faced Spoonbills at the loafing site increased as a consequence of these conservation efforts, but this increase was only temporary and numbers gradually decreased thereafter. Eventually, the birds changed their loafing site to a neighboring river, once construction of the bridge had begun. Fortunately, their numbers in the Yatsushiro Sea have been increasing since changes to the habitat have taken place. Our observations suggest that conserving and maintaining both remaining and potential habitats are very important for the conservation of this endangered species.

Notes on feeding structures of the Black-faced Spoonbill Platalea minor

The bills of the spoonbills differ from the bills of most birds by being wider near the downward curved tip than in the middle, and having the mandibles dorso-ventrally extremely flattened. The mandibles have rounded lateral borders and lack cutting edges. The inward directed sides have a dense cover of thin parallel ridges on the distal parts and rows of teeth-like tubercles in the proximate parts. Their skeletons have numerous small pits in the distal parts especially along the edges and the insides. These pits are similar to the spaces for sensory corpuscles for touch in the bills of Scolopacidae (sandpipers, snipes) and are presumed to have the same function in spoonbills. The bill seems adapted for tactile feeding with lateral movements (sweeping) and for pecking, but not for probing into sediments. The wide gape with gular pouch allows the swallowing of rather large food items. The muscular layer of the gizzard is weakly developed and the gizzard is more a digestive pocket than a chewing organ such as occurs for grinding hard shells and grains in molluscivorous and granivorous birds. The long legs are laterally flattened, perhaps for minimising resistance and not-disturbing prey when walking in water during feeding; the partly webbed feet with long toes allow walking over soft mud bottoms.

Yubu Island, the Important Waterbird Habitat on the West Coast of Korea and Its Conservation

Yubu Island is located within the estuary of the Geum River, South Chungcheong Province <TEX>$(35^{\circ}59'N,\;126^{\circ}36'E)$</TEX>, Korea. The island is surrounded by a broad and sandy mudflat, which is typical in the west coast of Korea, and is located 4km off from Gunsan City. Less than 100 humans live on the island, occupying 30 houses. After we discovered that this island was a very important waterbird habitat especially for the East Asian subspecies of the Eurasian oystercatcher, Haematopus ostralegus osculans. Waterbirds were monitored once every month from August 1999 to July 2000. The highest number of oystercatchers counted was 3,200 in December 1999, and the birds seemed to remain in the area continuously from September to next February. About 200 breeding and non-breeding birds remained during the breeding season. In August, early migrants returned to the island, with the number reaching 1,060 individuals. This island is also very important for other waterbirds. Endangered or significant species occurring at this site, and their maximum counts were: chinese egret Egretta eulophotes (5), black-faced spoonbill Platalea minor (17), brant Branta bernicla (1), common shelduck Tadorna tadorna (8,000), hooded crane Grus monacha (2), spoon-billed sandpiper Ewynorhynchus pygmeus (7), dunlin Calidris alpina (6,500), great knot Calidris tenuirostris (24,000), far eastern curlew Numenius madagascariensis (2,500), spotted greenshank Tringa guttifer (4) and Saunders's gull Larus saundersi (1,200). During the 12 month survey period, we observed 52 waterbird species and the total of the maximum counts for the separate species was 73,308, implying that perhaps 150,000 birds could be using the immediate area, if a turnover rate of 2 was assumed.

The status and conservation of threatened and near-threatened species of birds in the Red River Delta, Vietnam

SummaryThe Red River Delta in northern Vietnam is an important stopover and wintering site for migratory waterbirds. During the spring of 1994, six globally threatened and five near-threatened species were observed in the coastal areas of the Delta. According to current applications of threat categories, one of the species has Critical status (Black-faced Spoonbill Platalea minor), three are Endangered (Nordmann's GreenshankTringa guttifer, Saunders's Gull Larus saundersi and Chinese EgretEgretta eulophotes), two are Vulnerable (Spoonbill SandpiperEurynorhynchus pygmaeusand Spot-billed Pelican Pelecanus philippensis) and five are Near-threatened (Asian DowitcherLimnodromus semipalmatus, Grey-headed LapwingVanellus cinereus, Black-headed IbisThreskiornis melanocephalus, Painted Stork Mycterialeucocephalaand Japanese Paradise-FlycatcherTerpsiphone atrocaudata). A nature reserve, also listed as a Ramsar area, already exists in the middle of the Delta. The Cua Day Estuary in the southern part of the delta is not included in either the nature reserve or Ramsar area. However, observations of 260 Saunders's Gulls and 41 Black-faced Spoonbills, which represent 9% and 12% of the estimated respective world populations, indicates the international importance of this area. The major threats to the waterbirds using the delta are reclamation of intertidal sand- and mudflats for aquaculture, increased disturbance associated with collection of sea products and hunting. Recommendations are made for future conservation actions.