Wetlands are crucial habitats for waterbirds, but wetland loss and degradation have caused significant population declines in many waterbird species. Ecological restoration can improve habitat quality and protect threatened waterbirds, but restoration assessments are often based on diversity rather than fitness indicators. Breeding period is a critical life history stage and breeding output affects population dynamics, thus breeding success is a fitness indicator that truly reflects habitat quality and suitability. This study evaluated the breeding performance of three ground-nesting waterbird species: Pied Avocet (Recurvirostra avosetta), Black-winged Stilt (Himantopus himantopus), and Saunders's Gull (Saundersilarus saundersi) in a restored wetland at Chongming Dongtan in the Yangtze estuary, China in 2023 and 2024. We surveyed bird abundance and monitored breeding success rates and causes of breeding failure using camera traps. Breeding success at Chongming Dongtan was further compared with published data from other sites. Results showed that the restored wetland provided nesting habitats for the three species, while the breeding success rate was low: the apparent nest success (proportion of successful nests) for Pied Avocet (2023: n = 94; 2024: n = 7), Black-winged Stilt (2023: n = 40; 2024: n = 39), and Saunders's Gull (2023: n = 109; 2024: n = 24) was 6.9%, 20.3%, and 13.5%; the cumulative nest success (estimated from daily survival rate) was 10.9%, 25.8%, and 31.6%, respectively. Nest predation was the primary cause of breeding failure for the Pied Avocet, flooding for the Black-winged Stilt, and egg cracking for the Saunders's Gull. The factors affecting daily survival rate varied among species, including breeding period, distance to water surface, local temperature, precipitation, and year. Apparent nest success of all three species was significantly lower than that reported at other breeding sites worldwide. These results suggest that although the restored wetland attracts many waterbirds to nest, it may function as a sink for the breeding bird populations. We recommend controlling nest predators, avoiding nest flooding by water-level regulation, and providing shade conditions by planting sparse plants at nesting sites. Our findings highlight the importance of using fitness-related indicators in assessing habitat quality and the effectiveness of ecological restoration.

Elucidating the spatial-temporal characteristics and influencing factors of migration activities is the basis for understanding the life cycle of migratory birds and for making conservation measures. Short-distance migratory birds experience less time pressure during migration; they tend to migrate under suitable environmental conditions and thus the migration decision might be strongly influenced by external environmental conditions. To test this hypothesis, we deployed GPS tags on Far Eastern Oystercatchers (Haematopus ostralegus osculans) at the Yalu Jiang estuary in the northern Yellow Sea and tracked their annual migration. The tagged oystercatchers, including five adults and seven immatures (second/third-year birds), mainly wintered along the west coast of the Yellow Sea and bred inland in northeastern China. The migration distance between breeding and wintering sites was 1640.7 ± 260.4 km in spring and 1668.7 ± 306.1 km in autumn. Compared with adults, immatures departed from the wintering sites and arrived at the breeding sites later, while there were no significant differences between adults and immatures in the dates of departure from breeding sites and arrival at wintering sites. Migration initiation generally occurred around sunset. Wind conditions consistently provided tailwinds on departure days from wintering, breeding, and stopover sites during both seasons, with wind support exceeding the 5- or 10-day pre-departure average. During autumn migration, the temperature on departure days at stopover sites was lower than the mean temperature over the preceding 5 or 10 days. The Yalu Jiang estuary was the main stopover site for the tagged birds during both spring and autumn migrations. The stopover duration in autumn (adults: 118.3 ± 8.4 days; immatures: 130.4 ± 5.1 days) was the longest among the studied shorebirds, likely due to moulting of flight feathers at the stopover site. Our results indicate that the migratory decisions of oystercatchers were strongly influenced by wind conditions during the whole annual cycle, whereas they were also affected by temperature when departing from stopover sites in autumn. The extended stopover at the Yalu Jiang estuary in autumn highlights its importance for the species.

Charismatic species are often reported by the media, providing information for detecting population status and public perception. To identify the number and distribution of free-living Black Swan (Cygnus atratus), a charismatic alien species in Chinese mainland and to detect the public and the media attitudes to the species, we analyzed the reports and emotional tendency from media coverage in 2000–2022 using manual reading, crawler extraction and latent Dirichlet allocation. A total of 6654 Black Swans were reported at 711 sites, including 147 individuals at 30 nature reserves. Successful breeding was reported at one-fourth of the total sites, including five nature reserves. The proportion of positive emotional tendency to Black Swans was overwhelming in the reports and was higher than that to alien species in general, suggesting that the public and the media are unaware of the risk of biological invasion. Effective management of invasive species requires the media clarifies the invasion risk of charismatic alien species. Promoting the unity between the harmfulness of abstract concept of alien species and the charisma of a specific alien species among the public help effective management.

Many migratory birds exhibit interannual consistency in migration schedules, routes and stopover sites. Detecting the interannual consistency in spatiotemporal characteristics helps understand the maintenance of migration and enables the implementation of targeted conservation measures. We tracked the migration of Whimbrel (Numenius phaeopus) in the East Asian–Australasian Flyway and collected spatiotemporal data from individuals that were tracked for at least two years. Wilcoxon non-parametric tests were used to compare the interannual variations in the dates of departure from and arrival at breeding/nonbreeding sites, and the interannual variation in the longitudes when the same individual across the same latitudes. Whimbrels exhibited a high degree of consistency in the use of breeding, nonbreeding, and stopover sites between years. The variation of arrival dates at nonbreeding sites was significantly larger than that of the departure dates from nonbreeding and breeding sites. Repeatedly used stopover sites by the same individuals in multiple years were concentrated in the Yellow Sea coast during northward migration, but were more widespread during southward migration. The stopover duration at repeatedly used sites was significantly longer than that at sites used only once. When flying across the Yellow Sea, Whimbrels breeding in Sakha (Yakutia) exhibited the highest consistency in migration routes in both autumn and spring. Moreover, the consistency in migration routes of Yakutia breeding birds was generally higher than that of birds breeding in Chukotka. Our results suggest that the northward migration schedule of the Whimbrels is mainly controlled by endogenous factors, while the southward migration schedule is less affected by endogenous factors. The repeated use of stopover sites in the Yellow Sea coast suggests this region is important for the migration of Whimbrel, and thus has high conservation value.

China's coastal wetlands provide breeding, migration stopover, and wintering habitats for about 230 waterbird species, which is more than a quarter of all waterbirds in the world. Large-scale and high intensity human activities have resulted in serious loss and degradation of coastal wetlands over the past half century, causing population declines in many waterbirds. Through a literature review and expert surveys, this article reviews conservation measures taken in recent decades to protect waterbirds in China's coastal wetlands and provides recommendations for future conservation action from three aspects: policy and administration, habitat conservation and management, and multiparty participation. Over the past decades, many conservation legislation, regulations and action plans at the national level and more site-specific measures and interventions have been implemented, with notable improvement in the effectiveness in policy making and multi-stakeholder participation. Accordingly, some threats to waterbirds have been mitigated and many key sites for waterbirds have been designated as strictly protected nature reserves. However, some critical issues still remain, mostly related to habitat conservation and management, such as coastal wetland restoration, control of invasive Spartina alterniflora, control of environmental pollution, and improvement of artificial habitat quality. We highlight that protecting natural tidal wetlands and improving habitat quality are critical for the conservation of coastal waterbirds, especially those highly dependent on the intertidal wetlands. China has demonstrated strong commitment to ecological conservation and restoration for the future, in terms of both funding and policies for biodiversity and wetland ecosystems. It is important that this commitment to conserve coastal waterbirds is supported continuously by science- and evidence-based decisions and actions.

The Hooded Crane (Grus monacha) is listed as a Vulnerable species in the IUCN red list. Tidal wetland (tideland), the major habitat for wintering Hooded Cranes at East China's Chongming Dongtan, has dramatically changed in the past two decades, but there is limited knowledge about the population and habitat changes of the Hooded Cranes. This study investigated the population size and distribution of wintering Hooded Cranes at Chongming Dongtan from 2000 to 2021. We used remote sensing images combined with a vegetation classification algorithm to analyse the distribution of saltmarsh vegetation. The quadrat method was used to investigate the density and weight of the underground corms of Sea Bulrush (Scirpus mariquter), the main food on tideland for the Hooded Cranes. From 2000 to 2021, the population number of wintering Hooded Cranes at Chongming Dongtan remained stable at approximately 100. In 2000, the area of Scirpus spp. and Common Reed (Phragmites australis) accounted for approximately half of the total saltmarsh area at Chongming Dongtan, respectively. The invasive Smooth Cordgrass (Spartina alterniflora) rapidly expanded on tideland in the 2000s while the Scirpus spp. was competed out and thus significantly reduced in area. After the implementation of an ecological project to control Smooth Cordgrass and to restore Scirpus spp. in the 2010s, the area of the Smooth Cordgrass decreased considerably while the area of Scirpus spp. increased. The corms of Sea Bulrush decreased on the southeastern tideland during the study period, which might be the cause of the northward movement of the foraging Hooded Cranes on tideland. We also found Hooded Cranes foraged crops in the nearby farmland in mid-winter, causing human-bird conflicts in the recent decade. Our results found that changes in habitat and food conditions on tideland impacted wintering Hooded Cranes. Foraging in farmland with human disturbance in the recent decade might be related to insufficient food on tideland. We suggest active intervention to accelerate the restoration of Sea Bulrush on tideland and reduce human disturbance in farmland to improve the habitat quality of the wintering Hooded Crane at Chongming Dongtan.

Determining the migration routes and connections of migratory birds at the population level helps clarify intraspecific differences in migration. Five subspecies have been recognized in the Whimbrel (Numenius phaeopus) in Eurasia. Ssp. rogachevae is the most recently described subspecies. It breeds in Central Siberia, while its non-breeding region and migration routes are still unclear. We tracked the migration of Eurasian Whimbrels captured at three non-breeding sites (Moreton Bay in east coast of Australia, Roebuck Bay in Northwest Australia and Sungei Buloh Wetland in Singapore) and two migration stopover sites (Chongming Dongtan and Mai Po Wetland in China). We determined the breeding sites and inferred the subspecies of the tagged birds in the East Asian – Australasian Flyway (EAAF) based on the known breeding distribution of each subspecies. Of the 30 tagged birds, 6 and 21 birds bred in the breeding range of ssp. rogachevae and variegatus, respectively; one bred in the presumed transition area between the breeding range of ssp. phaeopus and rogachevae, and two bred in the region between the breeding range of ssp. rogachevae and variegatus. The birds that bred in the ssp. rogachevae breeding range spent their non-breeding season in the northern Sumatra, Singapore, East Java and Northwest Australia and mainly stopped over along China's coasts during migration. None of our birds bred in the exclusive breeding range of the phaeopus subspecies. Previous studies have predicted that rogachevae whimbrels migrate along the Central Asian Flyway and spend the non-breeding season in West India and East Africa. We found that at least some rogachevae whimbrels migrate along the EAAF and spend the non-breeding season in Southeast Asia and Australia. The ssp. phaeopus is at best sparsely distributed in the EAAF in the west region, or possibly does not occur at all.