BioOne.org will be down briefly for maintenance on 12 February 2025 between 18:00-21:00 Pacific Time US. We apologize for any inconvenience.
Registered users receive a variety of benefits including the ability to customize email alerts, create favorite journals list, and save searches.
Please note that a BioOne web account does not automatically grant access to full-text content. An institutional or society member subscription is required to view non-Open Access content.
Contact helpdesk@bioone.org with any questions.
Waterbirds publishes content regarding the biology, status, ecology, management and conservation of all waterbird species living in habitats worldwide.
We studied shorebird diversity, abundance, distribution, and behavior on Bulls Island, South Carolina, a protected and minimally disturbed barrier island on the mid-Atlantic coast of the United States during the non-breeding seasons of 2018 and 2019. We recorded 21 shorebird species on Bulls Island. Average densities of shorebirds ranged from 4102505 birds per linear km of beach throughout the two study seasons. Shorebird species richness was significantly affected by the number of local microhabitats (χ21 = 83.51, P < 0.0001, n = 35) and by number of invertebrate taxa (χ21 = 10.21, P = 0.001). Foraging behavior of four focal species varied across available habitats and both location and rate of foraging were associated with greater invertebrate availability and proximity to other foraging shorebirds. Dunlin (Calidris alpina) exhibited the highest foraging rate compared to Piping Plovers (Charadrius melodus), Semipalmated Plovers (Charadrius semipalmatus) and Sanderling (Calidris alba). Despite some differences between species, foraging rates were highest on marsh relicts and mudflats in March and April, and lowest during high tide in all habitats. Aggressive interactions occurred in 12225% of observations depending on the species and were more frequent in habitats with greater invertebrate availability. Bulls Island, through its mosaic of habitats, provides conditions for a diverse and abundant shorebird community, and thus is an important non-breeding location worthy of further protection.
Foraging behavior of Snowy Egrets (Egretta thula) was studied in a tidal estuary in the northeastern USA over a three-year period. Among all observations of egrets foraging (n = 1,223), 8.4% were of “tongue-fluttering', a foraging technique in which an egret inserts the tip of its bill into the water surface and flutters its tongue so that a stream of ripples is generated. Tongue-fluttering was usually practiced when the bird stood in deep water and oriented downstream to produce an expanding ‘V’ of ripples. Limited observations suggested that the ripples attracted small fish and that the egrets had high capture success. Multiple observations suggested that egrets feeding simultaneously by tongue-fluttering distributed themselves in echelon formation, so that downstream birds were located near to ripples generated by upstream birds. These observations provide new information on tongue-fluttering, show that it is locally frequent in a tidal estuary, and suggest that Snowy Egrets practicing this technique can catch fish at rates comparable to those that have been reported for other foraging techniques.
Malaysia lies within the East Asian-Australasian Flyway (EAAF), among the world's most species-rich and threatened flyways, which provides stop-over sites for millions of passages and wintering birds. Although some mudflats along the west coast of Peninsular Malaysia are classified as Important Bird and Biodiversity Areas (IBA), no detailed studies have been conducted to compare shorebird composition and diversity between these locations. Hence, the species composition and diversity of shorebirds was assessed in established plots on mudflats of the North-central Selangor Coast (NCSC) and Teluk Air Tawar Kuala Muda Coast (TAT-KMC) between December 2022 and January 2023. A total of 31 species from three families, Charadriidae, Scolopacidae, and Laridae, were documented throughout the study. There was a significant difference in shorebird species composition between the two sites. TAT-KMC recorded more threatened species including the Far Eastern Curlew Numenius madagascariensis and Nordmann's Greenshank Tringa guttifer. Despite the presence of more threatened species at TAT-KMC, the results showed both stop-over sites are important for migratory shorebirds along EAAF. The data obtained are valuable for assessing the current species richness and abundance, highlighting the importance for these IBAs to be designated as another Flyway Site Network representing west coast Peninsular Malaysia in order to enhance their protection and conservation efforts.
Lake Izunuma-Uchinuma in northern Japan experienced extensive flooding in July 2022, resulting in significant damage to the vegetation of the lotus Nelumbo nucifera. Lake Izunuma which has an area of 357 ha, was 62% covered by lotus vegetation in October 2021, but only 11% in September 2022. Whooper Swans (Cygnus cygnus) that winter in Lake Izunuma-Uchinuma forage mainly on the rhizomes of the lotus. The number of Whooper Swans wintering from November 2022 to January 2023 decreased significantly compared to the preflood season of 2021/2022. The number of swans in Lake Izunuma-Uchinuma decreased significantly compared to the populations of swans at other wintering sites, despite the fact that the daily average temperatures at the three sites on the migration route of the swans did not differ significantly between these seasons. The significant decrease in lotus vegetation caused by flooding in July 2022 is considered the cause of the decrease in the number of Whooper Swans wintering on the lake in the 2022/2023 season.
This article is only available to subscribers. It is not available for individual sale.
Access to the requested content is limited to institutions that have
purchased or subscribe to this BioOne eBook Collection. You are receiving
this notice because your organization may not have this eBook access.*
*Shibboleth/Open Athens users-please
sign in
to access your institution's subscriptions.
Additional information about institution subscriptions can be foundhere