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Flooding rice (Oryza sativa) agricultural fields during winter to facilitate rice straw decomposition has mitigated the loss of some of the natural wetlands in California’s Central Valley. We conducted bird surveys in 253 rice checks (2,158 ha) within 177 rice fields in the Sacramento Valley during the fall and winter of 2021–2022 and 2022–2023 to evaluate factors that influence bird use of winter-flooded, post-harvest rice fields enrolled in the California Winter Rice Habitat Incentive Program. We counted 143,932 birds from 57 species, including dabbling ducks (86.4%), geese (8.0%), shorebirds (0.9%), wading birds (0.7%), and other birds (4.0%). Extrapolating from the lowest densities observed in rice fields during the 70-day mandatory flooding period, we estimated that properties enrolled in this public–private partnership provided habitat for at least 271,312 birds day-1 (16,248 ha; 2021–2022) and 147,315 birds day-1 (8,448 ha; 2022–2023), totaling >10 million bird-use-days each winter. Water depth had the greatest influence on bird abundance and diversity. Relatively shallow water depths (≤13 cm) had greater abundance of shorebirds, wading birds, and geese, and higher diversity, whereas intermediate depths (~23 cm) resulted in the greatest dabbling duck abundance. Duck, goose, and wading bird abundances were greatest—and species richness and family diversity were highest—8 days after the onset of flooding in rice fields (typically late October), followed by a decline in bird use until 65 to 87 days post-flooding, after which bird use increased slightly. Bird abundance and species diversity were lowest in rice fields with the greatest hunting intensity (≥3 days week-1). We identified several habitat variables that could be managed and prioritized by land-owner incentive programs to increase bird use of winter-flooded rice, including water depth, variation in emergent vegetation height, mudflat habitat availability, rice check shape, hunting intensity, and post-harvest treatment of residual rice straw.

Knowledge of the habitat requirements for migratory species throughout their full annual cycle is necessary for comprehensive species protection plans. By describing seasonal shifts of space‐use patterns in a key nonbreeding area, the Senegal Delta (Mauritania, Senegal), this study addresses a significant knowledge gap in the annual cycle of the rapidly declining continental Black‐tailed Godwit Limosa limosa limosa. We fitted continuous‐time stochastic‐process movement models with GPS location data to describe the core areas used by 22 GPS‐tagged godwits over the 2022–2023 nonbreeding period. We mapped key habitat types, such as floodplain wetlands and rice fields, via supervised classification of satellite imagery. Godwits in the Senegal Delta show a distinct shift in habitat use over the nonbreeding period. The core areas of godwits in the early stages of the nonbreeding period (the wet season) were primarily in natural wetlands and fields with newly planted rice. As the rice crop matured and became too dense, godwits moved towards more recently sown rice fields. Later, as floodwaters receded and rice fields dried out, godwits abandoned rice fields and shifted towards natural wetlands with fewer invasive plants, particularly within the marshes and shallow floodplains of nature‐protected areas in the lower Delta. Synthesis and applications: Our findings illustrate the shifting importance of natural and agricultural wetlands for godwits at different stages of the nonbreeding season. Protected areas in the Senegal Delta, particularly the Djoudj National Bird Sanctuary (Senegal) and Diawling National Park (Mauritania), are crucial habitats during the dry season as godwits prepare for their northward migration, whilst rice fields take a key role during the wet season. Conservation efforts should prioritize eradicating invasive plants from the Djoudj and Diawling, as well as promote agroecological management in specific rice production complexes indicated in this study. [ABSTRACT FROM AUTHOR]

Collecting empirical data is essential for understanding the ecology and biology of a species. If the data collection procedure includes direct interaction with the study subject, particularly regarding repeated measures, there may be a risk of introducing biases on the collected dataset due to changes in the behaviour and/or physiology of the studied individuals. This can be particularly relevant during the breeding season when disturbance by researchers can affect birds on various aspects, including nest and chick survival, physiology, and chick body condition. Researcher effects on the chicks' body condition have been shown in some species, but were apparently absent in others. Here, we investigate whether varying levels of handling influences the body condition of Eurasian whimbrel (Numenius phaeopus) chicks, using data collected on 88 individuals handled up to 11 times, during two breeding seasons. We found that neither the handling event (ordinal occasion when a chick was handled) nor the handling interval (period between two consecutive handling events) affected the chick's body condition, but we found evidence that body condition is individually consistent during development. Hence, the levels of handling in our study did not have an apparent effect on Eurasian whimbrel chicks' body condition. Although other potential effects may arise via researchers' disturbance, our findings contribute to the discussion on researchers' impacts on their study subjects, emphasizing the importance of species-specific evaluations to improve research methodologies and ethical practices. [ABSTRACT FROM AUTHOR]

Sexing bird species with monomorphic plumage is generally challenging, and sexual size dimorphism (SSD) is often used to develop morphometric-based sexing tools, e.g., using discriminant functions. Within species, local selection pressures, age-related and season-related growth may, however, induce geographical and temporal variations in body size and SSD. Such variations may complicate the development of reliable morphometric-based sexing methods at a broad scale. We first investigated body size variations in a migratory shorebird species with wide breeding and wintering ranges, the Sanderling Calidris alba, within the two breeding populations (Greenland and Russia) and three staging/wintering populations (United Kingdom, Iceland and Mauritania), which belong to the same flyway. Then, for samples from each region, we tested whether site-specific (i.e., "regional") functions performed better than functions developed for birds from the other sites (i.e., "foreign" functions) or than an overall ("flyway") function that combined all sampled individuals. We found minor variations in SSD between regions, but significant differences in body size between sexes and regions. Females were larger than males and, for instance, breeders had longer wings than staging and wintering birds. Regional functions had similar sexing efficiency as any other functions applied to sample from each region, except for Western Africa where the regional function performed slightly better than some of the other functions. Furthermore, the flyway function developed after merging all subsamples had a similar efficiency than the regional functions, i.e., from 75.4% to 90% of correct sex assignment depending on the region. Given the small or lack of benefit in using regional functions, we conclude that the flyway function can be used reliably to sex Sanderlings measured at different sites, years or seasons within the East Atlantic flyway. Our results may help to develop global sexing function for other bird species. [ABSTRACT FROM AUTHOR]

Migrating animals are thought to be important spillover sources for novel pathogens. Haemosporidians (malaria‐related parasites) are one such group of pathogens that commonly spillover into novel host communities if competent vectors are present. In birds, shorebirds (sandpipers, plovers and allies) perform some of the longest avian migrations, yet they are traditionally perceived as relatively free from haemosporidians. Although low prevalence fits several theories, such as effective immune responses or low exposure to vectors, few studies have been carried out in freshwater inland sites, where the vectors of haemosporidians (e.g. mosquitoes) are abundant, with a mixture of actively migrating (staging) and breeding hosts. Here we report the prevalence of three haemosporidian parasites, Haemoproteus, Leucocytozoon and Plasmodium, screened in 214 shorebirds from 15 species sampled in a freshwater marshland, southern Belarus. Contrary to most previous studies, we found that haemosporidians were frequent, with an overall prevalence in the community of 16.36%, including the locally breeding shorebirds (23.13%, 134 individuals of 10 species). However, actively migrating shorebirds had much lower prevalence (0.05%, 55 individuals of five species). We suggest that blood parasite infections are more common in shorebirds than currently acknowledged. Yet, actively migrating species may be free from haemosporidians or carry suppressed infections, leading to lower prevalence or even apparent absence in some species. Taken together, we theorize that a combination of sampling biases has driven our understanding of haemosporidian prevalence in shorebirds and future studies should take the migratory status of individuals into account when reporting prevalence. Furthermore, we argue that birds undergoing active migration may be less likely sources of spillover events than previously assumed. [ABSTRACT FROM AUTHOR]

Measures to boost populations can help ensure population persistence in the short‐term while longer‐term conservation interventions take effect. Headstarting, involving the collection of wild early life‐stage individuals, rearing in captivity, and release into a new or existing population once independent, has recently been identified as a potential translocation technique to assist small breeding populations of waders declining due to low levels of productivity. However, the demographic rates of headstarted individuals have not been quantified, and their impact on target populations not understood, which is required to determine the efficacy of this technique as a tool for species recovery. Between 2017 and 2022, headstarting was trialled as a tool to supplement the critically small sub‐population of black‐tailed godwit (Limosa limosa limosa) breeding at the Ouse Washes, Eastern England. We demonstrate that a high survival rate for eggs and chicks can be achieved through artificial incubation and hand‐rearing, and that headstarting can substantially increase the overall productivity of a small population. Using survival analysis and mixed effects modelling, we show that apparent survival and breeding success of headstarted individuals is comparable to wild‐reared conspecifics. The survival rate of released birds was sufficient to significantly boost the breeding population, reaching over five times the number of breeding pairs at the release site during the trial. Providing demographic rates remain the same, the number of godwits breeding at the Ouse Washes is predicted to continue to increase moderately over the next 20 years. This study highlights the potential of headstarting to boost small populations of breeding waders, and demonstrates the value of this technique to assist with the recovery of threatened populations when there is a clear justification that headstarting can negate the effects of population limiting factors. [ABSTRACT FROM AUTHOR]

A combination of life history traits and environmental conditions has been highlighted as the main drivers of avian breeding success. While drivers of breeding success are well known in some species, especially birds in northern, temperate regions; species in other parts of the world have received relatively little attention. In this study, we used a long‐term dataset on breeding success of tropical plovers from south‐west Madagascar to investigate whether nest survival changed over time and whether the drivers of nest survival were similar for multiple species breeding in the same arid habitat. In the 12‐year period of 2009–2020, we monitored 2077 nests for three species with different breeding strategies: 1185 nests of Kittlitz's plovers (Anarhynchus pecuarius) with a flexible breeding strategy and uniparental care; and 565 nests of white‐fronted plovers (A. marginatus) and 327 nests of Madagascar plovers (A. thoracicus) which both have biparental care. We found that nest survival was associated with a combination of clutch‐size, age of nest and year among the three plover species. In addition, annual variation in climatic conditions associated with El Niño/La Niña events were included in the most supported survival models for Kittlitz's and white‐fronted plovers, but the effects were not significant. Overall estimates of daily nest survival were similar for all three species: Kittlitz's plover: 0.950 ± 0.002 SE, Madagascar plover: 0.919 ± 0.007 SE, and white‐fronted plover: 0.862 ± 0.047 SE. Estimates of nest success for the breeding season, based on increases in daily nest survival with the clutch age during the incubation periods (26 days for Kittlitz's plovers and 29 days for Madagascar and white‐fronted plovers), were relatively low: Kittlitz's plover: 0.161 ± 0.056 SE, Madagascar plover: 0.287 ± 0.022 SE, and white‐fronted plover: 0.228 ± 0.019 SE. All three species had a combination of factors affecting nest survival, both environmental and life history traits. [ABSTRACT FROM AUTHOR]

A robust understanding of the mechanisms driving demographic change in wild animal populations is fundamental to the delivery of effective conservation interventions. Demographic change can be driven by variation in adult survival, recruitment of juveniles into the breeding population or breeding productivity – the number of fledglings produced per breeding pair. Across Europe, low breeding productivity in wader populations has been a significant driver of population decline, increasing the importance of gathering accurate data on breeding productivity. Monitoring wader breeding productivity is challenging because finding nests can be time‐consuming and requires experienced fieldworkers; wader chicks are nidifugous and difficult to count due to their cryptic behaviour; and waders often have high re‐laying rates following nest failure, meaning that hatching or fledging can be highly asynchronous. This paper reviews approaches to estimating breeding productivity where fieldworkers either record the agitation or alarm‐calling behaviour of adults with dependent young, make direct observations of broods on survey visits, or both. Using a systematic literature search (restricted to Europe where most of these studies have taken place) we identified 38 peer‐reviewed papers which used this approach. The productivity metrics produced can be divided into the following categories: (i) 'Hatching Success' (HS), (ii) 'Fledging Success' (FS) and (iii) 'Young Fledged Per Pair' (YFP), from the coarsest to the most precise. The first two metrics are most often used when direct observations of broods are not possible due to the behaviour of broods or vegetation structure; YFP is preferred if brood counts are possible. Design of an appropriate metric depends on (i) whether accurate brood counts are possible; (ii) whether adults exhibit diagnostic agitation behaviour when young are present; (iii) whether individual breeding territories are separable; (iv) whether re‐nesting rates are assumed to be high; and (v) the availability of experienced surveyors (particularly where behavioural observations are required). Globally there are many wader species for which the methods described here could provide valuable information and we hope this review encourages further development or adoption of these methods. [ABSTRACT FROM AUTHOR]

The ecosystem services and functions of tidal flats have been overlooked for many decades, and tidal flat loss has been identified as a serious threat to many taxa in recent years, especially for migratory waterbirds. Despite the understanding of tidal flats change on the global scale, there are still a lot of unknowns on the small scale, including tidal flats in Taiwan, which are important stopover sites for migratory waterbirds along the East Asian–Australasian Flyway. Therefore, we collated historic topographic maps, Landsat Archive images between the 1920s and the 2020s to determine the trajectories of tidal flat change along the coastline of Taiwan. Our results show that tidal flat coverage expanded between the 1920s and the 1950s, but lost approximately 266 km2 (58%) between the 1950s and the 2010s. The status of the tidal flats along the western coastline of Taiwan has been identified as “Endangered” based on the criteria of the IUCN Red List of Ecosystems. According to the aims of the Global Biodiversity Framework, we suggest rethinking the land use plans along the coastline to mitigate the tidal flat loss, especially the controversial issues concerning the expansion of green energy infrastructure. To realize the Nature Positive goals by 2030, recovering and restoring the tidal flat ecosystem could be one of the key strategies. [ABSTRACT FROM AUTHOR]

Shorebirds represent key indicator species for evaluating the health of wetlands, as they rely on specific habitats for breeding and foraging. Several restoration actions were initiated to restore these wetlands in the Hortobágy (Hungary), however, their effects have never been assessed. Since birds are good indicators of the health and quality of natural environment and sensitive to changes in land use and climate, we evaluated the restoration actions conducted in the last 20 years using bird monitoring data. Our study focuses on the long-term effects of different habitat restoration actions implemented in the region, which involved no restoration, targeted and non-targeted type of interventions for shorebird management as well as long-term and short-term management. The evaluation is based on long-term monitoring data of shorebird species: Black-winged Stilt, Northern Lapwing, Black-tailed Godwit, Common Redshank and Common Snipe. The effectiveness of restoration actions found to have a species-specific aspect, but in general, our findings indicate positive effects of targeted and long-term restoration actions on breeding shorebird populations. By contrast, targeted but short-term actions led to even worse results for shorebird breeding population size than where no restoration actions were initiated. These findings contribute to a better understanding of the specific habitat requirements of breeding shorebirds in the steppe region and can inform future habitat management strategies. The results can be used in conservation planning and management and highlight the importance of long-term and targeted habitat reconstruction projects in restoring and maintaining breeding shorebird populations.

The Sanderling (Calidris alba) is the most widely distributed shorebird that winters on both coasts of America, with records of vagrant individuals in the interior of the continent. On 14 September 2022, we observed and photographed two juvenile Sanderlings at a small pool adjacent to the Río Mezquites in the Cuatro Ciénegas protected area, Coahuila, Mexico. This sighting represents the first record of this species in this RAMSAR site, and increases the known inland distribution in northeastern Mexico, as well as the first documented for the state of Coahuila.

Conserving bird populations is a key goal for management of the Sacramento–San Joaquin Delta ecosystem and is likely to have effects well beyond its boundaries. To inform bird- conservation strategies, we identified Priority Bird Conservation Areas for riparian landbirds and waterbirds in the Delta, defined as the most valuable 5% of the landscape for each group. We synthesized data from 2,547 surveys for riparian landbirds and 7,820 surveys for waterbirds to develop predictive distribution models, which then informed spatial prioritization analyses. We identified a total of 26,019 ha that are a high priority for conserving riparian landbirds, waterbirds, or both, representing the most important places in the Delta to protect and manage, as well as strategic areas where adjacent restoration could expand valuable habitat. These Priority Bird Conservation Areas include the Yolo Bypass Wildlife Area, Cosumnes River Preserve, Stone Lakes National Wildlife Refuge, and bufferlands that surround the Sacramento County Regional Sanitation District. However, we also found that over 60% of the Priority Bird Conservation Areas are not currently protected, indicating a vulnerability to changes in land cover or land use. We recommend advancing strategies for bird conservation in the Delta by developing more specific objectives and priorities, extending these analyses to include other bird species, and planning to mitigate the loss of Priority Bird Conservation Areas where they are most vulnerable to land cover change. The predictive models and analysis framework we developed represent the current state of the science on areas important to bird conservation, while also providing a foundation for an evolving bird-conservation strategy that reflects the Delta’s continuously evolving knowledge base and landscape.

Conventional life-history theory predicts that energy-demanding events such as reproduction and migration must be temporally segregated to avoid resource limitation. Here, we provide, to our knowledge, the first direct evidence of 'itinerant breeding' in a migratory bird, an incredibly rare breeding strategy (less than 0.1% of extant bird species) that involves the temporal overlap of migratory and reproductive periods of the annual cycle. Based on GPS-tracking of over 200 female American woodcock, most female woodcock (greater than 80%) nested more than once (some up to six times) with short re-nest intervals, and females moved northwards on average 800 km between first and second nests, and then smaller distances (ca 200+ km) between subsequent nesting attempts. Reliance on ephemeral habitat for breeding, ground-nesting and key aspects of life history that reduce both the costs of reproduction and migration probably explain the prevalence of this rare phenotype in woodcock and why itinerant breeding so rarely occurs in other bird species. [ABSTRACT FROM AUTHOR]

Highly migratory shorebirds are among the fastest declining avian guilds, so determining causes of mortality is critically important for their conservation. Most of these species depend on a specific geographic arrangement of suitable sites that reliably provide resources needed to fuel physiologically demanding life histories. Long-term mark-resight projects allow researchers to investigate specific potential sources of variation in demographic rates between populations. Red Knots (Calidris canutus) occur in three relatively distinct regions across the northern Gulf of Mexico, and two of these areas have been experiencing episodic harmful algal blooms (red tide) with increased frequency in recent decades. Since knots are mostly molluscivorous during the nonbreeding season in the Gulf, they are potentially exposed to red tide toxins at high concentrations via their filter-feeding prey. We used long-term mark-resight data from Texas, Louisiana, and Florida (USA) to estimate apparent survival, and to assess the effects of red tides on survival of Red Knots. We also assessed effects of tracking devices deployed in conjunction with the projects over the years. While overall apparent annual survival rates were similar across the three locations (0.768-0.819), several red tide events were associated with catastrophically low seasonal (fall) survival in Florida (as low as 0.492) and Texas (as low as 0.510). Leg- mounted geolocators, but not temporary glued-on VHF tags, were associated with a reduction in apparent survival (~8%/year). Movement of knots between the three areas was rare and site fidelity is known to be high. Harmful algal blooms are predicted to increase in frequency and severity with climate change and increased anthropogenic degradation of coastal habitats, which may further endanger these as well as other shorebird populations around the world. [ABSTRACT FROM AUTHOR]

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There is often substantial variation in habitat type and quality within species ranges and management units, especially in wetland ecosystems. This variation necessitates quantifying behavioral and habitat associations to inform conservation of wetland-dependent species. This study explored drivers of American Avocet (Recurvirostra americana) energy expenditure to evaluate patterns of habitat use during the non-breeding season at Mustang Island in Texas, U.S.A. and Rockefeller Wildlife Refuge in Louisiana, U.S.A., on the coast of the Gulf of Mexico. A Bayesian linear mixed model was used to analyze GPS-acceleration data from tracking devices on 31 American Avocets, with overall dynamic body acceleration (a proxy for energy expenditure) as a response variable and tide, time of day, day of year, and landcover as hypothesized drivers. Results suggested that landcover, tide amplitude, and time of day explained substantial variation in energy expenditure, and each site showed unique patterns in these relationships. For example, the interaction of landcover and tide was heavily influential at Rockefeller, whereas Mustang Island birds showed a substantial dichotomy in energy expenditure between day and night. Using energy expenditure to understand habitat associations could be helpful to better understand variation in habitat use and behavior and customize conservation planning in dynamic ecosystems. [ABSTRACT FROM AUTHOR]

Artificial structures are often used as a tool for habitat restoration and the recreation of degraded coastal ecosystems and their associated food webs. However, it is often unknown if and how these artificial structures may influence the habitat use of target species, thereby hampering restoration goals. In this study, we test how artificial barriers, deployed to enhance the creation of an intertidal mussel bed, influenced the mussel‐habitat use by two bird species under pressure, Eurasian oystercatchers and Eurasian curlews. Average bird presence was monitored using time‐lapse camera's from the start of the mussel bed restoration in August 2018 until April 2019. We found that in the first few months of the experiment, both oystercatchers and curlews avoided the restored mussel beds containing artificial structures in the form of metal barriers that act as traps for dislodged mussels. Thereafter, the presence of barriers had no negative influence on the average presence of oystercatchers or curlews. In fact, curlews were significantly attracted to the mussel beds with barriers in January and February. In addition, we found a negative effect of the presence of European herring gulls on the presence of oystercatchers and curlews. The higher herring gull densities in the first 2 months of the experiment might explain the lower‐than‐expected curlew and oystercatcher densities observed in August. To our knowledge, no other studies have investigated the effect of artificial restoration structures on the abundance or habitat use of specific shorebirds. [ABSTRACT FROM AUTHOR]

Sexual behavior, including courtship and mating strategies, remains unexplored for numerous tropical birds. The Andean Lapwing (Vanellus resplendens) is a shorebird inhabiting the High Andes with a poorly known reproductive biology. Here, we aimed to describe behaviors of this species at the beginning of the breeding season. We performed 49 standardized observations of 20 pairs of Andean Lapwings at Laguna de Salinas, Arequipa, Peru, at 4,315 m asl, during the 2021–2022 breeding season. Lapwings in this studied population show (1) social monogamy and evident territoriality, (2) a defined breeding season apparently triggered by rainfall, and (3) a male-biased investment in courtship and territorial defense. Andean Lapwing pairs devoted 15% of their time to courtship activities, males on average doubled the amount of time of females—consisting mostly of nest scraping activities, various displays, and territory defense. Although these observations of Andean Lapwings increase our understanding of breeding strategies in populations inhabiting high-altitude landscapes, the reproductive behavior of most endemic species in the Neotropical mountains remains understudied and requires targeted investigations. El comportamiento sexual, incluyendo las estrategias de cortejo y apareamiento, siguen sin explorarse en numerosas especies de aves tropicales. Vanellus resplendens es un ave playera que habita los altos Andes, con una biología reproductiva poco conocida. En esta investigación, nuestro objetivo fue describir los comportamientos de esta especie durante el comienzo de la temporada reproductiva. Realizamos 49 observaciones estandarizadas de 20 parejas de Vanellus resplendens en la Laguna de Salinas, Arequipa, Perú a 4,315 m snm durante la temporada reproductiva 2021–2022. Las aves en esta población estudiada muestran: (1) monogamia social y territorialidad evidente; (2) una temporada reproductiva definida aparentemente por el inicio de las lluvias; y (3) una inversión en el cortejo y la defensa territorial sesgada hacia los machos. Las parejas de Vanellus resplendens dedicaron el 15% de su tiempo a actividades del cortejo, los machos en promedio duplicaron en tiempo a las hembras—que consisten principalmente en escarbar nidos y actividades relacionadas, despliegues terrestres y aéreos, y defensa de territorio. Aunque estas observaciones aumentan nuestra comprensión de las estrategias de reproducción en las poblaciones que habitan paisajes a gran altitud, el comportamiento reproductivo de la mayoría de las especies endémicas de las montañas neotropicales sigue siendo poco estudiado y requiere investigaciones específicas. Palabras clave: Andes, apareamiento, aves playeras, fenología, neotropical, reproducción. [ABSTRACT FROM AUTHOR]

Highly migratory shorebirds are among the fastest declining avian guilds, so determining causes of mortality is critically important for their conservation. Most of these species depend on a specific geographic arrangement of suitable sites that reliably provide resources needed to fuel physiologically demanding life histories. Long-term mark-resight projects allow researchers to investigate specific potential sources of variation in demographic rates between populations. Red Knots (Calidris canutus) occur in three relatively distinct regions across the northern Gulf of Mexico, and two of these areas have been experiencing episodic harmful algal blooms (red tide) with increased frequency in recent decades. Since knots are mostly molluscivorous during the nonbreeding season in the Gulf, they are potentially exposed to red tide toxins at high concentrations via their filter-feeding prey. We used long-term mark-resight data from Texas, Louisiana, and Florida (USA) to estimate apparent survival, and to assess the effects of red tides on survival of Red Knots. We also assessed effects of tracking devices deployed in conjunction with the projects over the years. While overall apparent annual survival rates were similar across the three locations (0.768 – 0.819), several red tide events were associated with catastrophically low seasonal (fall) survival in Florida (as low as 0.492) and Texas (as low as 0.510). Leg-mounted geolocators, but not temporary glued-on VHF tags, were associated with a reduction in apparent survival (~8%/year). Movement of knots between the three areas was rare and site fidelity is known to be high. Harmful algal blooms are predicted to increase in frequency and severity with climate change and increased anthropogenic degradation of coastal habitats, which may further endanger these as well as other shorebird populations around the world.

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.

Grasslands are among the most impacted ecosystems globally. In the midcontinent of North America, a > 80% loss of grasslands has made their conservation a major priority for resource managers. Grassland ecosystems evolved under periodic disturbances; consequently, grassland management often involves regular actions such as grazing, haying, or burning to maintain ecosystem integrity. The timing of such practices has direct implications on grassland ecology, agricultural economics, and survival and fecundity of grassland nesting birds (hereafter grassland birds). We conducted a meta-analysis on the nesting phenology of grassland birds throughout North America, focusing on nest-survival literature. We constructed a well-fitting model to predict median date of expected nest departure (hereafter fledge date) for grassland birds across the midcontinent. Predictions from our model demonstrate considerable spatial variation in median nesting phenology that is predictable using a spatially explicit spring phenology index. Median fledge dates were 8 or 13 days earlier in years of extreme weather conditions (dry or wet, respectively) than in years of average conditions. Species that generally nest in taller vegetation tended to have later median nest phenologies than those using shorter vegetation. Our results incorporate the most rigorous information available in the literature on nesting phenology of 36 grassland bird species and improve information available to managers about nesting phenology of grassland birds in the midcontinent of North America. Our predictions approximate the day when one-half of the nesting efforts would be complete for a given area within the midcontinent grasslands and can inform management and conservation decisions about the timing of management actions in grassland ecosystems.

There has been an increasing number of coastal restoration projects to eradicate Smooth cordgrass (Spartina alterniflora) and restore bare tidal flats to conserve waterbirds. However, the evidence for the assumed benefits to waterbirds and benthic organisms after such restoration efforts remains limited. We evaluated the impact of S. alterniflora eradication on waterbirds and benthic organisms in southern China. We deployed time‐lapse cameras and satellite trackers to quantify and compare the occurrence frequency and habitat use of birds in different habitats. We compared the density and biomass of benthic organisms collected in bare tidal flats and areas where S. alterniflora had been eradicated. We found that almost all waterbirds, except gulls, avoided areas where S. alterniflora was present. Once S. alterniflora was eradicated, the species richness and species‐level diversity of shorebirds and waterbirds did not differ significantly from those of the bare tidal flats. At least 9 out of 14 tracked individual shorebirds used areas where S. alterniflora had been eradicated, with Common Redshank (Tringa totanus) demonstrating a clear preference for such habitat. The density and biomass of benthos in deeper sediments (5–20 cm below the surface) were significantly lower in areas where S. alterniflora had been eradicated than in bare tidal flats, indicating that the food resources for birds may take longer than 1 year to recover. This research demonstrates that the eradication of S. alterniflora is important for the restoration of waterbird habitats, and such efforts should be made in areas that are important to waterbirds. [ABSTRACT FROM AUTHOR]

In biparental Charadriinae plovers, male and female incubation duties often resemble daily routines, with males typically incubating at night and females incubating during the day. By analysing incubation behaviour in three Arctic populations of Common Ringed Plover Charadrius hiaticula, we show that these diel routines are lost in the 24-h sunlight of the Arctic. In contrast, a non-Arctic population in East Scotland exhibited significant daily routines, with males dominating incubation during the late afternoon and night, and females dominating incubation during the early morning and midday hours. These patterns suggest that clear light/dark cycles are necessary for daily incubation routines to form in the Common Ringed Plover, although further research is needed to understand the specific drivers of this behaviour. [ABSTRACT FROM AUTHOR]

Mercury (Hg) pollution remains a concern to Arctic ecosystems, due to long-range transport from southern industrial regions and melting permafrost and glaciers. The objective of this study was to identify intrinsic, extrinsic, and temporal factors influencing Hg concentrations in Arctic-breeding shorebirds and highlight regions and species at greatest risk of Hg exposure. We analyzed 1094 blood and 1384 feather samples from 12 shorebird species breeding at nine sites across the North American Arctic during 2012 and 2013. Blood Hg concentrations, which reflect Hg exposure in the local area in individual shorebirds: 1) ranged from 0.01–3.52 μg/g ww, with an overall mean of 0.30 ± 0.27 μg/g ww; 2) were influenced by species and study site, but not sampling year, with birds sampled near Utqiaġvik, AK, having the highest concentrations; and 3) were influenced by foraging habitat at some sites. Feather Hg concentrations, which reflected Hg exposure from the wintering grounds: 1) ranged from 0.07–12.14 μg/g fw in individuals, with an overall mean of 1.14 ± 1.18 μg/g fw; and 2) were influenced by species and year. Most Arctic-breeding shorebirds had blood and feather Hg concentrations at levels where no adverse effects of exposure were predicted, though some individuals sampled near Utqiaġvik had Hg levels that would be considered of concern. Overall, these data increase our understanding of how Hg is distributed in the various shorebird breeding areas of the Arctic, what factors predispose Arctic-breeding shorebirds to Hg exposure, and lay the foundation for future monitoring efforts. [ABSTRACT FROM AUTHOR]

Copyright of Ibis is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

All animals host a microbial community within and on their reproductive organs, known as the reproductive microbiome. In free‐living birds, studies on the sexual transmission of bacteria have typically focused on a few pathogens instead of the bacterial community as a whole, despite a potential link to reproductive function. Theory predicts higher sexual transmission of the reproductive microbiome in females via the males' ejaculates and higher rates of transmission in promiscuous systems.We studied the cloacal microbiome of breeding individuals of a socially polyandrous, sex‐role‐reversed shorebird, the red phalarope (Phalaropus fulicarius). We expected (i) higher microbial diversity in females compared to males; (ii) low compositional differentiation between sexes; (iii) lower variation in composition between individuals (i.e. microbiome dispersion) in females than in males; (iv) convergence in composition as the breeding season progresses as a consequence of sexual transmission and/or shared habitat use; and (v) higher similarity in microbial composition between social pair members than between two random opposite‐sex individuals.We found no or small between‐sex differences in cloacal microbiome diversity/richness and composition. Dispersion of predicted functional pathways was lower in females than in males. As predicted, microbiome dispersion decreased with sampling date relative to clutch initiation of the social pair. Microbiome composition was significantly more similar among social pair members than among two random opposite‐sex individuals. Pair membership explained 21.5% of the variation in taxonomic composition and 10.1% of functional profiles, whereas temporal and sex effects explained only 0.6%–1.6%. Consistent with evidence of functional convergence of reproductive microbiomes within pairs, some select taxa and predicted functional pathways were less variable between social pair members than between random opposite‐sex individuals.As predicted if sexual transmission of the reproductive microbiome is high, sex differences in microbiome composition were weak in a socially polyandrous system with frequent copulations. Moreover, high within‐pair similarity in microbiome composition, particularly for a few taxa spanning the spectrum of the beneficial–pathogenic axis, demonstrates the link between mating behaviour and the reproductive microbiome. Our study is consistent with the hypothesis that sexual transmission plays an important role in driving reproductive microbiome ecology and evolution. [ABSTRACT FROM AUTHOR]

Targeted management actions to boost key demographic rates can help to restore rare and localized populations but are increasingly required to stabilize or reverse declines of formerly common and widespread species. Many breeding wader populations across Europe are declining because of unsustainably low rates of productivity, and the conservation tools designed to boost wader breeding productivity have been most effectively used for semi‐colonial species within protected areas. Targeted management for wader species that breed at low densities across human‐modified landscapes, such as the rapidly declining Eurasian Curlew Numenius arquata, is likely to be more challenging. Here, we quantify variation in Curlew nest survival to explore how management could be targeted to boost this key component of breeding productivity. Up to 80 pairs of Eurasian Curlew were monitored annually between 2019 and 2021 in eight locations across Breckland, eastern England, where nesting densities range from <1 to c 0.7 pairs/km2. For 136 nests across grassland‐ and arable‐dominated sites, the majority of failures (86%) were caused by (primarily nocturnal) predation and the mean probability of surviving incubation (PSI) for all hatched or predated nests (127) was c. 0.25. Nest survival showed little annual or seasonal variation but did vary slightly between sites; however, this spatial variation was not clearly related to management conditions or nest concealment at these sites. Fencing to exclude mammalian nest predators can be effective for waders, but too few Eurasian Curlews currently nest within fenced areas in Breckland to produce observable effects. Fencing the few sites with high nesting densities could potentially double the number of chicks hatched each year within the study area, but landscape‐scale actions to reduce predator impacts on nests and chicks are likely to be needed to maintain breeding numbers in the wider countryside. [ABSTRACT FROM AUTHOR]

Managing for the effects of climate change on species whose populations are currently imperiled requires detailed knowledge of the relationship between their demographic rates and climate variables. We sought this information for the West Coast breeding population of snowy plover (Charadrius nivosus), which was federally listed as threatened in 1993 due to substantial declines in the numbers of plovers breeding along the coast and in the number of sites occupied for breeding. Snowy plovers employ a serially polygamous breeding system in which the male typically tends chicks to independence. This unusual breeding system is favored by male‐biased sex ratios in local populations. As part of a multispecies study of the effect of climate change on population growth, we used mark–capture models to examine climate drivers of adult survival for 1219 snowy plovers banded at Monterey Bay over 38 years and known to overwinter on the surrounding north‐central California outer coast. Nonclimate variables, including sex and unmeasured annual mortality risks (e.g., predator abundance), were the primary factors affecting adult survival. However, there is evidence that cold weather, particularly extended cold snaps with daily low temperatures below 2°C and daily high temperatures below 10°C, decreases overwinter survival. Exceptionally cold winters had a particularly strong effect on adult female plovers, contributing to the male‐biased adult sex ratios. Future winter climate on the north‐central California coast is projected to be generally warmer with fewer and shorter cold snaps. Reduced mortality from cold winter weather may mitigate other threats faced by plovers, such as anthropogenically enhanced predator populations, habitat loss, and accelerated sea level rise, while altering the adult sex ratio and potentially shifting the evolutionary landscape maintaining the plover's unusual breeding system. [ABSTRACT FROM AUTHOR]

Copyright of Avian Conservation & Ecology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Integrating tracking technology and molecular approaches provides a comprehensive picture of contemporary and evolutionary mechanisms promoting connectivity. We used mitochondrial DNA and double digest restriction-site associated DNA (ddRAD) sequencing combined with satellite telemetry to investigate the connectivity of geographically disparate breeding populations of a declining boreal shorebird, the lesser yellowlegs (Tringa flavipes). We were able to track 33 individuals on their round-trip migrations to Central and South America and back to the boreal wetlands of North America. Nearly all (93%) adults captured on the breeding grounds returned to within 5 km of the original capture site, with a median dispersal distance of 629 m. While our telemetry data revealed limited breeding dispersal in adults, genetic data uncovered significant interconnectedness across the species' range. Very little genetic structure was estimated at ddRAD autosomal (ΦST = 0.001), Z-linked (ΦST = 0.001), and mtDNA loci (ΦST = 0.020), and maximum likelihood-based clustering methods placed all individuals in a single cluster regardless of capture location, indicating the species is panmictic. Our data indicate that large-scale juvenile dispersal is the main mechanism maintaining connectivity in this species, resulting in the absence of genomic structure. [ABSTRACT FROM AUTHOR]

Habitat use of indicator species is used to prioritize management activities. However, habitat use can vary temporally in response to changes in predation risk and foraging rewards. We deployed satellite tags on 20 black oystercatchers (Haematopus bachmani) in four regions of British Columbia, Canada, to examine habitat use and selection decisions across seasonal, diel and tidal cycles. We characterized the shoreline in each region and used GLMMs to investigate how habitat characteristics influenced shoreline use by tracked birds. For individuals, we estimated home range size and the frequency key features of the shoreline were re‐visited. Black oystercatchers generally made greater‐than‐expected use of rocky islets and shoreline with freshwater outflows, less tree cover and greater intertidal area. However, while black oystercatchers preferred islets and shoreline with less tree cover at most/all time periods, they only exhibited preferences for greater intertidal area during low tides, and preferences for shoreline with freshwater outflows during the nonbreeding season, day, and high tides. Individual home ranges, on average, contained 46 km of shoreline (range: 12–156 km) and individuals used 10.4 km (range: 6.7–13.9 km). Individuals made greater use of larger islets with less tree cover that were closer to outflows, and greater use of outflows associated with larger streams, greater intertidal areas and gravel substrates. Black oystercatchers' habitat preferences likely reduce predation risk (rocky islets and shoreline with less tree cover) and increase foraging rewards (shoreline with freshwater outflows, greater intertidal area, and gravel substrates). However, habitat preferences appear sensitive to constraints on movement in the breeding season and changes in foraging rewards across the diel and tidal cycle, highlighting the importance of examining habitat use at multiple temporal scales. Black oystercatchers are considered indicators of rocky intertidal health; therefore, critical habitat is expected to be important for a suite of wildlife dependent on safe and productive coastline. [ABSTRACT FROM AUTHOR]

Bahrain is a cluster of islands in the mid-section of the Arabian Gulf that serves as an important wintering and stop-over ground for many migratory shorebirds in the Central Asian Flyway (CAF). However, natural and anthropogenic factors have had a significant impact on these ecosystems over the last few decades. Long-term, systematic studies based on standardized survey observations are needed to understand the population dynamics and diversity changes of shorebirds in these critical sites. We systematically surveyed the shorebird population and community in Bahrain between 2010 January to 2021 December. This is the first comprehensive study from the entire Kingdom of Bahrain, and covered 13 sites over 12 years to establish the results. A total of 39 species were encountered during the study period from all 13 sites in Bahrain, of which 27 species were common and regular migrants to all the study sites; these were selected to analyze the population trend. Five species represented 77% or more of the total wintering shorebird population. All the shorebird species assessed exhibited significant declining trends over the years, and majority of them had over 1% relative abundance. Shorebirds in Bahrain were severely threatened at these sites, indicating that their population trend in the area could be crucially affected. Further conservation efforts are needed, aided by an understanding of the mechanisms driving the decline and diversity changes of shorebirds in the most stressed coastal regions of Bahrain. Further studies organized throughout the country's coasts may aid in establishing improved conservation measures to protect the shorebirds of the CAF in Bahrain. [ABSTRACT FROM AUTHOR]

Migratory shorebirds feed in intertidal wetlands during the winter non-breeding season, to meet their daily needs and accumulate reserves for the flight to their breeding grounds. However, these habitats may be impacted by development. Eastern Curlew (Numenius madagascariensis) populations are declining in Australia, where we assessed relationships among the curlews' feeding behaviours, prey types, broad substrate types, feeding microhabitat preferences, and population density, across 11 tidal flats in Moreton Bay, South East Queensland, Australia. Most prey were crustaceans, of varied size. Within flats, the types and rates of feeding actions, and feeding success, varied with sex, microhabitat and tidal stage. Among different flats, the estimated rate of prey biomass intake was strongly correlated with curlew density, explaining 57 per cent of its variation (2–77 birds/100 ha); whereas neither feeding attempts nor successful feeding acts per unit time were good density predictors. Substrate resistance was negatively correlated with both biomass intake and curlew density, because curlews were able to use their long bills to extract larger prey from deep burrows in more penetrable flats. The curlews, therefore, chose feeding areas directly according to food supply, but the substrate penetrability provides a promising rapid indicator of regional-scale variation in habitat quality. [ABSTRACT FROM AUTHOR]

Abstract Wire cages (i.e., predator exclosures) are frequently used to protect shorebird nests from predation. While exclosed nests often have higher survival than unexclosed nests, concerns exist over whether the conspicuous structures might draw attention of predators, potentially increasing risks to adults and newly‐hatched chicks. We present a new approach to investigating predator responses to exclosures and other stimuli at shorebird nests. We used location data from GPS‐collared red foxes (Vulpes vulpes) to examine short‐term spatial responses of foxes to exclosure setup and hatching at piping plover (Charadrius melodus) nests on Fire Island, New York. We compared mean distances between fox locations and piping plover nests, and the proportions of fox locations within a 100‐m buffer of nests, before and after exclosure setup and before, during, and after hatching. Mean distances from fox locations to nests were similar before versus after exclosure setup (x̄ = 641 m before, 675 m after; permutation test for matched pairs, [PTMP], T = 0.28, P = 0.56, n = 9 foxes), before versus during hatching (x̄ = 417 m before, 340 m during; PTMP, T = −0.93, P = 0.18, n = 5 foxes) and during versus after hatching (x̄ = 340 m during, 330 m after; PTMP, T = 1.00, P = 0.84, n = 5 foxes). The proportions of fox locations within 100‐m buffers surrounding nests were similar before versus after exclosure setup (x̄ = 0.01 before, 0.03 after; PTMP, T = 0.26, P = 0.53, n = 9 foxes), before versus during hatching (x̄ = 0.04 before, 0.15 during; PTMP, T = −1.44, P = 0.09, n = 5 foxes), and during versus after hatching (x̄ = 0.15 during, 0.14 after; PTMP, T = 0.84, P = 0.80, n = 5 foxes). In 10 of 19 of our individual‐level comparisons, there were no significant differences in the distances from fox locations to nests between paired event periods. In the other 9 individual‐level comparisons, we found evidence of shifts in fox space use between paired event periods, but no clear directional trend across individuals. We conclude that the foxes in our study did not appear to consistently key in on exclosure setup or hatching at piping plover nests at the spatial scales considered in our comparisons. We recommend that managers continually re‐evaluate the effects of exclosures at their management sites, as changes in nest predation, abandonment rates, and adult plover survival may all influence the relative benefit of exclosures for population growth. Our study illustrates the potential for using spatial data to investigate predator responses to various management actions taken to protect nesting shorebirds and other prey species of conservation interest.

Assessing the quality of migratory shorebird stopover sites requires good measures of food availability. We developed simple methods to measure biofilm grazing by migrant western sandpipers (Calidris mauri), a species for which biofilm is an important dietary component. We used a field-portable chlorofluorometer to measure the density of chlorophyll-a (Chl-a) in surficial biofilms on Roberts Bank, a large intertidal mudflat in British Columbia, Canada, during northward migration.Chl-a density begins at a low level during each diurnal emersion period, and increases steadily during emersion at 4.1 mg m−2 h−1 for a total of ∼24.6 mg m−2 over a typical 6 h emersion period and ∼41 mg m−2 over a 10 h emersion period. Western sandpipers grazed at 1.35–1.45 mg Chl-a m−2 min−1, thus biofilm production supports 17.6 min m−2 of grazing time during a 6 h low tide period and 29.3 min m−2 during a 10 h period. During peak northward migration, the average grazing intensity of western sandpipers over an intertidal emersion period was 3.3–6.4 min m−2, suggesting that biofilm accumulation was 2.7–8.8 fold greater than the amount consumed. We found Chl-a density was highest (∼65 mg per m2) within 40 m of the shoreline. Grazing intensity was lowest close to shore, where predation risk from falcon attacks is highest. Grazing intensity peaked at 240 m and then declined, lowering Chl-a density at greater distances to a uniform level of ∼54 mg m−2. These results indicate that interactions between biofilm production and sandpiper grazing underlie spatio-temporal patterns in biofilm abundance on Roberts Bank.

Telemetry is a powerful and indispensable tool for evaluating wildlife movement and distribution patterns, particularly in systems where opportunities for direct observation are limited. However, the effort and expense required to track individuals often results in small sample sizes, which can lead to biased results if the sample of tracked individuals does not fully capture spatial, temporal, and individual variability within the target population. To better understand the influence of sampling design on results of automated radio telemetry studies, we conducted a retrospective power analysis of very high frequency (VHF) radio telemetry data from the Motus Wildlife Tracking System for two species of birds along the United States Atlantic coast: a shorebird, the piping plover (Charadrius melodus), and a nearshore seabird, the common tern (Sterna hirundo). We found that ~ 100–150 tracked individuals were required to identify 90% of locations known to be used by the tracked population, with 40–50 additional individuals required to include 95% of used locations. For any number of individuals, the percentage of stations included in the sample was higher for common terns than for piping plovers when tags were deployed within a single site and year. Percentages of stations included increased for piping plovers when birds were tagged over multiple sites and, to a lesser extent, years, and increased with average length of the tracking period. The probability that any given receiver station used by the population would be included in a subsample increased with the number of birds tracked, station proximity to a migratory stopover or staging site, number of receiving antennas per station, and percentage of the tracked population present. Our results provide general guidance for the number and distribution of tagged birds required to obtain representative VHF telemetry data, while also highlighting the importance of accounting for station network configuration and species-specific differences in behavior when designing automated radio telemetry studies to address specific research questions. Our results have broad applications to remotely track movements of small-bodied migratory wildlife in inaccessible habitats, including predicting and monitoring effects of offshore wind energy development. [ABSTRACT FROM AUTHOR]

The Prairie Pothole Region of central Canada supports a diverse community of breeding waterbirds, but many species have declining populations and the demographic mechanisms driving the declines remain unknown. We conducted a 7‐year field study during 1995–2001 to investigate the demographic performance of Marbled Godwits (Limosa fedoa) and Willets (Tringa semipalmata) breeding in managed wetlands near Brooks, Alberta. Mark‐recapture analyses based on Cormack–Jolly–Seber models revealed that the annual rates of apparent survival for Marbled Godwits (ϕ̂$$ \hat{\phi} $$ = 0.953 ± 0.012SE) and Willets (ϕ̂$$ \hat{\phi} $$ = 0.861 ± 0.015SE) are among the highest rates of survivorship reported for any breeding or nonbreeding population of large‐bodied shorebirds. Our estimates of life expectancy for males were comparable to longevity records in godwits (17.3 years ±5.8SE vs. 25–29+ years) and willets (7.7 ± 1.5SE vs. 10+ years). The two species both showed strong breeding site fidelity but differed in rates of mate fidelity. Pairs that reunited and males that switched mates usually nested <300 m from their previous nests, whereas females that switched mates usually moved longer distances >1.1–1.5 km. Returning pairs usually reunited in godwits (85%) but not in willets (28%), possibly because of species differences in adult survival or patterns of migration. Baseline estimates of annual survival for banded‐only birds will be useful for evaluating the potential effects of new tracking tags or the environmental changes that have occurred during the past 20 years. Conservation strategies for large‐bodied shorebirds should be focused on reduction of exposure to anthropogenic mortality because low rates of natural mortality suggest that losses to collisions at breeding sites or harvest at nonbreeding areas are likely to cause additive mortality. [ABSTRACT FROM AUTHOR]

Summary: The Wood Snipe Gallinago nemoricola is one of the least known shorebird species, and its habitat associations are very poorly understood. Here we provide the first assessment of the habitat use of the Wood Snipe during the breeding season. Between May and July 2021 at a 4-km2 alpine meadow in Sichuan province, China, we conducted population surveys and behavioural observations to identify sites where breeding Wood Snipe occurred and foraged. We quantified the habitat characteristics and food resource availability of these sites and compared them with randomly selected "background" sites. Comparison between 34 occurrence sites and 25 background sites indicated that during the breeding season, Wood Snipes are not distributed evenly across alpine meadow habitats, but preferred habitats in the lower part (3,378–3,624 m) of the alpine meadow with intermediate levels of soil moisture. In addition, comparison between 17 foraging sites and 24 background sites showed that the Wood Snipe tended to forage at sites with higher soil fauna abundance. We found weak evidence for denser vegetation cover at its height and no evidence for other biotic habitat variables such as vegetation composition or other abiotic habitat variables such as slope, soil penetrability, or disturbance level to influence Wood Snipe habitat associations. Our results suggest that the actual distribution range of the Wood Snipe during the breeding season may be smaller than expected from the extent of apparently suitable habitat. We advise caution in evaluating the potential habitat availability and distribution of the Wood Snipe, and call for further research to better understand the ecology of this rare species to inform its conservation. [ABSTRACT FROM AUTHOR]

Weather conditions experienced by birds can influence their migration decision‐making and strategy both within and across seasons. Additionally, decision‐making during migration may influence subsequent fitness (reproductive success and/or survival). Examining the effects of fine‐scale weather variables on individuals throughout the year could help identify stages of the annual cycle when species may be most affected by weather. In this study, we captured 24 black‐bellied plovers (gray plovers; Pluvialis squatarola) on nonbreeding areas along the western Gulf of Mexico coast and tracked their locations once every 2 h through their breeding season in the Alaskan and Canadian Arctic. We quantified migration strategies and weather conditions experienced by each individual throughout the nonbreeding, northward migration, and breeding seasons. We used a Bayesian hierarchical model which connected regressions linking weather with migration metrics, and migration metrics and breeding season weather with reproductive success. We found strong negative relationships between two migration metrics (migration duration and number of stopovers) and reproductive success, but no substantial relationships between breeding season weather variables and reproductive success. We found negative relationships between nonbreeding season temperature, migration temperature, and migration NDVI and both migration duration and number of stopovers, in addition to positive relationships between the number of stopovers and storms during migration, migration duration, and nonbreeding season precipitation. These results suggest that reproductive success is influenced by weather throughout the annual cycle and migration strategy is a key mechanism through which these effects operate. Our findings suggest that environmental factors throughout the year influence shorebird fitness, and, because black‐bellied plovers are often associated with mixed‐species flocks, many species likely experience similar constraints. [ABSTRACT FROM AUTHOR]

We investigate the relationship between weed invasion within naturally frequently disturbed areas on Broughton Island in New South Wales, Australia. One-hundred and five 5 × 5 m plots were placed across dunal areas of the island which are favoured locations for ground nesting birds. All vascular flora was recorded and scored for percent cover along with the number of burrows, percent of area covered by burrows, level of activity, if activity was recent and the percent of bare ground. Floristic analysis highlighted two divergent vegetation assemblages one dominated predominantly by mat-forming introduced taxa and one by natives. Areas of high weed dominance were associated with apparent low current Wedge-tailed Shearwater (WTS) activity and abandoned burrows. Conclusion: Our results indicate that low growing mat-forming introduced weeds may be promoted by frequent disturbance but also pose a threat to breeding by reducing the area that can be used by WTS. [ABSTRACT FROM AUTHOR]

Many shorebirds rely on a set of key sites to complete their annual cycles at the flyway, regional, and landscape scales. Coastal wetlands on Chiloé Island, Chile, (Chiloé) support a high proportion of the Hudsonian Godwits (Limosa haemastica) spending the boreal winter along the Pacific coast of the Americas. We conducted annual counts of godwits on Chiloé between 2010 and 2020 to estimate trend in the population. To understand use of individual sites and local networks of sites (clusters), we conducted monthly counts September 2013–March 2014 and September 2017–March 2018. Because of wide variation in annual counts, we did not detect a significant trend in abundance of godwits on Chiloé. Mean monthly abundance summed across all sites during December–February varied markedly among site clusters, with godwits being most abundant in the central Chiloé cluster. Across Chiloé, variation in monthly counts of godwits at individual sites was twice as great as variation in counts summed within a cluster. Casual re-sightings of color-flagged godwits supported the idea that godwits used clusters consistently across years. Our results illustrate the importance of conserving a network of sites across multiple scales as an important step in maintaining Hudsonian Godwit populations. [ABSTRACT FROM AUTHOR]

Reproduction investment is a prominent trade-off in life-history theory and is subject to strong selection pressure. The avian eggshell, as a crucial barrier between the bird embryo and the surrounding environment, undergoes optimization under different environmental selection regimes to ensure the successful development of embryos, which can be linked to local adaptation. Therefore, understanding the variation in eggshell microstructure and composition in wild bird populations living in contrasting ambient environments is of great significance. In this study, we utilized electron microscope ultrastructure measurement and elemental analyses to measure and compare the microstructure and element composition of eggshells from three wild plover populations (Charadrius alexandrinus and C. dealbatus) residing in heterogeneous habitats across varied climatic zones. These populations include the high-altitude Qinghai Lake population, the temperate coastal Tangshan population, and the tropical coastal Zhanjiang population. Our findings revealed that the palisade layer was thinner in the Qinghai Lake population compared to its lowland populations. This difference might be attributed to hypoxia which facilitates the hatching process by allowing chicks to easily break through their shells. Additionally, the variations in the elemental composition of the eggshells among populations well reflected the distribution of element content in different geographical regions. The Qinghai Lake population displayed low zinc and low manganese levels but high calcium levels, while the Zhanjiang population exhibited high zinc, high iron, high manganese, and high phosphorus levels. Furthermore, these variations in elemental composition could also account for the observed microstructural differences among populations. Collectively, we propose that the dissimilarities in eggshell microstructure and elemental composition among populations could be attributed to adaptations to different environmental conditions. Our findings lay the groundwork for future research to explore the mechanisms behind the variations in eggshell characteristics among wild bird populations, and contribute to a broader understanding of biodiversity mechanisms.

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.

Abstract Background Dispersal is a critical life history strategy that has important conservation implications, particularly for at-risk species with active recovery efforts and migratory species. Both natal and breeding dispersal are driven by numerous selection pressures, including conspecific competition, individual characteristics, reproductive success, and spatiotemporal variation in habitat. Most studies focus on dispersal probabilities, but the distance traveled can affect survival, fitness, and even metapopulation dynamics. Methods We examined sources of variation in dispersal distances with 275 natal dispersal and 1335 interannual breeding events for piping plovers (Charadrius melodus) breeding in the Northern Great Plains between 2014 and 2019. Results Natal dispersal was on average longer (mean: 81.0 km, median: 53 km) than adult breeding movements (mean: 23.7 km, median: 1 km). Individuals moved the shortest distances when hatched, previously nested, or settling on river habitats. When more habitat was available on their natal area than in the year prior, hatch-year birds moved shorter distances to their first breeding location. Similarly, adults also moved shorter distances when more habitat was available at the settling site and when in closer proximity to other known nesting areas. Additionally, adult movement distance was shorter when successfully hatching a nest the year prior, retaining a mate, or initiating a current nest earlier. Conclusion Habitat availability appears to be associated with dispersal distance for both hatch-year and adult piping plovers. Conservation efforts that integrate dispersal distances may benefit from maintaining nesting habitat within close proximity to other areas for adults and a network of clustered sites spread out across a larger landscape for natal dispersal.

Programs that incentivize private landowners to create habitats that offset losses due to conversion and climate change are increasingly being used to bolster sensitive wildlife populations. In the Central Valley of California, shorebird habitat incentive programs pay landowners to create additional habitat during the non‐breeding season by flooding their fields. However, it remains unclear how successful these programs have been in supporting baseline shorebird population needs or meeting established population goals, particularly in the face of changing environmental conditions. To address these questions, we used bioenergetics modeling to estimate shorebird food energy needs over four consecutive years that had the highest annual mean air temperatures ever recorded in California, and included years of extreme drought, as well as the second wettest winter on record. Our objectives were to (1) characterize annual variability in the timing and magnitude of shorebird food energy shortfalls, (2) estimate the contributions that incentive programs made to meeting these needs, and (3) develop recommendations for implementation of future habitat programs to advance shorebird conservation in the region. Overall, we found a high level of consistency in the timing and magnitude of habitat shortfalls, especially in fall, despite large differences in annual rainfall, a result that was unexpected, but that emphasizes how highly managed the hydrological system is in the Central Valley. We also found that the magnitude of both fall and spring energy shortfalls increased, relative to recent (2007–2014) estimates, perhaps due to aberrantly warm conditions. Incentive programs implemented to provide supplemental habitat were somewhat effective in reducing shortfalls for the assumed baseline population, but there were consistent unmet habitat needs when there were not enough shallow open water foraging areas available. Strategies to offset these remaining food energy deficits include scaling up habitat investments, adjusting the timing of habitat programs to better match the migration patterns of the birds, and adapting programs to new geographies. To the extent that there is variability in annual habitat need we recommend implementing a dynamic conservation approach. This involves scaling the amount of additional habitat created to match the shifting needs of the birds to maximize return on investment. [ABSTRACT FROM AUTHOR]

Worldwide populations of shorebirds are declining, associated with a complex interplay of climate change, predation, human disturbance and habitat degradation. Comprehensive information on the distribution and breeding ecology of shorebird populations is crucial to understand and mitigate these threats. Kazakhstan, the largest country in Central Asia, comprises multiple flyways and breeding habitats for shorebird species, including the Kentish Plover Charadrius alexandrinus, but information on the population size and breeding distribution of shorebird species in the region is highly limited. We conducted a wide‐scale survey of Kentish Plover across Kazakhstan during the breeding season and utilize species distribution modelling to outline key anthropogenic and environmental variables that determine Kentish Plover presence. Our results reveal widespread distribution of Kentish Plovers across Kazakhstan but indicate that breeding densities are generally low. Our distribution modelling stresses the primary importance of proximity to water bodies and climate as the main predictors of Kentish Plover presence, but reveals a weak association with indicators of human disturbance. We utilize our distribution modelling to provide the first quantitative estimate of the breeding population size of Kentish Plover in Kazakhstan, which indicates a modest number of individuals given the size of the country (between 12 000 and 32 000 individuals). Our results indicate the key routes via which climate change may impact on population‐level distributions of Kentish Plover and provide a platform for future studies investigating species distributions across similarly vast and inaccessible regions. [ABSTRACT FROM AUTHOR]

Migration patterns in birds vary in space and time. Spatial patterns include chain, leapfrog and telescopic migration. Temporal patterns such as migration duration, number, and duration of stopovers may vary according to breeding latitude, sex, and season. This study aimed to verify these patterns in a long‐distance migrant, the Eurasian curlew Numenius arquata arquata, and to provide a synopsis of spatio‐temporal migration patterns in this species of concern throughout the East Atlantic Flyway. We tagged 85 adults with GPS‐data loggers in Germany, Poland, France and Estonia between 2013 and 2019. We computed the distance flown, linear loxodromic distance, duration, stopover number, total stopover duration, mean stopover duration, departure time and arrival time for 177 out of 187 tracks. On average (± standard deviation), spring migration occurred from 4 to 14 April (10.2 ± 8.4 days), curlews flew 3.623 ± 1.366 km, and had 5.8 ± 3.6 stopovers, with a duration of 29.4 ± 38.2 h per stopover, while autumn migration occurred from 18 to 29 June (10.9 ± 9.9 days), curlews flew 3.362 ± 1.351 km, and had 5.4 ± 4.0 stopovers, with 31.8 ± 32.3 h per stopover. Curlews displayed chain migration because wintering curlews maintained the latitudinal sequence to their breeding sites. Southern curlews had a longer nesting period due to their earlier arrivals. While spring arrival at breeding sites did not differ between the sexes, in autumn females departed earlier than males. Migration duration and distance, as well as stopover number and duration, showed a significant increase with breeding site latitude but did not differ between the sexes or between spring and autumn migrations, suggesting that curlews took a comparable amount of time migrating during both seasons. The high site faithfulness in curlews suggests that rapid autumn migration allows them to return to defend their winter foraging areas. [ABSTRACT FROM AUTHOR]

Sanderling (Calidris alba) is a type of shorebird that migrates from the northern hemisphere to the southern hemisphere. Indonesia is a migration route for East Asia-Australasia. The southern coastal area of the Jember Regency, one of the wetlands, especially in East Java, has become an air route and a stopover for shorebirds every year. The research objective was to determine the population of Sanderling (Calidris alba) on the southern coast of Puger and Getem, Jember Regency. Method of collecting encounter rates. Bird watching is carried out in the morning at 06.00-08.00 and in the afternoon at 15.30-17.30. Data recording includes species, number of birds, and other supporting data. Identification using the book by Mac Kinnon et al. (2010) and Bhushan, B., et al. (1993). Tools used for binocular observation, monocular, camera, and GPS. Data analysis used the density index for individual bird species using the formula method (Alikodra, 1990). The results of the study were a total of 445 individuals. Data analysis of Muara Sungai population density was the location with the four other survey locations' highest number.