Seabirds are vital, but overlooked, components of coastal marine ecosystems and may connect the marine and terrestrial environment at a global scale, significantly contributing to inter-habitat ...connectivity and the provision of multiple ecosystem services. Although the ecological and functional role of birds in terrestrial areas, islands in particular, has been deeply studied since the last century, the same does not hold true for coastal marine areas. Given the importance of coastal areas for seabirds worldwide and, at the same time, the high vulnerability of both, looking into the role of seabirds in influencing the ecosystem functioning in coastal areas is needed nowadays. Here, we review the current knowledge regarding the role of seabirds on coastal ecological processes giving particular emphasis on the linkage between the seabird functions that are crucial in influencing the ecological processes and the provision of ecosystem services, and disservices, for the human well-being. Seabirds can contribute to shaping coastal ecological processes and services in a multitude of ways, among which directly influencing trophic status, environmental contamination, biodiversity and food webs through trophic (bottom-up or top-down) and non-trophic processes. We identified areas for future research to further clarify this linkage and promote seabird conservation.
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•Seabirds contribute to inter-habitat connectivity at global scale.•Seabird influence on coastal systems is overlooked compared to terrestrial systems.•Seabirds greatly influence ecological processes and functioning of recipient systems.•Seabird functions influence the provision of many ecosystem services.•More studies are needed to improve the knowledge in this field.
Sandy coasts are specific habitats of high ecological significance for many species of shorebirds. The Gulf of Catania, in the Eastern coast of Sicily, is considered one of the most important sandy ...coastal areas of the region for the wintering of different species of Charadriidae and Scolopacidae, also due to the presence of River Simeto’s mouth and other freshwater streams. Since the area has been subject to many changes in the last few decades and recent data were not available, a ten-year monitoring of the wintering shorebird community has been carried out, from January 2011 to January 2020, to understand its current ecological role and to update the knowledge about numbers and trends of Sicilian wintering shorebirds along the coast. A total of 3,171 individuals and 16 different species were observed, including a considerable amount of individuals of Calidris alba and Charadrius alexandrinus, despite the latter showed an 80% decrease in number in the last 20 years in the area. For each species, maximum numbers observed per winter and related five-year averages, estimates, IKA (Index of Abundance per Kilometre) and percentages in relation to the national wintering population have been reported. Furthermore, data about species associations were collected and analysed. This survey shows how the ecological value of River Simeto’s mouth has decreased considerably in the last decades in favour of other locations, such as the mouth of Canale Arci, where almost 50% of the birds were observed.
Gut microbiota plays a vital role in maintaining the health and immunity of wild birds. However, less is known about the comparison of fecal microbiota between different ecological groups of wild ...birds, particularly in the Yellow River National Wetland in Baotou, China, an important transit point for birds migrating all over the East Asia-Australian and Central Asian flyways. In this study, we characterized the fecal microbiota and potential microbial function in nine bird species of raptors, waders, and waterfowl using 16S rRNA gene amplicon sequencing to reveal the microbiota differences and interaction patterns. The results indicated that there was no significant difference in α-diversity, but a significant difference in β-diversity between the three groups of birds. The fecal bacterial microbiota was dominated by Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes in all groups of birds. Furthermore, we identified five bacterial genera that were significantly higher in raptors, five genera that were significantly higher in waders, and two genera that were more abundant in waterfowl. The bacterial co-occurrence network results revealed 15 and 26 key genera in raptors and waterfowls, respectively. The microbial network in waterfowl exhibited a stronger correlation pattern than that in raptors. PICRUSt2 predictions indicated that fecal bacterial function was significantly enriched in the antibiotic biosynthesis pathway in all three groups. Metabolic pathways related to cell motility (bacterial chemotaxis and flagellar assembly) were significantly more abundant in raptors than in waders, whereas waders were enriched in lipid metabolism (synthesis and degradation of ketone bodies and fatty acid biosynthesis). The fecal microbiota in waterfowl harbored more abundant vitamin B6 metabolism, RNA polymerase, and tyrosine and tryptophan biosynthesis. This comparative study revealed the microbial community structure, microbial co-occurrence patterns, and potential functions, providing a better understanding of the ecology and conservation of wild birds. Future studies may focus on unraveling metagenomic functions and dynamics along with the migration routine or different seasons by metagenomics or metatranscriptomics.
•Iceland supports huge populations of breeding waders in agricultural landscapes.•Breeding wader density increases with amount of wetland in surrounding landscapes.•In more fertile lowland areas, ...wader densities decline with amount of agriculture.•In less fertile upland areas, wader densities increase with amount of agriculture.
The capacity of different landscapes to sustain viable populations depends on the spatial and temporal availability of key population-specific resources. Heterogeneous landscapes provide a wider range of resources and often sustain higher levels of biodiversity than homogeneous ones. Across the globe, agricultural expansion has resulted in large-scale homogenisation of landscapes with associated declines in many taxa. However, during the early stages of agricultural development, in terms of area and intensity, increased landscape heterogeneity and changes in local productivity through fertilizer inputs can potentially increase resource availability for some species. Agriculture in Iceland is currently neither highly intensive nor extensive, and primarily occurs as hayfields (>90% of agricultural land) embedded within a mosaic of semi-natural wetlands and heaths. These landscapes support internationally important breeding populations of several wader species but the role of agricultural land in promoting or constraining breeding wader densities is currently unknown. Understanding the relationship between cultivation and wader populations is important as the area of cultivated land is predicted to expand in Iceland in near future, largely through conversion of the remaining semi-natural wetlands. Here we (a) quantify relationships between breeding wader densities in lowland Iceland and the amount of cultivated land and wetland in the surrounding landscape using density estimates from 200 transects in common semi-natural habitats, (b) assess the extent to which cultivated land affects wader densities in these landscapes, and the potential effects of future agricultural expansion at the expense of wetlands on wader populations. Wader densities in semi-natural habitats were consistently greater when surrounding landscapes had more wetland at scales ranging from 500 m to 2500 m, indicating the importance of wetland availability. However, the effects of cultivated land in the surrounding landscape varied with altitude (ranging from 0 to 200 m); in low-lying coastal areas, wader numbers decline with increasing amounts of cultivated land (and the lowest densities (<1 km2) occur in areas dominated with cultivated land), the inverse occurs at higher altitudes (>100 m a.s.l., where lowest densities occur in areas without cultivated land). This suggests that additional resources provided by cultivated land may be more important in the less fertile uplands. Further agricultural conversion of wetlands in low-lying areas of Iceland is likely to be detrimental for breeding waders, but such effects may be less apparent at higher altitudes.
Changes in demographic rates underpin changes in population size, and understanding demographic rates can greatly aid the design and development of strategies to maintain populations in the face of ...environmental changes. However, acquiring estimates of demographic parameters at relevant spatial scales is difficult. Measures of annual survival rates can be particularly challenging to obtain because large‐scale, long‐term tracking of individuals is difficult and the resulting data contain many inherent biases. In recent years, advances in both tracking and analytical techniques have meant that, for some taxonomic groups, sufficient numbers of survival estimates are available to allow variation within and among species to be explored. Here we review published estimates of annual adult survival rates in shorebird species across the globe, and construct models to explore the phylogenetic, geographical, seasonal and sex‐based variation in survival rates. Models of 295 survival estimates from 56 species show that survival rates calculated from recoveries of dead individuals or from return rates of marked individuals are significantly lower than estimates from mark–recapture models. Survival rates also vary across flyways, largely as a consequence of differences in the genera that have been studied and the analytical methods used, with published estimates from the Americas and from smaller shorebirds (Actitis, Calidris and Charadrius spp.) tending to be underestimated. By incorporating the analytical method used to generate each estimate within a mixed model framework, we provide method‐corrected species‐specific and genus‐specific adult annual survival estimates for 52 species of 15 genera.
In an attempt to standardize elements of the station routine, the book describes the procedures used in passerine and wader ringing stations. It offers a comparative analysis of versatile evaluation ...techniques such as measurements, orientation experiments and monitoring. The authors meticulously analyze different methods used to track birds, including catching passerines with mist-nets in land and wetland habitat, as well as the use of the Heligoland trap. The monograph, as a successful bid to establish a bird station routine that is favourable to both birds and ringers, will benefit all professional and amateur ringers.
Introduction. Information on historical changes in the fauna of geographical regions and biota habitats is important for understanding the processes that take place in ecosystems. The results of such ...an analysis in combination with modern research can indicate not only the global trends in changes of animal associations and the status of particular populations of species, but also reveal the reasons that caused the situation. Materials and discussion. The first lists of bird species in the 18th – early 19th centuries showed the nesting of 12 species of waders. However, during the 19th century 37 species of waders were found, 12 of which were nesting. 13 wader species were permanent migratory and 8 – rare migratory species. In the first half of the 20th century, there were 27 species of waders on the territory of Prykarpattia, and 25 in Volyn, among which there is a larger list of migratory and vagrant species in the foothills of the Carpathians. In the second half of the 20th century, 39 species of waders were described within the western regions of Ukraine, of which 17 were nesting, and four of them were recorded during the last decade. Conclusions. There are 42 species of waders (39 of them are recent) registered in the western part of Ukraine. Among them 17 species are nesting, 15 – migratory and seven – vagrant species. During the 20th–21st centuries, 23 species of waders, including only 7 nesting species, have not changed their status of stay. However, it has changed for 17 species: two species have disappeared; four – have become vagrant; the Ruff Calidris pugnax and the Marsh Sandpiper Tringa stagnatilis have changed their status from nesting to migratory. The Northern Lapwing Vanellus vanellus, the Green Sandpiper Tringa ochropus and the Wood Sandpiper T. glareola that were common, somewhere numerous bird, – have become few in numbers; and the Great Snipe Gallinago media and the Black-tailed Gotwit Limosa limosa – have become rare. The Jack Snipe Lymnocryptes minimus has become migratory. The nesting of sandpipers, with a southern area of distribution, in the western regions of Ukraine proves the fact of the global warming. However, the drop of the water level, drying out of wet meadows and swamps and, as a consequence, plant succession, have terminated the nesting of such species as the Ruff and the Marsh Sandpiper; the Black-tailed, the Great Snipe and the Wood Sandpiper become rare; the Northern Lapwing and the Green Sandpiper have become much less numerous.
Coastal grasslands are semi-natural habitats used for agriculture, but they are also vital habitats for many taxa, such as waders. The importance of this habitat for wildlife has found recognition in ...the policies of the European Union, resulting in the implementation of biodiversity-friendly agri-environment schemes (AES) to ensure the sustainable management of these areas. However, the performance of AESs has often been questioned and data to analyse their effectiveness is mostly lacking.
To fill this knowledge gap, we used freely available European Space Agency's Sentinel-1 Synthetic Aperture Radar (SAR) images and ground truth data to describe the vegetation height based habitat suitability of coastal grasslands as breeding sites for waders at a country-wide scale in Estonia, where the main threat to this habitat is overgrowing with high sward plant species.
We show that satellite remote sensing can be used as a straight-forward and reliable tool to estimate the grazed coastal grassland habitat suitability for breeding waders in terms of vegetation height in two broad classes.
We demonstrate that the AES applied on Estonian coastal grasslands is important for improving the suitability of this habitat for the breeding wader community: compared to 24% of suitable habitat in areas where no agricultural subsidies are paid, 60% of the land under the targeted AES is suitably managed for breeding waders. The highest proportion of habitat suitability (76%) is achieved in areas receiving targeted top-up subsidy for wader conservation.
Continued monitoring of the performance of the AES is essential for taking timely and targeted conservation actions and we strongly recommend the wider use of remotely sensed data for this purpose. We promote the continuation of the AES scheme applied on Estonian coastal grasslands while improving its efficiency through carefully raised stocking rates and increased uptake of the top-up scheme.
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•Radar remote sensing can be used to assess vegetation suitability for breeding waders.•Country-scale assessment shows 43% of coastal grasslands managed suitably.•Room for improvement: within agri-environment scheme 60% of land is suitably managed.•Only 24% of land is managed suitably where no subsidies are applied.
Abstract
Correct assessment of species limits and phylogenetic relationships is a prerequisite for studies in ecology and evolution. Even in well-studied groups such as birds, species delimitation ...often remains controversial. Traditional avian taxonomy is usually based on morphology, which might be misleading because of the contingent nature of evolutionary diversification. The sand plover complex (genus Charadrius) may be such an example wherein 2 Lesser Sand Plover C. mongolus subspecies groups have been proposed to comprise 2 species. We use genome-wide data of 765K SNPs to show that the widely accepted taxonomic treatment of this sand plover complex appears to be a paraphyletic grouping, with two Lesser Sand Plover subspecies groups found not to be each other’s closest relatives, and with the mongolus subspecies group being the sister taxon of Greater Sand Plover C. leschenaultii. Based on genomic and acoustic analyses, we propose a three-way split of the Sand Plover complex into the Siberian Sand Plover C. mongolus, Tibetan Sand Plover C. atrifrons, and Greater Sand Plover C. leschenaultii. The similar sizes of the Siberian and Tibetan Sand plovers may be the result of niche conservatism coupled with rapid morphological and ecological differentiation in the Greater Sand Plover. Gene flow between the non-sister Tibetan and Greater Sand plovers might have happened in phases of secondary contact as a consequence of climate-driven range expansions. We call for further studies of the Sand Plover complex, and suggest that speciation with intermittent gene flow is more common in birds than currently acknowledged.
Lay Summary
The use of an integrative approach combining molecular and phenotypic data has revolutionized modern avian taxonomy.
Using mitochondrial and genomic-wide variants, we show that the Lesser Sand Plover (Charadrius mongolus) appears to be paraphyletic taxa, with its two subspecies groups (“mongolus” and “atrifrons”) found not to be each other’s closest relatives, and with the “mongolus” group being the sister taxon of Greater Sand Plover Ch. leschenaultii.
The pairwise sequentially Markovian coalescent (PSMC) method indicated contrasting demographic histories between the three taxa in the sand plover complex.
We further demonstrated that the two subspecies groups in Lesser Sand Plover differ significantly in vocalizations.
These evidences suggest that the migratory Palearctic shorebird Lesser Sand Plover should be split into 2 species: Ch. mongolus Pallas, 1776, and Ch. atrifrons Wagler, 1829.
Graphical Abstract
Graphical Abstract
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