Grey Plover Pluvialis Squatarola Research Articles

First record of grey plover pluvialis squatarola in the sahara and an update on its distribution in algeria

Grey Plover Pluvialis squatarola, is one of Algeria’s rare bird species. During the international waterbird census in the month of May for the year 2023 using the direct observation method, a single individual of the Grey Plover was spotted at Kef Doukhane wetland in Ghardaïa on May 16, 2023. This is the first observation in the Sahara with a new locality in Algeria.

The complete mitochondrial genome of grey plover Pluvialis squatarola (Charadriiformes, charadriidae)

The complete mitochondrial genome of grey plover Pluvialis squatarola was obtained by next-generation sequencing. The circular genome was 16,860 bp in length, consisting of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and a control region. The overall nucleotide composition was A: 30.9%, T: 23.4%, C: 31.6%, G: 14.1%. Nine genes were encoded on the light strand, and the remaining 28 genes were encoded on the heavy strand. Most of the PCGs began with the ATG as the start codon, and four kinds of termination codons were used in this mitogenome. This study improves our understanding of the mitogenomic characteristics and its phylogenetic relationships within Charadriiformes.

Roost selection of the endangered Spotted Greenshank (Tringa guttifer) in critical habitat in the Inner Gulf of Thailand

BackgroundRoost-site quality can significantly affect the individual fitness of shorebirds, but roost sites remain poorly described for many threatened species on the East Asian–Australasian Flyway. We studied roost-site selection of the globally endangered Spotted Greenshank (Tringa guttifer) in the Inner Gulf of Thailand, an area which supports approximately 24% of their global wintering population, during two non-breeding seasons (October 2014–May 2015 and December 2015–February 2016).MethodsWe measured nine variables associated with roost site characteristics including water depth, indicators of disturbance/predation risk, and associations with other shorebird species. We predicted that roost ponds with shallow water in proximity to foraging sites would receive higher usage than those further away.ResultsA total of 94 sites were measured of which 46 were used for roosts with 23 used repeatedly. All used sites were human-modified ponds, of which 44 were used for salt farming and two used for aquaculture. Roosts were on average 1.10 ± 0.78 (SE) km from foraging sites and 5.8 ± 2.4 cm deep. The most supported model indicated that roost sites were negatively associated with distance to foraging sites and positively associated with the presence of Grey Plover (Pluvialis squatarola) and water depth.ConclusionsTraditional saltpans and other artificial wetlands near (< 1 km) mudflats serve as the primary high-tide roost habitat in the Inner Gulf of Thailand for this Spotted Greenshank population and perhaps seven other globally threatened or near-threatened species. Critically, all observed roost sites are on private land with no formal protection and thus will require creative public–private partnerships to manage sustainably.

Alternative habitat: the importance of the Nanpu Saltpans for migratory waterbirds in the Chinese Yellow Sea

SummaryThe natural coastal wetlands of the East Asian-Australasian Flyway (EAAF) are disappearing at alarming rates, leading to rapid declines of many populations of waterbirds in the most species-rich flyway in the world. The identification and assessment of possible alternative habitats that may buffer the loss of natural wetlands should, therefore, be a priority for the conservation of migratory waterbirds using this flyway. Coastal saltpans are functional wetlands that support large numbers of waterbirds worldwide. The Nanpu Saltpans in the northern Bohai Bay of the Yellow Sea in China are one of the largest (290 km2) saltpan complexes in the world. In this paper, we document the value of the Nanpu Saltpans for supporting waterbirds. The surveys, carried out from 2013 to 2016, included waterbird counts in the saltpans (93 km2) at high and low tide and on the adjacent natural tidal flats (57 km2) at low tide. Of the 89 waterbird species recorded, 27 had maximum counts exceeding the 1% threshold value of estimated flyway populations. The maximum counts of waterbirds in northward migration and southward migration in the Nanpu Saltpans were 96,000 and 93,500, respectively, including both foraging and roosting birds; these figures do not account for turnover, so the total number of birds using the site is likely to be higher. The maximum counts on the adjacent tidal flats at low tide amounted to 73,000 and 20,000 waterbirds during northward and southward migration, respectively, and most of them were foraging birds. In the boreal winter, few birds fed in the saltpans, but several thousand fed on the tidal flats. Waterbirds used the inland ponds (2.0–18.0 km from the intertidal area) mainly for feeding both during low tide and high tide and used the nearshore ponds (0.3–4.3 km from the intertidal area) mainly for high-tide roosting. Some species, such as Black-tailed Godwit Limosa limosa, Marsh Sandpiper Tringa stagnatilis, Pied Avocet Recurvirostra avosetta, and Black-winged Stilt Himantopus himantopus, occurred mainly in the saltpans; other species preferred tidal flats, such as Red Knot Calidris canutus, Great Knot Calidris tenuirostris, Bar-tailed Godwit Limosa lapponica, Eurasian Curlew Numenius arquata, Relict Gull Larus relictus, and Grey Plover Pluvialis squatarola. This study clearly demonstrates the joint ecological function of the Nanpu Saltpan complex and adjacent tidal flats as a key staging area for waterbirds in the EAAF, and as such both urgently warrant protected status.

Use of the Swale Estuary, SE England, by Grey Plovers Pluvialis squatarola

Use of the Swale Estuary, SE England, by Grey Plovers Pluvialis squatarola

Variability in the area, energy and time costs of wintering waders responding to disturbance

Birds’ responses to human disturbance are interesting due to their similarities to anti‐predator behaviour, and understanding this behaviour has practical applications for conservation management by informing measures such as buffer zones to protect priority species. To understand better the costs of disturbance and whether it will impact on population size, studies should quantify time‐related responses as well as the more commonly reported flight initiation distance (FID). Using waders wintering on an estuarine area, we experimentally disturbed foraging birds on the Wash Embayment, UK, by walking towards them and recording their responses (FID, alert time, time spent in flight, time taken to resume feeding, and total feeding time lost). We present data for 10 species of conservation concern: Curlew Numenius arquata, Oystercatcher Haematopus ostralegus, Bar‐tailed Godwit Limosa lapponica, Grey Plover Pluvialis squatarola, Redshank Tringa totanus, Knot Calidris canutus, Turnstone Arenaria interpres, Ringed Plover Charadrius hiaticula, Sanderling Calidris alba and Dunlin Calidris alpina. Larger species responded more strongly, response magnitude was greater under milder environmental conditions, and responses varied over both small and large spatial scales. The energetic costs of individual responses, however, were low relative to daily requirements and disturbance events were unlikely to be frequent enough to seriously limit foraging time. We suggest, therefore, that wintering wader populations on the Wash are not currently significantly negatively impacted by human disturbance during the intertidal foraging period. This is also likely to be the case at other estuarine sites with comparable access levels, visitor patterns, invertebrate food availability and environmental conditions.

Use of artificial intertidal sites by birds in a Mediterranean lagoon and their importance for wintering and migrating waders

Man-made habitats provide suitable nesting, resting and feeding habitats for many birds at coastal sites. Despite intensive study outside Europe, very few data are available to date on the bird communities that exploit artificial intertidal sites along the European coasts. Between July 2009 and December 2010, 32 ornithological surveys were performed at six artificial intertidal sites in the lagoon of Venice (Italy). Overall, 101 species (with 23,399 birds) were observed, about a third of those occurring in the lagoon of Venice; 58 of these species were of conservation concern. Ten species comprised about 80 % of the total; bird abundance was the highest during the post-breeding migration and wintering period. Multivariate analysis identified similarity among sites, seasons and observed behaviours. Dredge islands were mostly used by waders as foraging sites, when surrounding tidal flats were still flooded. In winter the six dredged islands supported about 2 % of the dunlins Calidris alpina occurring in the whole lagoon of Venice and about 10 % of the grey plovers Pluvialis squatarola. Since the study sites comprised just the 6 % of the total dredge island area available in 2009–2010, the results indicate as large fractions of these shorebird populations might exploit the dredge island habitats for foraging. Among the newly created habitats, intertidal ponds and inner tidal flats were the most heavily used by birds, followed by dykes and mounds with ruderal vegetation. Maintenance of the habitat mosaic is a need for a conservation- based management of the dredge islands.

In Tundra Plovers the Frequency of Inner Flight Feather Replacement Varies with Length of Long-Distance Flights

The repair jobs that birds have to do to maintain high quality plumage take energy and time, so should be under intense selection. Recently, we have shown that secondary moult in the Eurasian Golden Plover Pluvialis apricaria is incomplete, irregular and asymmetric between wings, and argued that this reflected their ‘relaxed’ migratory habits. On the basis of this hypothesis, we predict that relatives of this species that have to make long flights between breeding areas and winter quarters would invest more in the moult of secondaries. To test this we collected data on moult patterns in two populations of Pacific Golden Plovers Pluvialis fulva (Siberia and Alaska), on American Golden Plovers Pluvialis dominica (Alaska) and Grey Plovers Pluvialis squatarola. Data were from the breeding, staging (Mongolia and Indiana) and wintering (Uruguay) areas. We found patterns consistent with our prediction: Pacific Golden Plovers from Siberia, and Grey Plovers have a similar moulting pattern to Eurasian Golden Plovers. Although both go to remote winter quarters, they migrate mainly over land, probably making short or moderate flights, as they are able to stage frequently. In contrast, the Alaskan populations of Pacific Golden Plovers and American Golden Plovers tend to renew all their secondaries from their second wing moult onwards. In line with their moult patterns, these two populations are known to make very long non-stop flights between breeding and winter areas. We argue that irregular moult and the partial renewal of secondaries is a primitive character in all four species. The full replacement of secondaries in the Pacific Golden Plovers and American Golden Plovers from Alaska may be considered as an adaptation for very long demanding flights. Regular moult patterns of secondaries, as found in many other shorebirds, could be a further refinement of this adaptation.

강화도 남단에 도래하는 도요새들의 해안 내륙 휴식지 이용과 이들의 이용에 영향을 미치는 환경요인들

도요 물떼새들은 만조시에 해안 내륙 휴식지에서 휴식을 취하는데, 휴식지를 선택할 때 여러 가지 요소들을 고려한다. 우리는 도요 물떼새 8종(알락꼬리마도요 Numenius madagascariensis, 청다리도요 Tringa nebularia, 큰뒷부리도요 Limosa lapponica, 개꿩 Pluvialis squatarola, 민물도요 Calidris alpine, 중부리도요 Numenius phaeopus, 마도요 Numenius arquata, 뒷부리도요 Xenus cinereus)을 대상으로 휴식지의 시공간적 이용과 그 이용에 영향을 미치는 요인들을 분석하였다. 휴식지 내 고인 물의 면적과 길이, 기온, 풍속, 종별로 이동시기, 방해정도를 변수로 고려하였다. 시공간적으로, 이용하는 종이 달랐으며 개체수 또한 변동을 거듭하였다. 그리고 도요 물떼새의 휴식지 이용에 영향을 미치는 요인은 종-특이적이었다. 연구지역의 휴식지는 폐장한 새우양식장이었으나 조사 기간 중 염생습지에서 자라는 함초 Salicornia herbacea 농장으로 전환하였다. 휴식지가 필요한 상황에서, 도요 물떼새들의 생태를 기초로 해서 기존 휴식지를 관리할 것을 권한다. 더불어, 여름철 가뭄에는 양식장의 수문을 열어주어 도요 물떼새들이 물을 이용해 체온관리를 할 수 있게 해주고, 만조시 도요 물떼새들이 양식장 안으로 날아 들어올 수 있도록 새들이 휴식지를 찾기 시작하는 만조 전네 시간부터는 농장 작업을 안 할 것을 권한다. There are some factors affecting the shorebirds in selecting a coastal inland roost site where they have to stay during the high tide when the entire intertidal zone is covered with water. We investigated eight species (Eastern Curlews Numenius madagascariensis, Green Shanks Tringa nebularia, Bar-tailed Godwits Limosa lapponica, Grey Plovers Pluvialis squatarola, Dunlins Calidris alpine, Whimbrels Numenius phaeopus, Eurasian Curlews Numenius arquata and Terek Sandpipers Xenus cinereus) to identify the spatial and temporal variability in coastal inland roost use in the area and the factors influencing the use. We considered the area and length of the standing water in the roost site, temperature, wind speed, the time of migration and the intensity of disturbance. As a result, number of individuals and type of species using the roost site varied across spatial and temporal scales. And the factors affecting the roost use was species-specific. The roost site of the study area was a closed shrimp farm however, it has been converted to a Salicornia herbacea, a salt marsh plant, farm recently. In a situation where coastal inland roost site is needed, we hereby describe a resolution for the juxtaposition of shorebirds and farming.

Habitat Choice and Niche Characteristics Under Poor Food Conditions. A Study on Migratory Nearctic Shorebirds in the Intertidal Flats of Brazil

The tidal flats of the Bragantinian Peninsula in the tropical part of Brazil harbour wintering and migratory nearctic shorebirds in very high densities, whereas the benthic food supply is very low. In 2001 and 2002 a study was conducted on the habitat choice and distribution of shorebirds to investigate the formation of niches and the spatial distribution under the constraint of a limited food supply. We showed that shorebird densities were not correlated with a range of abiotic variables or with prey density within sites, but that between sites birds tended to select sites with peak prey densities. Two foraging guilds were differentiated: Whimbrel Numenius phaeopus, Willet Tringa semipalmata and Short-billed Dowitcher Limnodromus griseus preferred to forage in the water or on wet sand at the water's edge; while Red Knot Calidris canutus, Grey Plover Pluvialis squatarola, Ruddy Turnstone Arenaria interpres, Semipalmated Sandpiper Calidris pusilla and Semipalmated Plover Charadrius semipalmatus, were found predominantly on dry substrate. Although the birds showed species-specific preferences for characteristics defining microhabitats, niches were broadly overlapping. The results of our study suggest that, in case of a very low food supply, individuals might not be able to react to competition by niche segregation but might be forced to feed in a broad range of available niches.

The spring migration of Grey Plover Pluvialis squatarola in Sweden

In 1976—1995, 74,650 Grey Plovers Pluvialis squatarola were recorded on spring passage, 87% in the southern third of Sweden, and 59% while in migratory flight. Few were observed before May. The passage peaked 24 May—2 June (83%). About one fourth of all birds were observed on a few occasions, when grounded by inclement weather, showing that only a tiny fraction stops over regularly. In northern Sweden, passage peaked earlier (18 May) than in the south (29 May), and these early birds were presumably destined for breeding or staging in the White Sea region. The peak dates in southern Sweden correlate well with arrival time in Siberia, indicating a non-stop flight to these breeding areas. Flocks counted up to several hundred birds in the south but at most 34 birds in the north. Migration patterns along the East Atlantic Flyway were similar with those of the East African/ West Asian and Mediterranian/Black Sea flyways. The spring passage of the Grey Plover conforms to the migration system of other tundra waders passing up through the western Palaearctic.

Behavioural Plasticity in Foraging Mode of Typical Plovers

The foraging behaviour of typical plovers is highly stereotyped, and short-billed plovers all forage visually in a run—stop—search manner. To date, the use of a sandpiper-like foraging method by typical plovers is considered anecdotal in non-breeding plovers, since only one study has described Grey Plovers Pluvialis squatarola foraging as sandpipers do, striding slowly and pecking at the water surface during short periods. We studied the behaviour and intake rate of Grey and Ringed Plovers Charadrius hiaticula foraging like sandpipers on suspended prey items in the water column of hypersaline pans, and investigated factors that may influence their occurrence. The feeding rate was 48.9 ± 18.0 (SD) and 19.1 ± 6.3 prey min-1 for Ringed and Grey Plover, respectively. For Ringed Plovers, the net intake rate was 0.23 ±0.05 kJ min-1, and for Grey Plovers 0.09 ± 0.01 kJ min-1. The sandpiper-like foraging method was particularly important for Ringed Plovers, since up to 24% of the population foraged in this way at high tide. We found that the sandpiper-like foraging method is a common foraging method in Ringed Plover feeding in prey-abundant pans and is occasionally used by Grey Plovers as well. We showed that behavioural plasticity in foraging methods of typical plovers may be greater than has been assumed previously. These results suggest that typical plovers can successfully locate and capture small prey items while walking continuously and without the need to stop to improve visual acuity.

Analysing Faecal Samples of Ragworm Predators: Not Just a Matter of Counting Mandibles

Ragworms Hediste diversicolor are an important prey item in the diet of many estuary birds. The standard method for estimating the number of Ragworms in faeces or pellets is simply dividing the counted number of Ragworm mandibles by two, which can easily lead to an underestimation of the real number of Ragworms present. Here, I present two alternative methods, which avoids bias in estimates of the number of Ragworms in samples. I compared the three methods by applying them to faecal samples of Grey Plover Pluvialis squatarola and Redshank Tringa totanus from the Tagus estuary, Portugal. The alternative methods yielded significantly higher estimates of the number of Ragworms present in each sample, a difference that can have repercussions on the outcome of dietary studies of Ragworm predators. The pros and cons of each method are discussed with regard to the use of faeces and pellets for ecological research, and the situation in which each method could be applied is discussed.

Primary moult, body mass and migration of Grey Plovers Pluvialis squatarola in Britain

Long‐distance migrants have evolved complex strategies for the timing of their annual moult, fattening and migration cycles. These strategies are likely to vary at different stages of a bird's life. Ringing data on 6079 Grey Plovers Pluvialis squatarola, caught on the Wash, England, between 1959 and 1996, were analysed to relate migratory strategies to patterns of primary moult and body mass changes. Adults returning from breeding grounds had a shorter and delayed primary moult (duration 90 days, starting date 19 August) in comparison with over‐summering birds (duration 109 days, starting date 5 June). Three categories of migrant adults were identified on the basis of primary moult and body mass: (1) birds which did not moult, but increased body mass and migrated further south; (2) birds which moulted 1–3 inner primaries, suspended moult, increased body mass and migrated; and (3) birds which completed or suspended moult and wintered locally. In birds of the second category, timing of primary moult and body mass increase overlapped. Among wintering birds, 38% were in suspended moult. Ninety‐six per cent of birds that suspended moult at the beginning of winter were males and almost all completed moult in spring. Grey Plovers which left Britain in autumn had an average body mass of 280 g, enough to reach southern Morocco without refuelling. Both wintering adults and first‐year birds showed a prewinter body mass increase, peaking in December. Adults had a synchronized premigratory body mass increase in May, which suggested a negligible presence of African migrants. The average departure mass for spring migration, estimated at 316 g, would allow birds to fly non‐stop to the Siberian breeding grounds in western Taymyr.

Predicting site quality for shorebird communities: a case study on the Humber estuary, UK

The conservation importance of estuaries is often measured by bird numbers, but monitoring numbers is not necessarily a reliable way of assessing changes in site quality. We used an individual-based model, comprised of fitness-maximising individuals, to assess the quality of the Humber estuary, UK, for 9 shorebirds; dunlin Calidris alpina, common ringed plover Charadrius hiaticula, red knot Calidris canutus, common redshank Tringa totanus, grey plover Pluvialis squatarola, black-tailed godwit Limosa limosa, bar-tailed godwit L. lapponica, Eurasian oystercatcher Haematopus ostralegus and Eurasian curlew Numenius arquata. We measured site quality as predicted overwinter survival. The model accurately predicted the observed shorebird distribution (if non-starving birds were assumed to feed on any prey or patch on which intake rate equalled or exceeded their requirements), and the diets of most species. Predicted survival rates were highest in dunlin and common ringed plovers, the smallest species, and in Eurasian oystercatchers, which consumed larger prey than the other species. Shorebird survival was most strongly influenced by the biomass densities of annelid worms, and the bivalve molluscs Cerastoderma edule and Macoma balthica. A 2 to 8 % reduction in intertidal area (the magnitude expected through sea level rise and industrial developments) decreased predicted survival rates of all species except the dunlin, common ringed plover, red knot and Eurasian oystercatcher. This paper shows how an individual-based model can assess present-day site quality and predict how site quality may change in the future. The model was developed using existing data from intertidal invertebrate and bird monitoring schemes plus new intertidal invertebrate data collected over 2 winters. We believe that individual-based models are useful tools for assessing estuarine site quality.

Environmental heterogeneity, spatial segregation of prey, and the utilization of southwest Atlantic mudflats by migratory shorebirds

We studied the relationships between the habitat use of migratory shorebirds and the spatial distributions of the Southwestern Atlantic Fiddler Crab Uca uruguayensis, polychaetes, sediment characteristics and tidal levels in the Río de La Plata estuary, Argentina, where U. uruguayensis is one of the most important intertidal species. Crabs have a well‐defined patchy distribution that is segregated spatially from that of polychaetes. Crab density on the surface varied across the tidal cycle, reaching maximum values during low tide. Polychaete density decreased with depth but showed no change through the tidal cycle; however, given that sediment penetrability did change during the same period, their availability to probing shorebirds is expected to change. Habitat use by shorebirds followed the spatial distribution of prey; shorebirds that foraged on polychaetes (White‐rumped Sandpiper Calidris fuscicollis, Two‐banded Plover Charadrius falklandicus and Hudsonian Godwit Limosa haemastica) focused their attention on the areas with the highest densities of polychaetes, whereas species that preyed mostly on crabs (Ruddy Turnstone Arenaria interpres, Whimbrel Numenius phaeopus and Grey Plover Pluvialis squatarola) predominantly used areas with crabs. This segregation occurred particularly during low tide, a period in which polychaetes became fully available. Results show that the spatial and temporal heterogeneity of mudflats in relation to the types and availability of prey has a strong effect on shorebird habitat use.

Duration of primary moult affects primary quality in Grey Plovers Pluvialis squatarola

Feather wear is the natural degradation and breakage of feather structure during the interval between moults. Different rates of feather wear have been observed for primaries of free‐living populations of several species of passerines and waders, and this variability has been linked to different concentrations of melanins. In this study primary moult duration explained 59% of the variation in annual rates of primary abrasion (percentage wing length loss) of seven Grey Plover wintering populations, while migration distance explained 14%. The analysis suggests that primary moult duration plays a key role in determining primary durability and hence primary quality. Long distance migrants might evolve more durable primaries, despite the higher predation risks and energetic costs of a prolonged moult. Partial or complete pre‐breeding primary moults of first‐year waders and complete biannual moults of some passerines might have evolved under selective forces favouring migration with unabraded primaries.

Biometrics of adult Grey Plovers Pluvialis squatarola breeding in the Lena Delta, NE‐Siberia (the Sakha republic, Yakutia)

The Grey Plover Pluvialis squatarola is a circumpolar breeding wader with slight clinal but discontinuous morphometric variations in the Palearctic. Birds breeding in eastern Siberia seem to be larger than birds breeding in western Siberia as well as those breeding in northern Canada and Alaska. Biometric data on 15 Grey Plovers trapped in the Lena Delta 1997 are supplied. In all morphometrical measurements females were on average larger than males, and significant differences occurred for tarsus length (48.1 vs 45.9mm). Furthermore, during incubation females were significantly heavier than males (228.9 vs 217.7g). Sexes could be distinguished by discriminant functions. Most measurements support the view that Palearctic birds are larger than Nearctic ones, but differentiation within the Palearctic remains obscure. Wing, tarsus and bill length of the Lena birds correspond with data from western Siberian birds rather than from eastern Siberia/Alaska; bill length coincides with measurements from Wrangel Island. Besides sex‐specific and geographical differences, migration routes and location of overwintering areas are discussed.

A model describing the exchange of individuals between turnstone Arenaria interpres roosts on the North Wales coast

A recent study of the dispersal of wader species using ringing data from the Wash, modelled the movements of three estuarine species. Using similar methods, the movements of Turnstone Arenaria interpres along the North Wales coast are modelled to provide a rocky shore comparison. Survival rates are also estimated, and shown to be similar to other studies, at 86%. The degree of exchange between Turnstone roosts was strongly influenced by distance, with very little movement between roosts more than 3km apart. Compared to results from the Wash, the modelled dispersal of Turnstones was similar to that of Grey Plover Pluvialis squatarola and Dunlin Calidris alpina, but less than Redshank Tringa totanus, although Turnstones appear to show the most rapid decline in capture probability with distance.

Organochlorine and mecury concetrations in eggs of grey plovers (Pluvialis squatarola) breeding in the Lena Dlta, north-east Sibveria, 1997

Organochlorine and mecury concetrations in eggs of grey plovers (Pluvialis squatarola) breeding in the Lena Dlta, north-east Sibveria, 1997