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Quantifying foraging success in space and time and among individuals is essential for answering many ecological questions and may guide conservation efforts. However, collecting this information is challenging for species that forage on mobile prey and are difficult to observe visually, for example, because they forage in inaccessible areas or at night. In such cases, the use of tracking devices that simultaneously collect location and acceleration data may provide a solution if foraging success can be extracted successfully. The aim of this study was to assess how well searching for and ingesting prey, among other behaviours, could be distinguished from 20 Hz acceleration data collected by GPS/ACC-trackers mounted on the back of Eurasian spoonbills Platalea leucorodia. Upon capturing a prey, spoonbills make a distinct movement with their head and back to throw the prey from the tip of the bill into the throat.

Item does not contain fulltext, BACKGROUND: Pooled analyses of previous randomised studies have suggested that very early treatment with glyceryl trinitrate (also known as nitroglycerin) improves functional outcome in patients with acute ischaemic stroke or intracerebral haemorrhage, but this finding was not confirmed in a more recent trial (RIGHT-2). We aimed to assess whether patients with presumed acute stroke benefit from glyceryl tr initrate started within 3 h after symptom onset. METHODS: MR ASAP was a phase 3, randomised, open-label, blinded endpoint trial done at six ambulance services serving 18 hospitals in the Netherlands. Eligible participants (aged ≥18 years) had a probable diagnosis of acute stroke (as assessed by a paramedic), a face-arm-speech-time test score of 2 or 3, systolic blood pressure of at least 140 mm Hg, and could start treatment within 3 h of symptom onset. Participants were randomly assigned (1:1) by ambulance personnel, using a secure web-based electronic application with random block sizes stratified by ambulance service, to receive either transdermal glyceryl trinitrate 5 mg/day for 24 h plus standard care (glyceryl trinitrate group) or to standard care alone (control group) in the prehospital setting. Informed consent was deferred until after arrival at the hospital. The primary outcome was functional outcome assessed with the modified Rankin Scale (mRS) at 90 days. Safety outcomes included death within 7 days, death within 90 days, and serious adverse events. Analyses were based on modified intention to treat, and treatment effects were expressed as odds ratios (ORs) or common ORs, with adjustment for baseline prognostic factors. We separately analysed the total population and the target population (ie, patients with intracerebral haemorrhage, ischaemic stroke, or transient ischaemic attack). The target sample size was 1400 patients. The trial is registered as ISRCTN99503308. FINDINGS: On June 24, 2021, the MR ASAP trial was prematurely terminated on the advice o

1. Evolutionary theories of seasonal migration generally assume that the costs of longer migrations are balanced by benefits at the non‐breeding destinations.2. We tested, and rejected, the null hypothesis of equal survival and timing of spring migration for High Arctic breeding sanderling Calidris alba using six and eight winter destinations between 55°N and 25°S, respectively. 3. Annual apparent survival was considerably lower for adult birds wintering in tropical West Africa (Mauritania: 0.74 and Ghana: 0.75) than in three European sites (0.84, 0.84 and 0.87) and in subtropical Namibia (0.85). Moreover, compared with adults, second calendar‐year sanderlings in the tropics, but not in Europe, often refrained from migrating north during the first possible breeding season. During northward migration, tropical‐wintering sanderlings occurred at their final staging site in Iceland 5–15 days later than birds wintering further north or south. Namibia‐wintering sanderlings tracked with solar geolocators only staged in West Africa during southward migration.4. The low annual survival, the later age of first northward migration and the later passage through Iceland during northward migration of tropical‐wintering sanderlings, in addition to the skipping of this area during northward but not southward migration by Namibia‐wintering sanderlings, all suggest they face issues during the late non‐breeding season in West Africa.5. Migrating sanderlings defy long distances but may end up in winter areas with poor fitness prospects. We suggest that ecological conditions in tropical West Africa make the fuelling prior to northward departure problematic.

1. Satellite‐based technologies that track individual animal movements enable the mapping of their spatial and temporal patterns of occurrence. This is particularly useful in poorly studied or remote regions where there is a need for the rapid gathering of relevant ecological knowledge to inform management actions. One such region is East Asia, where many intertidal habitats are being degraded at unprecedented rates and shorebird populations relying on these habitats show rapid declines.2. We examine the utility of satellite tracking to accelerate the identification of coastal sites of conservation importance in the East Asian–Australasian Flyway. In 2015–2017, we used solar‐powered satellite transmitters to track the migration of 32 great knots (Calidris tenuirostris), an “Endangered” shorebird species widely distributed in the Flyway and fully dependent on intertidal habitats for foraging during the non‐breeding season. 3. From the great knot tracks, a total of 92 stopping sites along the Flyway were identified. Surprisingly, 63% of these sites were not known as important shorebird sites before our study; in fact, every one of the tracked individuals used sites that were previously unrecognized.4. Site knowledge from on‐ground studies in the Flyway is most complete for the Yellow Sea and generally lacking for Southeast Asia, Southern China and Eastern Russia.5. Synthesis and applications. Satellite tracking highlighted coastal habitats that are potentially important for shorebirds but lack ecological information and conservation recognition, such as those in Southern China and Southeast Asia. At the same time, the distributional data of tracked individuals can direct on‐ground surveys at the lesser known sites to collect information on bird numbers and habitat characteristics. To recognize and subsequently protect valuable coastal habitats, filling knowledge gaps by integrating bird tracking with ground‐based methods should be prioritized.

Accurate predictions of population dynamics require an understanding of the ways by which environmental conditions and species-specific traits affect the magnitude of density dependence. Here, we evaluated the potential impact of season and habitat (characterized by sediment grain size and seagrass biomass) on the magnitude of density dependence in shell growth of 3 infaunal bivalve species dominating the tropical intertidal benthic communities of Banc d’Arguin, Mauritania. Two of our focal species were filter feeders (Senilia senilis and Pelecyora isocardia) and one was a facultative mixotroph (Loripes orbiculatus), mainly relying on organic carbon provided by sulphide-oxidizing endosymbiotic gill-bacteria (i.e. chemosymbiotic). Distinguishing 2 seasons, winter and summer, we manipulated local bivalve densities across habitats (from bare sandy sediments to seagrass-covered mud). In situ growth of individually tagged and relocated clams was measured and compared with those of tagged clams that were allocated to adjacent sites where local bivalve densities were doubled. Growth was negatively density-dependent in both winter and summer in P. isocardia and L. orbiculatus, the 2 species that mainly inhabit seagrass sediments, but not in S. senilis, usually found in bare sediments. As reproduction and survival rates are generally size-dependent in bivalves, our results suggest that in our tropical study system, the bivalve community of seagrass-covered sediments is more strongly regulated than that of adjacent bare sediments, regardless of species-specific feeding mode or season. We suggest that ecosystem engineering by seagrasses enhances environmental stability, which allows bivalve populations within tropical seagrass beds to stay close to carrying capacity.

After an historical absence, over the last decades Eurasian Spoonbills Platalea leucorodia leucorodia have returned to breedon the barrier islands of the Wadden Sea. The area offers an abundance of predator-free nesting habitat, low degrees ofdisturbance, and an extensive intertidal feeding area with increasing stocks of brown shrimp Crangon crangon, the assumedmain prey of P. leucorodia leucorodia. Nevertheless, newly established and expanding colonies of spoonbills have surprisinglyquickly reached plateau levels. Here we tested the often stated assertion that spoonbills mainly rely on brown shrimpas food, by quantifying the diet of chicks on the basis of regurgitates and by analysis of blood isotopes using stable isotopeBayesian mixing models. Both methods showed that, rather than brown shrimp being the staple food of spoonbill chicks,small flatfish (especially plaice Pleuronectes platessa) and gobies (Pomatoschistus spp.) were their main prey. Unlike shrimp,small flatfish have been reported to be rather scarce in the Wadden Sea in recent years, which may explain the rapid saturationof colony size due to food-related density-dependent recruitment declines of growing colonies. By way of their diet andcolony growth characteristics, spoonbills may thus indicate the availability of small fish in the Wadden Sea. We predict thatthe recovery to former densities of young flatfish and other juvenile/small fish in the Wadden Sea will be tracked by changingdiets (more fish) and an increase in the size of Eurasian Spoonbill colonies across the Wadden Sea.

1. Migration is a widespread phenomenon in the animal kingdom. On the basis of theconsiderable variation that exists between and within species, and even withinpopulations, we may be able to infer the (age- and sex-specific) ecological trade-offsand constraints moulding migration systems from assessments of fitness associatedwith migration and wintering in different areas.2. During three consecutive breeding seasons, we compared the reproductive performance(timing of breeding, breeding success, chick body condition and post-fledgingsurvival) of Eurasian spoonbills Platalea leucorodia that breed at a single breedingsite in The Netherlands, but migrate different distances (c. 4,500 vs. 2,000 km,eitheror not crossing the Sahara) to and from wintering areas in southern Europeand West Africa. Using mark–recapture analysis, we further investigated whethersurvival until adulthood (recruitment probability) of chicks hatched between 2006and 2010 was related to their hatch date and body condition.3. Long-distance migrants bred later, particularly the males, and raised chicks ofpoorer body condition than short-distance migrants. Hatch dates strongly advancedwith increasing age in short-distance migrants, but hardly advanced in longdistancemigrants, causing the difference in timing of breeding between long- andshort-distance migrants to be more pronounced among older birds.4. Breeding success and chick body condition decreased over the season, and chicksthat fledged late in the season or in poor condition were less likely to survive untiladulthood. As a result, long-distance migrants—particularly the males and olderbirds—likely recruit fewer offspring into the breeding population than short-distancemigrants. This inference is important for predicting the population-level consequencesof changes in winter habitat suitability throughout the wintering range.5. Assuming that the long-distance migrants—being the birds that occupy the traditionalwintering areas—are not the poorer qual

Although age-related spatial segregation is ubiquitous, the underlying mechanisms are poorly understood. Here, we aim to elucidatethe processes behind a previously established age-related foraging distribution of red knots (Calidris canutus canutus) in their mainwintering area in West Africa (Banc d’Arguin, Mauritania). Based on 10 years of observations of 1232 uniquely color-ringed individualsof 1 to 18+ years old, we examined whether the observed age-related foraging distribution resulted from 1) spatial differences in mortalityor 2) age-related shifts in habitat use. Using multistate capture–recapture modeling, we showed that with age foraging red knotsmoved away from the shoreline, that is, to areas with fewer surprise attacks by raptors. Considering uncertainties in the subjectivegradient in predation danger with increasing distance from shore (as assessed from correlations between vigilance and distance fromshore in foraging birds), we applied 2 different danger zone boundaries, at 40 m and 500 m from shore. Between years, red knots hada much higher chance to move from the dangerous nearshore area to the “safe” area beyond (71–78% and 26% for 40-m and 500-mdanger zone boundary, respectively), than vice versa (4% and 14%). For neither danger zone boundary value did we find differencesin annual mortality for individuals using either dangerous or safe zone, so the move away from the shore with age is attributed to individualcareers rather than differential mortality. We argue that longitudinal studies like ours will reveal that ontogenetic shifts in habitatuse are more common than so far acknowledged.

Like many migratory shorebird populations using the East Asian–Australasian Flyway, Bar-tailed GodwitsLimosa lapponica baueri in New Zealand have significantly declined since the mid-1990s, but census data indicate arelatively stable population since 2004. The demographic drivers of both the decline and stabilisation remain unknown.We estimated annual survival from mark–recapture data of adult godwits in New Zealand during 2005–2014. Annualadult survival declined over the study period from 0.89–0.96 in 2005–2010 to 0.83–0.84 in 2011–2012. The simultaneousdecline in annual survival found in a separate study of Bar-tailed Godwits L. l. menzbieri in north-west Australia suggestsa common effect of their high dependence on threatened migratory staging sites in the Yellow Sea; the more extreme declinein L. l. menzbieri may reflect ecological differences between the populations, such as timing and extent of use of these sites.At current apparent recruitment rates, persistent adult survival of ~0.84 would lead to a population decline of 5–6% per yearin L. l. baueri. Our study implies that the demographic precursors to a population decline developed during a period ofapparent population stability; this suggests that monitoring a single index of population stability is insufficient for predictingfuture trends.

Reductions in body size are increasingly being identified as a response to climatewarming. Here we present evidence for a case of such body shrinkage, potentially dueto malnutrition in early life. We show that an avian long-distance migrant (red knot,Calidris canutus canutus), which is experiencing globally unrivaled warming rates at itshigh-Arctic breeding grounds, produces smaller offspring with shorter bills duringsummers with early snowmelt. This has consequences half a world away at their tropicalwintering grounds, where shorter-billed individuals have reduced survival rates. This isassociated with these molluscivores eating fewer deeply buried bivalve prey and moreshallowly buried seagrass rhizomes. We suggest that seasonal migrants can experiencereduced fitness at one end of their range as a result of a changing climate at theother end.

There is increasing concern about the world’s animal migrations. With many land-use andclimatological changes occurring simultaneously, pinning down the causes of large-scale conservationproblems requires sophisticated and data-intensive approaches.2. Declining shorebird numbers along the East Asian–Australasian Flyway, in combinationwith data on habitat loss along the Yellow Sea (where these birds refuel during long-distancemigrations), indicate a flyway under threat.3. If habitat loss at staging areas indeed leads to flyway-wide bird losses, we would predictthat: (i) decreases in survival only occur during the season that birds use the Yellow Sea, and(ii) decreases in survival occur in migrants that share a reliance on the vanishing intertidalflats along the Yellow Sea, even if ecologically distinct and using different breeding grounds.4. Monitored from 2006–2013, we analysed seasonal apparent survival patterns of threeshorebird species with non-overlapping Arctic breeding areas and considerable differences inforaging ecology, but a shared use of both north-west Australian non-breeding grounds andthe Yellow Sea coasts to refuel during northward and southward migrations (red knot Calidriscanutus piersmai, great knot Calidris tenuirostris, bar-tailed godwit Limosa lapponicamenzbieri). Distinguishing two three-month non-breeding periods and a six-month migrationand breeding period, and analysing survival of the three species and the three seasons in asingle model, we statistically evaluated differences at both the species and season levels.5. Whereas apparent survival remained high in north-west Australia, during the time awayfrom the non-breeding grounds survival in all three species began to decline in 2011, havinglost 20 percentage points by 2012. By 2012 annual apparent survival had become as low as0?71 in bar-tailed godwits, 0?68 in great knots and 0?67 in red knots. In a separate analysisfor red knots, no mortality occurred during the migration from Australia t

Reductions in body size are increasingly being identified as a response to climate warming. Here we present evidence for a case of such body shrinkage, potentially due to malnutrition in early life. We show that an avian long-distance migrant (red knot, Calidris canutus canutus), which is experiencing globally unrivaled warming rates at its high-Arctic breeding grounds, produces smaller offspring with shorter bills during summers with early snowmelt. This has consequences half a world away at their tropical wintering grounds, where shorter-billed individuals have reduced survival rates. This is associated with these molluscivores eating fewer deeply buried bivalve prey and more shallowly buried seagrass rhizomes. We suggest that seasonal migrants can experience reduced fitness at one end of their range as a result of a changing climate at the other end.

Explanations for the wide variety of seasonal migration patterns of animals all carry the assumption that migration is costly and that this cost increases with migration distance. Although in some studies, the relationships between migration distance and breeding success or annual survival are established, none has investigated whether mortality during the actual migration increases with migration distance. Here, we compared seasonal survival between Eurasian spoonbills (Platalea leucorodia leucorodia) that breed in The Netherlands and migrate different distances (ca 1000, 2000 and 4500 km) to winter in France, Iberia and Mauritania, respectively. On the basis of resightings of individually marked birds throughout the year between 2005 and 2012, we show that summer, autumn and winter survival were very high and independent of migration distance, whereas mortality during spring migration was much higher (18%) for the birds that wintered in Mauritania, compared with those flying only as far as France (5%) or Iberia (6%). As such, this study is the first to show empirical evidence for increased mortality during some long migrations, likely driven by the presence of a physical barrier (the Sahara desert) in combination with suboptimal fuelling and unfavourable weather conditions en route.

Chick body condition can be a sensitive indicator of local environmental conditions and has been shown to be correlated with chick survival. Designing a reliable index of chick body condition for a given species from a single measurement point requires knowledge about the extent of variation in body size, about chick age and about the relative sensitivity of the growth of different biometric measures to variation in environmental conditions. To gain this knowledge, we describe sex-specific variation in growth of several morphometric measures and body mass of Eurasian Spoonbills Platalea leucorodia. We repeatedly measured 35 chicks that grew up in small colonies on the island ofSchiermonnikoog to derive detailed growth curves until fledging (based on the 12 surviving chicks) and to assess the extent of reduction in growth of starved chicks measured at least twice (n = 11) compared to those that survived. Growth curves until fledging were compared with biometric measurements of two to fiveweek old chicks from (mostly) larger colonies of which hatching date was accurately estimated (n = 631). Growth of all measures, except the eighth primary, was sex-specific, with the most pronounced sex effect on the asymptotic values of tarsus length and body mass: adult males were predicted to become 17%heavier than females and to have 22% longer tarsi than females. Body mass and tarsus growth tended to be more reduced under food deprivation than (head-)bill and eighth primary growth. As an index of chick body condition, we propose to use the proportional deviation in body mass from the predicted body mass for a given age and sex. To do so, measurements of nearly fledged Spoonbillchicks should include at least eighth primary length to estimate age, tarsus length to estimate sex, and body mass as a measure that integrates age, seks and environmental effects.

We used stable isotope tracers in the growing primary feathers of Eurasian Spoonbill chicks (Platalea leucorodia leucorodia) to study seasonal variation in their diet on one of the Frisian islands, Schiermonnikoog, The Netherlands. Using growing individual primaries as natural samplers over time, samples were taken along the length of primary feathers to estimate both within- and between-individual variation in diet. Absolute isotopic ratios of feather material ranged from -26.2 to -14.7 ‰ for carbon (d13C) and from 13.0 to 18.7 ‰ for nitrogen (d15N). The variation in d13C values suggests the use of a variety of feeding habitats, ranging from freshwater to marine. Across the breeding season, there was a shift from predominantly freshwater prey early on to a more marine diet later in the season. Surprisingly, this shift did not occur within the growth trajectory of early born chicks which instead showed the opposite, but it did occur within individual chicks born later in the season. Stable isotope Bayesian mixing-model (SIAR) outcomes demonstrated that the freshwater/brackish prey had the highest isotopic contribution “(51 %; 95 % confidence interval 39–63 %) to the diet early in the breeding season, whereas marine prey contributed most (78 %; 66–89 %) to the diet later. That chicks fed with either freshwater or marine food items had similar body condition indices suggests that the eating of marine prey did not come at a major cost for growing Spoonbill chicks.

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Density dependence in vital rates is key to population regulation. Rather than being constant, the strength of density dependence may vary throughout the year, but empirical evidence is limited. Based on 22 years of data of color-banded birds from a recovering population of Eurasian Spoonbills Platalea leucorodia leucorodia, we show, for the first time, seasonal variation in density dependence in survival of a long-distance migrating bird. Combining resightings and dead recoveries at breeding, stopover, and nonbreeding areas enabled us to (1) separate true survival from permanent emigration from the breeding area, and (2) estimate survival in three seasons: summer, early winter (including autumn migration), and late winter (including spring migration). Accompanying the rapid population growth, juvenile annual survival initially increased, manifested in early winter, but thereafter, at high population sizes, it strongly decreased through a combination of decreasing survival in all seasons. Annual survival of subadult (second- and third-year) and adult birds decreased more gradually with increasing population size, with density dependence occurring in early winter for subadults and late winter for adults. Thus, the shape and strength of density dependence in survival varied with age and season. Understanding the seasonal timing of density dependence, especially with reference to underlying mechanisms, is important for the design of effective conservation strategies.

When populations grow or decline, habitat selection may change due to local density-dependent processes, such as site dependence and interference. In seasonally migrating animals, nonbreeding distributions may be determined through these mechanisms of density dependence, which we examine here at a hemispheric scale for a long-distance migrating bird. Using summer and winter resightings of 2,095 Eurasian spoonbills Platalea leucorodia leucorodia that were ringed in the Netherlands during 16 years of fast population growth, we show that neither site dependence nor interference fully explains their patterns of survival and winter distribution. Within their three main wintering areas, annual survival decreased with an increase in population size. While survival was consistently higher in the two European wintering areas (France, Iberia), most spoonbills migrated onward to winter in west Africa. The number of birds wintering in Europe increased, but not enough to maximize annual survival. We conclude that a constraint of tradition (their "migration tendency") inhibits birds from changing their migratory habits. We pose that this phenomenon may similarly constrain other migratory populations from rapidly responding to large-scale climate- and/or human-driven habitat changes at their wintering grounds.

Mauritanian Spoonbills (Platalea leucorodia balsaci) only breed at Banc d'Arguin, Mauritania, West Africa. Their populations have declined; however, nothing is known about possible ecological factors involved, including their primary food and foraging habits. Home range sizes, habitat selection, and foraging rhythm in six adult Mauritanian Spoonbills were documented by attaching backpack harnesses with solar-powered satellite GPS-transmitters. Based on 18 bird-months of data (5,844 selected ground positions) collected between 2008 and 2010, these individuals never left the study area centered on the island of Tidra. The fixed kernel home range size was 23-101 km(2) ((x) over bar = 62 km(2)) and the core area 2-14 km(2) ((x) over bar = 7 km(2)). Home range sizes did not differ between breeding and non-breeding seasons. Mauritanian Spoonbills fed only in intertidal areas where they preferred the seagrass-covered (Zostera noltii) areas and they fed primarily during the ebbing tide. Furthermore, the GPS-positions away from the high tide roosts were strongly associated with creeks dissecting the seagrass beds. During the non-breeding season, foraging occurred throughout the 24-hr period, but during the breeding season they foraged exclusively by night. Received 30 July 2012, accepted 2 January 2013.

Estimates of seasonal mortality for long-distance migrant birds are extremely challenging to collect and consequently reports are scarce. Determining when and where mortality occurs within the annual cycle is important for an understanding of population dynamics and the evolutionary drivers of long-distance migration. We collected data on seasonal survival in a mark-recapture study of colour-marked Red Knots Calidris canutus canutus in their main wintering area at tropical Banc d'Arguin, Mauritania, West Africa. Our study population breeds 9,000 km to the northeast on Taymyr Peninsula, central northern Siberia. Our results show that annual apparent survival decreased from 0.87 +/- A 0.01 (SE) in 2002-2005 to 0.78 +/- A 0.02 in 2006-2009. During the 3-year time-window between 2006 and 2009, additional resightings just before migration and after return to the wintering grounds allowed us to partition the year into two periods: the non-breeding period on the Banc d'Arguin, and the migration and breeding period away from it. We estimated that, on the Banc d'Arguin, the 2-month apparent survival rate was 0.94 +/- A 0.01, whereas 2-month survival approached unity during the rest of year. Hence, most mortality occurred on the tropical wintering grounds. We review the possible physiological and ecological stressors involved and discuss the generality of these results.