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Migratory connectivity is a metric of the co-occurrence of migratory animals originating from different breeding sites, and like their spatio-temporal distributions, can vary substantially during the annual cycle. Together, both these properties affect the optimal times and sites of population censusing.We tracked taiga bean geese (Anser fabalis fabalis) during 2014–2021 to study their migratory connectivity and non-breeding movements, and determine optimal periods to assess the size of their main flyway population. We also compared available census data with tracking data, to examine how well two existing censuses covered the population.Daily Mantel’s correlation between breeding and non-breeding sites lay between 0 and 0.5 during most of the non-breeding season, implying birds from different breeding areas were not strongly separated other times in the annual cycle. However, the connectivity was higher among birds from the westernmost breeding areas compared to the birds breeding elsewhere. Daily Minimum Convex Polygons showed tracked birds were highly aggregated at census times, confirming their utility. The number of tracked birds absent at count sites during the censuses however exceeded numbers double-counted at several sites, indicating that censuses might have underestimated the true population size.Our results show that connectivity can vary in different times during the non-breeding period, and should be studied throughout the annual cycle. Our results also confirm previous studies, which have found that estimates using marked individuals usually produce higher population size estimates than total counts. This should be considered when using total counts to assess population sizes in the future.

Night-brooding of nestlings in cavity-nesting avian species carries predation risks to parents. Anecdotally, several species are known to shift from constant adult night-brooding behaviour to leaving nestlings unattended at night during offspring development but the timing, speed of change and sex-specific differences between parents, and the factors shaping this behaviour have rarely been described. Moreover, the location and nature of night roosts used by adults whilst provisioning nestlings has received little research attention. We studied breeding Common Starlings Sturnus vulgaris and hypothesised that, in such a cavity-nesting species, 1) nestlings would only be night-brooded until they achieved thermal independence, 2) since the species is frequently polygynous, female parents would most likely exclusively night-brood offspring despite provisioning by both sexes and 3) night-brooding would be more likely during nights with lowest temperatures. Nightly video recordings throughout the nestling phase at eight Starling nests together with data from 18 Starlings fitted with GPS-loggers during 26 nights provided support for hypotheses 1) and 2), while we found no support for hypothesis 3). All tagged male Starlings always roosted far from the nesting site (up to 8 km) independent of nestling age; all females brooded nestlings, usually up to the first seven-nine days after hatching (when the nestlings achieve thermoregulation), but roosted with males after day 10, when all tagged Starlings from the same nesting ‘colony’ roosted together. These results confirm differential sex-related parental effort in provisioning Starlings, suggesting females only night-brood until young achieve homeothermy.

To test for the degree of species-specific variation in clutch initiation date in relation to spring thaw, we recorded first egg dates in 1433 nests of seven large bodied long-distance migratory waterbird species breeding on Ayopechan Island in the Chaun Delta, Chukotka, in the Russian Arctic during 2002–2020. Pacific Loon Gavia pacifica, Sandhill Crane Grus canadensis and Glaucous Gull Larus hyperboreus all adjusted timing of clutch initiation completely to annual variation in first frost-free dates. First egg dates of Spectacled Eider Somateria fischeri also significantly advanced in warmer springs, but the rate of change was significantly less than unity, implying a reduced capacity to accommodate change in vernal thaw that may not be able to keep up with greater change in the future. Long-tailed Duck Clangula hyemalis and Vega Gull Larus vegae showed a tendency for earlier first egg dates in years with earlier first frost-free date, but for both species, the relationship failed to reach statistical significance. Bewick’s Swan Cygnus columbianus showed almost no change in mean first egg date across the observed variation in first frost-free dates. Based on these data, we suggest that while all seven species showed signs of plasticity in their timing of onset of breeding, Pacific Loon, Sandhill Crane and Glaucous Gull showed greater adaptability to adjust the timing of their breeding season to recent variation in spring thaw than the other four species studied here over this period.

Arctic-nesting geese face energetic challenges during spring migration, including ecological barriers and weather conditions (e.g., precipitation and temperature), which in long-lived species can lead to a trade-off to defer reproduction in favor of greater survival. We used GPS location and acceleration data collected from 35 greater white-fronted geese of the North American midcontinent and Greenland populations at spring migration stopovers, and novel applications of Bayesian dynamic linear models to test daily effects of minimum temperature and precipitation on energy expenditure (i.e., overall dynamic body acceleration, ODBA) and proportion of time spent feeding (PTF), then examined the daily and additive importance of ODBA and PTF on probability of breeding deferral using stochastic antecedent models. We expected distinct responses in behavior and probability of breeding deferral between and within populations due to differences in stopover area availability. Time-varying coefficients of weather conditions were variable between ODBA and PTF, and often did not show consistent patterns among birds, indicating plasticity in how individuals respond to conditions. An increase in antecedent ODBA was associated with a slightly increased probability of deferral in midcontinent geese but not Greenland geese. Probability of deferral decreased with increased PTF in both populations. We did not detect any differentially important time periods. These results suggest either that movements and behavior throughout spring migration do not explain breeding deferral or that ecological linkages between bird decisions during spring and subsequent breeding deferral were different between populations and across migration but occurred at different time scales than those we examined.

Population growth rates in geese can be sensitive to small changes in survival and/or production of young, explain more variation in population change can be crucial for implementing effective conservation actions. Here, we show that annual adult survival and production of young (assessed in winter) explained most variation in annual population growth rate across 36 years in GreenlandWhite-fronted Geese Anser albifrons flavirostris, during which time the population showed a sustained increase followed by a decline. In contrast, there was no strong relationship between annual population growth rate and juvenile survival following autumn migration, suggesting that variation in this demographic parameter contributed little to the population trajectory over the same period. Quantifying the influence of decisions made by Greenland White-fronted Geese throughout the annual cycle will improve our ability to target seasonal conservation actions that reduce adult mortality and/or increase pro duction of young where possible.

Twenty Far East Greylag Geese, Anser anser rubrirostris, were captured and fitted with Global Positioning System/Global System for Mobile Communications (GPS/GSM) loggers to identify breeding and wintering areas, migration routes and stopover sites. Telemetry data for the first time showed linkages between their Yangtze River wintering areas, stopover sites in northeastern China, and breeding/molting grounds in eastern Mongolia and northeast China. 10 of the 20 tagged individuals provided sufficient data. They stopped on migration at the Yellow River Estuary, Beidagang Reservoir and Xar Moron River, confirming these areas as being important stopover sites for this population. The median spring migration duration was 33.7 days (individuals started migrating between 25 February and 16 March and completed migrating from 1 to 9 April) compared to 52.7 days in autumn (26 September-13 October until 4 November-11 December). The median stopover duration was 31.1 and 51.3 days and the median speed of travel was 62.6 and 47.9 km/day for spring and autumn migration, respectively. The significant differences between spring and autumn migration on the migration duration, the stopover duration and the migration speed confirmed that tagged adult Greylag Geese traveled faster in spring than autumn, supporting the hypothesis that they should be more time-limited during spring migration.

Background As digital peer support is quickly expanding across the globe in the wake of the COVID-19 pandemic, standardization in the training and delivery of digital peer support can advance the professionalism of this field. While telehealth competencies exist for other fields of mental health practice, such as social work, psychiatry, and psychology, limited research has been done to develop and promote digital peer support competencies. Objective The goal of this study is to introduce the coproduction of core competencies that can guide digital peer support. Methods Peer support specialists were recruited through an international listserv and participated in a 1-hour virtual focus group. A total of four focus groups were conducted with 59 peer support specialists from 11 US states and three countries. Results Analysis was conducted using the rigorous and accelerated data reduction (RADaR) technique, and 10 themes were identified: (1) protecting the rights of service users, (2) technical knowledge and skills in the practice of digital peer support, (3) available technologies, (4) equity of access, (5) digital communication skills, (6) performance-based training, (7) self-care, (8) monitoring digital peer support and addressing digital crisis, (9) peer support competencies, and (10) health literacy (emerging). The authors present recommendations based on these themes. Conclusions The introduction of digital peer support core competencies is an initial first step to promote the standardization of best practices in digital peer support. The established competencies can potentially act as a guide for training and skill development to be integrated into US state peer support specialist competencies and to enhance competencies endorsed by the Substance Abuse and Mental Health Services Administration (SAMHSA).

Several alien predator species have spread widely in Europe during the last five decades and pose a potential enhanced risk to native nesting ducks and their eggs. Because predation is an important factor limiting Northern Hemisphere duck nest survival, we ask the question, do alien species increase the nest loss risk to ground nesting ducks? We created 418 artificial duck nests in low densities around inland waters in Finland and Denmark during 2017–2019 and monitored them for seven days after construction using wildlife cameras to record whether alien species visit and prey on the nests more often than native species. We sampled various duck breeding habitats from eutrophic agricultural lakes and wetlands to oligotrophic lakes and urban environments. The results differed between habitats and the two countries, which likely reflect the local population densities of the predator species. The raccoon dog (Nyctereutes procyonoides), an alien species, was the most common mammalian nest visitor in all habitats and its occurrence reduced nest survival. Only in wetland habitats was the native red fox (Vulpes vulpes) an equally common nest visitor, where another alien species, the American mink (Neovison vison), also occurred among nest visitors. Although cautious about concluding too much from visitations to artificial nests, these results imply that duck breeding habitats in Northern Europe already support abundant and effective alien nest predators, whose relative frequency of visitation to artificial nests suggest that they potentially add to the nest predation risk to ducks over native predators.

To test for the degree of species-specific variation in clutch initiation date in relation to spring thaw, we recorded first egg dates in 1433 nests of seven large bodied long-distance migratory waterbird species breeding on Ayopechan Island in the Chaun Delta, Chukotka, in the Russian Arctic during 2002-2020. Pacific Loon Gavia pacifica, Sandhill Crane Grus canadensis and Glaucous Gull Larus hyperboreus all adjusted timing of clutch initiation completely to annual variation in first frost-free dates. First egg dates of Spectacled Eider Somateria fischeri also significantly advanced in warmer springs, but the rate of change was significantly less than unity, implying a reduced capacity to accommodate change in vernal thaw that may not be able to keep up with greater change in the future. Long-tailed Duck Clangula hyemalis and Vega Gull Larus vegae showed a tendency for earlier first egg dates in years with earlier first frost-free date, but for both species, the relationship failed to reach statistical significance. Bewick's Swan Cygnus columbianus showed almost no change in mean first egg date across the observed variation in first frost-free dates. Based on these data, we suggest that while all seven species showed signs of plasticity in their timing of onset of breeding, Pacific Loon, Sandhill Crane and Glaucous Gull showed greater adaptability to adjust the timing of their breeding season to recent variation in spring thaw than the other four species studied here over this period.

Background: Evidence suggests that wintering waterbirds have become conspicuously more concentrated at two largest lakes of the Yangtze River Floodplain, East Dong Ting Lake (Hunan Province, 29°20′N, 113°E) and Poyang Lake (Jiangxi Province, 29°N, 116°20′E), relative to other lakes, despite the establishment of reserves elsewhere. While this relationship is likely due to greater extent of undisturbed habitats in larger lakes, we understand little of the drivers affecting individual behaviours behind this tendency. Methods: We tracked wintering movements of three duck species (Eurasian Wigeon Mareca penelope, Falcated Duck M. falcata and Northern Pintail Anas acuta) using GPS transmitters, examining differences between the two largest lakes and other smaller lakes in ducks’ habitat use, duration of stay at each lake and the daily distances moved by the tagged birds while at these sites. Results: The Eurasian Wigeon and Falcated Duck stayed five times longer and almost exclusively used natural habitat types at the two large lakes (91‒95% of positions) compared to length of stay time at smaller lakes, where they spent 28‒33 days on average (excluding the capture site) and exploited many more different habitats (including c. 50% outside lakes). Conclusions: Our study is the first to show that shorter length of stay and more varied habitat use by ducks at small lakes may contribute to explaining the apparent regional concentration of numbers present of these and other species at the largest lakes in recent years. This compares with their declining abundance at smaller lakes, where habitat loss and degradation has been more manifest than on the larger lakes.

An estimated 50% decline in Taiga Bean Geese A. fabalis between the mid-1990s and 2015 contrasted increasing numbers of Tundra Bean Goose A. serrirostris wintering in Western Europe at the same time. Seber dead-recovery analysis of metal-ringed individuals used to investigate year- and age effects on survival estimates from historical ringing data of both taxa caught in The Netherlands 1964–1987 generated annual survival rates of 0.716 (0.013 SE) and 0.803 (0.007) for A. fabalis and 0.824 (0.006) and 0.831 (0.005) for A. serrirostris for first-winter and adults, respectively.

Background The Bar-headed Goose (Anser indicus) breeds across the high plains and plateau of Central Asia and winters in the Qinghai-Tibet Plateau (QTP), the Yunnan-Guizhou Plateau and the Indian sub-continent. Of the two recognized discrete flyways of the Bar-headed Goose, the Eastern Tibetan Flyway (ETF) is the larger, comprising at least six migration routes. However, we remain ignorant about their migratory connectivity, habitat use and effectiveness of site-safeguard mechanisms set in place for the species. Methods We tracked 30 ETF Bar-headed Geese from Chinese and Mongolian breeding areas to their wintering grounds using GPS/GSM transmitters, to determine their migration routes and stopover staging patterns within the QTP, overlaying these upon GIS layers of protected area status and habitat type, to model their habitat selection. Results In total, 14 tagged Bar-headed Geese provided information on their entire autumn migration and 4 geese on their entire spring migration. Qinghai Lake marked birds overwintered in the QTP (n = 2), geese tagged in Mongolia wintered either in the QTP (n = 3) or in India/Bangladesh (n = 9), representing three of the migration routes within the ETF. In total, tagged birds staged at 79 different stopover sites within QTP in autumn and 23 in spring, of which 65% (autumn) and 59% (spring) of all fixes fell within the boundaries of either National Nature Reserves (NNRs) or Important Birds Areas (IBAs) in the QTP. Bar-headed Geese predominantly occurred on four land-cover types: grassland (mostly by day), water bodies (at night), wetlands and bare substrates (salt flats, dry lake/river substrates and plough) with little change in proportion. Generalized linear mixed models comparing presence with pseudo-absence data suggested geese strongly selected for wetlands as staging habitat, avoiding bare substrates in spring. Conclusions Based on our limited observations of these tagged geese, this study is the first to show that the current designated National Nature Reserves in place in the staging areas within the QTP appear adequate to protect this increasing population. In addition, Hala Lake in Qinghai Province and adjacent areas used as initial QTP staging during autumn migration (currently outside of designated as NNRs/IBAs) are recommended for protection, based on their use by tagged birds from this study. Habitat modelling confirmed the importance of natural wetlands as feeding areas and safe areas of open water as roosting places.

Annual Finnish breeding duck surveys over the last 30 years show declining abundance among several species and greater declines on eutrophic waters than oligotrophic lakes. It has been suggested that habitat-related differences in the rate of increase in predation pressure is a potential explanation for contrasting duck population trajectories between habitats. We assessed potential duck nest predation risk and predator presence in various duck breeding habitats in Finland and Denmark by monitoring 333 artificial duck nests with wildlife cameras during 2017-2019. Predation rates differed between landscapes and habitats: nest predation rate and predator diversity were lowest in forested and highest in agricultural landscapes. Forest nests further from water bodies survived better than nests around shorelines of permanent lakes. Of the 16 different predator species detected, the most common were Eurasian magpie (Picapica), hooded crow (Corvus corone) and raccoon dog (Nyctereutes procyonoides). While predation by specific native predator species was typically associated with particular habitats and landscapes, the alien raccoon dog appeared to be a true habitat generalist, ubiquitous and common across all habitats and landscapes. Based on these results, the higher duck nest predation pressure along shorelines, especially in agricultural landscape lakes, due to increased diversity and abundance within the predator community, may contribute to the declining population trends of ducks. (C) 2020 Gesellschaft fir okologie. Published by Elsevier GmbH. All rights reserved.

Aim: Understanding connectivity between avian breeding and non-breeding areas is essential to understand processes affecting threatened migrants throughout their annual cycle. We attempted to establish migratory connectivity and flyway structure of the IUCN vulnerable Swan Geese (Anser cygnoides) by combining citizen science species' distribution models (SDMs) and feather stable isotope analysis. Locations: Russia, Mongolia and China. Methods: We established migratory origins and movements of 46 Swan Geese from five wintering locations by integrating citizen science SDMs and feather stable hydrogen isotope (δ 2H) measurements by linking feathers to precipitation isoscapes in a Bayesian probability framework. Results: We determined multiple summering origins among Swan Geese from the most important wintering location, Poyang Lake, Jiangxi Province, China. As predicted, we found no evidence for sex-biased differences in δ 2H measurements. Four geese tracked with GPS/GSM loggers all migrated to moulting areas, which confirmed the accuracy of our predictions from δ 2H assignments. Differences between summering ranges inferred from historical and modern samples coincided with major wetland loss in northeastern China since the 1950s. Despite limited historical data, we contend that this supports the hypothesis that the summering range prior to 1950 was much wider than that of the current population. Main conclusions: This was the first Asian study to establish migratory origins of wintering Anatidae based on stable isotopes and citizen science SDMs. We advocate the wider combined application of SDMs, telemetry studies and stable isotopes to investigate effectively avian migratory connectivity, as the results from this study provided important contributions to the development of conservation measures for this threatened and declining species in East Asia.

Capsule: Eurasian Bitterns Botaurus stellaris caught in winter in eastern China summered in the Russian Far East. Aims: To identify migration timing, duration and routes, as well as stopover sites, used by Eurasian Bitterns in the Russian Far East flyway and obtain basic information on behaviour and ecology from tracking data. Methods: We tracked two Eurasian Bitterns caught in China with global positioning system/mobile communications loggers for one and three years respectively, to identify their migration routes and schedules. We used the distance moved between successive fixes to determine their diurnal activity patterns. Results: The two individuals wintered in eastern China and travelled a mean of 4221 ± 603 km (in 2015–17) and 3844 km (2017) to summer in the Russian Far East. Results from one bird have shown that in all three years, the bird was significantly more active during the day than at night, although the absolute differences varied with season, being most nocturnally active in summer. The most surprising result from this bird was the flexibility in spring migration and the lack of summer site fidelity. Conclusion: The study identified previously unknown migration routes of the Eurasian Bittern in East Asia, and suggested that the species is generally more active during the day throughout the year.

Analysis of coordinated Greater Scaup (Aythya marila) count data from the last 30 years showed a 38.1% decrease in wintering numbers in North-West Europe, from 309,000 during 1988–1991 to c.192,300 individuals during 2015–2018. Annual trends in wintering numbers differed throughout the range. Numbers decreased in the UK, Ireland, and in the Netherlands, while numbers were stable in Denmark. Germany, Poland, Sweden, and Estonia showed increasing numbers, suggesting a shift in the distribution of the species within its wintering grounds towards the east and north. Higher temperatures in northern and eastern areas were correlated with the range shift of the wintering distribution. Deaths from bycatch drowning of Scaup in fishing gear have significantly decreased in recent decades in the Netherlands, where currently the greatest threat is considered the deterioration of food resources. The increasing concentration of wintering Scaup in coastal Poland and Germany (where lack of effective implementation of conservation measures fail to protect the species from the impacts of bycatch and declining food quality) pose major threats to the entire population.

The proliferation of ever-larger wind turbines poses risks to wildlife, especially from avian collision, yet avoidance behaviour of large-bodied, long-lived bird species in relation to wind turbines remains little studied away from collision “black spots” and offshore marine environments. Here, three-dimensional flight trajectory data are reported from a laser range-finder study of local movements of large-bodied birds (e.g. swans, geese, gulls, cormorants, raptors and cranes, whose populations are relatively more demographically sensitive to collision mortality) in relation to seven terrestrial 150-222 m high (mean 182 m) wind turbines constructed in Denmark in a N-S line. Comparisons of two-dimensional flight passages between turbines pre- (n = 287) and post-construction (n = 1210) showed significant (P < 0.0001) reductions from 48% to 35% within 150 m of each turbine, with corresponding increase 200-300 m from turbines. Results also showed a significant (P < 0.001) 50% reduction in the percentage of avian passages (from 21% to 10%) through the maximum turbine sweep area after construction and that the proportion of birds that passed between turbines at heights below (0-45 m) and above the turbine sweep area (> 182 m) were significantly greater (P < 0.0001) post-construction than prior to construction. These are the first results from tracking large-bodied bird flight trajectories to show the magnitude of their vertical and horizontal adjustments to the presence of turbines, which have implications for assumptions of even flight densities made by collision risk models currently used to predict avian turbine collision rates.

Common pochard Aythya ferina are rapidly declining globally, partly due to water quality change at breeding habitats. Lake restoration at two southern Danish lakes (external nutrient loading reduction, bream Abramis brama and roach Rutilus rutilus removal and stocking of pike Esox lucius) improved water clarity and submerged macrophyte cover. Nesting pochard on one lake increased from 2.3 females per annum pre-treatment to 13.9 afterwards and from 22.7 females to 99.6 post-treatment at a second. Numbers fell from 27.7 to 11.3 at a third untreated lake with consistently high water clarity, but which was colonised and became dominated by holly-leaved naiad Najas marina, which provides no food resources for breeding pochard. Linear modelling (controlling for serial autocorrelation) showed statistically significant effects of annual summer measurements of suspended solids (negative) and Secchi depth (positive) on pochard abundance at both restored lakes and chlorophyll (negative) at one of those lakes, but no effects at the third. Breeding pochard numbers also correlated positively with submerged macrophyte cover at one restored lake with adequate data. Results support the hypothesis that lake restoration to improve water quality enhances conditions for locally breeding pochard, as long as restored conditions secure appropriate submerged macrophyte communities for nesting pochard.

Continuing declines in abundance of many waterbird species on wetland ecosystems require explanations to support effective management interventions. We used 6 year survey data from Shengjin Lake National Nature Reserve in the Yangtze River Floodplain, China, to study the effects of ecological and anthropogenic variables as determinants of waterbird species abundance. Our results showed that effects were guild-dependent, although distance to nearest human settlements had the largest adverse effects on bird abundance across all guilds. These results suggested that although the abundance of waterbird species could be affected by habitat conditions and buffalo grazing activities, Yangtze River Wetlands would most likely benefit most from reduced pressure from the proximity to the surrounding human population. We suggest that screening and/or restricting public access at some key sites may be the most cost-efficient way to restrict or reduce human activity in these wetlands, to improve the conservation status and wintering conditions for these waterbirds. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13280-018-1076-1) contains supplementary material, which is available to authorized users.

We tracked 39 western flyway white-naped cranes (Antigone vipio) throughout multiple annual cycles from June 2017 to July 2020, using GSM-GPS loggers providing positions every 10-min to describe migration routes and key staging areas used between their Mongolian breeding and wintering areas in China’s Yangtze River Basin. The results demonstrated that white-naped cranes migrated an average of 2556 km (±187.9 SD) in autumn and 2673 km (±342.3) in spring. We identified 86 critical stopover sites that supported individuals for more than 14 days, within a 100–800 km wide migratory corridor. This study also confirmed that Luan River catchment is the most important staging region, where white-naped cranes spent 18% of the annual cycle (in both spring and autumn) each year. Throughout the annual cycle, 69% of the tracking locations were from outside of the currently protected areas, while none of the critical staging areas enjoyed any form of site protection. We see further future potential to combine avian tracking data and remote-sensing information throughout the annual range of the white-naped crane to restore it and other such species to a more favourable conservation status.

Understanding how individuals manage costs during the migration period is challenging because individuals are difficult to follow between sites; the advent of hybrid Global Positioning System–acceleration (ACC) tracking devices enables researchers to link spatial and temporal attributes of avian migration with behavior for the first time ever. We fitted these devices on male Greenland white-fronted geese Anser albifrons flavirostris wintering at 2 sites (Loch Ken, Scotland and Wexford, Ireland) to understand whether birds migrating further during spring fed more on wintering and staging areas in advance of migration episodes. Although Irish birds flew significantly further (ca. 300 km) than Scottish birds during spring, their cumulative hours of migratory flight, flight speed during migration, and overall dynamic body ACC (i.e., a proxy for energy expenditure) were not significantly different. Further, Irish birds did not feed significantly more or expend significantly more energy in advance of migration episodes. These results suggest broad individual plasticity in this species, although Scottish birds arriving on breeding areas in Greenland with greater energy stores (because they migrated less) may be better prepared for food scarcity, which might increase their reproductive success.

SummaryThe 2020 EU biodiversity strategy aims to halt the loss of biodiversity and ecosystem services, but this requires effective monitoring to determine whether these aims are achieved. Common bird monitoring continuously assesses changes in the avian community, providing a powerful tool for monitoring temporal changes in the abundance and distribution of these upper trophic level consumers. Two-thirds of Denmark’s land area is intensively farmed, so agricultural habitats make a major contribution to Danish biodiversity. We looked for changes in abundance amongst farmland birds in Denmark during 1987–2014 to test for reductions in declines and to predict whether the 2020-target can be expected to be achieved. Sixteen specialist farmland species were those showing the most rapid declines amongst 102 common breeding species in Denmark. Of these, those species nesting on the ground showed significant long-term declines, which was not the case for those that nest elsewhere, i.e. in hedgerows, trees and buildings. There was no evidence to suggest that these trends were attributable to widespread declines in long-distance migrant species (as reported elsewhere), which may be affected by conditions at other times in the annual cycle. We therefore conclude that continued declines in specialist farmland breeding bird species are due to contemporary agricultural changes within Denmark and urge habitat- and species-specific analysis to identify the core causes of these changes and halt the declines.

The energy and nutrient content of most agricultural crops are as good as or superior to natural foods for wild geese and they tend to be available in agricultural landscapes in far greater abundance. Artificial grasslands (fertilised native swards and intensively managed reseeds) offer far superior quality forage and higher intake rates than seminatural or natural grasslands. The availability of such abundant artificial food explains the abandonment of traditional habitats for farmland by geese over the last 50–100 years and favours no reduction in current levels of exploitation of agriculture. Continental scale spatial and temporal shifts among geese undergoing spring fattening confirm their flexibility to respond rapidly to broadscale changes in agriculture. These dramatic changes support the hypothesis that use of agricultural landscapes has contributed to elevated reproductive success and that European and North American farmland currently provides unrestricted winter carrying capacity for goose populations formerly limited by wetlands habitats prior to the agrarian revolution of the last century.

Wild geese wintering in western Europe were declining by the 1930s probably due to loss of natural habitat and over exploitation through hunting, although the causes will never be known. Refuge provision and hunting restrictions from the 1950s enabled numbers to recover. Improved monitoring systems enabled the description of progressive increases and extensions of wintering range since that time, especially amongst those goose populations that increasingly exploited agricultural landscapes. This introductory article sets the scene for the special issue on the increasing interactions and conflicts created by recent increases in the range and abundance of wild geese throughout the northern hemisphere, especially with regard to agricultural damage, but including issues associated with air flight safety, human and animal health, ecosystem effects and conflicts with other biodiversity objectives. It also provides the context for finding common solutions to problems, presenting experiences from regional-, national- and flyway-coordinated management to find solutions to conflict.

Telemetry data from sympatric Eastern Tundra Bean Geese Anser serrirostris captured on their winter quarters in the Yangtze River Floodplain, China, tracked to two discrete breeding areas (the Anadyr Region (AR) at 65°N and Central Russian Arctic (CRA) at 75°N) showed that, despite longer migration distance (6300 vs. 5300 km), AR geese reached their destination 23 days earlier than CRA geese as a result of increasingly delayed date of 50% snow cover along the route of CRA geese (based on satellite imagery data). Both groups arrived at breeding areas 8–9 days prior to the local date of 50% snow cover thaw, suggesting optimal timing of arrival for subsequent reproduction. Despite small sample sizes from one season of tracking, these intra-specific data are the first to suggest that, in time-limited Arctic-nesting geese, snowmelt conditions regulated the individual progress and duration of spring migration along the flyway to coincide with arrival at optimal spring conditions on breeding areas.

Background The Oriental Stork (Ciconia boyciana) breeds in southeastern Siberia and parts of northeast China, and winters mainly in southeast China. Although the autumn migration pattern of Oriental Storks has been previously described, differences between spring and autumn migration travel speed in relation to wind assistance were unknown. Methods Using GPS/GSM transmitters, we tracked the full migrations of 18 Oriental Storks during 2015‒2018 to compare differences in autumn and spring migration patterns, and combined the satellite telemetry data with the National Center for Environmental Prediction Reanalysis data to explain the relationship between 850 mbar wind vectors and seasonal differences in travel speed. Results Differences in tailwinds contributed to significant differences in daily average Oriental Storks travel speed in spring (258.11 ± 64.8 km/day) compared to autumn (172.23 ± 49.7 km/day, p p p = 0.3) did not differ significantly. Tailwinds at 850 mbar pressure level (extracted from the National Center of Environmental Prediction Reanalysis data archive) significantly affected daily flying speed during spring and autumn migration. Tailwind conditions in spring (mean 4.40 ± 5.6 m/s) were always more favourable than in autumn when they received no net benefit (0.48 ± 5.6 m/s, p p = 0.17), large individual variation meant that this duration did not differ significantly from each other. Conclusions For long distance migratory soaring birds (such as storks), relative duration of spring and autumn migration likely relates to the interaction between imperative for earliest arrival to breeding grounds and seasonal meteorological conditions experienced en route.

Breeding waterbird communities have suffered globally from the effects of anthropogenic changes in water quality (especially nutrient enrichment) in recent decades, but few studies have demonstrated the positive effects of restorative actions. Annual breeding waterbird surveys in the period 1977–2005 at two restored southern Danish lake basins (combining nutrient load reduction and biomanipulation) showed an up to five-fold increase in abundance, and considerable changes in species richness and diversity, following restoration to clear water status in both lakes. Parallel surveys at a third lake, which retained clear water quality throughout, offering a form of natural ‘control’, showed no such changes over the same time period. Consistent relationships between breeding waterbird abundance, species richness, and diversity with measures of water clarity (Secchi disc depth, chlorophyll a, and suspended matter) suggest that water clarity mainly drives the relationship; inverse relationships between these measures and total nitrogen and phosphorus were less consistent than for water clarity. The results suggest that an improvement in water clarity plays a key role in restoring breeding waterbird communities and suggest that breeding waterbirds can be indicators of the success of lake restoration projects, but more studies are needed to confirm their wider utility under a variety of conditions.

Use of lead shot for hunting was banned under legislation on 26 Ramsar sites in Denmark from 1986, based on evidence of poisoning in waterbirds ingesting lead shot and high lead shot pellet densities in Danish wetland sediments caused by intensive hunting. To assess the fate of lead shot from hunting prior to 1986 and the degree to which such shot remains available to waterbirds, this study replicated the survey of shot pellet densities in substrates in Ringkøbing Fjord undertaken in the late 1970s. 287 shotgun pellets (282 lead, five steel) were recovered from 123 sediment samples at four locations, equivalent to a mean of 127 pellets m −2 in the top 20 cm of the sediment at the four locations, in certain hot spots equating to >250 kg lead ha −1, broadly similar to densities found in the 1970s. Possible explanations were given for the persistence of such high lead shot densities despite >30 years of regulation, during which time steel shot has been widely used as the alternative to lead. Field experiments showed that steel shot corroded in the marine environment, which likely contributes to lower steel shot densities found in this study. It is concluded that lead gunshot pellet dispersal and accumulation in natural ecosystems remains as a persistent and irreversible hazard to wildlife and ecosystems. Based on these Danish experiences, it is urgently recommended that international and national bodies in countries where hunting with lead shot continues recognise these results and act to prevent the accumulation of this toxic metal.

The Common Scoter (Melanitta nigra) is a common sea duck, which predominantly feeds on sedentary benthic bivalve prey and occurs in large late-summer moulting concentrations in the German North Sea in areas which differ from those used by later wintering concentrations. Assuming scoters distribute in response to prey accessibility, abundance and profitability, we hypothesis that their contrasting distribution during moult compared to winter potentially reflects differences in prey type and distribution. We compared benthic bivalve community composition, abundance, ash-free dry mass and flesh-to-shell ratios between both areas to investigate factors influencing the seasonal difference in areas used by scoters. The American Razor Clam (Ensis leei) was the most common bivalve in the moulting area (mean abundance 1004 ± 1681 ind. m−2, mean ± SD) with the highest flesh-to-shell ratio (0.341 g m−2 ± 0.729 g m−2), whereas the American Piddock (Petricolaria pholadiformis) showed the highest ash-free dry mass (0.635 g m−2 ± 0.392 g m−2). In the wintering area, the most common bivalve was the Bean-like Tellin (Fabulina fabula, 13 ± 17 ind. m−2), Spisula solida had the highest ash-free dry mass (1.639 g m−2 ± 1.262 g m−2) and F. fabula and Abra alba had the highest flesh-to-shell ratios. Overall benthic species community composition differed considerably between moulting and wintering areas, with fewer species and lower abundances in the wintering area. The high abundance and food quality (flesh-to-shell ratio) of E. leei (an invasive alien to the German North Sea since the 1980s) in the moulting area suggests its relative importance and potentially explains the seasonal differences of Common Scoter distributions.

While many avian populations follow narrow, well-defined “migratory corridors,” individuals from other populations undertake highly divergent individual migration routes, using widely dispersed stopover sites en route between breeding and wintering areas, although the reasons for these differences are rarely investigated. We combined individual GPS-tracked migration data from Mongolian-breeding common shelduck Tadorna tadorna and remote sensing datasets, to investigate habitat selection at inland stopover sites used by these birds during dispersed autumn migration, to explain their divergent migration patterns. We used generalized linear mixed models to investigate population-level resource selection, and generalized linear models to investigate stopover-site-level resource selection. The population-level model showed that water recurrence had the strongest positive effect on determining birds’ occupancy at staging sites, while cultivated land and grassland land cover type had strongest negative effects; effects of other land cover types were negative but weaker, particularly effects of water seasonality and presence of a human footprint, which were positive but weak or non-significant, respectively. Although stopover-site-level models showed variable resource selection patterns, the variance partitioning and cross-prediction AUC scores corroborated high inter-individual consistency in habitat selection at inland stopover sites during the dispersed autumn migration. These results suggest that the geographically widespread distribution (and generally rarity) of suitable habitats explained the spatially divergent autumn migrations of Mongolian breeding common shelduck, rather than the species showing flexible autumn staging habitat occupancy.