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Roads are among the most widespread anthropogenic structures, and their presence can impact biodiversity in surrounding landscapes through disturbance and collision risk, particularly when traffic volumes are high. However, the impact of roads with low traffic volumes in open landscapes is much less clear. In the open landscapes of lowland Iceland, road traffic is still relatively low but increasing, and the surrounding landscapes support internationally important populations of several breeding wader species. Here, we used transect counts perpendicular to low‐traffic (≤ 15 000 vehicles day−1) roads across the lowlands of southern Iceland to quantify variation in the densities of ground‐nesting birds with distance from roads, and to assess how far from the roads any such effects extended. The total abundance of birds increased significantly by 6% per 50 m interval from roads, and densities within 200 m of roads were ~ 20% lower than densities between 200 and 400 m from roads. Four species – whimbrel Numenius phaeopus, golden plover Pluvialis apricaria, dunlin Calidris alpina and meadow pipit Anthus pratensis – were found in significantly lower densities closer to roads, while four – black‐tailed godwit Limosa limosa, redshank Tringa totanus, snipe Gallinago gallinago and redwing Turdus iliacus – showed no change with distance from roads. Redwing was found in higher densities, and dunlin in lower densities, surrounding roads with higher traffic volumes. As approximately 20% of lowland Iceland is within 200 m of roads, the impact of roads on the overall abundance of ground‐nesting birds could be substantial. The results show that even relatively low‐traffic roads can have a significant impact on adjacent wildlife populations. Road construction, along with other anthropogenic structures, has been shown to have negative effects on bird abundance, and identifying areas for protection from such developments may be the most effective approach to reducing human impacts on the internationally important wildlife of lowland Iceland.

The red fox (Vulpes vulpes) is a widely distributed generalist meso-predator implicated in declines of wading bird populations. In the wet grassland habitats where waders breed, wildlife managers work to mitigate fox predation risk to waders during the nesting period through lethal and non-lethal control methods. However, limited knowledge on fox movement ecology in these habitats makes it difficult to design effective management strategies. We used GPS telemetry to understand fox home range size, daily activity and movement patterns, and how these metrics may vary among wet grassland sites with different management. We caught and GPS-tagged 35 foxes in the March–June wader nesting period on two wet grassland sites in central southern England; Britford during 2016/17 and Somerley during 2018/19. We estimated home range areas from location data using local convex hulls, and from these estimates we derived the minimum fox density at each site and year. Daily activity patterns and movement behaviour of each fox were obtained using both telemetry and trail camera data. Mean fox home range area at Britford (0.21 km2, SE = 0.025) was significantly smaller than at Somerley (0.68 km2, SE = 0.067), and estimated minimum densities were around four times higher (Britford = 10.6 foxes/km2, Somerley = 2.4 foxes/km2). Foxes were more active and moved faster during twilight and night hours, but both telemetry and camera data indicate they were also active for one-third of daylight hours. Distances moved per day were variable between foxes but generally smaller at Britford. We also found evidence for dispersal during spring, with movements of up to 19 km per day. Home ranges at both wet grassland sites were smaller than comparable sites elsewhere. These indicated foxes were living at exceptionally high densities at Britford, where there is no fox control, increased food availability and where waders no longer breed. Spatio-temporal movement patterns were closely related to home range metrics, with higher levels of fox activity at Somerley, where home ranges were larger. The movements of itinerant and dispersing foxes during the nesting period suggests that lethal control would need to be very intensive to be effective. The likely anthropogenic food subsidy of fox density at Britford suggests that controlling access to similar food resources would help reduce predation pressure on breeding waders.

Migratory animals often display remarkable adaptations in order to successfully complete their journeys. While there is substantial evidence on immunomodulation during breeding and at stopover sites en route, the immune status of migratory birds upon reaching their non‐breeding grounds and throughout this stationary season remains poorly understood. Here we used the Hudsonian godwit Limosa haemastica—an extreme long‐distance migrant that breeds in the Arctic and spends the non‐breeding season in Patagonia—to investigate constitutive immune function (CIF) in adult individuals under contrasting conditions: on birds moulting primary feathers when they had recently arrived at non‐breeding grounds (post‐arrival birds), and four months later on birds moulting into breeding plumage, a couple of weeks before their departure to breeding areas (pre‐migratory birds). We found comparable CIF between post‐arrival and pre‐migratory birds. When each group was analysed separately, agglutination titres and bacterial killing ability increased as birds completed their breeding plumage moult, although the association with bacterial killing ability appeared to be driven primarily by males. Bacterial killing ability was also higher in pre‐migratory females than in males. None of the evaluated CIF parameters were affected by primary feather moult in post‐arrival birds. Our results suggest important immunomodulation occurring at the end of the non‐breeding season in pre‐migratory godwits, probably due to the profound physiological and metabolic changes required in preparation for endurance migration. Our work contributes to the little‐known topic of immune dynamics in extreme long‐distance migratory birds across the non‐breeding season.

Aim The rapidly changing Arctic is ideal for investigating uncertainties in climate projections. Despite the challenges of collecting data in this region, an unprecedented large‐scale survey of shorebirds has been conducted over the last 30 years. Our study aimed to (1) develop probabilistic estimates for the change in suitable habitat for 10 Arctic shorebird species in Canada by 2075 and (2) assess the contribution of modelling decisions to the uncertainty in these estimates. Location Arctic Canada. Methods To evaluate uncertainty, we considered six classes of modelling decisions, yielding 216 unique projections for each species. We tested three decisions that are less commonly explored − the pool of candidate variables, a method for selecting variables, and the maximum distance of tree line dispersal, as well as the modelling algorithm, carbon emissions scenario, and global circulation model. We used a bootstrapping approach, creating a probability distribution for the proportional change in suitable habitat for each species. Results Our findings indicated a substantial risk for 8/10 species to lose over half of their suitable breeding habitat, but this projection is much less certain than has been described previously. While much uncertainty is unexplained, we were surprised that the largest source of uncertainty among our modelling decisions was from our choice of methods for variable selection, that the other modelling decisions were relatively small sources of uncertainty, overshadowing other modelling decisions. Main Conclusions While most scenarios predict a northward shift and significant habitat loss for Arctic‐breeding shorebirds, the Arctic Archipelago of Canada will remain an important refuge because in many other Arctic regions, there is no land farther north for these species to shift into. A comprehensive understanding of uncertainty is important for deciding if future projections can or should be used when planning climate‐resilient protected area networks.

Several ground‐nesting wader species rely on Baltic coastal meadows for breeding. Drastic reduction in the area of the habitat at the end of the 20th century has been followed by habitat restoration activities over the last 20 years. However, wader populations are not responding as hoped to the current conservation effort. Therefore, identifying which grassland characteristics are essential for waders to select their nesting location and which ones enhance their clutch survival probability is vital to implementing efficient conservation plans. However, many vegetation structural characteristics, such as sward height or heterogeneity, can be logistically complex to measure using traditional methods in relatively large areas, especially considering the highly accurate resolution needed. Here, we assessed several sward characteristics together with other key landscape features by combining very high‐resolution images from unmanned aerial vehicle (UAV) surveys with nest survival monitoring, in five key Estonian coastal grasslands for waders. We found that the main four wader species, Northern Lapwing ( Vanellus vanellus ), Common Redshank ( Tringa totanus ), Common Ringed Plover ( Charadrius hiaticula ) and the Baltic Dunlin ( Calidris alpina schinzii), do not significantly differ in their nest‐site selection in terms of vegetation height, growth rates, or sward heterogeneity. Yet, we found that vegetation sward height and heterogeneity surrounding the nest sites within a 2‐meter buffer positively increased the daily nest survival probability from 0.883 to 0.979 along the gradients observed. Additionally, the distance between the nest location and flooded areas (≥20m 2 ) was negatively correlated, and all variables affected the wader community similarly. Our results signal the need for a higher diversity of sward structures and the importance of constantly flooded areas in Estonian coastal meadows. Moreover, our study highlights the importance of integrating UAV remote sensing techniques within the animal conservation research field to unveil ecological patterns that may remain hidden using more traditional methods.

1. Wetland ecosystems throughout the world are threatened by drainage and intensification of agriculture. Consequently, many wetland species of conservation concern are now restricted to fewer and smaller sites, and maintaining these species often requires intensive habitat management. 2. In Western Europe, breeding wader populations have declined severely as a result of wetland degradation, but very high levels of prédation on eggs and chicks are now preventing population recovery. Wet grassland management for breeding waders has focussed on providing suitable nesting habitats, but the potential for management of landscape features to influence prédation rates remains largely unknown. 3. Using a 7-year study of breeding lapwing Vanellus vanellus and redshank Tringa totanus we first identify features that influence nest predation, and then use this information to compare the magnitude of change in nest predation rates that could potentially result from future landscape management scenarios. 4. As lapwing nest predation rates are higher (i) in fields further from patches of tall vegetation, (ii) close (<50 m) to field edges in wet fields, (iii) further from field edges in dry fields and (iv) in areas of low lapwing nesting density, we modelled a series of realistic scenarios in which the area of tall vegetation and the extent and distribution of surface water were varied across the reserve, to quantify the magnitude of change in nest predation rate that could potentially have been achieved through management. 5. Modelled scenarios of changes in surface water and area of tall vegetation indicated that reduced surface flooding combined with removal of tall vegetation could result in significant increases in lapwing nest predation rates in areas with low nesting densities and nests in field centres. By contrast, a ~20% reduction in nest prédation, corresponding to -100 more chicks hatching per year, is predicted in scenarios with expansion of tall vegetation in areas with high lapwing nest density and nests close to field edges. 6. Synthesis and applications. These management scenarios suggest that, for breeding waders in wet grassland landscapes, creating areas of tall vegetation and concentrating surface flooding (to encourage high nesting densities and influence nesting distribution) can potentially help to reduce the unsustainably high levels of nest prédation that are preventing population recovery.

Preen oil, the secretion from the uropygial gland of birds, may have a specific function in incubation. Consistent with this, during incubation, the chemical composition of preen oil is more likely to differ between sexes in species where only one sex incubates than in species where both sexes incubate. In this study, we tested the generality of this apparent difference, by investigating sex differences in the preen oil composition of a shorebird species, the Kentish plover ( Anarhynchus , formerly Charadrius , alexandrinus ). As both sexes incubate in this species, we predicted the absence of sex differences in preen oil composition during incubation. In the field, we sampled preen oil from nine females and 11 males during incubation, which we analysed with gas chromatography–mass spectrometry (GC–MS). Consistent with predictions, we found no sex difference in preen oil composition, neither in beta diversity (Bray-Curtis dissimilarities) nor in alpha diversity (Shannon index and number of substances). Based on these results, we cannot conclude whether preen oil has a function during incubation in Kentish plovers. Still, we discuss hypothetical roles, such as olfactory crypsis, protection against ectoparasites or olfactory intraspecific communication, which remain to be tested.

Global biodiversity loss is a major environmental concern. The wildlife on islands are particularly vulnerable to threats posed by alien predators, habitat loss and overexploitation. Effective conservation management of vulnerable species requires reliable information on vital population rates for all life stages and an understanding of key environmental drivers. However, demographic data are often not available for island populations before they decline or are extirpated. Here, we use Cormack–Jolly–Seber (CJS) models and 15 years of data for 1370 juveniles and 687 adults to estimate apparent survival for a genetically distinct resident population of Kentish plovers Charadrius alexandrinus on the island of Maio, Cabo Verde. We report two main findings. First, environmental conditions have a large effect on demographic performance since chicks that hatch during dry years experience a tenfold reduction in first-year survival compared to chicks that hatch during wet years. Second, female and male plovers in Maio are expected to live for 7.41 ± 0.69 (mean ± SE) years and 6.75 ± 0.64 years, respectively, due to relatively high annual survival among comparable-sized shorebirds. High adult survival thus could buffer the population against low reproductive success that this population has experienced over the last decade. Cabo Verde is typical of tropical islands with increased development that can impact native breeders and/or will accelerate habitat loss. Thus, more frequent droughts associated with climate change may exacerbate the prospects of native wildlife on many islands. apparent survival, demography, island conservation, Kentish plover, Macaronesia, wader

Migration during spring is usually faster than during autumn because of competition for breeding territories. In some cases, however, the costs and benefits associated with the environment can lead to slower spring migration, but examples are quite rare. We compared seasonal migration strategies of the endangered Baltic population of the dunlin Calidris alpina schinzii using light-level geolocator data from 26 individuals breeding in Finland. Autumn migration was faster, with individuals showing a ‘jump’ and ‘skipping’ migration strategy characterised by fewer stationary periods, shorter total stopping time and faster flight. Spring migration was slower, with individuals using a ‘skipping’ strategy. The duration of migration was longer for early departing birds during spring but not during autumn suggesting that early spring migrants are prevented from arriving to the breeding areas or that fueling conditions are worse on the stopover sites for early arriving individuals. Dunlins showed high migratory connectivity. All individuals had one long staging at the Wadden Sea in the autumn after which half of the individuals flew 4500 km non-stop to Banc d’Arguin, Mauritania. The other half stopped briefly on the Atlantic coast on their way to Mauritania. One bird wintered on the coast of Portugal. Nine individuals that carried geolocators for two years were site faithful to their final non-breeding sites. Based on the strategies during the non-breeding period we identified, Baltic dunlin may be especially vulnerable to rapid environmental changes at the staging and non-breeding areas. Consequently, the preservation of the identified non-breeding areas is important for their conservation.

To test whether the occupancy of shorebirds has changed in the eastern Canadian Arctic, and whether these changes could indicate that shorebird distributions are shifting in response to long-term climate change.Location Foxe Basin and Rasmussen Lowlands, Nunavut, Canada.Methods We used a unique set of observations, made 25 years apart, using general linear models to test if there was a relationship between changes in shorebird species' occupancy and their species temperature Index, a simple version of a species climate envelope.Results Changes in occupancy and density varied widely across species, with some increasing and some decreasing. This is despite that overall population trends are known to be negative for all of these species based on surveys during migration. The changes in occupancy that we observed were positively related to the species temperature index, such that the warmer-breeding species appear to be moving into these regions, while colder-breeding species appear to be shifting out of the regions, likely northward.Main Conclusions Our results suggest that we should be concerned about declining breeding habitat availability for bird species whose current breeding ranges are centered on higher and colder latitudes.