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.
Avian influenza viruses from wild birds can cause outbreaks in poultry, and occasionally infect humans upon exposure to infected poultry. Identification and characterization of viral reservoirs and ...transmission routes is important to develop strategies that prevent infection of poultry, and subsequently virus transmission between poultry holdings and to humans. Based on spatial, temporal and phylogenetic analyses of data generated as part of intense and large-scale influenza surveillance programs in wild birds and poultry in the Netherlands from 2006 to 2011, we demonstrate that LPAIV subtype distribution differed between wild birds and poultry, suggestive of host-range restrictions. LPAIV isolated from Dutch poultry were genetically most closely related to LPAIV isolated from wild birds in the Netherlands or occasionally elsewhere in Western Europe. However, a relatively long time interval was observed between the isolations of related viruses from wild birds and poultry. Spatial analyses provided evidence for mallards (Anas platyrhynchos) being more abundant near primary infected poultry farms. Detailed year-round investigation of virus prevalence and wild bird species distribution and behavior near poultry farms should be used to improve risk assessment in relation to avian influenza virus introduction and retarget avian influenza surveillance programs.
Regime shifts are likely to have strong impacts on all trophic levels and their interactions. In addition, weather conditions and sea level rise together with tidal currents may change sediment ...morphology in coastal areas and estuaries. Here, we studied the effects of these drivers of ecosystems on abundance of seven wader species feeding on macrozoobenthos in the German sector of the Wadden Sea. We hypothesized that regime shift caused decreases in wader abundance and that changes in sediment morphology driven by sea level rise and tidal amplitude affected these changes. We analyzed numbers of waders on a short term, 1998–2016, that matched a large-scale geographical study of sediment morphology in the German sector, and at a long term, 1987–2019. Changes in numbers of waders were estimated as slope of coefficients of the trends of wader species numbers in the two periods. The average (se) year of decreases in numbers of waders was initiated for most species and tidal basins in the year 1992 (± 0.4) that followed a regime shift in the Southern North Sea and in the Wadden Sea in 1988–1989. There were no statistical differences between the years when numbers of waders started to decrease between the northern and the southwestern tidal basins of the German sector, indicating that the drives affected both coastal sections simultaneously. Significant relationships were found between slopes of coefficients of wader species and sediment morphology and physical features as sea level rise and tidal amplitude. Relationships were most pronounced for the long term, 1987–2019 compared to the short term, 1998–2016. We conclude that regime shift and changes in sediment morphology driven by sea level rise and sediment change can affect abundance of migratory wader species in large estuaries and shallow coastal waters.
In recent decades, conflict between geese and agriculture has increased. Management practices to limit this conflict include concentrating geese in protected areas, derogation shooting or population ...reduction. To justify such management, we need to understand their effects on goose‐related damages, which requires an understanding of how yield loss is influenced by goose abundance and species interactions.
We combined data from monthly goose counts and GPS‐tracked geese to estimate grazing pressures by barnacle, white‐fronted and greylag geese on agricultural grassland in Fryslân, the Netherlands. Using linear mixed models, we related this to damages assessed by professional inspectors.
Our results show a positive nonlinear relationship between yield loss and barnacle goose grazing pressure, where assessed damage increases with a decelerating rate as grazing pressure increases. For white‐fronted geese, we find a negative relationship, while for greylag geese both positive and negative relationships occur. For each species, the relationship is influenced by the abundance of the other two.
For barnacle geese, the relationship can be explained by selection of fields offering the best balance between food intake and energy expenditure, and by grass regrowth, with highest grazing pressures occurring over a longer time period. The results for the other species are likely due to spatial and temporal differences in foraging preferences compared to barnacle geese, where larger species avoid areas with highest damages.
Synthesis and applications. Our results suggest that decreasing herbivore abundance may not translate directly to decreased yield loss, and management tools such as population reduction or derogation shooting should be used with care. Management aimed at concentrating geese in refuges could help to alleviate farmer–goose conflict, although further studies are required to determine if it would lead to damage reduction. We also find that not all species contribute equally to agricultural damage; care should be taken to ensure wildlife management targets the right species.
Samenvatting
Het conflict tussen landbouw en ganzen is in de afgelopen decennia toegenomen. Opties om het conflict te verminderen zijn bijvoorbeeld het concentreren van ganzen in beschermde gebieden, derogatie, of actief populatiebeheer. Om zulk beheer te kunnen rechtvaardigen, is het belangrijk te weten hoe opbrengstderving door ganzen wordt beïnvloed door begrazingsdruk en door interacties tussen soorten.
Met lineaire mixed‐effect modellen relateerden we getaxeerde schade aan de begrazingsdruk van drie ganzensoorten op gecultiveerd grasland binnen accommodatiegebied (ganzenrustgebieden) in Fryslân. De begrazingsdruk berekenden we door maandelijkse ganzentellingen te koppelen aan GPS‐data van gezenderde ganzen.
Onze resultaten laten een positieve, non‐lineaire relatie zien tussen getaxeerde schade en begrazingsdruk van brandganzen, waar de toename in schade steeds kleiner wordt met hogere begrazingsdruk. Voor kolganzen vinden we een negatieve relatie, terwijl voor grauwe ganzen zowel positief als negatief mogelijk is. Voor zowel brandgans, kolgans als grauwe gans verandert de snelheid waarmee schade toe‐ of afneemt met de aanwezigheid van de andere twee ganzensoorten.
De relatie voor brandgans kan mogelijk worden verklaard door een voorkeur voor velden met de beste verhouding tussen voedselopname en energieuitgaven en/of door hergroei van gras, waarbij de grootste concentraties ganzen gevonden worden over een langere tijdsperiode. De resultaten voor de andere twee soorten volgt uit verschillen in (foerageer)gedrag, zowel in tijd als ruimte, waardoor deze grotere soorten minder voorkomen in de gebieden met hoogste schade.
Synthese en applicaties. Onze resultaten suggereren dat afnemende aanwezigheid van herbivoren mogelijk niet direct vertaalt naar een afname in schade. Opties zoals derogatie of populatiebeheer moeten daarom voorzichtig worden gebruikt. Beheer waarbij ganzen geconcentreerd worden in een opvanggebied zou kunnen helpen om conflict tussen boeren en ganzen te verminderen, maar of dit ook zal leiden tot vermindering in opbrengstderving is nog onduidelijk. We zien ook dat de bijdrage aan schade door verschillende ganzensoorten niet gelijk is; daarom moet er goed worden opgelet dat beheer de juiste diersoort beïnvloedt.
Our results suggest that decreasing herbivore abundance may not translate directly to decreased yield loss, and management tools such as population reduction or derogation shooting should be used with care. Management aimed at concentrating geese in refuges could help to alleviate farmer–goose conflict, although further studies are required to determine if it would lead to damage reduction. We also find that not all species contribute equally to agricultural damage; care should be taken to ensure wildlife management targets the right species.
Climate change is predicted to cause changes in species distributions and several studies report margin range shifts in some species. However, the reported changes rarely concern a species' entire ...distribution and are not always linked to climate change. Here, we demonstrate strong north‐eastwards shifts in the centres of gravity of the entire wintering range of three common waterbird species along the North‐West Europe flyway during the past three decades. These shifts correlate with an increase of 3.8 °C in early winter temperature in the north‐eastern part of the wintering areas, where bird abundance increased exponentially, corresponding with decreases in abundance at the south‐western margin of the wintering ranges. This confirms the need to re‐evaluate conservation site safeguard networks and associated biodiversity monitoring along the flyway, as new important wintering areas are established further north and east, and highlights the general urgency of conservation planning in a changing world. Range shifts in wintering waterbirds may also affect hunting pressure, which may alter bag sizes and lead to population‐level consequences.
Climate warming is driving changes in species distributions and community composition. Many species have a so‐called climatic debt, that is, shifts in range lag behind shifts in temperature ...isoclines. Inside protected areas (PAs), community changes in response to climate warming can be facilitated by greater colonization rates by warm‐dwelling species, but also mitigated by lowering extirpation rates of cold‐dwelling species. An evaluation of the relative importance of colonization‐extirpation processes is important to inform conservation strategies that aim for both climate debt reduction and species conservation. We assessed the colonization‐extirpation dynamics involved in community changes in response to climate inside and outside PAs. To do so, we used 25 years of occurrence data of nonbreeding waterbirds in the western Palearctic (97 species, 7071 sites, 39 countries, 1993–2017). We used a community temperature index (CTI) framework based on species thermal affinities to investigate species turnover induced by temperature increase. We determined whether thermal community adjustment was associated with colonization by warm‐dwelling species or extirpation of cold‐dwelling species by modeling change in standard deviation of the CTI (CTISD). Using linear mixed‐effects models, we investigated whether communities in PAs had lower climatic debt and different patterns of community change than communities outside PAs. For CTI and CTISD combined, communities inside PAs had more species, higher colonization, lower extirpation, and lower climatic debt (16%) than communities outside PAs. Thus, our results suggest that PAs facilitate 2 independent processes that shape community dynamics and maintain biodiversity. The community adjustment was, however, not sufficiently fast to keep pace with the large temperature increases in the central and northeastern western Palearctic. Our results underline the potential of combining CTI and CTISD metrics to improve understanding of the colonization‐extirpation patterns driven by climate warming.
Beneficios de las Áreas Protegidas para las Aves Acuáticas No Reproductoras que Están Ajustando su Distribución Debido al Calentamiento Climático
Resumen
El calentamiento climático está generando cambios en la distribución y en la composición comunitaria de las especies. Muchas de ellas tienen una deuda climática, es decir, los cambios en la distribución se atrasan con respecto a los cambios en las isoclinas térmicas. Dentro de las áreas protegidas (APs), los cambios comunitarios como respuesta al calentamiento climático pueden facilitarse mediante tasas mayores de colonización por especies de climas cálidos, pero también pueden mitigarse al reducir las tasas de extirpación de las especies de climas fríos. Se requiere una evaluación de la importancia relativa de los procesos de colonización‐extirpación para orientar las estrategias de conservación que buscan la reducción de la deuda climática y la conservación de las especies. Analizamos las dinámicas de colonización‐extirpación que participan en los cambios comunitarios como respuesta al clima dentro y fuera de las APs. Para realizar lo anterior, usamos datos tomados durante 25 años de la presencia de aves acuáticas no reproductoras en el Paleártico occidental (97 especies, 7,071 sitios, 39 países, 1993–2017). Usamos un marco de trabajo del índice de temperatura comunitaria (ITC) basado en las afinidades térmicas de las especies para así investigar la rotación de especies inducida por el incremento en la temperatura. Determinamos si el ajuste térmico en la comunidad estuvo asociado con la colonización por especies de climas cálidos o con la extirpación de especies de climas fríos al modelar el cambio mediante una desviación estándar del ITC (ITCDS). Con los modelos lineales de efectos mixtos investigamos si las comunidades dentro de las APs tenían una deuda climática más baja y patrones diferentes de cambio comunitario que las comunidades localizadas fuera de las APs. Con la combinación del ITC y deL ITCDS, las comunidades dentro de las APs tuvieron más especies, una mayor colonización, una menor extirpación y una deuda climática más baja (16%) que las comunidades fuera de las APs. Por lo tanto, nuestros resultados sugieren que las APs facilitan dos procesos independientes que moldean las dinámicas comunitarias y mantienen la biodiversidad. Sin embargo, el ajuste comunitario no fue lo suficientemente rápido para mantener el paso de los grandes incrementos en la temperatura de las regiones central y noreste del Paleártico occidental. Nuestros resultados resaltan el potencial que tiene la combinación de las medidas del ITC y del ICTDS para mejorar el entendimiento de los patrones de colonización‐extirpación causados por el calentamiento climático.
【摘要】
气候变暖正在引起物种分布和群落组成的变化。许多物种都背负着所谓的 “气候债务”, 即分布范围的变化滞后于温度的变化。气候变暖背景下, 保护地中适应温暖环境的物种较高的定殖率可以促进群落变化, 适应寒冷环境的物种灭绝率下降也可以减缓影响。评估定殖–灭绝过程的相对重要性, 对于制定旨在减少气候债和促进物种保护的保护战略而言十分重要。本研究利用西古北界非繁殖水鸟 25 年的出现记录 (97 个物种, 7071 个位点, 39 个国家, 1993–2017 年) , 评估了保护地内外鸟类群落响应气候变化过程中的定殖–灭绝动态。我们使用基于物种对温度亲和性的群落温度指数框架探究了温度升高引起的物种更替。通过模拟群落温度指数标准偏差的变化, 我们确定了群落对温度的调整是否与适应温暖环境的物种的定殖或适应寒冷环境的物种的灭绝有关。接下来, 我们利用线性混合效应模型分析了保护地内与保护地外的群落相比是否具有较低的气候债务和不同的群落变化格局。结合群落温度指数与其标准偏差, 我们发现保护地内的群落比保护地外的具有更多的物种、更高的定殖率、更低的灭绝率和更低的气候债务 (16%) 。因此, 我们的结果表明, 保护地促进了群落动态形成和生物多样性维持这两个独立过程。然而, 群落调整的速度不足以跟上古北界中部和东北部地区气温的大幅上升。我们的结果强调了群落温度指数和群落温度指数标准偏差这两个指标相结合, 有潜力提高对气候变暖导致的定殖–灭绝格局的理解。【翻译: 胡怡思; 审校: 聂永刚】
Article impact statement: Protected areas are needed to facilitate waterbird distribution change in response to climate warming in the western Palearctic.
Migratory waterbirds require an effectively conserved cohesive network of wetland areas throughout their range and life-cycle. Under rapid climate change, protected area (PA) networks need to be able ...to accommodate climate-driven range shifts in wildlife if they are to continue to be effective in the future. Thus, we investigated geographical variation in the relationship between local temperature anomaly and the abundance of 61 waterbird species during the wintering season across Europe and North Africa during 1990–2015. We also compared the spatio-temporal effects on abundance of sites designated as PAs, Important Bird and Biodiversity Areas (IBAs), both, or neither designation (Unlisted). Waterbird abundance was positively correlated with temperature anomaly, with this pattern being strongest towards north and east Europe. Waterbird abundance was higher inside IBAs, whether they were legally protected or not. Trends in waterbird abundance were also consistently more positive inside both protected and unprotected IBAs across the whole study region, and were positive in Unlisted wetlands in southwestern Europe and North Africa. These results suggest that IBAs are important sites for wintering waterbirds, but also that populations are shifting to unprotected wetlands (some of which are IBAs). Such IBAs may therefore represent robust candidate sites to expand the network of legally protected wetlands under climate change in north-eastern Europe. These results underscore the need for monitoring to understand how the effectiveness of site networks is changing under climate change.
Aim
Many species are showing distribution shifts in response to environmental change. We explored (a) the effects of inter‐annual variation in winter weather conditions on non‐breeding distributional ...abundance of waterbirds exploiting different habitats (deep‐water, shallow water, farmland) and (b) the long‐term shift in the population centroid of these species and investigate its link to changes in weather conditions.
Location
Europe.
Methods
We fitted generalized additive mixed Models to a large‐scale, 24‐year dataset (1990–2013) describing the winter distributional abundance of 25 waterbird species. We calculated the annual and long‐term (3‐year periods) population centroid of each species and used the winter North Atlantic Oscillation (NAO) index to explain the inter‐annual and long‐term shifts in their location.
Results
(a) Year‐to‐year southwestwards shifts in the population centroids of deep‐ and shallow‐water species were linked to negative NAO values. Shallow‐water species shifted northeastwards associated with positive NAO values and the distance shifted increased with increasing NAO. Deep‐water species shifted northeastwards up to zero NAO indices, but showed no further increase at higher NAO values. (b) Deep‐water species showed long‐term northeastwards shifts in distributional abundance throughout the 1990s and the 2000s. Shallow‐water species, on the other hand, shifted northeastwards during the 1990s and early 2000s, but southwestwards thereafter. There were no significant links between the NAO and year‐to‐year movements or long‐term shifts in farmland species’ population centroid.
Main Conclusions
We provide evidence for a link between both year‐to‐year and long‐term changes in waterbird winter distributional abundances at large geographical scales to short‐ and long‐term changes in winter weather conditions. We also show that species using shallow water, deep‐water and farmland habitats responded differently, especially at high NAO values. As well as important ecological implications, these findings contribute to the development of future conservation measures for these species under current and future climate change.
The Netherlands is important for wintering migratory herbivorous geese, numbers of which have rapidly increased, leading to conflict with agriculture. In 2005/2006, a new goose management policy ...aimed to limit compensation payments to farmers by concentrating foraging geese in 80 000 ha of designated 'go' areas—where farmers received payment to accommodate them—and scaring geese from 'no go' areas elsewhere. Monthly national counts of four abundant goose species during 10 years prior to the new policy and in 8 years following implementation found that 57% of all goose days were spent within 'go' areas under the new management, the same as prior to implementation. Such lack of response suggests no predicted learning effects, perhaps because of (i) increases in abundance outside of 'go' areas, (ii) irregularly shaped boundaries and enclaves of 'no go' farmland within 'go' areas and/or (iii) insufficient differences in disturbance levels within and outside designated areas.