Project

Waterbirds in a changing world: impact of climate, habitat and conservation policy on European waterbirds

Goal: Waterbird ecology in a changing world.

Date: 1 January 2013

Updates
0 new
0
Recommendations
0 new
0
Followers
0 new
148
Reads
2 new
1690

Project log

Diego Pavón‐Jordán
added a research item
Based on the Baltic Earth Assessment Reports of this thematic issue in Earth System Dynamics and recent peer-reviewed literature, current knowledge about the effects of global warming on past and future changes in climate of the Baltic Sea region is summarized and assessed. The study is an update of the Second Assessment of Climate Change (BACC II) published in 2015 and focusses on the atmosphere, land, cryosphere, ocean, sediments and the terrestrial and marine biosphere. Based on the summaries of the recent knowledge gained in paleo-, historical and future regional climate research, we find that the main conclusions from earlier assessments remain still valid. However, new long-term, homogenous observational records, e.g. for Scandinavian glacier inventories, sea-level driven saltwater inflows, so-called Major Baltic Inflows, and phytoplankton species distribution and new scenario simulations with improved models, e.g. for glaciers, lake ice and marine food web, have become available. In many cases, uncertainties can now be better estimated than before, because more models can be included in the ensembles, especially for the Baltic Sea. With the help of coupled models, feedbacks between several components of the Earth System have been studied and multiple driver studies were performed, e.g. projections of the food web that include fisheries, eutrophication and climate change. New data sets and projections have led to a revised understanding of changes in some variables such as salinity. Furthermore, it has become evident that natural variability, in particular for the ocean on multidecadal time scales, is greater than previously estimated, challenging our ability to detect observed and projected changes in climate. In this context, the first paleoclimate simulations regionalized for the Baltic Sea region are instructive. Hence, estimated uncertainties for the projections of many variables increased. In addition to the well-known influence of the North Atlantic Oscillation, it was found that also other low-frequency modes of internal variability, such as the Atlantic Multidecadal Variability, have profound effects on the climate of the Baltic Sea region. Challenges were also identified, such as the systematic discrepancy between future cloudiness trends in global and regional models and the difficulty of confidently attributing large observed changes in marine ecosystems to climate change. Finally, we compare our results with other coastal sea assessments, such as the North Sea Region Climate Change Assessment (NOSCCA) and find that the effects of climate change on the Baltic Sea differ from those on the North Sea, since Baltic Sea oceanography and ecosystems are very different from other coastal seas such as the North Sea. While the North Sea dynamics is dominated by tides, the Baltic Sea is characterized by brackish water, a perennial vertical stratification in the southern sub-basins and a seasonal sea ice cover in the northern sub-basins.
Petr Musil
added a research item
In total, 56 individuals (among those 34 males and 14 females) of Ferruginous Duck were recorded on 175 fishponds near Třeboň, Kardašova Řečice and Soběslav towns in 2004 –2019. The frequency of records was higher in later years (2015 –2019) than in the beginning of the study period. A female rearing 8 ducklings was recorded on fishponds near Břilice village close to Třeboň town in 2019. The singly breeding females can be poorly detected during the breeding season (especially during incubation). Breeding of this rare duck species can perhaps be expected in the future as well.
Petr Musil
added a research item
Fishponds and fishpond systems represent the common wetland types in Central European Landscape, including the Czech Republic. Fishponds were created in suitable sites since the Middle Ages and often replaced the original wetlands (peat bogs, flooded meadows, riparian forests, etc.). Recently, they have been represented as shallow, eutrophic water bodies, often over-grown with littoral macrophytes. Almost all fishponds are recently aimed at fish production (mostly Carp Cyprinus carpio) which increased since the 1880s. In Czech fishponds, the numbers of breeding populations of many waterbird species have increased till the early 1980s when the numbers of 67 % of 27 waterbird species, esp. ducks, grebes, coots and Black-headed Gull dramatically declined. We lose more than 75 % of the total abundance of breeding waterbirds and mean species richness per individual site/fishpond decreased up to 52 %. Nevertheless, a total number of species fluctuated without significant changes. This decline is likely explained by a direct effect of increasing fish stocks. The important grazing effect of fish (especially Carp) has been recognized as a factor affecting benthic and plankton communities, the extent of littoral vegetation and, consequently, water transparency. Three approaches of reduced fish stock, i.e. (1) Tench and Pikeperch, (2) Tench and Pikeperch and invasive fish Pseudorasbora parva or (3) low-density Carp, was applied on fishpond Rod (Třeboň Biosphere Reserve, South Bohemia, Czech Republic) in 2014–2020. Regarding the reduced fish stock, we recorded an increase in water transparency as an indicator of the trophic status of fishponds as well as an increase in the numbers of waterbird species on Rod fishpond. We can conclude, that the establishment of a functional network of fishponds with reduced fish stock acting as a biodiversity hotspot can reverse the ongoing unfavourable changes in waterbird biodiversity in the fishponds systems.
Diego Pavón‐Jordán
added a research item
• Understanding species habitat use and factors affecting changes in their distributions are necessary to promote the conservation of any biological community. We evaluated the changes in wetland use of the non-breeding waterbird community. Based on long-term citizen-science data (1988–2020), we tested the hypotheses that wetland use is associated with species diet and potential range-shift drivers (the tendency to occupy the same sites in consecutive years—site affinity—and the species' average temperature across its wintering range—species temperature index). • We analysed species-specific wetland use of 25 species of waterbirds wintering in Czechia over a period of 33 years. The analyses explained variability in trends in numbers of the studied waterbird species across four inland wetland types: reservoirs; fishponds; industrial waters created by flooding of former mining sites; and running waters. • Trends in waterbird abundance positively correlated with species’ diet on fishponds, industrial and running waters. Among the diet groups, invertivores showed the largest increase in abundances on industrial waters, closely followed by herbivores. Herbivores showed the largest increase in abundances in fishponds, and piscivores did so in running waters. Regarding range-shift drivers, species with higher site affinity showed higher abundances on running waters, while species with low species temperature index (i.e. wintering on average in sites with lower temperature) were more abundant on reservoirs. The abundance of both warm-dwelling and species with low site affinity increased on fishponds and industrial waters. • Our findings suggest that the increased importance of the wetland types considered here for wintering waterbirds is likely to be linked to diet related changes in habitat use and changes in species distributions; and highlight that wintering waterbirds are expected to select sites with higher availability of food, higher energy content, and lower foraging cost. • Recent and rapid changes in species distributions may lead to a decrease in the effectiveness of national and international conservation efforts. When planning conservation measures, it should be kept in mind that climate change does not only imply large-scale north/north-eastwards shifts of entire waterbird distributions, but can also modify the use of the habitats by waterbird species inside their traditional wintering range.
Diego Pavón‐Jordán
added a research item
This Climate Change Fact Sheet provides the latest scientific knowledge on how climate change is currently affecting the Baltic Sea and how it is expected to develop in the foreseeable future. It is aimed at guiding policymakers to take climate change into account, but also to the general public. Updated Baltic Sea Climate Change Fact Sheets are expected to be published approximately every seven years.
Diego Pavón‐Jordán
added a project goal
Waterbird ecology in a changing world.
 
Diego Pavón‐Jordán
added a research item
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 northeastern Europe. These results underscore the need for monitoring to understand how the effectiveness of site networks is changing under climate change.
Diego Pavón‐Jordán
added a research item
Although biological conservation is based on international agreements, its effectiveness depends on how countries implement such recommendations as effective conservation tools. The Ramsar Convention is the oldest international treaty for wetland and waterbird conservation, establishing the world's largest network of protected areas. However, since it does not constitute any binding measure, its effectiveness in protecting wintering waterbird populations at an international scale has been questioned. Here, we use long-term (1991–2012) count data to assess the effectiveness of the Ramsar Convention in the Mediterranean Basin. We compared abundance and temporal trends of 114 waterbird species between 251 Ramsar wetlands and 3486 non-Ramsar wetlands. We found that the Ramsar network is critical for wintering waterbirds, concentrating nearly half of all waterbirds counted in the Mediterranean Basin in only 7% of monitored wetlands. Waterbird trends followed a northwest-southeast gradient, with a population decrease in the East. A significant and positive Ramsar effect on population trends was only found for the species of higher conservation concern in the Maghreb, particularly when a management plan was implemented. The Ramsar Convention was previously used on very important wetlands for waterbirds in Southern Europe, but is now an underused conservation tool. Our study suggests weaknesses in the use of Ramsar as an effective conservation tool in most of the Mediterranean Basin. However, the Ramsar Convention effectiveness to enhance waterbird populations in the Maghreb should encourage strengthening the Ramsar Convention. It should be done particularly in countries with limited environmental agreements and by systematic implementation of management plans. Article impact statement Identification of the regional disparities in the Ramsar Convention effectiveness to enhance waterbird populations across the Mediterranean Basin.
Petr Musil
added a research item
The number of occurring waterfowl broods on fishponds in the Trebon region (South Bohemia, Czech Republic) was recorded in 1992-94. Among 1165 broods of 13 species, Gadwall was the most common. Preference of fishponds with higher water transparency was found in diving ducks, which were negatively associated with the age of dominant fish cohort. On the contrary, a positive dependence on age of stocked fish was recorded in Great Crested Grebe broods. The occurrence of Mallard broods was dependent on water surface area and Coot broods prefer relatively isolated fishponds with well-developed littoral vegetation.
Łukasz Ławicki
added 2 research items
The aerial and ground methods of counting birds in a coastal area during different ice conditions were compared. Ice coverage of water was an important factor affecting the results of the two methods. When the water was ice-free, more birds were counted from the ground, whereas during ice conditions, higher numbers were obtained from the air. The first group of waterbirds with the smallest difference between the two methods (average 6%) contained seven species: Mute Swan Cygnus olor , Whooper Swan Cygnus cygnus , Greater Scaup Aythya marila , Tufted Duck Aythya fuligula , Common Goldeneye Bucephala clangula , Smew Mergellus albellus and Goosander Mergus merganser ; these were treated as the core group. The second group with a moderate difference (average 20%) included another six species: Mallard Anas platyrhynchos , Eurasian Wigeon Mareca penelope , Common Pochard Aythya ferina , Great Crested Grebe Podiceps cristatus and Eurasian Coot Fulica atra . The third group with a large difference (average 85%) included five species, all of the Anatini tribe: Gadwall Mareca strepera , Northern Pintail Anas acuta , Northern Shoveler Spatula clypeata , Eurasian Teal Anas crecca and Garganey Spatula querquedula . During ice conditions, smaller numbers of most species were counted from the ground. The exception here was Mallard, more of which were counted from the ground, but the difference between two methods was relatively small in this species (7.5%). Under ice-free conditions, both methods can be used interchangeably for the most numerous birds occupying open water (core group) without any significant impact on the results. When water areas are frozen over, air counts are preferable as the results are more reliable. The cost analysis shows that a survey carried out by volunteer observers (reimbursement of travel expenses only) from the land is 58% cheaper, but if the observers are paid, then an aerial survey is 40% more economical.
Diego Pavón‐Jordán
added a research item
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.
Petr Musil
added 2 research items
Heterospecific brood parasitism (HBP) frequently occurs in waterfowl, though much less often than conspecific brood parasitism. In this study, we assess the rate of HBP among clutches and broods of five sympatric breeding duck species: Gadwall Anas strepera, Mallard Anas platyrhynchos, Red-crested Pochard Netta rufina, Common Pochard Aythya ferina and Tufted Duck Aythya fuligula from nest and brood surveys carried out in the Třeboň Biosphere Reserve and surrounding area (South Bohemia, Czech Republic) in 2006-2015 inclusive. Assessment of 2,323 clutches and 3,056 broods found a higher rate of HBP in clutches than in broods. The rate of HBP in the broods of host birds did not increase with the rate of HBP in host clutches for the five species investigated. The highest proportion of brood parasitism recorded was among Red-crested Pochard. Tufted Duck showed the lowest difference in the HBP rate between clutches and broods; Mallard the highest. From the parasitising female's perspective, the rate of HBP in clutches increased with the rate of HBP in broods for each species investigated. We can conclude that the choice of host affects the success of HBP (i.e. the frequency of HBP in clutches vs. rate of HBP in broods), and that this can differ between the five species included in the study. Tufted Duck seems to be the most suitable host species as well as the most successful parasite.
Inter-specific parasitism in duck species in Central Europe may be an accidental consequence of conspecific breeding parasitism. Analysis of 1,237 nest records for five duck species in South Bohemia from 1999-2008 found that parasitism, where a bird lays its eggs in the nest of another species, had occurred in 6.6% of nests. Three Red-crested Pochard Netta rufina clutches were all parasitised and Red-crested Pochard most often laid parasitic eggs in the nests of other species. Gadwall Anas strepera was the second most parasitised species, with non-Gadwall eggs found in 16.4% of 152 Gadwall nests checked. Mallard nests were the least likely to be parasitised and Mallard Anas platyrhyncbos also laid relatively few parasitic eggs. There was a significant correlation between the probability of each species being parasitised and of its being a parasite. The results were compared with those in an earlier publication on the frequency of inter-specific clutch and nest parasitism in South Bohemia. Inter-specific breeding parasitism was more frequent in 1975-1980, in the years of increasing population size for all five species, when 13.9% (n = 284 nests) of clutches were found to have been parasitised.
Private Profile
added a research item
The counts coordinated by the B.I.R.O.E. (French equivalent of I.W.R.B.) have been used in order to analyse the variations in the numbers of dabbling ducks wintering in the Baie de l'Aiguillon, Charente-Maritime, western France. Between 1967 and 1983 the numbers in the Baie de l'Aiguillon correlate with those censused at 64 other sites in the north-west of France. As from 1984, there is less correlation; even though the numbers at the 64 other sites are either stable or increasing, depending on the species, numbers of ducks wintering in the Baie has declined. Local habitat change may be the cause of this decline.
Private Profile
added 2 research items
Detecting coherent signals of climate change is best achieved by conducting expansive, long-term studies. Here, using counts of waders (Charadrii) collected from ca. 3500 sites over 30 years and covering a major portion of western Europe, we present the largest-scale study to show that faunal abundance is influenced by climate in winter. We demonstrate that the ‘weighted centroids’ of populations of seven species of wader occurring in internationally important numbers have undergone substantial shifts of up to 115 km, generally in a northeasterly direction. To our knowledge, this shift is greater than that recorded in any other study, but closer to what would be expected as a result of the spatial distribution of ecological zones. We establish that year-to-year changes in site abundance have been positively correlated with concurrent changes in temperature, but that this relationship is most marked towards the colder extremities of the birds' range, suggesting that shifts have occurred as a result of range expansion and that responses to climate change are temperature dependent. Many attempts to model the future impacts of climate change on the distribution of organisms, assume uniform responses or shifts throughout a species' range or with temperature, but our results suggest that this may not be a valid approach. We propose that, with warming temperatures, hitherto unsuitable sites in northeastern Europe will host increasingly important wader numbers, but that this may not be matched by declines elsewhere within the study area. The need to establish that such changes are occurring is accentuated by the statutory importance of this taxon in the designation of protected areas.
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. © 2013 Blackwell Publishing Ltd.
Private Profile
added 3 research items
Species with known long-term changes in abundance and distribution enable exploring the role of newly accessible sites in population regulation. In Western Europe, the Black-tailed Godwit Limosa limosa islandica is one of the few wintering shorebirds with increasing populations. The French coasts comprise a major wintering site within its global wintering area, with several thousand individuals at some sites. Nevertheless, the role and importance of French sites in general distribution patterns of the species remain unclear, especially as its hunting was legal there until 2008. In contrast, recent increases in protected areas in France (from 4,000 ha in 1973 to 28,000 ha in 2005) offer new safe sites and suitable habitats for the species. In this study, we assessed the numbers and distribution of Black-tailed Godwits along the coasts of Western France. The main wintering sites in France are progressively occupied from August, reaching peak occupation in late autumn or early winter although few of the ten sites listed showed similar patterns of monthly variations in the distribution of Godwit numbers. France welcomes c. 28% of the total L. l. islandica population in mid-winter over the period 2003–2007. Numbers declined steadily from the base year (1977) until 1991, then progressively increased, reaching a maximum in 2010 (c. 27,000 individuals). The creation of Nature Reserves throughout the 1990s probably contributed to the increasing number of Godwits in France, with new accessible sites visited and occupied intensively during the period of population increase. The clearly contrasting phenologies between the British Isles and France suggest that most of the individuals first arrive in the United Kingdom after the breeding season, and then some of the birds move to southern sites in either France or Iberia, while very few birds fly directly to France from Iceland.
French wetlands are at the crossroads of several shorebirds’flyways. During the non-breeding period, these wetlands host four Numeniini species: Black-tailed Godwit Limosa limosa (migration & winter), Bar-tailed Godwit Limosa lapponica (migration & winter), Curlew Numernus arquata (migration & winter) and Whimbrel Numenius phaeopus (migration). Except for the islandica subspecies population of Black-tailed Godwit, populations have decreased at the European scale, while in France, the occurrence of these species in winter is increasing. Here, we explore national trends of mid-January IWC (International Waterbird Counts 1979–2012) and monthly counts on key coastal sites (2001–2012) to understand these positive trends. In the last ten years, Black-tailed Godwit numbers have increased from 10,000 to 20,000 individuals. Both Curlews and Bar-tailed Godwits seem stable in midwinter. Moreover, we observed an increase in the over-summering population of Bartailed Godwits. Numbers of staging Whimbrels, at the end of summer were also increasing. IWC counts highlight the importance of the French wetlands as refuge for Curlews during cold spells (hosting from 20,000 to 60,000 individuals). Black-tailed Godwit and Curlew have been protected by a hunting moratorium during the past six years (2007–2013). We suggest that the moratorium has greatly improved the status of these species, but also positively affected the two other hunted species, Whimbrel and Bar-tailed Godwit. They potentially have been spared by hunters due to the high risk of identification mistakes. If climate change leads to a further concentration of shorebird along the French coasts, European populations might be caught in the mousetrap of French lobby of ‘traditional’ hunters.
The dynamic nature and diversity of species’ responses to climate change poses significant difficulties for developing robust, long-term conservation strategies. One key question is whether existing protected area networks will remain effective in a changing climate. To test this, we developed statistical models that link climate to the abundance of internationally important bird populations in northwestern Europe. Spatial climate–abundance models were able to predict 56% of the variation in recent 30-year population trends. Using these models, future climate change resulting in 4.0ºC global warming was projected to cause declines of at least 25% for more than half of the internationally important populations considered. Nonetheless, most EU Special Protection Areas in the UK were projected to retain species in sufficient abundances to maintain their legal status, and generally sites that are important now were projected to be important in the future. The biological and legal resilience of this network of protected areas is derived from the capacity for turnover in the important species at each site as species’ distributions and abundances alter in response to climate. Current protected areas are therefore predicted to remain important for future conservation in a changing climate.
Leif Nilsson
added 2 research items
In the early decades of the 20th century the Whooper Swan was a rare breeding bird in northern Sweden, estimated at only 20 pairs. After protection from hunting in 1927, the population increased slowly and then more markedly after 1950. A large scale aerial survey was undertaken in 1972-75, when the population of the two northernmost provinces of Sweden (118 000 km2] was estimated at 310 pairs. These provinces were re-surveyed in 1997, producing an estimated 2, 775 pairs. In 1997, breeding Whooper Swans were found in all areas between the coast and the mountain chain, whereas the distribution in the 1970s iras restricted to some core areas in the north and to scattered pairs. Whooper Swans showed a clear association with wet mires and small lakes. The increase in the population is probably related to increased protection, as well as to better feeding conditions in the agricultural areas in the wintering quarters, thought to have improved the swans' condition at the start of the breeding season.
The Greylag Goose Anser anser has increased markedly in South Sweden in recent years. During 1985-1996 the field choice and local distribution of post-breeding foraging Greylag Geese was studied in an inland breeding area (with marked changes in land-use), and in a coastal area (with small changes in land-use) used by the same population. During late summer the geese gathered into one or two major flocks in the lake area and one or a few flocks in the coastal area. In the first years, geese in the inland area only made short feeding flights to crop fields close to the roosts, but with the introduction of large set-asides close to the roosts feeding flights were extended; the average distance increased threefold at two roosts and fivefold at a third. In the last year of the study, the fields close to the roost were again grown with cereals and the geese returned to their old pattern. The preferred feeding areas in the lake area were stubble fields and the geese started to leave the area when fields were ploughed. When available, peas were a preferred food before the harvest of cereals. In the first years of the set-aside programme, some set-asides were highly preferred early in the season. During the first years, relatively few geese used the coastal area, mainly in late autumn, but increased markedly in importance during the study period, whereas only a slight increase was found in the lake area. During the study period the Greylags in the coastal area established the new habit of feeding on sugar beet spill.
Łukasz Ławicki
added 4 research items
The European population of Greater Scaup Aythya marila has experienced an alarming, ~60% decline in numbers over the last two decades. The brackish lagoons of the Odra River Estuary (ORE) in the south-western Baltic Sea, represent an important area for the species during the non-breeding season in Europe. The lagoons regularly support over 20 000 Scaup, with peaks exceeding 100 000 (38%-70% of the population wintering in NW Europe and the highest number recorded in April 2011-105 700). In the ORE, Scaup feed almost exclusively on the non-native Zebra Mussel Dreissena polymorpha. This mussel was present in the ORE already in the 19th century and continues to be superabundant. Using the results of 22 Scaup censuses (November to April 2002/2003 to 2013/2014) from the whole ORE (523 km2 of water), we show that Scaup flocks follow areas with the greatest area of occurrence and biomass of the Zebra Mussel, while areas with low mussel densities are ignored. The numbers of Scaup in the ORE are primarily related to the area of Zebra Mussel occurrence on the lagoon's bottom (km2) in a non-linear fashion. Zebra Mussels were absolutely prevalent (97% of biomass) in the digestive tracts of birds unintentionally by-caught in fishing nets (n = 32). We estimate that Scaup alone consume an average of 5 400 tons of Zebra Mussels annually, which represents 5.6% of the total resources of the mussel in the ORE. Our results provide a clear picture of the strong dependence of the declining, migratory duck species on the non-native mussel, its primary food in the ORE. Our findings are particularly important as they can form the basis for the conservation action plan aimed at saving the north-western European populations of Scaup.
Some species of birds react to climate change by reducing the distance they travel during migration. The Odra River Estuary in the Baltic Sea is important for wintering waterfowl and is where we investigated how waterbirds respond to freezing surface waters. The most abundant birds here comprise two ecological groups: bottom-feeders and piscivores. Numbers of all bottom-feeders, but not piscivores, were negatively correlated with the presence of ice. With ongoing global warming, this area is increasing in importance for bottom-feeders and decreasing for piscivores. The maximum range of ice cover in the Baltic Sea has a weak and negative effect on both groups of birds. Five of the seven target species are bottom-feeders (Greater Scaup Aythya marila, Tufted Duck A. fuligula, Common Pochard A. ferina, Common Goldeneye Bucephala clangula and Eurasian Coot Fulica atra), and two are piscivores (Smew Mergellus albellus and Goosander Mergus merganser). Local changes at the level of particular species vary for different reasons. A local decline of the Common Pochard may simply be a consequence of its global decline. Climate change is responsible for some of the local changes in the study area, disproportionately favoring some duck species while being detrimental to others.
The study area lies in the south-western Baltic Sea and includes the Polish part of the Odra River Estuary (hereafter ORE). The ORE is protected in the form of four Natura 2000 SPAs. The waters of ORE are brackish – the salinity in the central part of the lagoon varies from 0.3 psu to 4.5 psu. The benthic communities are typical of freshwater bodies and are characterised by a high percentage of the Zebra Mussel. The species composition of fish is anadromous and typical of freshwaters, but large-scale incursions of marine fish (e.g. Herring) also take place from time to time. These factors and the shallowness of the lagoon (average 3.8 m) make food easily available; consequently, very large numbers of benthivorous and piscivorous diving ducks congregate there during the non-breeding period. Such large flocks of diving ducks in the ORE were first reported in the early 20th century, and the first accurate census was carried out in 1991-92. Since the beginning of the 21st century the West-Pomeranian Nature Society has been monitoring this area annually during the migration and wintering periods. The ORE is of crucial importance on a European scale as a migration stopover site and a wintering area for several diving ducks, namely, Greater Scaup (max. 105 733 individuals.; 38-70% of the NW European wintering population), Smew (max. 3 983 inds.; 10-17%), Common Merganser (max. 24 826 inds.; 9-15%), Tufted Duck (max. 48 799 inds.; up to 6%), Pochard (max. 4 488 inds.; 2%) and Goldeneye (max. 9 184 inds.; 1%). Several threats have been identified, the most important of which are the by-catch in fishing nets, the growth in recreational water sports and the accumulation of trace elements in the bodies of ducks. Management plans setting out specific conservation measures are being prepared for the Szczecin and Kamień Lagoons, two of the Natura 2000 SPAs.
Private Profile
added a research item
We analysed annual changes in abundance of Eurasian Wigeon (Anas penelope ) derived from mid-winter International Waterbird Census data throughout its northwest European flyway since 1988 using log-linear Poisson regression modelling. Increases in abundance in the north and east of the wintering range (Norway, Sweden, Denmark, Germany, Swit - zerland), stable numbers in the central range (Belgium, Netherlands, UK and France) and declining abundance in the west and south of the wintering range (Spain and Ireland) sug - gest a shift in wintering distribution consistent with milder winters throughout the range. However, because over 75% of the populatio n of over 1 million individuals winters in Belgium, the Netherlands, UK and France, there was no evidence for a major movement in the centre of gravity of the wintering distribution. Between-winter changes in overall flyway abundance were highly si gnificantly positively correlated ( P = 0.003) with repro- ductive success measured by age ratios in Danish hunter wing surveys and less strongly and inversely correlated (P = 0.05) with mean January temperatures in the centre of the wintering range, suggesting that winter severity may also contribute to influence survival. However, adding winter severity to a model p redicting population size based on annual reproductive success alone did not contribute to more effect ively modelling the observed changes in population size. Patterns in annual reproductive success seem therefore to largely explain the recent dynamics in popul ation size of northwest European Wigeon. Summer NAO significantly and positively explai ned 27% of variance in annual breeding success. Other local factors such as eutrophication of breeding sites and changes in preda- tion pressure undoubtedly contribute to change s in the annual production of young and differences in hunting pressure as well as winter severity affect annual survival rates. However, it seems likely that the observed flyway population trend since 1988 has been mostly influenced by climate effects on the breeding grounds affecting reproductive suc- cess and marginally on the winter quarters affecting survival. We urge improved demo- graphic monitoring of the population to be tter assess annual survival and reproductive success. We also recommend development of an adaptive management framework to re- move uncertainties in our knowledge of Wigeon population dynamics as information is forthcoming to better inform management, es pecially to attempt to harmonise the harvest with annual changes in demography to ensure sustainable exploitation of this important quarry species now and in the future.
Private Profile
added a research item
DÉNOMBREMENTS D’ANATIDÉS ET DE FOULQUES HIVERNANTS EN FRANCE À LA MI-JANVIER 2016 Résumé Comptage des oiseaux d’eau hivernant en France – Janvier 2016 Les comptages de la mi-janvier 2016 ont été réalisés sur 472 sites fonctionnels, soit une couverture de 90 % des entités de comptages décrites. L’effectif national dénombré d’anatidés et de foulques était de 1 137 057 oiseaux, soit une légère baisse par rapport à 2015 (1.139.872 oiseaux) mais une relative stabilisation après une baisse sensible sur trois années consécutives. Pour les espèces suivantes, la France accueille, au mois de janvier, une forte proportion de l’effectif des régions biogéographiques concernées (critère Ramsar n° 6 NW Europe et W Méditerranée) : le Canard souchet (20 sites), la Bernache cravant à ventre sombre (12 sites), le Canard chipeau (9 sites), le Tadorne de Belon (5 sites). Des effectifs relativement faibles des espèces suivantes ont été dénombrés : Canard pilet, Canard siffleur, Nette rousse, Fuligule milouin et milouinan, canards marins, Oie rieuse, Cygne de Bewick et chanteur, bernaches. Les espèces suivantes ont progressé sensiblement par rapport à 2015 : Canard chipeau, souchet, Tadorne de belon, Fuligule nyroca, Harle bièvre, Oie des moissons, le Cygne tuberculé, Foulque macroule. Vingt-cinq sites ont hébergé plus de 10 000 canards et foulques, totalisant 54,6 % de l’effectif national compté, soit une proportion légèrement supérieure à celle de 2015 (53,4%) et de 2014 (52,8 %), mais toujours sensiblement inférieure à celle de 2013 (59%). Trente-cinq sites ont atteint ou dépassé au moins un des seuils numériques des critères Ramsar fixant l’importance internationale des zones humides, soit un site de plus qu’en 2015. Ils ont tous accueilli plus de 1 % de la population biogéographique d’au moins une espèce et 10 d’entre eux hébergeaient plus de 20 000 anatidés et foulques (critère n° 5 de la Convention de Ramsar). Summary Census of Anatids and coots wintering in France – January 2016. In 2016, mid-January waterbird counts have been made on 472 sites, or a 90% coverage of the described functional count sites. Total national count of Anatids and Coots was 1,137,057 birds. Total count is slightly decreasing compared to 2015 total count but is relatively stabilized now, after a sensitive decrease which occurred during the three previous years. Some sites meet thresholds of international importance (Ramsar Convention criterion n°6) for the following species wintering in France with a high proportion of the flyway populations (NW Europe and W Mediterranean): Nothern Shoveler (20 sites), Dark-bellied Brant Goose (12 sites), Gadwall (9 sites), Shelduck (5 sites). Relatively low numbers of the following species have been counted: Northern Pintail, Eurasian Wigeon, Red-crested Pochard, Common Pochard, Greater Scaup, sea ducks, White-fronted Goose, Tundra and Whooper Swan and Brant Goose. Although, compared to 2015, high numbers of Gadwall, Shoveler, Shelduck, Ferruginous Duck, Common Merganser, Taiga Bean Goose, Mute Swan and Eurasian Coot. Twenty-five sites had more than 10,000 ducks and coots. These main sites gathered more than 54.6% of the total national count, or a slightly higher proportion than for 2015 count (53.4%) and 2014 count (52.8%) but still significantly lower than in 2013 (59%). Thirty-five sites met or exceeded at least one numerical threshold of the Ramsar criteria, showing the international importance of wetlands, or one site more than in 2015. All of them had more than 1% of the flyway population for at least one species. Among them, 10 had more than 20,000 anatids and coots (criterion n°5 of the Ramsar Convention).
Private Profile
added 2 research items
Census of Anatidae and coots wintering in France – January 2008. In 2008, mid-January waterbird counts have been made on 388 sites, or a 964.5 % coverage of the functional count sites. Total national count (Anatidae & Coots) reaches 1,159,524 birds. Some species occur in France with a high proportion of the flyway populations (NW Europe and W Mediterranean): the Shoveler (>40%), Gadwall (21%), Pintail (20%), Common Teal (25%)Red-crested Pochard (10%) and Brent Goose (nearly 60%). 24 sites had more than 10,000 ducks and coots. These main sites gathered more than 59.4% of the total national count. 30 sites reached, or exceeded at least one numerical threshold of the Ramsar criteria, showing the international importance of wetlands. Every of these 30 sites had more than 1% of the flyway population for at least one species (criterion n° 6 of the Ramsar Convention). Among them, 9 had more than 20,000 Anatids and coots (crit. n° 5 of the Ramsar Convention). In January 2008, French wetlands have been specially important for the following four species: Brent Goose (12 internationally important sites), Shoveler (10 internationally important sites), Gadwall (5 sites) and Shelduck (7 internationally important sites).
Private Profile
added a research item
Ornithos 17 (2010) : 266-283. An analysis of mid-winter counts of wildfowl in France. This paper presents the trends of wintering wildfowl obtained by the two national networks : one coordinated by ONCFS and hunters NGOs and the other by conser vationists (LPO-Wetlands International). They work in an independent way, and are using the same data only to some extent . The results obtained by the two networks are coherent, showing comparable trends for nine of the ten duck species monitored since 1988. Tuf ted Duck decreased signif icantly according to both networks, whereas Common Pochard decreased according to the ONCFS network only (it appears stable in Wetlands International counts). The other eight species are increa-sing. Analyses show that these two networks are complementary. ONCFS monthly counts make it possible to grasp the phenology of the wintering period and indicate that January is not always when the number of ducks is the highest. LPO-Wetlands International counts are more exhaustive and allow a better approach to national numbers, while also considering the sites of lesser impor tance.
Private Profile
added a research item
Census of Anatidae and coots wintering in France – January 2011. In 2010, mid-January waterbird counts have been made on 417 sites, or a 99% coverage of the functional count sites. Total national count of Anatidae and Coots was 1,364.151 birds. A light increase occurred with respect of 2010 and previous year counts. Some species occur in France with a high proportion of the flyway populations (NW Europe and W Mediterranean). Hence some sites meet thresholds of international importance for the following species: the Shoveler (8 sites), the Pochard (5 sites), Gadwall (4 sites), Pintail (6 sites), Shelduck (7 sites), Common Teal (6 sites) and Brent Goose (11 sites). In January 2011, relatively high numbers of the following species have been counted: dabbling ducks, Merginae, coots, swans and geese. 32 sites had more than 10,000 ducks and coots. These main sites gathered more than 60% of the total national count. 25 sites reached, or exceeded at least one numerical threshold of the Ramsar criteria, showing the international importance of wetlands, or four more than in 2010. All these sites had more than 1% of the flyway population for at least one species (criterion n° 6 of the Ramsar Convention). Among them, 11 had more than 20,000 Anatids and coots (crit. n° 5 of the Ramsar Convention).
Diego Pavón‐Jordán
added a research item
Anthropogenic habitat loss and climate change are among the major threats to biodiversity. Bioclimatic zones such as the boreal and arctic regions are undergoing rapid environmental change, which will likely trigger changes in wildlife communities. Disentangling the effects of different drivers of environmental change on species is fundamental to better understand population dynamics under changing conditions. Therefore, in this study we investigate the synergistic effect of winter and summer weather conditions and habitat type on the abundance of 17 migratory boreal waterbird species breeding in Finland using three decades (1986–2015) of count data. We found that above-average temperatures and precipitations across the western and northern range of the wintering grounds have a positive impact on breeding numbers in the following season, particularly for waterbirds breeding in eutrophic wetlands. Conversely, summer temperatures did not seem to affect waterbird abundance. Moreover, waterbird abundance was higher in eutrophic than in oligotrophic wetlands, but long term trends indicated that populations are decreasing faster in eutrophic than in oligotrophic wetlands. Our results suggest that global warming may apparently benefit waterbirds, e.g. by increased winter survival due to more favourable winter weather conditions. However, the observed population declines, particularly in eutrophic wetlands, may also indicate that the quality of breeding habitat is rapidly deteriorating through increased eutrophication in Finland which override the climatic effects. The findings of this study highlight the importance of embracing a holistic approach, from the level of a single catchment up to the whole flyway, in order to effectively address the threats that waterbirds face on their breeding as well as wintering grounds.
Petr Musil
added 2 research items
Waterbird monitoring is generally well organized in non-breeding season. Nation-wide programmes aimed at monitoring of breeding populations and its recruitment are developed only in some countries, such as Finland or Czech Republic. There can be methodological problems with variable detectability of individual species in various stages of the breeding season. Therefore, we analyse recording probability (i.e. probability to be counted in any single count during breeding season in three sympatric duck species, i.e. in Red-Crested Pochard Netta rufina, Common Pochard Aythya ferina and Tufted Duck Aythya fuligula. We analysed the probability of recording of individually marked ducks in relation to independent variables such as stage of breeding season (pre-breeding, incubation, brood rearing, post-brood period), timing (month), individual year and actual local population size. The recording probability of all three investigated diving duck species was significantly affected by their actual reproductive status and timing of breeding season. The highest probability to record marked individual duck female was in pre-breeding, brood rearing and post-brood periods, i.e. in April, May and the 2ndhalf of July and finally in the 1sthalf of August. We found no effect of year and local population size. Duck census at the beginning of the incubation season (i. e. in May) can provide reasonable data for estimating the annual population size of the investigated diving duck species.
CapsuleOf 26 species of wintering waterbirds, 18 showed an increase in numbers, five showed a decrease and two showed no change. AimTo assess long-term trends in the numbers and distribution of the 26 most abundant wintering waterbird species in the Czech Republic. Methods We used International Waterbird Census data from between 48 and 639 wetland sites which had been counted annually in the Czech Republic from 1966 to 2008. From these data long-term changes in numbers and distributions were determined. Log-linear Poisson regression analysis was used to estimate missing data using trim software. The distribution of each species was described as the ratio of the number of sites occupied by that species to the total number of sites investigated. ResultsIncreasing trends were found for 18 species, five species were found to be declining, one species was stable and two species were found with uncertain trends. Wintering distributions (the ratio of sites occupied by a given species to the total number of sites counted) increased in 16 species and decreased in two species, broadly correlated with the species changes in numbers. Conclusion In most species changes in numbers as well as changes in distribution followed the Western Palearctic population trends. Those species which increased were mainly piscivores and included geese, ducks and gulls. Scarcer species also exhibited an increase in numbers. The changes in numbers (both positive and negative) were more frequent among species associated with running water, whereas species which showed uncertain trends were more frequently recorded on standing water, which is more affected by variable weather conditions.
Diego Pavón‐Jordán
added 7 research items
We review the current and future threats to duck populations that breed, stage, moult and/or winter in the Nordic countries. Migratory duck species are sensitive indicators of their changing environment, and their societal value confirms the need to translate signals from changes in their distribution, status and abundance into a better understanding of changes occurring in their wetland environments. We used expert opinion to highlight 25 major areas of anthropogenic change (and touch briefly on potential mitigation measures through nature restoration and reserve management projects) that we consider key issues likely to influence Nordic duck populations now and in the near future to stimulate debate, discussion and further research. We believe such reviews are essential in contributing to development of successful management policy as well as stimulating specific research to support the maintenance of duck species in favourable future conservation status in the face of multiple population pressures and drivers.