Biodiversity is increasingly negatively affected by climate warming, making this issue a major conservation concern. Many bird species respond to warming temperatures by shifting distribution ranges, but these shifts often lag behind temperature changes. Protected areas (PAs) can facilitate such shifts, but a growing body of literature suggests that not all PAs facilitate climate warming responses equally, as realized management actions can differ. Here, we study waterbird community change as a response to climate warming in relation to targets of conservation projects implemented in Natura 2000 protected areas across the EU. We combine long-term waterbird survey data (i.e. International Waterbird Census) with data on conservation funded by the EU LIFE program, the main EU instrument for conservation. We used the community temperature index to measure thermal community changes over 28 years. We found community adjustment to climate warming lagged behind temperature. However, community change was twice as fast in sites were conservation was targeting wetland habitats compared with sites without habitat conservation. Targeting waterbirds directly did not lead to variation in community change compared with other types of species conservation. Our results imply that on the management level conservation targeting a community's habitat (rather than targeting the species group directly) is more likely to provide benefits for community adjustment to climate warming. This study demonstrates that management actions currently not targeting climate warming impacts on biodiversity, have the potential to support species responding to climate warming. However, conservation strategies need to be adapted to the challenges arising with climate warming.

The 39.4% decline in numbers in the Northeast/Northwest European population of Bewick's Swan Cygnus columbianus bewickii between 1995 (29,780 birds) and 2010 (18,057 birds) was of major conservation concern, alleviated by a partial recovery to 20,149 recorded in the January 2015 census. The most recent census, in January 2020, however found that the recovery was not sustained. The results described in this paper found a further 29.7% decline between 2015 and 2020, with 12,702 individuals counted in 2020 and the population estimated at 12,930 birds. This represents a 56.7% decrease over the 25-year period from 1995-2020; an annual average decrease of 3.3% per year, with a higher rate of decline (8.5%/year) over the most recent 5year period. Changes in the Bewick's Swans distribution were evident, with a significant increase in the proportion of the population recorded in countries in the northeastern part of the wintering range compared with those further south and west. More sites of international importance for Bewick's Swans in mid-winter (i.e. with >= 1% of the total population) consequently were found in Germany during the 2020 census than in previous censuses. Moreover, the swans were found to be more widely dispersed, rather than being concentrated at key sites, in 2015 and 2020. Annual productivity data, based on the percentage of cygnets (first-winter birds) recorded in wintering flocks, indicate that the recruitment to the population was consistently lower than estimated survival rates between 2010 and 2020, and moreover this has continued up to and including winter 2024/25. A population model predicts that a further reduction in population size to an estimated 11,068 Bewick's Swans will be found during the next census scheduled for January 2026, unless the swans have a good breeding season in summer 2025, which would represent a decrease of 14.4% since 2020.

Protected area networks help species respond to climate warming. However, the contribution of a site's environmental and conservation-relevant characteristics to these responses is not well understood. We investigated how composition of nonbreeding waterbird communities (97 species) in the European Union Natura 2000 (N2K) network (3018 sites) changed in response to increases in temperature over 25 years in 26 European countries. We measured community reshuffling based on abundance time series collected under the International Waterbird Census relative to N2K sites' conservation targets, funding, designation period, and management plan status. Waterbird community composition in sites explicitly designated to protect them and with management plans changed more quickly in response to climate warming than in other N2K sites. Temporal community changes were not affected by the designation period despite greater exposure to temperature increase inside late-designated N2K sites. Sites funded under the LIFE program had lower climate-driven community changes than sites that did not received LIFE funding. Our findings imply that efficient conservation policy that helps waterbird communities respond to climate warming is associated with sites specifically managed for waterbirds.

Mapping the relative risk of impact on nature by a human infrastructure at a landscape scale (“sensitivity mapping”) is an essential tool for minimising the future impact of new development or for prioritising mitigation of existing impacts. High-voltage power lines (“transmission lines”) are known to increase bird mortality by collision. Here we present a method to derive a high resolution map of relative risk of transmission line impacts across one entire country, Belgium, from existing bird distribution data. First, all the bird species observed in Belgium were systematically assessed using literature and casualty records to select those to be included in the sensitivity map. Species were selected on the basis of their intrinsic susceptibility to collision and the conservation relevance of avoiding additional mortality for that species in Belgium. Each of the selected species was included in one or several spatial layer constructed from existing data, emerging from citizen science bird monitoring schemes. The resulting 17 layers were then combined into one final sensitivity map, where a “risk score” estimates the relative collision risk across Belgium at a 1×1 km resolution. This risk score is relatively robust to the subtraction of any of the 17 layers. The map identifies areas where building new transmission lines would create high risk of collision and, if overlapped with existing power lines, helps to prioritise spans where mitigation measures should be placed. Wetlands and river valleys stand out as the most potentially dangerous areas for collision with transmission lines. This sensitivity map could be regularly updated with new bird data or adapted to other countries where similar bird data are available.

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.

Climate warming is driving changes in species distributions, although many species show a so-called climatic debt, where their range shifts lag behind the fast shift in temperature isoclines. Protected areas (PAs) may impact the rate of distribution changes both positively and negatively. At the cold edges of species distributions, PAs can facilitate species distribution changes by increasing the colonization required for distribution change. At the warm edges, PAs can mitigate the loss of species, by reducing the local extinction of vulnerable species. To assess the importance of PAs to affect species distribution change, we evaluated the changes in a non-breeding waterbird community as a response to temperature increase and PA status, using changes of species occurrence in the Western-Palearctic over 25 years (97 species, 7,071 sites, 39 countries, 1993– 2017). We used a community temperature index (CTI) framework based on species thermal affinities to investigate the species turn-over induced by temperature increase. In addition, we measured whether the thermal community adjustment was led by cold-dwelling species extinction and/or warm-dwelling species colonization, by modelling the change in standard deviation of the CTI (CTI sd ). Using linear mixed-effects models, we investigated whether communities within PAs had lower climatic debt and different patterns of community change regarding the local PA surface. Thanks to the combined use of the CTI and CTI sd , we found that communities inside PAs had more species, higher colonization, lower extinction and the climatic debt was 16% lower than outside PAs. The results suggest the importance of PAs to facilitate warm-dwelling species colonization and attenuate cold-dwelling species extinction. The community adjustment was however not sufficiently fast to keep pace with the strong temperature increase in central and northeastern Western-Palearctic regions. Our study underlines the potential of the combined CTI and CTI sd metrics to understand the colonization-extinction patterns driven by climate warming.

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.

Watervogels - Wintering waterbirds in Flanders, Belgium is a sampling event dataset published by the Research Institute for Nature and Forest (INBO). It contains more than 94,000 sampling events (site counts), covering over 710,000 species observations (and zero counts when there is no associated occurrence) and 36 million individual birds for the period 1991-2016. The dataset includes information on 167 different species in nearly 1,100 wetland sites. The aim of these bird counts is to gather information on the size, distribution, and long-term trends of wintering waterbird populations in Flanders. These data are also used to assess the importance of individual sites for waterbirds, using quantitative criteria. Furthermore, the waterbird counts contribute to international monitoring programs, such as the International Water-bird Census (coordinated by Wetlands International) and fulfil some of the objectives of the European Bird Directive, the Ramsar Convention, and the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA). Here the dataset is published as a standardized Darwin Core Archive and includes for each event: a stable event ID, date and location of observation and a short description of the sampling protocol, effort and conditions (in the event core), supplemented with specific information for each occurrence: a stable occurrence ID, the scientific name and higher classification of the observed species, the number of recorded individuals, and a reference to the observer of the record (in the occurrence extension). Issues with the dataset can be reported at https://github.com/inbo/data-publication/issues. The following information is not included in this dataset and available upon request: roost site counts, counts from historical (inactive) locations and counts from before 1991. We have released this dataset to the public domain under a CC0 1.0 Universal (CC0 1.0) Public Domain Dedication (https://creativecommons.org/publicdomain/zero/1.0/). We would appreciate it if you follow the INBO norms for data use (https://www.inbo.be/en/norms-data-use) when using the data. If you have any questions regarding this dataset, do not hesitate to contact us via the contact information provided in the metadata or via opendata@inbo.be.