The future distribution of wetland birds breeding in Europe validated against observed changes in distribution

Wetland bird species have been declining in population size worldwide as climate warming and land-use change affect their suitable habitats. We used species distribution models (SDMs) to predict changes in range dynamics for 64 non-passerine wetland birds breeding in Europe, including range size, position of centroid, and margins. We fitted the SDMs with data collected for the first European Breeding Bird Atlas and climate and land-use data to predict distributional changes over a century (the 1970s-2070s). The predicted annual changes were then compared to observed annual changes in range size and range centroid over a time period of 30 years using data from the second European Breeding Bird Atlas. Our models successfully predicted ca. 75% of the 64 bird species to contract their breeding range in the future, while the remaining species (mostly southerly breeding species) were predicted to expand their breeding ranges northward. The northern margins of southerly species and southern margins of northerly species, both, predicted to shift northward. Predicted changes in range size and shifts in range centroids were broadly positively associated with the observed changes, although some species deviated markedly from the predictions. The predicted average shift in core distributions was ca. 5 km yr(-1) towards the north (5% northeast, 45% north, and 40% northwest), compared to a slower observed average shift of ca. 3.9 km yr(-1). Predicted changes in range centroids were generally larger than observed changes, which suggests that bird distribution changes may lag behind environmental changes leading to 'climate debt'. We suggest that predictions of SDMs should be viewed as qualitative rather than quantitative outcomes, indicating that care should be taken concerning single species. Still, our results highlight the urgent need for management actions such as wetland creation and restoration to improve wetland birds' resilience to the expected environmental changes in the future

Porownanie skladu pokarmu blotniaka lakowego Circus pygargus L. w sezonie legowym na dwoch odleglych powierzchniach w zachodniej Bialorusi

The study of diet composition of the Montagu`s Harrier (Circus pygargus (L) in two distinct breeding populations in 1996 in Hrodna and Smarhon` districts in Western Belarus have found different occurence of small mammals: 72,6% (n=2034) for the population #1 and 85,0% (n=254) for the population #2. Main prey in both populations was represented by vole species Microtus spp.: 68,5% and 78,3% for populations #1 and #2 accordingly. Significant difference was found in share of birds, mainly ground-nesting Passerines (17,5% and 12,6% for the population #1 and #2 accordingly) and large grasshoppers Tettigonia sp. (6,4% and 0,4% accordingly). Other prey categories (mice, shrews, hares, eggs of birds, lizards, dragonflies, large beetles and frogs) did not form an important part of the diet of these populations. We believe that opportunistic hunting behavior of the Montagu’s Harrier (which can easy switch on seasonally or locally abundant and accessible prey) is one of the reasons why the species did not form any subspecies throughout its wide range.Badania składu pokarmu 2 odległych populacji lęgowych błotniaka łąkowego Circus pygargus w 1996 r. w obwodzie Grodna i Smarhon w zachodniej Białorusi wykazały różny udział drobnych ssaków 72,6% (n=2034) w 1 populacji i 85,0% (n=254) w 2 populacji. Głównymi ofiarami w obydwu populacjach były różne gatunki norników Microtus spp.: 68,5% i 78,3% odpowiednio dla 1 i 2 populacji. Wykazano także dwie istotne statystycznie różnice między udziałem ptaków, głównie gniazdujących na ziemi Passeriformes (17,5% i 12,6% odpowiednio dla 1 i 2 populacji) i dużych pasikoników Tettigonia sp. (6,4% i 0,4% odpowiednio). Inne ofiary (myszy, ryjówki, zające, jaja ptaków, jaszczurki, ważki, duże chrząszcze i żaby) nie miały istotnego znaczenia w składzie pokarmu żadnej z populacji. Prawdopodobne przyczyny uzyskanych wyników przedyskutowano porównując dane z innych gatunków ptaków drapieżnych oraz innych populacji błotniaka łąkowego. Uważamy, że oportunistyczna strategia żerowania błotniaka łąkowego (który może łatwo zmieniać sezonowo i lokalnie dostępną zdobycz) jest jedną z przyczyn braku wytworzenia podgatunków w szerokim areale występowania

Local colonisations and extinctions of European birds are poorly explained by changes in climate suitability

Climate change has been associated with both latitudinal and elevational shifts in species' ranges. The extent, however, to which climate change has driven recent range shifts alongside other putative drivers remains uncertain. Here, we use the changing distributions of 378 European breeding bird species over 30 years to explore the putative drivers of recent range dynamics, considering the effects of climate, land cover, other environmental variables, and species' traits on the probability of local colonisation and extinction. On average, species shifted their ranges by 2.4 km/year. These shifts, however, were significantly different from expectations due to changing climate and land cover. We found that local colonisation and extinction events were influenced primarily by initial climate conditions and by species' range traits. By contrast, changes in climate suitability over the period were less important. This highlights the limitations of using only climate and land cover when projecting future changes in species' ranges and emphasises the need for integrative, multi-predictor approaches for more robust forecasting.</p

Local colonisations and extinctions of European birds are poorly explained by changes in climate suitability

Abstract Climate change has been associated with both latitudinal and elevational shifts in species’ ranges. The extent, however, to which climate change has driven recent range shifts alongside other putative drivers remains uncertain. Here, we use the changing distributions of 378 European breeding bird species over 30 years to explore the putative drivers of recent range dynamics, considering the effects of climate, land cover, other environmental variables, and species’ traits on the probability of local colonisation and extinction. On average, species shifted their ranges by 2.4 km/year. These shifts, however, were significantly different from expectations due to changing climate and land cover. We found that local colonisation and extinction events were influenced primarily by initial climate conditions and by species’ range traits. By contrast, changes in climate suitability over the period were less important. This highlights the limitations of using only climate and land cover when projecting future changes in species’ ranges and emphasises the need for integrative, multi-predictor approaches for more robust forecasting