Ecology

Numerous studies have shown that climate changes associated with increasing global temperature affect bird species. For instance, long-distance migrants are not able to respond adequately to rapid advances in spring phenology, and thus their populations decline due to lower breeding performance. Moreover, many species in the Northern Hemisphere have shifted their northern breeding range boundaries further north. However, studies focusing on bird populations at the scale of individual countries, which are responsible for creating environmental policies, are rather scarce. We hypothesized that bird species with different European latitudinal breeding distributions would have different long-term population trends in the Czech Republic, a small central European country, as a result of range dynamics caused by increasing spring temperature. In accordance with this prediction, the results of an analysis based on large-scale monitoring data (from 1982 to 2006) showed that species with more northern latitudinal distributions had more negative population trends in the Czech Republic. However, the strength of the relationship depended on the approach used for characterization of the species latitudinal distributions. When a phylogenetic regression was applied, the only significant explanatory variable was the latitudinal distribution expressed in categories defined by species range areas in different latitudinal bands. A more detailed analysis showed that southern and northern species groups have opposite population trajectories: the former increased and the latter declined throughout the study period. The effect of climate change remained significant when habitat association and the migratory strategy of each species were taken into account. However, it is difficult to determine whether climate change or habitat change is the more important driver of long-term trends in bird populations as the effects of both factors are dependent on interspecific variability in levels of species specialization.

Recent studies show diVerences in population trends between groups of species occupying diVerent habitats. In Czech birds, as well as in many other European countries, populations of forest species have increased, whereas populations of farmland species have declined. The aim of our study was to test whether population trends of particular species were related to Wner bird-habitat associations within farmland and forest birds. We assessed bird-habitat associations using canonical correspondence analysis based on data from a 400 km long transect across the Czech Republic. We calculated population trends of 62 bird species using log-linear models based on data from a large-scale annual monitoring scheme, which covers the time series from 1982 to 2005. Within forest birds, species with a closer association with lowland broad-leaved forest have had more positive population trends, whereas species with a closer association with montane and coniferous forest revealed more negative population trends. We attribute these opposite trends to the gradual replacement of coniferous forests by deciduous ones, which took place in the Czech Republic during recent decades. Our analyses revealed a hump-shaped relationship within farmland birds, species most closely associated with farmland habitat revealing the most negative trends, whereas species with intermediate association to farmland habitat showed the most positive population trends. Such a pattern can be explained by the abandonment of Biodivers Conserv (2008) 17:3307-3319 1 C previously cultivated areas followed by the spread of unmanaged meadows and scrubland. Changes in quantity or quality of preferred habitats may thus represent major drivers of observed bird population changes.

A species' susceptibility to environmental change might be predicted by its ecological and life-history traits. However, the effects of such traits on long-term bird population trends have not yet been assessed using a comprehensive set of explanatory variables. Moreover, the extent to which phylogeny affects patterns in the interspecific variability of population changes is unclear. Our study focuses on the interspecific variability in long-term population trends and annual population fluctuations of 68 passerine species in the Czech Republic, assessing the effects of eight life-history and five ecological traits. Ordination of life-history traits of 68 species revealed a life-history gradient, from 'r-selected' (e.g. small body mass, short lifespan, high fecundity, large clutch size) to 'K-selected' species. r-selected species had more negative population trends than K-selected species, and seed-eaters declined compared with insectivores. We suggest that the r-selected species probably suffer from widespread environmental changes, and the seed-eaters from current changes in agriculture and land use. Populations of residents fluctuated more than populations of short-distance migrants, probably due to the effect of winter climatic variability. Variance partitioning at three taxonomic levels showed that whereas population trends, population fluctuations and habitat specialization expressed the highest variability at the species level, most life-history traits were more variable at higher taxonomic levels. These results explain the loss of statistical power in the relationship between life histories and population trends after controlling for phylogeny. However, we argue that a lack of significance after controlling for phylogeny should not reduce the value of such results for conservation purposes.

The relationship between agricultural intensification and a decline in farmland bird populations is well documented in Europe, but the results are mostly based on data from the western part of the continent. In the former socialist eastern and central European countries, political changes around 1990 resulted in a steep decline in the intensity of agriculture. Therefore, one would expect populations of farmland birds to have recovered under these conditions of lower agricultural intensity. We explored population trends of 19 farmland bird species in the Czech Republic between 1982 and 2003 using data from a large-scale monitoring scheme, and, additionally, we looked for relationships between such population changes and a number of variables describing the temporal development of Czech agriculture. Most farmland species declined during the focal period, and this decline was steepest in farmland specialists (Northern Lapwing Vanellus vanellus , Skylark Alauda arvensis , Linnet Carduelis cannabina and Yellowhammer Emberiza citrinella ). Although the intensity of agriculture was lower after than before 1990, the overall decline continued in most farmland bird species, albeit at a slower rate. The correlations between agricultural intensity and farmland bird decline showed opposite patterns to that found in other European studies, because bird populations were highest in years with the most intensive agriculture. We speculate that this pattern could have resulted from the impact of different driving forces causing farmland bird decline in different periods. The high intensity of agriculture could have caused the decline of the originally abundant populations before 1990. After 1990, the decreasing area of arable land could be the most important factor resulting in the continued decline of farmland bird populations. Our results demonstrate that the drivers of farmland bird population changes could differ across Europe, and thus investigations into the effect of farmland management in different parts of the continent are urgently required.

European birds have been significantly affected by dramatic environmental changes during the last decades. The effects of these changes on species richness and distribution in particular countries are still poorly understood because of a lack of high-quality, large-scale data standardized over time. This is especially true in Central and Eastern Europe. On a model group of birds in the Czech Republic (countrywide atlas mapping data), we examined whether long-term changes of species richness and distribution between 1985-1989 and 2001-2003 differed among groups of species defined by their habitat requirements, type of distribution in Europe, migratory strategy and the degree of national legal protection. Further, we investigated the effects of colonizers and local extinctions on these changes. Whereas the number of species in the whole country remained the same in both periods (208 species), species composition had changed. Increasing occupancy (i.e., number of occupied mapping squares) was observed in species of forest and wetland habitats, in short-distance migrants and in non-protected species. Southern species also positively changed their occupancy, but this pattern disappeared after the inclusion of six species dependent on extensively cultivated farmland that went extinct between mappings. The overall occupancy of all species together showed positive changes after excluding colonizers and extinct species. We suggest that the improvement of environmental conditions after 1990 caused the stability of or increased the distribution of common birds in the Czech Republic, and it was the disappearance of specific farmland practices that might have caused the loss of several species. J Ornithol (2010) 151:923-932 925

European birds have been significantly affected by dramatic environmental changes during the last decades. The effects of these changes on species richness and distribution in particular countries are still poorly understood because of a lack of high-quality, large-scale data standardized over time. This is especially true in Central and Eastern Europe. On a model group of birds in the Czech

Reif J., Šťastný K., Bejček V. 2010. Contrasting effects of climatic and habitat changes on birds with northern range limits in central Europe as revealed by an analysis of breeding bird distribution in the Czech Republic. Acta Ornithol. 45: 83-90.

Capsule Two nationwide monitoring schemes, the International Waterbird Census (IWC) and Atlas of Wintering Birds (AWB), provide comparable estimates of national population sizes of wintering waterbirds. Differences between these estimates for several species can be explained by differences in their migratory strategy. Aims We tested whether species-specific variables, i.e. the total numbers, distribution and migration strategy affected the accuracy of wintering population estimates provided by two different monitoring schemes, the IWC and AWB. Methods Estimates of the numbers of 81 waterbird species are compared, using data from IWC (mid-January) and AWB (December, January and February) in the Czech Republic between 1982 and 1985. Log-linear Poisson regression analysis was used to estimate missing IWC data from long-term IWC data series using Trends and Indices for Monitoring data software. A series of generalized linear models was estimated to analyse the effect of species-specific variables on the presence of overlap between IWC and AWB national population estimates. Results The range of numbers recorded by IWC data overlap the range of AWB numbers in 22 of the 53 investigated species recorded by both monitoring schemes. Numbers of most other species based on the IWC counts were lower when compared with those generated from AWB data and included several widespread species, e.g. White-tailed Eagle Haliaeetus albicilla and White-throated Dipper Cinclus cinclus. In contrast, population size estimates based on IWC counts were higher than those generated from AWB estimates for one species, the Ferruginous Duck Aythya nyroca. The differences between IWC and AWB estimates were significantly higher in late-departing and early-arriving migrants. There was no effect of species distribution and population size. Conclusions Based on a single-country data sample, we support the relevance of the IWC Census methodology to produce estimates of wintering waterbird numbers and to calculate 1% thresholds for waterbird species, which we use to indicate nationally important wetland sites for future conservation and protection in the Czech Republic. Bird Study (2014) 61, 321-331 http://dx.. 2006. Identifying declines in waterbirds: the effects of missing data, population variability and count period on the interpretation of long-term survey data. Biol. Conserv 130: 549-559. © 2014 British Trust for Ornithology, Bird Study, 61, 321-331 Wintering waterbird numbers estimates 329 Downloaded by [Petr Musil]

Data on altitudinal distribution of birds breeding in the Czech Republic were dispersed in many breeding atlases, publications and monographs devoted to single mountain ranges so far. However, such information are very important, because altitudinal distribution of breeding birds can be liable to relatively fast changes apparent sometimes already in 10 year intervals. Thus, a numerous dataset on altitudinal distribution of birds in the country, from published and unpublished sources, is gathered in this article. The data are simply evaluated for water and terrestrial species, for differences between individual mountain ranges, and for known long-term changes in altitudinal distribution of some species. Differences between Czech and other central European mountain ranges are briefly discussed.

Fledgling behaviour and movement patterns throughout the post-fledging dependence period (PFDP), especially in relation to changing environmental conditions, have been rarely studied, despite the fact that this period is recognized as of crucial significance in terms of high mortality of juveniles. The PFDP can extend over quite a protracted period, particularly in birds of prey, and a knowledge of the movement patterns of individuals is fundamental for understanding mechanisms underlying survival, habitat use and dispersion. We radiotracked 39 fledglings of the Tengmalm's owl (Aegolius funereus) in two years with different availability of prey: 2010 (n = 29) and 2011 (n = 10) and obtained 1455 daily locations. Fledglings reached independence on average in 45 days after fledging in 2010 (n = 22) and 57 days in 2011 (n = 6). Within years, the most important measures influencing the distance moved from the nest box were age of fledglings and number of surviving siblings present. Individual home range size and duration of PFDP in particular were dependent on maximal number of siblings seen outside the nest box. In the season with low prey availability fledglings were observed at greater distances from the nest box than in the year with higher prey availability (mean distance: 350 m in 2010 and 650 m in 2011) and occupied larger home ranges (mean: 30.3 ha in 2010 and 57.7 ha in 2011). The main factor causing these differences between years was probably the different availability of prey in these two years, affecting breeding success and postfledging survivorship of the Tengmalm's owls.

In recognition of the importance of environmental specimen banking (ESB) as an important component of the described ongoing real-time environmental and heath-related monitoring programmes, a proposal for a planned ESB pilot study in the Czech Republic is presented. Selection of biomonitors, analytes, sampling techniques and sites is discussed, especially with regard to the possible harmonization with ESB already operational abroad. Availability of validated analytical techniques for determination of up to 30 elements using nuclear and spectroscopic techniques, including speciation of several metals, and of the most important organic pollutants employing various chromatographic techniques in biological and environmental samples is demonstrated. 0 1997

Environmental variation across space and time can strongly influence life-history strategies in vertebrates. It has been shown that the reproductive success of birds of prey is closely related to food availability. However, relatively little is known about intraspecific differences in reproductive success of birds in relation to varying ecological conditions across environmental gradients. We investigated the reproductive performance of Tengmalm's Owls Aegolius funereus in a temperate (Czech Republic, 50°N) and a boreal (Finland, 63°N) population in relation to long-term variations in the abundance of their main prey (small rodents). Prey densities at the northern site were much higher, but there were also large inter-annual fluctuations and years with steep summer declines of vole densities. Northern owls laid larger clutches but offspring production per nest was similar at both study sites. This resulted from higher nestling mortality in the northern population, especially in nests established later in the season. Despite much greater nesting losses due to predation by Pine Martens Martes martes, productivity at the population level was about four times greater at the temperate site, mainly due to the much higher breeding densities compared with Finland. Tengmalm's Owls at the temperate study site may benefit from relatively stable prey abundance, a more diverse prey community that offers alternative prey during vole scarcity, longer nights in summer that allow more time for foraging, and a lower level of interspecific competition with other vole-specialized predators.