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Most ecological studies use remote sensing to analyze broad-scale biodiversity patterns, focusing mainly on taxonomic diversity in natural landscapes. One of the most important effects of high levels of urbanization is species loss (i.e., biotic homogenization). Therefore, cost-effective and more efficient methods to monitor biological communities' distribution are essential. This study explores whether the Enhanced Vegetation Index (EVI) and the Normalized Difference Vegetation Index (NDVI) can predict multifaceted avian diversity, urban tolerance, and specialization in urban landscapes. We sampled bird communities among 15 European cities and extracted Landsat 30-meter resolution EVI and NDVI values of the pixels within a 50-m buffer of bird sample points using Google Earth Engine (32-day Landsat 8 Collection Tier 1). Mixed models were used to find the best associations of EVI and NDVI, predicting multiple avian diversity facets: Taxonomic diversity, functional diversity, phylogenetic diversity, specialization levels, and urban tolerance. A total of 113 bird species across 15 cities from 10 different European countries were detected. EVI mean was the best predictor for foraging substrate specialization. NDVI mean was the best predictor for most avian diversity facets: taxonomic diversity, functional richness and evenness, phylogenetic diversity, phylogenetic species variability, community evolutionary distinctiveness, urban tolerance, diet foraging behavior, and habitat richness specialists. Finally, EVI and NDVI standard deviation were not the best predictors for any avian diversity facets studied. Our findings expand previous knowledge about EVI and NDVI as surrogates of avian diversity at a continental scale. Considering the European Commission's proposal for a Nature Restoration Law calling for expanding green urban space areas by 2050, we propose NDVI as a proxy of multiple facets of avian diversity to efficiently monitor bird community responses to land use changes in the cities.

Risk-taking in birds is often measured as the flight initiation distance (FID), the distance at which individuals take flight when approached by a potential predator (typically a human). The ecological factors that affect avian FID have received great attention over the past decades and meta-analyses and comparative analyses have shown that FID is correlated with body mass, flock size, starting distance of the approaching human, density of potential predators, as well as varying along rural to urban gradients. However, surprisingly, only few studies (mainly on reptiles and mammals) have explored effects of different types of refugia and their availability on animal escape decisions. We used Bayesian regression models (controlling for the phylogenetic relatedness of bird species) to explore changes in escape behaviour recorded in European cities in relationship to the birds' distance to the nearest refuge and distance fled to the refuge. In our analyses, we also included information on the type of refuge, built-up and vegetation cover, starting distance, flock size, urbanization level, and type of urban habitat. We found that birds preferred tree refuges over artificial and bush refuges. Birds escaped earlier if the distance to the nearest refuge of any type was longer and if birds fled longer distances to the refuge. FID was shorter when birds used bushes as refugia or landed on the ground after flushing compared to using artificial refugia. Similarly, the distance fled to a refuge was shortest when using bushes, and increased when escaping to artificial substrates and trees. Birds were more timid in suburban than core areas of cities, cemeteries than parks, and in areas with higher bush cover but lower cover of built-up areas and trees. Our findings provide novel information regarding the importance of refuge proximity and type as factors affecting the escape behaviour of urban birds., MD was funded by MCIN/AEI/10.13039/501100011033 to the project URBILAND (PID2019-107423GA-I00).

The coronavirus disease 2019 (COVID-19) pandemic has dramatically altered human activities, potentially relieving human pressures on urban-dwelling animals. Here, we evaluated whether birds from five cities in five countries (Czech Republic – Prague, Finland – Rovaniemi, Hungary – Budapest, Poland – Poznan, and Australia – Melbourne) changed their tolerance towards human presence (measured as flight initiation distance) during the COVID-19 shutdowns. We collected 6369 flight initiation distance estimates for 147 bird species and found that birds tolerated approaching humans to a similar level before and during the COVID-19 shutdowns. Moreover, during the shutdowns, bird escape behaviour did not consistently change with the level of governmental restrictions (measured as the stringency index). Hence, our results indicate that birds do not flexibly and quickly adjust their escape behaviour to the reduced human presence; in other words, the breeding populations of urban birds examined might already be tolerant of human activity and perceive humans as relatively harmless.

Flight initiation distance (FID), the distance at which individuals take flight when approached by a potential (human) predator, is a tool for understanding predator–prey interactions. Among the factors affecting FID, tests of effects of group size (i.e., number of potential prey) on FID have yielded contrasting results. Group size or flock size could either affect FID negatively (i.e., the dilution effect caused by the presence of many individuals) or positively (i.e., increased vigilance due to more eyes scanning for predators). These effects may be associated with gregarious species, because such species should be better adapted to exploiting information from other individuals in the group than nongregarious species. Sociality may explain why earlier findings on group size versus FID have yielded different conclusions. Here, we analyzed how flock size affected bird FID in eight European countries. A phylogenetic generalized least square regression model was used to investigate changes in escape behavior of bird species in relation to number of individuals in the flock, starting distance, diet, latitude, and type of habitat. Flock size of different bird species influenced how species responded to perceived threats. We found that gregarious birds reacted to a potential predator earlier (longer FID) when aggregated in large flocks. These results support a higher vigilance arising from many eyes scanning in birds, suggesting that sociality may be a key factor in the evolution of antipredator behavior both in urban and rural areas. Finally, future studies comparing FID must pay explicit attention to the number of individuals in flocks of gregarious species., Higher Education Institutional Excellence Program, Grant/Award Number: 1783‐3/2018/FEKUTSTRAT; Estonian Ministry of Education and Research, Grant/Award Number: 34‐8; Czech Science Foundation GAČR, Grant/Award Number: 18‐16738S

Knowing the ecological requirements of bird species is essential for their successful conservation. We studied the niche characteristics of birds in managed small-sized green spaces in the urban core areas of southern (Kavala, Greece) and northern Europe (Rovaniemi, Finland), during the breeding season, based on a set of 16 environmental variables and using Outlying Mean Index, a multivariate ordination technique. Overall, 26 bird species in Kavala and 15 in Rovaniemi were recorded in more than 5% of the green spaces and were used in detailed analyses. In both areas, bird species occupied different niches of varying marginality and breadth, indicating varying responses to urban environmental conditions. Birds showed high specialization in niche position, with 12 species in Kavala (46.2%) and six species in Rovaniemi (40.0%) having marginal niches. Niche breadth was narrower in Rovaniemi than in Kavala. Species in both communities were more strongly associated either with large green spaces located further away from the city center and having a high vegetation cover (urban adapters, e.g., Common Chaffinch (Fringilla coelebs), European Greenfinch (Chloris chloris), Eurasian Blue Tit (Cyanistes caeruleus)) or with green spaces located closer to the city center and having high gray area cover and anthropogenic disturbance level (urban exploiters, e.g., Western Jackdaw (Corvus monedula), House Sparrow (Passer domesticus), Eurasian Magpie (Pica pica)). The eleven species that were common to both study areas similarly used the environmental variables and had similar niches, indicating that birds respond similarly to urbanization irrespective of latitude. Sixteen species in Kavala and eleven species in Rovaniemi were identified as conservation priority species, based on their niche specialization level and conservation status. The management actions proposed for the conservation of priority species will also benefit other species with similar ecological requirements and ultimately help maintain diverse bird communities in small-sized green spaces in urban core areas.

Warm thanks to Jacqui Sykoff for substantially improving the readability of former versions of the manuscript. GM was supported by the Hungarian Ministry for Innovation and Technology within the framework of the Thematic Excellence Programme 2020 (TKP2020-IKA-12, TKP2020-NKA-16).. KT was supported by institutional research funding IUT (34-8) of the Estonian Ministry of Education and Research. This paper is a contribution to the project URBILAND (PID2019-107423GA-I00/SRA 1013039/501100011033), funded by the Spanish Research Agency., Climate and land use are rapidly changing environmental conditions. Behavioral responses to such global perturbations can be used to incorporate interspecific interactions into predictive models of population responses to global change. Flight initiation distance (FID) reflects antipredator behaviour defined as the distance at which an individual takes flight when approached by a human, under standardized conditions. This behavioural trait results from a balance between disturbance, predation risk, food availability and physiological needs, and it is related to geographical range and population trends in European birds. Using 32,145 records of flight initiation distances for 229 bird species during 2006-2019 in 24 European localities, we show that FIDs decreased with increasing temperature and precipitation, as expected if foraging success decreased under warm and humid conditions. Trends were further altered by latitude, urbanisation and body mass, as expected if climate effects on FIDs were mediated by food abundance and need, differing according to position in food webs, supporting foraging models. This provides evidence for a role of behavioural responses within food webs on how bird populations and communities are affected by global change., Hungarian Ministry for Innovation and Technology TKP2020-IKA-12 TKP2020-NKA-16, Ministry of Education and Research, Estonia 34-8, Spanish Research Agency PID2019-107423GA-I00/SRA 1013039/501100011033

Patch, matrix and human-induced disturbance variables are important in determining the structure of urban bird communities. Although green spaces in urban core areas are usually small and disturbed, they can be important for local bird diversity. Because such areas are often overlooked, their study is critical for successfully incorporating biodiversity conservation in urban planning. Furthermore, comparing bird communities from different biogeographical areas would help identify generalizable patterns and propose common management actions. We compared the structure of breeding season bird assemblages of managed small public green spaces in the urban core areas of two similar-sized European cities, Kavala (Greece) and Rovaniemi (Finland), and studied the influence of environmental variables on community structure. Species composition differed between the cities. Abundance and evenness were higher in Kavala, while richness and diversity did not differ between the cities. Abundance did not respond in a general way to the same variables in the two cities. It increased with decreasing shrub cover and distance from the city center and with increasing midday noise and ground cover in Kavala, but increased with increasing distance from the city center and decreased with increasing car traffic and midday noise in Rovaniemi. This might be explained by the lower abundance of bird dwellers in Rovaniemi. Primarily gray cover, but also other variables, at both the patch and matrix levels (e.g., noise, car traffic, distance from the city center), negatively affected richness, evenness and diversity in both cities. Green space size was positively correlated with richness and diversity in Kavala, but not in Rovaniemi, possibly due to the smaller size variation in Rovaniemi. Results emphasized that increasing gray cover is harmful for birds in small-sized green spaces in urban core areas. However, urban managers should note that not all bird community metrics responded in similar ways to same environmental variables.

We are grateful to Vojt.ech Brlik and all people who helped observers during the fieldwork in the 15 European cities. F.M., Y.B. and J.R. were financially supported by the Czech Science Foundation GA.CR (project number 18-16738S). J.D.I.A. and M.D. were funded by the Spanish Ministry of Science and Innovation (PID2019-107423GA-I00/SRA State Research Agency/10.13039/501100011033). G.M. was supported by the Hungarian Ministry for Innovation and Technology within the framework of the Thematic Excellence Programme 2020 (TKP2020-IKA12, TKP2020-NKA-16). J.R. was supported by Charles University (PRIMUS/17/SCI/16)., Urban and suburban areas are among the fastest-growing land-use types globally, reducing and fragmenting natural habitats for many animal species and making human-wildlife interactions more common. However, cities also create habitat for several species considered urban tolerant or urban exploiter species. Additionally, the environmental characteristics of urban areas can strongly affect the life quality of citizens. This study aimed to assess the effectiveness of common bird species as indicators of urban areas with high environmental quality within cities. Our study recorded 128 bird species in 1441 point counts distributed in fifteen different European cities. We classified urban areas as “high environmental quality” – HEQ when they were simultaneously characterized by a high vegetation cover and heterogeneity, low level of light pollution, and avian communities with high potential resilience to face ecological stress. Species indicators of HEQ urban areas were identified using the species-level indicator value (IndVal) analysis. Such species can be used as ecological indicators of HEQ in different European cities. The list of top ten birds indicators of HEQ in European cities is led by the Eurasian blackcap, selected as an indicator in more than half of the survey cities. Other birds indicators of HEQ in multiple cities are Blackbird (47%), Great tit (40%), Blue tit, Tree sparrow and Magpie (all 33%). The mean specificity of the top-ranked bird indicator of HEQ urban areas (Eurasian blackcap) was 0.778. Most of the HEQ-indicators are resident or resident/short migratory species characterized by territorial behaviour. Our findings support using multiple species as bioindicators of urban changes by using specific groups with few common species as surrogates of HEQ urban areas. The approach proposed in this study can be applied in different European cities to monitor biodiversity status periodically, even involving citizen science initiatives., Grant Agency of the Czech Republic 18-16738S, Spanish Government PID2019-107423GA-I00/SRA, Hungarian Ministry for Innovation and Technology TKP2020-IKA12 TKP2020-NKA-16, Charles University PRIMUS/17/SCI/16

Urbanization is affecting avian biodiversity across the planet and potentially increasing species vulnerability to climate change. Identifying the resilience of urban bird communities to climate change is critical for making conservation decisions. This study explores the pattern in bird communities across nine European cities and examines the projected impact of climate change in order to detect communities facing a higher risk of functional change in the future. First, generalized linear mixed models were used to explore the potential resilience of urban bird communities in nine European cities and the effects of land cover, latitude, abundance of potential predators (dogs and cats), and bird species richness in each trophic guild. Bird community resilience was represented by an index of functional evenness, because it indicates relatively uniform functional space within the species assemblages. Second, bird community resilience in each city was compared with projected changes in temperature and precipitation for the year 2070 to explore potential future threats to conservation. The results showed that community resilience was not significantly associated with land use or abundance of predator. The number of granivorous and granivorous-insectivorous species increases the potential resilience of the community, while the numbers of insectivores, carnivores, and omnivores was negatively correlated with resilience. Of the nine cities, Madrid and Toledo (Spain) are projected to experience the largest change in temperature and precipitation, although their bird communities are characterized by relative high resilience. In contrast, Rovaniemi, at the Arctic Circle (Finland) is projected to experience the second highest increase in temperature among the focused cities, and their bird communities are characterized by low resilience. These findings indicate the importance of future research on the combined effect of functional diversity of species assemblages and climate change on urban biodiversity., F.M. and Y.B. were financially supported by the Czech Science Foundation GAČR (project number 18-16738S).

Urban areas are expanding globally as a consequence of human population increases, with overall negative effects on biodiversity. To prevent the further loss of biodiversity, it is urgent to understand the mechanisms behind this loss to develop evidence-based sustainable solutions to preserve biodiversity in urban landscapes. The two extreme urban development types along a continuum, land-sparing (large, continuous green areas and high-density housing) and land-sharing (small, fragmented green areas and low-density housing) have been the recent focus of debates regarding the pattern of urban development. However, in this context, there is no information on the mechanisms behind the observed biodiversity changes. One of the main mechanisms proposed to explain urban biodiversity loss is the alteration of predator–prey interactions. Using ground-nesting birds as a model system and data from nine European cities, we experimentally tested the effects of these two extreme urban development types on artificial ground nest survival and whether nest survival correlates with the local abundance of ground-nesting birds and their nest predators. Nest survival (n = 554) was lower in land-sharing than in land-sparing urban areas. Nest survival decreased with increasing numbers of local predators (cats and corvids) and with nest visibility. Correspondingly, relative abundance of ground-nesting birds was greater in land-sparing than in land-sharing urban areas, though overall bird species richness was unaffected by the pattern of urban development. We provide the first evidence that predator–prey interactions differ between the two extreme urban development types. Changing interactions may explain the higher proportion of ground-nesting birds in land-sparing areas, and suggest a limitation of the land-sharing model. Nest predator control and the provision of more green-covered urban habitats may also improve conservation of sensitive birds in cities. Our findings provide information on how to further expand our cities without severe loss of urban-sensitive species and give support for land-sparing over land-sharing urban development., This paper is a contribution by M. Diaz to the thematic net-work REMEDINAL3-CM (S2013/MAE-2719). F. Morelli and Y. Benedetti were financially supported by the Czech Science Foundation GACR (project number 18-16738S). P. Tryjanowski was supported by the BIOVEINS “Connectivity of green and blue infrastructure: living veins for biodiverse and healthy cities” (2016/22/Z/NZ8/00004).

Actions taken against the COVID-19 pandemic have dramatically affected many aspects of human activity, giving us a unique opportunity to study how wildlife responds to the human-induced rapid environmental changes. The wearing of face masks, widely adopted to prevent pathogen transmission, represents a novel element in many parts of the world where wearing a face mask was rare before the COVID-19 outbreak. During September 2020–March 2021, we conducted large-scale multi-species field experiments to evaluate whether face mask-use in public places elicits a behavioural response in birds by comparing their escape and alert responses when approached by a researcher with or without a face mask in four European countries (Czech Republic, Finland, Hungary, and Poland) and Israel. We also tested whether these patterns differed between urban and rural sites. We employed Bayesian generalized linear mixed models (with phylogeny and site as random factors) controlling for a suite of covariates and found no association between the face mask-wear and flight initiation distance, alert distance, and fly-away distance, respectively, neither in urban nor in rural birds. However, we found that all three distances were strongly and consistently associated with habitat type and starting distance, with birds showing earlier escape and alert behaviour and longer distances fled when approached in rural than in urban habitats and from longer initial distances. Our results indicate that wearing face masks did not trigger observable changes in antipredator behaviour across the Western Palearctic birds, and our data did not support the role of habituation in explaining this pattern., Graphical abstract Unlabelled Image

Because the amount of urban areas has increased, it is important to investigate the abundance of wildlife species in relation to urban environments. Analyzing the impact of urbanization on the presence of forest-dwelling mammals is of interest due to the possible effects of urbanization on human-wildlife relationships and urban biodiversity. The Eurasian red squirrel ( Sciurus vulgaris ) is a declining forest species, and its occurrence in urban environments has been inadequately studied. The loss and fragmentation of forests due to urbanization may be detrimental for squirrels, whereas the abundant and predictable food resources and the low number of natural predators in urban areas may encourage squirrels to invade towns. We used large-scale data collected by volunteer bird watchers along a 950 km south-north gradient to study whether the winter abundance of squirrels in Finland is dependent on urbanization, while controlling for effects of habitat type, food abundance (spruce cone crop; number of winter feeding sites), predator abundance (northern goshawk, Accipiter gentilis ; feral cat Felis catus ), season and latitude. We found that squirrel abundance increased with human population density, number of feeding sites and spruce cone crop and decreased with latitude and season. Feral cats showed weak negative connection with squirrel numbers, but there were no effect of goshawks. Relative squirrel abundance was approximately twice as high in urban habitats than in forests. Artificial feeding rather than a low number of predators may attract squirrels in urban environments. Planting spruce trees in urban environments will also benefit squirrels. Our results indicate that urban areas are an important habitat for the red squirrel even along the northern edge of their distribution range, where natural forest areas are still widespread. We conclude also that a citizen science −based bird survey protocol associated with mammal surveys seems to be a good large-scale monitoring method to study the urbanization of squirrels.

Urbanization is an important ecological factor that modifies the living conditions of species at multiple levels. Urbanization is also influenced by human-animal relationships. We studied the effects of human-related factors on nest site selection of the Eurasian Magpie (Pica pica) by using both historical and contemporary data on the nest sites of the Magpie both at landscape and micro-habitat levels in Finland. The nest site data on the Magpie were collected by searching old nest site data as well as by collecting data from current nest sites in two Finnish towns. Our results indicate that the population densities of the Magpie have increased in both study areas during 1950–2010, and that the actual adjustment to urban conditions began around 1980. The relative nest height of Magpies has decreased in urban, but no in rural habitats. The Magpie preferred breeding sites with great green area cover and less built-up areas. Moreover, Magpies preferred ever-green coniferous trees over deciduous tree species as their nest sites. The Magpie made its nest in the upper parts of the tree canopies, regardless of the tree species. Our results support the idea that urbanization by the Magpie is related both to changes in human disturbance, and to species-specific habitat needs. Planting coniferous trees may promote the breeding of the Magpie in urban environments in northern areas. We suggest that, the Magpie, as a common and well-known species, may be a good candidate to monitor the state of the urban environment.

More and more of the globe is becoming urbanized. Thus, characterizing the distribution and abundance of species occupying different towns is critically important. The primary aim of this study was to examine the effect of urbanization and latitude on the patterns of species occupancy frequency distribution (SOFD) in urban core zones of European towns (38 towns) along a 3850-km latitudinal gradient. We determined which of the three most common distributional models (unimodal-satellite dominant, bimodal symmetrical, and bimodal asymmetrical) provides the best fit for urban bird communities using the AICc-model selection procedure. Our pooled data exhibited a unimodal-satellite SOFD pattern. This result is inconsistent with the results from previous studies that have been conducted in more natural habitats, where data have mostly exhibited a bimodal SOFD pattern. Large-sized towns exhibited a bimodal symmetric pattern, whereas smaller-sized towns followed a unimodal- -satellite dominated SOFD pattern. The difference in environmental diversity is the most plausible explanation for this observation because habitat diversity of the study plots decreased as urbanization increased. Southern towns exhibited unimodal satellite SOFD patterns, central European towns exhibited bimodal symmetric, and northern towns exhibited bimodal asymmetric SOFD patterns. One explanation for this observation is that urbanization is a more recent phenomenon in the north than in the south. Therefore, more satellite species are found in northern towns than in southern towns. We found that core species in European towns are widely distributed, and their regional population sizes are large. Our results indicated that earlier urbanized species are more common in towns than the species that have urbanized later. We concluded that both the traits of bird species and characteristics of towns modified the SOFD patterns of urban-breeding birds. In the future, it would be interesting to study how the urban history impacts SOFD patterns and if the SOFD patterns of wintering and breeding assemblages are the same.

The new corona virus infection SARS-CoV2 which was later renamed COVID-19 is a pandemic affecting public health. The fear and the constraints imposed to control the pandemic may correspondingly influence leisure activities, such as birding, which is the practice of observing birds based on visual and acoustic cues. Birders are people who carry out birding observations around the globe and contribute to the massive data collection in citizen science projects. Contrasting to earlier COVID-19 studies, which have concentrated on clinical, pathological, and virological topics, this study focused on the behavioral changes of birders. A total of 4484 questionnaire survey responses from 97 countries were received. The questionnaire had an open-ended style. About 85% of respondents reported that COVID-19 has changed their birding behavior. The most significant change in birdwatchers&rsquo, behavior was related to the geographic coverage of birding activities, which became more local. People focused mostly on yard birding. In total, 12% of respondents (n = 542 cases) reported having more time for birding, whereas 8% (n = 356 cases) reported having less time for birding. Social interactions decreased since respondents, especially older people, changed their birding behavior toward birding alone or with their spouse. Women reported more often than men that they changed to birding alone or with their spouse, and women also reported more often about canceled fieldtrips or society meetings. Respondents from higher developed countries reported that they spend currently more time for birding, especially for birding alone or with their spouse, and birding at local hotspots. Our study suggests that long lockdowns with strict regulations may severely impact on leisure activities. In addition, a temporal and spatial shift in birding due to the pandemic may influence data quality in citizen science projects. As nature-based recreation will be directed more toward nearby sites, environmental management resources and actions need to be directed to sites that are located near the users, e.g., in urban and suburban areas. The results can be applied with caution to other nature-based recreational activities.

© The Author(s) 2018., Life-history theory predicts that current behaviour affects future reproduction, implying that animals should optimise their escape strategies to reflect fitness costs and benefits of premature escape. Both costs and benefits of escape may change temporally with important consequences for the evolution of escape strategies. Moreover, escape strategies of species may differ according to their positions on slow–fast pace of life gradients. We studied risk-taking in long-distance migratory animals, waders (Charadriiformes), during the annual cycle, i.e., breeding in Europe, stopover in the Middle East and wintering in tropical Africa. Phylogenetically informed comparative analyses revealed that risk-taking (measured as flight initiation distance, FID) changed significantly over the year, being lowest during breeding and peaking at stopover sites. Similarly, relationships between risk-taking and life-history traits changed among stages of the annual cycle. While risk-taking significantly decreased with increasing body mass during breeding, risk-taking–body mass relationship became marginally significant in winter and disappeared during migration. The positive trend of risk-taking along slow–fast pace of life gradient measured as adult survival was only found during breeding. The season-dependent relationships between risk-taking and life history traits suggest that migrating animals respond to fluctuating environments by adopting behavioural plasticity., Te study was fnancially supported by project OPV ITMS26110230119 and VEGA 1/0977/16. TA and PM were supported by Czech Science Foundation project (14–36098G). This paper is a contribution by MD to the thematic network REMEDINAL3-CM (S2013/ MAE-2719).

Recent studies showed contrasting results about the homogenising force of urbanisation on bird community composition at large and regional scales. We studied whether urbanisation promotes the homogenisation of wintering bird communities and if this varies when comparing towns located within a specific region and towns located in two different biomes of two countries. We used both similarity indices based on the presence/absence data and the abundance data in comparing communities. Processes governing bird community dissimilarity between urbanisation levels were examined with the partitioning of Sörensen index in species turnover and nestedness. We made bird surveys in town centres and suburban habitats of three cities located in the Pampean region of Argentina and in the boreal region of Finland using a single-visit study plot method. Rarefacted species richness did not differ amongst the town centres between the countries, but it was higher in the suburban areas of Argentina than in Finland. At the country-level comparison, we found a higher similarity amongst the town centres than amongst the suburban areas; whereas at the regional comparison, similarity between town centres was comparable to the similarity between suburban areas. The use of an abundance-based index produced a higher similarity between town centre communities of both countries than when using a presence-based index. The dissimilarity between habitats in Argentina was related to nestedness and to species turnover in Finland. Our results indicate that urban-based biotic homogenisation of bird communities is dependent on the scale used, being more evident when comparing cities of different biomes where the same and abundant bird species, such as sparrows and doves, dominate. At the regional scale, quite a high beta-diversity can still be found within urban habitats. Processes of community dissimilarity between urban habitats may differ according to the regional pool of species, being more related to nestedness toward the tropics. Fil: Leveau, Lucas Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina Fil: Jokimäki, Jukka. University of Lapland; Finlandia Fil: Kaisanlahti Jokimäki, Marja Liisa. University of Lapland; Finlandia

Changes in the timing of reproduction of birds should provide good evidence of large-scale climate fluctuations. However, geographically separate populations of one species may respond variably. We analyzed egg laying dates of nine Eurasian populations of the Common Redstart Phoenicurus phoenicurus collected between 1969 and 2010. The timing of breeding differed greatly with latitude: the populations in the north started later, a breeding pair produced only one brood per season and the breeding season was shorter. Both yearly minimum and median first-egg laying dates advanced with increases in local air temperature, but the more northern populations had started at much lower temperatures, which was probably caused by the stimulation of photoperiod. The effects of large-scale climatic patterns (North Atlantic Oscillation, East Atlantic, Scandinavia/Eurasia-1) on the first-egg laying date were low. The egg laying dates advanced over the observed decades in all populations, although at a variable rate. Seven selected populations with the most complete data for the period 1986–2010 revealed an advancement of median first-egg laying dates of 0.11 days/year and 1.31 days/°C. The effect on minimum first-egg laying dates was smaller. The changes observed in two populations in Ural and western Siberia were smaller than those found in more westerly populations (Finland, central Europe). The timing of the start of breeding is probably less affected by climate change than the timing of spring migration, documented by European ornithological stations.

Spatial variation in wintering bird communities in different types of urban residential areas is poorly understood. The objective of tills study was to find out which bird species from the regional species pool are able to inhabit residential areas, whether bird communities in different types of residential area differ from one another, and what are the factors affecting birds. We conducted our study in five apartment-building areas, five family-house areas, and five villages in northern Finland by using the single-visit study plot method during five winters, i.e. 1998/1999–2003/2004. Oldgrowth-forest-specialist species, in particular, avoided residential areas, whereas the other species appeared to benefit from residential development. The species richness, the total number of individuals, and the abundance of most of the species were higher in the family-house areas and in villages than in apartment-building areas. The proportion of individuals belonging to resident species was higher in the apartment-b...

Aim Despite the increasing pace of urbanization, little is known about how this process affects biodiversity globally. We investigate macroecological patterns of bird assemblages in urbanized areas relative to semi-natural ecosystems. Location World-wide. Methods We use a database of quantitative bird surveys to compare key assemblage structure parameters for plots in urbanized and semi-natural ecosystems controlling for spatial autocorrelation and survey methodology. We use the term ‘urbanized’ instead of ‘urban’ ecosystems as many of the plots were not located in the centre of towns but in remnant habitat patches within conurbations. Results Some macroecological relationships were conserved in urbanized landscapes. Species–area, species–abundance and species–biomass relationships did not differ significantly between urbanized and non-urbanized environments. However, there were differences in the relationships between productivity and assemblage structure. In forests, species richness increased with productivity; in both forests and open habitats, the evenness of species abundances declined as productivity increased. Among urbanized plots, instead, both species richness and the evenness of species abundances were independent of variation in productivity. Main conclusions Remnant habitats within urbanized areas are subject to many ecological alterations, yet key macroecological patterns differ remarkably little in urbanized versus non-urbanized plots. Our results support the need for increased conservation activities in urbanized landscapes, particularly given the additional benefits of local experiences of biodiversity for the human population. With increasing urbanization world-wide, broad-scale efforts are needed to understand and manage the effects of this driver of change on biodiversity.

The main objective of this study was to analyze between-winter stability of bird communities along latitudinal (950 km) and urban gradients (from small village to towns) in Finland. Birds were surveyed at the same 30-ha study plots using the same methods in 31 villages and town centres in the winters of 1991–1992 and 1999–2000. Species richness did not differ between the 2 study winters, but variation in total abundance of birds increased with increasing urbanization. However, urbanization reduced variation in wintering bird community structure. Species richness, density of wintering birds, and dissimilarity of wintering bird communities did not vary with latitude. According to our results, the level of urbanization was a more important factor than latitude in explaining the structure of the bird community in winter. We assume that the presence of a continuous, rich, and diverse supply of food offered by humans with increasing urbanization may explain variation in species abundances and stabilit...

Brood parasitism selects for defensive mechanisms that enhance host fitness. Therefore, host populations under different parasitism pressures may express different levels of defense against brood parasites. We tested the rejection responses of currently parasitized and unparasitized Common Redstart (Phoenicurus phoenicurus) populations in Finland to artificial Common Cuckoo (Cuculus canorus) eggs. We predicted a higher level of defense in the parasitized population, but in fact the rejection rate was higher in the nonparasitized population. Nonmimetic artificial eggs were rejected more often than mimetic ones. Desertion probability was higher in the nonparasitized population and was independent of artificial egg type. Common Redstarts in the parasitized population rejected the artificial eggs mostly through ejection, whereas desertion was a more frequent rejection method in the nonparasitized population. Our results suggest that current selection pressures from brood parasites do not always explain the current levels of defense. Respuestas de Poblaciones Parasitadas y No Parasitadas de Phoenicurus phoenicurus Contra el Parasitismo Artificial de Cuculus canorus

Urban areas have been considered ‘‘safe zones’’ for nesting birds because of low abundance of predators, and consequently low predation pressure. We studied risk of artificial ground nest predation across an urban gradient at regional (100� /100 km) and local scales (5� /5 km, within town) in Finland, Italy, and Spain. Risk of nest predation differed between countries, being greatest in Spain (66%), intermediate in Finland (51%), and lowest in Italy (29%). At the regional scale, risk of nest predation in Finland was lower in small villages and in forest area than in more urbanized sites. In Spain, the risk of nest predation was lower in villages than in the other habitat types. No differences in nest predation risk among habitat types were observed in Italy. At the local level, the risk of nest predation in Finland was higher within the town than in the surrounding forest. In Spain, the risk of nest predation in the surrounding forest area was as high as in the most urbanized areas. No difference in nest predation risk was observed between study plots in Italy at the local level analysis. Our results indicate that nest predation in town centers and their residential areas is similar to or higher than in villages and forest areas refuting the safe nesting zone hypothesis. Risk of nest predation also differed between residential area types within towns. Moreover, the abundance of potential nest predators differed between countries. Magpies and crows were more abundant in Finland than in Italy and Spain, whereas cats, dogs and pedestrians were less abundant in Finland than in the other countries. In Finland, risk of nest predation increased with the abundance of magpies. In Italy and Spain, risk of nest predation increased with the number of pedestrians and in Italy also with the number of cats. In all countries, the risk of nest predation increased with the visibility of the nest. According to our results, urban areas cannot be seen as ‘‘safe nesting zones’’. Actually, changes in nest predation pressure may cause changes in habitat selection patterns and affect bird community structure in urban environments.

Aim Human land use, especially urbanization, might homogenize the world's biota. The objective of this study is to find out if urbanization homogenizes wintering bird communities, and if habitat type affects the spatial variation of urban bird communities across spatial scales. Location We compared the quantitative similarity of winter bird communities between town centres, apartment block areas and single-family house areas across regional and local scales in five towns in northern Finland. Methods The wintering birds were surveyed using a single-visit study plot (30 ha) method in January and February 2001. The validity of single-visit and single-year data was confirmed by using data from several-visit surveys and multi-year data set. The level of urbanization was measured according to the number of inhabitants and general structure of the habitat. Results Temporal variability in species richness and total number of individuals was low, both between winters and within winter. Bird community similarity between different habitat types within a single town was about the same as that in similar habitats in different towns. At the regional scale, bird community similarity between town centres (30%) was lower than between areas of apartment blocks (54%) or between areas of single-family houses (54%). We detected a threshold point between towns of 35,000 and 105,000 inhabitants and between town sizes of 5.0-8.5 km in diameter where human impact causes marked changes in bird community structure. At the local scale, bird community similarity level between apartment block areas (49%) and single-family house areas (62%) were about the same. Passer domesticus, Parus major and Pica pica dominated the bird communities in residential areas. Different habitat factors affected bird species abundances on the local and regional scales. Conclusions Urbanization cannot be seen as a process that monotonically increases the similarity of bird communities. Our results indicate that the similarity between urban bird communities is dependent on the size of the town, location of the study site within the town and especially the local habitat structure. Because different habitat factors affected bird species abundances, it is difficult to extrapolate bird-habitat relationships derived from one scale to other scales. In wintertime, single-family house areas are important biodiversity hotspots in cities. Therefore, it is especially important to understand the factors affecting the occurrence of birds in the single-family house area in order to maintain or even increase diversity on winter birds in other urban habitats.

International audience; We studied the homogenisation effects of urbanisation on avifauna in towns of three countries selected along a latitudinal gradient: Italy, France and Finland. In each town (n = 19), numbers of species were analysed along an urbanisation gradient using two urban sectors (centre and suburban) and one non-urban sector (periurban), representing the regional species pool. Firstly, we compared the avifauna by using species richness and similarity indexes along the urban gradient (S) and latitudinal gradient (L). In Europe, the number of exotic bird species in towns was low. The number of species decreased from the periurban and suburban sectors to the centre sector. Thus, the generally low number of species and few dominant birds indicate that urban bird communities are structurally simple. In addition, many habitat specialists were lacking from urban centres. The centre species represented about 43% of periurban species (similarity S). There was no correlation between town size and species trend in sectors. However, bird community similarity L was lower between town centres than between periurban areas. Latitude explained 89% of the species difference in periurban sector but only 52% in the centre, supporting the homogenisation effect of urbanisation. Secondly, we examined the homogenisation effect through the variability of some specific life-history traits (diets, nest heights, feeding habitats) by using data on Passeriformes. Our results suggested that urbanisation might cause homogenisation by decreasing the abundance of ground nesting bird species and bird species preferring bush-shrub habitats. Urbanisation appeared a cause of taxonomic homogenisation of the avifauna but the effects of latitude and urban habitat diversity may make generalisation difficult. (c) 2005 Elsevier Ltd. All rights reserved.

Aim Urbanization can lead to uniformity in urban bird communities, and the general biogeographical patterns found in natural communities may not be found in urban ones. Thus, it is important to know if urbanization might be seen as contributing to a general pattern that modifies the biogeographical processes of wildlife communities. Location We studied differences in suburban bird assemblages in France and Finland. Birds in each town included in the study were surveyed using 30 ha suburban study plots located within single-family housing area and apartment block area. Methods The wintering birds were surveyed using a single-visit study plot method in January and February 1999. The level of urbanization was measured according to the general structure of the habitat by using the town maps and field notes. In addition, we counted active winter feeding stations during bird surveys. Results The average number of species was higher in France than in Finland, both in single-family house areas and in apartment block areas. The most abundant bird species occurred in most of the study sites. The urbanization level affected bird community composition more in northern Finland than in France. In Finland, the number of wintering species and their total biomass were higher in single-house areas than in more urbanized areas. The total density and biomass of birds were higher in France than in Finland in areas of apartment blocks, but not in the areas of single-houses. Urbanization level affected the total bird density only in France, being higher in areas of apartment blocks. In Finland, the total biomass of birds was higher in the single-family house areas than in the areas of apartment blocks. Most of the bird species were more abundant in France than in Finland. The habitat factors associated with the bird community variables in France and in Finland differed from one another. Feeding tables increased the species richness and the abundance of birds in Finland. Conclusions The species decrease between France and Finland was mainly because of the large proportion of species in France that are migratory in northern Finland. The abundance of urban birds did not necessarily decrease northwards. Intensive winter feeding in northern latitudes may help birds to overcome natural range limitations. Our results differed from results obtained when studying town centres and they highlight the complexity of the urbanization process across a geographical gradient.