Bird Community Structure Research Articles

Bird community structure as a function of habitat heterogeneity: A case of Mardi Himal, Central Nepal

Abstract. Pandey N, Khanal L, Chapagain N, Singh KD, Bhattarai BP, Chalise MK. 2021. Bird community structure as a function of habitat heterogeneity: A case of Mardi Himal, Central Nepal. Biodiversitas 22: 262-271. Community structure of birds at different habitat types is underexplored in the montane environment of the central Himalaya. Therefore, this study explored bird community structure in different habitat types in Mardi Himal of the Annapurna Conservation Area, central Nepal, and tested association of different feeding guilds with the habitats. Data on the avian richness and abundance were collected in the winter and the summer of 2019 by point count method along the elevational gradient in every 100 m rise and analyzed using ordination methods. A total of 673 individuals of 112 bird species from 35 families under 13 orders were recorded. Among the observed orders and families, the order Passeriformes (77 species) and family Muscicapidae (16 species) were the most dominant. A linear species accumulation curve was obtained in both seasons. Species richness and abundance were found higher at forest edges of mid-elevations and insectivores were the most abundant birds. Frugivorous and carnivorous birds showed no specific association with habitat types, whereas, insectivores and omnivores were more abundant in pastureland and forest, respectively. Our results revealed that the community composition of birds varies with the habitat types and their feeding specialization is one of the major determinants.

Comparative Analysis of the Gut Microbial Communities of the Eurasian Kestrel (Falco tinnunculus) at Different Developmental Stages.

The gut microflora play a very important role in the life of animals. Although an increasing number of studies have investigated the gut microbiota of birds in recent years, there is a lack of research work on the gut microbiota of wild birds, especially carnivorous raptors, which are thought to be pathogen vectors. There are also a lack of studies focused on the dynamics of the gut microbiota during development in raptors. In this study, 16S rRNA gene amplicon high-throughput sequencing was used to analyze the gut microbiota community composition of a medium-sized raptor, the Eurasian Kestrel (Falco tinnunculus), and to reveal stage-specific signatures in the gut microbiota of nestlings during the pre-fledging period. Moreover, differences in the gut microbiota between adults and nestlings in the same habitat were explored. The results indicated that the Eurasian Kestrel hosts a diverse assemblage of gut microbiota. Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes were the primary phyla shared within the guts of adults and chicks. However, adults harbored higher abundances of Proteobacteria while nestlings exhibited higher abundances of Firmicutes and Actinobacteria, and consequently the majority of dominant genera observed in chicks differed from those in adults. Although no significant differences in diversity were observed across the age groups during nestling ontogeny, chicks from all growth stages harbored richer and more diverse bacterial communities than adults. In contrast, the differences in gut microbial communities between adults and younger nestlings were more pronounced. The gut microbes of the nestlings in the last growth stage were converged with those of the adults. This study provides basic reference data for investigations of the gut microbiota community structure of wild birds and deepens our understanding of the dynamics of the gut microflora during raptor development.

Seasonal fluctuations of urban birds and their responses to immigration: An example from Macau, China

Understanding interactions between resident and non-resident birds in urban areas is important for managing urban greenspace to protect urban bird diversity. Here, we determined how interactions between resident and non-resident species potentially affect bird diversity in the urban green species of Macau (subtropical area of China). We examined seasonal fluctuations in the habitat use and structuring of an avian community, along with potential drivers. We recorded habitat use relative to land-use/landcover configurations, focal habitat characteristics, and disturbance data in 13 semi-isolated urban parks to identify factors driving competition. We used line-transects to count individual birds and species, and analyzed the data using ANOVA, linear regression, and variance partitioning analysis. Species richness, the abundance of non-residents, and the population size of various resident feeding guilds noticeably fluctuated across seasons within the year. These phenomena were attributed to birds migrating through Macau during spring and fall, which drove structural changes to resident bird populations. Resident and non-resident insectivore and insectivore-frugivore populations responded positively to shrub cover in spring, and to proximity to large waterbodies in fall. However, while both resident insectivores and insectivore-frugivores utilized high quality habitat during summer (non-migratory season), when interspecific competition was low, these two groups competed for available habitat during the migratory seasons. Thus, resident and non-resident bird guilds appear to compete for optimal habitat in Macau during the migratory seasons. In particular, residents appeared to avoid direct competition with migrants, potentially associated with the trade-off between fitness costs and shifting patches. Our results provide new insights on the seasonal fluctuations in the community structure of urban birds and potential driving factors. By understanding how the importance of certain habitats changes with changing community dynamics, the management of urban green spaces could be guided to ensure certain habitat types are more available.

Do vegetal communities dominated by invasive exotic plant species affect the structure of bird communities in an Atlantic Forest area?

Do vegetal communities dominated by invasive exotic plant species affect the structure of bird communities in an Atlantic Forest area?

Landscape heterogeneity shapes bird phylogenetic responses at forest–matrix interfaces in Atlantic Forest, Brazil

AbstractAgricultural intensification is one of the major factors driving biodiversity loss. However, most studies in human‐dominated landscapes have used taxonomic diversity in their analysis, ignoring evolutionary relationships. Consequently, the relationship between landscape structure and phylogenetic diversity is not well understood. Here, we tested the hypothesis that landscape heterogeneity is positively related to bird phylogenetic indexes of diversity and structure, leading to over‐dispersed phylogenies in very heterogeneous landscapes. We analyzed phylogenetic responses in interfaces between forest edges and anthropogenic matrices (forest–pasture and forest–eucalyptus) using generalized linear mixed models. We also compared these indexes between land covers to assess which one best preserves the phylogenetic history of communities. We used both traditional phylogenetic indexes and those corrected for species richness. Our results showed that phylogenetic diversity varied significantly between land cover types, but this did not occur when we removed effects associated with species richness, suggesting that all land covers preserve similar levels of evolutionary history. Additionally, our best models showed a positive relationship between landscape heterogeneity and bird phylogenetic indexes of diversity and structure, but the strength of these relationships may be land cover dependent. In summary, our work highlights the influence of landscape heterogeneity on the phylogenetic diversity and structure of bird communities, reinforcing the need for its incorporation into conservation‐based studies.Abstract in Portuguese is available with online material

Bird community structure of small islands: a case study on the Pahawang Island, Lampung Province, Indonesia

Small islands are extremely vulnerable to ecosystem disturbances. One of the common factors im-pacting on island ecosystems is the rise of tourism activity and the associated conversion of man-grove forest’s function into tourism’s supporting facility. Those changes will ultimately affect the diversity of bird species inhabiting the island.  Therefore, this study aimed to analyse the structure of a bird community in the mangrove forests of the Pahawang Island. The study used the transect method with tracking implemented. The obtained data were analysed using the Shannon-Wienner diversity index. We recorded 28 species from 21 families. Out of 21 families, Columbidae had the highest number of species (three species). Seven feeding guilds were observed during the present study, the maximum number of species belonged to the insectivore group and the minimum – to the nectarivore and omnivore (1 species each) guilds. Based on the abundance rank, the most abundant species was the cave swiftlet (Collochalia linchi). Three of the recorded species are listed in the cat-egory “Protected” according to the Indonesia Law: the brahminy kite (Haliastur indus), sunda pied fantail (Rhipidura javanica), and the black-naped tern (Sterna sumatrana). All bird species that have been recorded during the present study is classified as “Least Concern” in the IUCN Red List. The values of the Shannon-Wienner index suggest neither high nor low diversity (H’ = 2.55). Mangrove forest ecosystems, including the mudflat on the Pahawang Island, are important supporting popula-tions of wild birds through providing foraging, roosting and nesting sites. 

The Composition of Gut Microbiota Community Structure of Jankowski's Bunting (Emberiza jankowskii).

Gut microbiota play a central role in the health of animals. The bacteria that individuals acquire as they age may therefore have a profound effect on their future fitness. Since most birds are capable of flight, they can be widely distributed in and adapted to various ecosystems. Moreover, birds are also challenged by the need to digest a wide range of food resources in their guts. However, little is known regarding how the microbial community structure in birds, especially wild birds, changes with host age. Here, we used high-throughput sequencing of the 16S rRNA V3-V4 region to depict the microbial composition and structure in the adults and nestlings of Jankowski's bunting (Emberiza jankowskii), an endangered species of bird, during the breeding season. The results showed that the phyla Proteobacteria (52.45%), Firmicutes (13.87%), Bacteroidetes (5.76%), Actinobacteria (4.95%), Planctomycetes (4.36%), Euryarchaeota (3.20%), Acidobacteria (2.59%), Fusobacteria (2.24%), and Chloroflexi (1.8%) dominated the gut microbial communities in Jankowski's bunting. There was no significant difference in the alpha diversity and richness among different age groups. There was also no significant difference in species richness and diversity between the nestlings and adults. However, we observed different bacterial compositions at the genus level. The genera Photobacterium and Brochothrix were detected only in the nestling groups (at days 3, 6, and 9), while Diplorickettsia was detected only in the adult group. In summary, this study can provide additional information regarding the intestinal microorganisms of wild passerine and grassland birds and provide theoretical evidence for methods to protect Jankowski's bunting.

BIRD COMMUNITY STRUCTURE IN MACROHABITATS OF THE AQUATICTERRESTRIAL TRANSITION ZONE IN THE PANTANAL WETLAND, BRAZIL

Ecological responses of bird communities in aquatic-terrestrial transition zones (ATTZs) are only partially understood. The aim of this study was to evaluate community structure of birds in different macrohabitats of ATTZs from a protected area in the Pantanal wetland, Brazil. The survey of birds was carried out in three types of macrohabitats: Erythrina fusca Lour. monospecific forest, shrubland and pioneer polyespecific forest, and flooded grassland. The bird community living within the ATTZ varied according to macrohabitat type and period of the wetland landscape. We emphasise the need to expand this protected area, and exert greater environmental control, since the region is not exempt from direct and indirect impacts derived from the Upper Paraguay River Basin.

Diversity and structure of bird communities in contrasting forests of the Hengduan Mountains, China

Rapid economic development has led to high rates of deforestation and widespread alteration of land cover in many regions in China, where many primary forests have been replaced by secondary and plantation forests. Therefore, we aimed to determine differences in bird community diversity and structure between three forest types. We assessed differences in species richness, phylogenetic and functional diversity and community structure of bird communities in primary, secondary and plantation forests. Data was collected over four meteorological seasons from bird communities in a nature reserve in the Hengduan Mountains, China. We found that functional and phylogenetic diversity in secondary forest were significantly greater than in primary forest, while species richness was not significantly different. Thus, simple metrics (i.e. species richness) may not be sufficient to assess forest conservation value. We suggest that it is necessary to use varied diversity metrics that incorporate species’ similarities and differences. It also appears that secondary forests play an important role in the maintenance of studied bird biodiversity. The results of community structure analyses show that the habitat filter was strongest in the primary forest, leading to primary forest species being lighter in weight, shorter in body length, and with longer tarsometatarsus. These species were specialized and forest-dependent, reflecting the value of primary forests as an irreplaceable habitat type for several species after nearby forests are degraded.

Abundance and community structure of birds breeding in Kalahari woodland used as rangeland

The line transect method was applied to assess the linear index of abundance and community structure of birds breeding in an area of Kalahari woodland used as range land for cattle. Four transects were designed along roads traversing the ranch. Each transect was 2.5 km long and was surveyed three times in 2014 and 2015. A total of 47 bird species were recorded but only 25-31 species were recorded on any particular transect. In the neighbouring pristine Kalahari woodland, the number of bird species on a12 km long transect was much higher (n = 88), and ranged in some sections (each 1.2 km in length) from 35 to 53. On any particular section, the number of dominant species ranged from 5 to 7, and their cumulative dominance on each section was similar, ranging from 53-56 %, while the community dominance index ranged from 0.23 to 0.35. The most numerous species were the Cape turtle dove and emerald-spotted wood dove, which were dominant on all sections. Together they comprised 28 % of all breeding birds. The avian community in the Kalahari woodland in Sachinga LDC did not differ from the neighbouring pristine woodland either in terms of species diversity or evenness. However, it differed significantly in terms of species richness, the proportion of main ecological guilds, and linear index of abundance of particular species. These differences could be mainly due to the structure of woody vegetation, which is much thicker in Sachinga than in the pristine woodland not used as pasture for cattle. The thickening of this vegetation on the ranch could have been caused by heavy grazing pressure by the cattle. Data published through GBIF (Doi: https://doi.org/10.15470/rova7r)

Composition and Diversity of Over-Wintering Aquatic Bird Community on Poyang Lake, China

The present study aimed to investigate the structure, composition and diversity of the over-wintering aquatic bird community of Poyang Lake, including Poyang Lake National Nature Reserve (PNNR), Nanji National Nature Reserve (NNNR) and Duchang Provincial Nature Reserve (DPNR), China. After the preliminary survey, birds surveyed from vantage points at each study site between the years 2016 and 2020 in the winter season. A total of 58 bird species belonging to nine orders and 13 families were observed. The study showed variation in effective species numbers (Species richness, Shannon’s diversity and Simpson’s diversity) among the three study sites and the survey years. Nanji National Nature Reserve had the highest avian diversity, whereas Duchang Provincial Nature Reserve had the lowest. Globally threatened bird species, Siberian Crane (critically endangered), Oriental Stork (endangered), found in our study sites. However, the current management practices of the nature reserve and conservation of this globally threatened bird species are inadequate, especially of Duchang Provincial Nature Reserve. Therefore, for long term conservation of birds in these areas, it needs continuing intentional improvement of the sites and awareness creation to the local community.

Yearly variation in the structure and diversity of a non-breeding passerine bird community in a Mediterranean wetland

BackgroundThe dynamics and structure of many bird communities are changing due to the global warming and changes in the land use and management. The Ebro Valley constitutes one of the chief wintering areas for several passerine species in Iberia, and the reed beds spread across this Valley concentrate huge numbers of birds that use them to roost, while the surrounding agricultural areas serve as main foraging habitats. The aims of this work are (1) to quantify how variable a non-breeding passerine bird community associated to a reed bed area in the Ebro Valley is, and, (2) to test for the effect of weather on possible annual fluctuations in species’ proportions at a regional/local scale.MethodsWe used for that ringing data collected at Badina de Escudera lagoon (Navarra) over a 12-year period.ResultsThough, overall, the assemblage did not vary strongly among years (most similarity values were > 0.8), we still found a significant linear effect of year on the proportion of captures of Reed Buntings (Emberiza schoeniclus), i.e., the dominant species detected in our passerine community. The increasing loss of weight of Reed Buntings in the community was due to a progressive decrease in its abundance.ConclusionsThe structure and diversity of passerine community in Badina Escudera was not influenced by meteorological conditions at a local scale, suggesting that local weather would not have an impact on numbers of Reed Buntings in winter.

Bird diversity along a riparian corridor in a moderate urban landscape

Civilization built around rivers directly affects riparian corridor structure and ecology. Degradation, pollution, and deterioration along riparian corridors in urban landscapes change species composition and biodiversity. Birds are one of the most vulnerable taxa to ecological changes. The main objective of our study was to spatially compare bird species richness, abundance, and community structure along the Asar River, an urban riparian corridor in Düzce, Turkey. We identified 63 bird species, comprising 6722 individuals, and classified them into one of three groups: generalist species (11 species), woodland species (40 species), and waterbird species (12 species). Bird species richness was positively related to vegetative cover and negatively to urbanization. Richness was low in the winter and was higher during spring and summer. Riparian Quality Index (RQI) scores (mean = 54.8 ± 33.7; max. = 97 and min. = 5) were relatively low for all sampling plots and was reduced by human activities (e.g., roads, farmland, settlement). The number of woodland bird species changed positively (r = 0.71) with RQI. The generalist bird species, adapted to urbanization, were more common around settlements and open areas. Human population and settlement around Asar River increased one-third and farmland and natural habitat decreased one-fifth during the last decade. The area has high potential for growth and increased urbanization, thus increasing the pressure on the natural areas. Activities that diminish the amount of tree cover in the riparian corridor should be avoided. Habitat restoration and rehabilitation will increase RQI values, which can be used as indicators for bird richness in urban landscapes and benefit avian diversity along the riparian corridor. The existing riparian corridor and any enhancements to the corridor will help conserve Düzce’s biodiversity in the future.

The effects of agricultural landscape composition and heterogeneity on bird diversity and community structure in the Chengdu Plain, China

Farmland is one of the most important ecosystems in the world, providing foods and habitats for humans as well as many wild animals. However, biodiversity in farmlands has been substantially impacted by the intensification of agriculture and changes in landscape. Increasing either the area of natural and semi-natural habitat or the proportion of biodiversity-friendly crops could potentially mitigate the decline of biodiversity, but at the same time they would affect the agricultural economic output and were not widely applied. To date, some studies have focused on whether crops or cropland heterogeneity has a positive impact on biodiversity, but the results were inconsistent and it is difficult to summarize the relationship between farmland heterogeneity and farmland biodiversity in general. Meanwhile, few papers have studied the differences in bird diversity among small-scale agriculture in China. We conducted a year-long field survey on the Chengdu Plain to explore the relationships of landscape composition and the heterogeneity of cropland and non-cropland with bird diversity and community structure across different seasons. Using generalized linear models (GLM) and generalized least squares (GLS) for data analysis, our results showed that bird diversity is positively correlated with natural woodlands but negatively correlated with commercial forests. Both crop and non-crop landscape compositional heterogeneity affect bird diversity and community structure, especially during the non-breeding season, as many high-altitude birds come down to the farmland for foraging. Both bird diversity and community structure are influenced by cropland configurational heterogeneity, but seldomly influenced by non-cropland configurational heterogeneity. We propose to maintain the area of natural habitat and increase the area of mixed commercial forests by replacing monocultures. Diversified crop and non-crop types with a reasonable layout could conserve farmland biodiversity and maintain the stability of local ecosystems. More research on landscape heterogeneity in small-scale agriculture is needed to provide better understanding of the relationship between the agricultural landscape and bird diversity.

Eggshell and environmental bacteria contribute to the intestinal microbiota of growing chickens

BackgroundThe initial intestinal microbiota acquired from different sources has profound impacts on animal health and productivity. In modern poultry production practices, the source(s) of the establishing microbes and their overall contribution during development of gastrointestinal tract communities are still unclear. Using fertilized eggs from two independent sources, we assessed the impact of eggshell- and environmental-associated microbial communities on the successional processes and bacterial community structure throughout the intestinal tract of chickens for up to 6 weeks post-hatch.ResultsCulturing and sequencing techniques identified a viable, highly diverse population of anaerobic bacteria on the eggshell. The jejunal, ileal, and cecal microbial communities for the egg-only, environment-only, and conventionally raised birds generally displayed similar successional patterns characterized by increasing community richness and evenness over time, with strains of Enterococcus, Romboutsia, and unclassified Lachnospiraceae abundant for all three input groups in both trials. Bacterial community structures differed significantly based on trial and microbiota input with the exception of the egg-exposed and conventional birds in the jejunum at week 1 and the ileum at week 6. Cecal community structures were different based on trial and microbiota input source, and cecal short-chain fatty acid profiles at week 6 highlighted functional differences as well.ConclusionWe identified distinct intestinal microbial communities and differing cecal short-chain fatty acid profiles between birds exposed to the microbiota associated with either the eggshell or environment, and those of conventionally hatched birds. Our data suggest the eggshell plays an appreciable role in the development of the chicken intestinal microbiota, especially in the jejunum and ileum where the community structure of the eggshell-only birds was similar to the structure of conventionally hatched birds. Our data identify a complex interplay between the eggshell and environmental microbiota during establishment and succession within the chicken gut. Further studies should explore the ability of eggshell- and environment-derived microbes to shape the dynamics of succession and how these communities can be targeted through interventions to promote gut health and mitigate food-borne pathogen colonization in poultry.

Structure of the breeding bird community along the urban gradient in a town on the Zambezi River, north-eastern Namibia

A simplified mapping method was employed to quantify avian assemblages in three study plots in a modified riparian forest on the Zambezi River in the town of Katima Mulilo, NE Namibia. The plots were arranged along the urbanization gradient: plot A (34 ha; 0–1 km from centre of the town), plot B (27 ha; 1–2 km from the centre), and plot C (24 ha; 2–3 km from the centre; periphery). In total, 51 breeding bird species were recorded in all three plots. Five of them, Columba livia domestica, Passer diffusus, Pycnonotus tricolor, Streptopelia senegalensis, and Uraeginthus angolensis were classified as dominant species. The cumulative dominance was 69.9%. The overall population density of all breeding species increased with the urban gradient. In general, granivorous birds were by far the most numerous feeding guild comprising 68.7% of all breeding birds. Two other guilds, frugivorous and insectivorous birds, together comprised 28.9%. While the proportion of granivores decreased along the urban gradient from the town centre to its periphery, the proportion of insectivores increased. The proportion of birds nesting in/on buildings decreased, and the share of tree/shrub- and hole-nesting birds increased along the urban gradient. The diversity indices were relatively high in all plots. They decreased only slightly along the urban gradient (from the centre to the periphery). However, the Pielou’s Evenness Index was comparatively low, but on a slight increase along the urbanization gradient. The Sorensen Similarity Index was low, but the values of the three studied plots were very similar.

Changes in bird species composition after a wind farm installation: A case study in South America

Facing the growing demand for renewable energy sources, the use of wind energy has been significantly increasing worldwide. Wind farms are known to present low environmental impact and their impact on bird fauna has been the most studied and discussed. In this study, we evaluated the composition of bird communities and changes in land use during three phases of wind farm development: pre-construction, construction and operation. Secondary data was obtained on bird communities, provided by the wildlife monitoring report submitted to the state environment agency of Rio Grande do Sul, Brazil. The total number of species recorded for all phases of wind farm construction was 163 species. One hundred species were present during all phases, and 20 were recorded during at least two phases, 32 species were exclusive to the pre-construction phase, four species were recorded only during the construction phase and seven recorded during the operation phase. The evaluation of bird community structure revealed that the pre-construction phase differed from the 4 years of operation, indicating that an impact on bird species' composition is evident, but more detailed and longer surveys are needed to confirm this trend. The bird community responded to landscape changes, mainly due to the reduction of native and exotic forest cover, in areas affected by wind farms installation and operation, in both, species' composition and environmental guilds. Analysis of secondary data allows us to evaluate which changes may have resulted from the implantation of the wind energy industry to the regional bird fauna, and our findings demonstrates tha the changes associated with the construction and operation of this wind farm have negatively affected the bird community.

Untangling the imprints of climate, geography and land use/cover on bird diversity in the South American Gran Chaco

AbstractAimTo evaluate the structure of bird communities throughout the South American Gran Chaco determining the effects of climate, geography and land use/land cover in bird beta diversity, as well as to understand the beta diversity processes underlying land use changes across broad spatial ranges.LocationSouth American Gran Chaco.TaxonBirds.MethodsWe constructed a site‐by‐species matrix with occurrence probabilities of 293 bird species across 2,669 spatial units tiling completely the study area. Based on this matrix, we calculated pairwise dissimilarities scores and performed a hierarchical cluster analysis for describing the spatial configuration of dissimilarities. The clustering result was spatially represented through an original venation map with boundaries between sites widened in the function of their distance in the dendrogram. We used the Generalized Dissimilarity Modelling approach to model beta diversity, using geographic distance, climatic and land use/land cover information as predictors. We mapped beta diversity patterns using colour theory and the HSV colour model.ResultsWe identified two main clusters of sites across the Gran Chaco, which represent environmentally different sites and harbour very distinct assemblages of species. These main groups are separated by two natural delimiters: The Bermejo‐Pilcomayo interfluvium and the Lower Paraná floodplain. Overall, we observed that the percentage of cropland and climatic variables were important shapers of bird beta diversity.Main conclusionsWe provide the first area‐wide assessment of land use/land cover effects on bird beta diversity for the Gran Chaco. The distribution of croplands has a marked influence on bird beta diversity at regional scale highlighting the role of anthropic changes in reshaping bird beta diversity within the ecoregion. Taking into account the global increasing conversion of forests into croplands, a growing footprint of land use changes over geographical patterns of bird diversity in forest biomes can be anticipated.

The effectiveness of point counts and mist-netting in surveying Afrotemperate forest bird community structure in South Africa

ABSTRACT Point counts and mist-netting are two frequently employed survey techniques used in assessing forest avian communities, although the reliability of these methods varies according to species composition and habitat. This study investigates how effectively these two methods survey forest bird community structures within South African Afrotemperate forests. Seven forests within the Eastern Cape were surveyed from 140 duplicate point count and 63 mist-netting stations. Both methods were compared for assessing species richness, as determined from bird atlas data. Generalised linear mixed-effect modelling was used to determine functional traits which most impacted species detection, and to identify detection biases for both methods. Both methods compared consistently across the seven forests, which shared similar community structure. Point counts detected 79.2% of the total diversity versus 41.0% using mist-netting, and mixed-effects modelling corroborated that species detection is more effective using point counts. All functional traits tested (body size, primary foraging stratum, feeding guild, habitat specialisation, and dispersal behaviour) affected detection outcome. Point counts better represented all aspects forest bird community structure, including mid- and understorey birds which are presumed to be better detected by mist-netting. Use of mist-netting only slightly enhanced diversity assessments, and combined survey efforts under-represented forest-edge foragers, woodland and grassland habitat generalists (~63.6% total diversity), large birds, Palaearctic migrants, and carnivores.

Species structure of the bird communities of the middle Uzh river flow in Zakarpattia province of Ukraine in the nesting period

The article analyzes characteristics of the species structure of the bird communities in the middle Uzh river valley in the breeding period by the ratio of the number of species and their abundance, the shares of dominant, background and rare species, the types of nesting and feeding, landscape and ornitho-geographic aspects. The main factors for the formation of the species diversity and the peculiarities of the species structure of bird communities have been identified.The goal of the study was to investigate and analyze the species structure of bird communities to determine the intensity of the urbanization impact onto the natural ecosystems in this segment of the Uzh valley.Material and Methods. Data were collected during the 2016-2018 years during nesting periods. The bird censuses were conducted by the route method, followed by processing of the collected data.Results and discussion. Within the study period, 71 bird species have been identified here. The bird population density is 839.64 ind./km2. Birds of forest landscapes (47.9%) are dominant. Tree-nesting (in crowns, hollows, and shrubs) birds composed in total 60.6%. The share of zoophagous birds is 57.7%. By the fauna type, trans-Palearctic species are dominant: 42.3%.By the fauna type, transpalearctic species are dominant (42.3). The urbanization of the Uzh valley is evidenced by the presence of a group of synanthropic bird species, which are inseparably linked to rural settlements, located along the river (share of all species - 12.7%, share of total bird population - 17.15%).Conclusions. The species structure of birds communities during the nesting season in the middle Uzh river flow evidences that the impact of urbanization on natural ecosystems of the river valley is low despite the close location of villages