Bird Survey Research Articles

Space-for-time substitutions exaggerate urban bird-habitat ecological relationships.

North American bird abundance has declined by 29% over the last 50 years. These continental population dynamics interact with local landscape changes to affect local bird diversity. Mitigating local declines in cities is particularly significant because (a) such declines greatly impact human-bird relationships since most people live in cities and (b) cities provide levers to create bird-friendly habitat, such as managing yards and gardens, street trees, and urban parks. Yet, the potential for cities to modify habitats to mitigate broader bird declines remains unclear. Studies have been stymied by the difficulty of assembling mutidecadal habitat-bird population datasets. Instead, studies have substituted space for time (e.g. used habitat associations across space at one time point to project future species abundance due to changing land use), but this method may fail amidst nonstationary environments of the Anthropocene. Here, we test the validity of space-for-time substitutions for explaining changes in bird abundance in a North American city over the past two decades by examining the degree to which these changes are explainable by changes in local landcover at multiple spatial scales. Specifically, we use longitudinal urban bird surveys of Metro Vancouver, BC, Canada from 1997 and 2020; deep learning models of remote sensing data to classify contemporaneous landcover; out-of-sample prediction and boosted regression trees to identify multiple spatial scales of landcover that best explained bird abundance (i.e. optimal scale of effect for each species by each habitat); and Bayesian multispecies abundance models in Stan to determine relationships between changes in landcover and bird abundance. We found that total bird abundance declined by 26% over the last two decades. Landcover measured at both 50 m and optimal scales explained spatial variation in bird abundance, but only landcover at the optimal scale explained temporal changes, and only partially. These results suggest that space-for-time substitutions overemphasize habitat-bird ecological relationships, urban habitats only partially determine bird abundance, and measuring habitat at the appropriate scale is important for capturing the most relevant changes in landscapes.

Acoustic detection rate can outperform traditional survey approaches in estimating relative densities of breeding waders

Passive acoustic devices are increasingly being used to monitor biodiversity. However, few studies have compared the accuracy of acoustic surveys and traditional surveys against ground‐truthed data. Here, we assess whether acoustic recorders used in conjunction with an artificial intelligence (AI) classifier can predict the relative breeding density of four wader species better than traditional fieldworker transect surveys. In a 27‐km2 upland study site, acoustic data were collected at 83 sampling points and analysed using the BirdNet bird‐sound classifier to estimate vocal detection rate at each location; we also carried out concurrent transect bird surveys. To ground‐truth these approaches, intensive field surveys were undertaken to identify each breeding territory of our focal species. With both the acoustic dataset and the transect dataset, we used similar analytical approaches (random forest regression trees) to predict relative territory density across the study site, and then compared these predictions with the territory density obtained from the intensive field surveys. The classifier performed well at identifying the presence of target species' vocalizations within 3‐s periods for Lapwing (accuracy = 0.911), Curlew (0.826) and Oystercatcher (0.841), but less well for Golden Plover (0.699). For Curlew and Oystercatcher, the predictions obtained from the acoustic approach were a better fit to actual territory density than the transect approach. In contrast, for Lapwing and Golden Plover, the transect predictions outperformed the acoustic predictions, with the acoustic model particularly poor for Golden Plover. We attributed these differences to the performance of the classifier, species' ecology and vocal behaviour. Data gathering for the acoustic approach was more time‐efficient than the transect surveys, requiring less than a quarter of the fieldworker days. We conclude that there is high potential for acoustic approaches to augment traditional methods, although species' ecological characteristics should be considered: species that vocalize more frequently, at higher amplitudes and hold larger territories will be better‐suited to sampling‐based acoustic methods.

Large invasive herbaceous plants decrease the taxonomic, functional and phylogenetic diversity of birds via their reproductive traits

Abstract Birds are among the organisms most impacted by plant invasions, the effects of which are particularly conspicuous during the breeding season. Birds can incorrectly assess the suitability of large, invasive hogweeds Heracleum sp. in south‐eastern Poland when selecting nesting sites early in spring when the developing invaders do not yet differ substantially in form from the rest of the vegetation. One would expect lower bird breeding success in areas with invasive hogweeds. Furthermore, this may shift bird community composition towards species with filtered traits, which may then be reflected in various measures of diversity. To assess these expectations, we conducted bird surveys at 74 sites, arranged as 37 pairs (with invasive Heracleum vs. control). The presence of Heracleum was associated with lower bird taxonomic and phylogenetic diversity. Functional richness (calculated based on species' reproductive traits) was also lower at sites with these invaders. The species detected at Heracleum sites were characterised by traits associated with rapid breeding, for example, small clutches, short incubation periods and short fledging periods. We show that the bird community at sites with hogweeds became less diverse and composed of random species sharing similar reproductive traits. Bird communities with low diversity at Heracleum sites tended to exhibit a common trait syndrome. These patterns provide insights into the mechanisms of how invasive plants may lead to the loss of some traits and species in bird communities. Read the free Plain Language Summary for this article on the Journal blog.

Retrospective comparison of the distribution and abundance of breeding Prairie Warbler (<i>Setophaga discolor</i>) along eastern Georgian Bay, Ontario, Canada

Species inhabiting rare habitats or unique geographic regions may be underrepresented in standard surveys. More intensive, periodic surveys may be required to improve data quality, especially for species of conservation concern. Prairie Warbler (Setophaga discolor) has experienced range-wide declines of >50% in recent decades and is a species of conservation concern in Canada. The largest continually occupied breeding population of this species in Canada occurs along the shoreline of eastern Georgian Bay, Ontario, where annual Breeding Bird Survey and eBird coverage is generally poor. In 2015, we replicated a spatially intensive 1997 survey of this species along the eastern shore of Georgian Bay, visiting the same sites and using comparable methods. We detected more male birds at the survey sites in 2015 (estimated >350 breeding pairs) than in 1997 (estimated 265 breeding pairs). We also surveyed sites farther north than those covered in 1997, but the breeding range appears not to have moved substantially northward. We also conducted additional surveys and canoe transects in the core range in southern Georgian Bay to ensure that breeding birds were not being missed. Combining data from all our surveys in 2015, we estimated a total of 427 singing males in eastern Georgian Bay. Although overall numbers here appear to have increased in recent decades, localized declines in some areas warrant further investigation. The population appears to be stable or increasing in this region, but we recommend intensively re-surveying this population on at least a 20-year basis.

MobVGG: Ensemble technique for birds and drones prediction

Detection of aerial activities, including drones and birds, has practical implications for automating bird surveys and developing radar systems for aerial object collision detection. Convolutional neural networks (CNNs) have been extensively utilized for image recognition and classification tasks, albeit prior research predominantly focuses on single-class 'drone' classification. However, a gap persists in achieving high accuracy for multi-class classification. To address the limitations of traditional CNNs, such as vanishing gradients and the necessity for numerous layers, this study introduces a novel model termed "MobVGG.” This model combines the architectures of MobileNetV2 and VGG16 to accurately classify images as either 'bird' or 'drone'. The dataset comprises 4212 images for each category of 'bird' and 'drone'. The stringent methodology was applied for dataset preparation and model training to ensure the reliability of the findings. Comparative analysis with previous research demonstrates that the proposed MobVGG model, trained on both 'bird' and 'drone' images, achieves superior accuracy (96 %) compared to benchmark studies. Our paper targets researchers and graduate students as its primary audience.

Avian diversity across guilds in North America versus vegetation structure as measured by the Global Ecosystem Dynamics Investigation (GEDI)

Avian diversity, a key indicator of ecosystem health, is closely related to canopy structure. Most avian diversity models are based on either optical remote sensing or airborne lidar data, but the latter is limited to small study areas. The launch of the Global Ecosystem Dynamics Investigation (GEDI) instrument in 2018 has opened new avenues for exploring the influence of vegetation structure on avian diversity. To examine how direct measurements of canopy structural characteristics explain bird diversity across North America, we analyzed 18 GEDI metrics from 2019 to 2022, along with corresponding Breeding Bird Survey (BBS) counts and AVONET morphological data, analyzing effects across broad regions and at varying spatial extents. We grouped 440 bird species into 20 ecological guilds under six guild categories and employed random forest algorithms to model avian diversity across eight spatial extents (1, 2, 3, 4, 5, 10, 20, and 39.2 km). The models predicted six diversity indices, including species richness (sRich), functional richness (fRich), evenness (fEve), dispersion (fDis), divergence (fDiv), and redundancy (fRed) across eight spatial extents. The best-predicted guilds varied for each diversity index. The most accurate models were sRich (pseudo-R2 = 0.71, RMSE = 4.28) and fRed (pseudo-R2 = 0.60, RMSE = 0.13) for forest specialists guilds; fRich (pseudo-R2 = 0.55, RMSE = 0.18) for urban guilds; fEve (pseudo-R2 = 0.28, RMSE = 0.08) for insectivore guilds; and fDiv (pseudo-R2 = 0.38, RMSE = 0.12) and fDis (pseudo-R2 = 0.53, RMSE = 0.87) for short distance migrants guilds. Our results highlight the critical role of canopy structure, including its horizontal and vertical distribution and variation, in predicting avian diversity, as measured by the mean number of detected modes (num_detectedmodes), the standard deviation of foliage height diversity (FHD), num_detectedmodes, canopy cover, and plant area index (PAI) across the spatial extents centered on BBS routes. Therefore, we recommend incorporating the GEDI metrics into avian diversity modeling and mapping across North America, thereby potentially enhancing bird habitat management and conservation efforts.

Slower but deeper community change: Intrinsic dynamics regulate anthropogenic impacts on species temporal turnover.

Understanding the mechanisms behind biodiversity dynamics is central to assessing and forecasting anthropogenic impacts on ecological communities. However, the manner in which external environmental drivers act in concert with intrinsic ecological processes to influence local temporal turnover is currently largely unexplored. Here, we determine how human impacts affect multiple metrics of bird community turnover to establish the ecological mechanisms behind compositional change. We used US Breeding Bird Survey data to calculate transect-level rates of three measures of temporal species turnover: (1) "short-term" (initial rate of decline of Sørensen similarity), (2) "long-term" (asymptotic Sørensen similarity), and (3) "throughput" (overall species accumulation rate from species-time relationship exponents) over 2692 transects across 27 regional habitat types. We then hierarchically fit linear models to estimate the effect of anthropogenic impact on these turnover metrics, using the Human Modification Index proxy, while accounting for observed species richness, the size of the species pool, and annual environmental variability. We found broadly consistent impacts of increased anthropogenic pressures across diverse habitat types. The Human Modification Index was associated with greater turnover at long timescales, but marginally slower short-term turnover. The species "throughput" (accumulation rate) was not notably influenced. Examining anthropogenic impacts on different aspects of species turnover in combination allows greater ecological insight. Observed human impacts on short-term turnover were the opposite of existing expectations and suggest humans are disrupting the background turnover of these systems, rather than simply driving rapid directed turnover. The increased long-term turnover without concurrent increases in species accumulation implies human impacts lead to shifts in species occurrence frequency rather than simply greater arrival of "new" species. These results highlight the role of intrinsic dynamics and caution against simple interpretations of increased species turnover as reflections of environmental change.

Biodiversity conservation and restoration of wetlands in suburban areas: challenges and prospects

Context Wetland loss threatens global biodiversity. Peri-urban wetlands face acute pressures from urban expansion. Aims Investigate biodiversity and land-cover changes in two wetlands undergoing suburbanisation near Hangzhou, China. Methods Seasonal field surveys of birds, fish and amphibians, coupled with remote-sensing analysis of land-cover changes from 2009 to 2020. Key results Suburban wetlands exhibited unique degradation patterns, including reduced species diversity, simplified community structures and proliferation of invasive species, with 91 bird species being recorded, dominated by common residents, 25 still-water fish species with few carnivores and migratory species, and 5 ubiquitous amphibian species detected. Species richness was lower than in nearby conserved wetlands. From 2009 to 2020, 6–7% of the wetlands were lost to urban expansion and converted to artificial vegetation or infrastructure. Conclusions Ecological degradation is driven by rapid urbanisation, with habitats being fragmented by roads and converted to artificial land covers. Water pollution from insufficient treatment and abandoned aquaculture further impairs habitats. Implications Innovative integrated-management framework was proposed for wetlands biodiversity restoration in suburban area. Key strategies include (1) modernising traditional circular economies to sustain wise use, (2) wildlife-friendly infrastructure design, (3) targeted invasive species control, and (4) adaptive co-management informed by ongoing monitoring. This socio-ecological systems approach aims to harmonise biodiversity conservation, cultural heritage and sustainable development in threatened suburban wetlands.

Towards automated detection of the endangered southern black-throated finch (Poephila cincta cincta)

Context Biodiversity is declining worldwide, with many species decreasing in both number and range. Acoustic monitoring is rapidly becoming a common survey method in the ecologist’s toolkit that may aid in the conservation of endangered species, but effective analysis of long-duration audio recordings is still challenging. Aims The aims of this study were to: (1) develop and test call recognisers for the endangered southern black-throated finch (Poephila cincta cincta) as well as the similar sounding, but non-endangered, double-barred finch (Taeniopygia bichenovii); and (2) compare the ability of these recognisers to detect these species with that of on-ground bird surveys at under-surveyed locations in the Desert Uplands bioregion which is at the edge of the known range of the black-throated finch. Methods A range of convolutional neural network call recognition models were built and tested for both target species, before being deployed over new audio recordings collected at 25 sites during 2020, 2021 and 2022, and compared with the results of on-ground bird surveys at those same sites. Key results Call recognisers for both species performed well on test datasets from locations in the same area as the training data with an average area under the precision-recall curve (PRAUC) of 0.82 for black-throated finch and 0.87 for double-barred finch. On-ground bird surveys in the Desert Uplands bioregion detected black-throated finches at two locations in different years, and our call recognisers confirmed this with minimal post-validation of detections. Similar agreement between methods were obtained for the double-barred finch, with site occupancy in the Desert Uplands bioregion confirmed with audio recognition in all nine surveys with on-ground detections, as well as during four additional surveys that had no on-ground detections. Conclusions Using call recognisers to survey new locations for black-throated finch presence was equally successful as on-ground surveys, and with further refinements, such as retraining models with examples of commonly misclassified vocalisations added to the training data, minimal validation should be required to detect site presence. Implications Acoustic monitoring should be considered as a valuable tool to be used alongside manual surveys to allow effective monitoring and conservation of this endangered species.

The Erosion of Seasonality in Avian Communities

ABSTRACTAimSeasonality governs species composition at a given place and time. However, the effects of climate and land‐use change can vary by season, altering species composition. These changes can lead to a loss of distinct seasonal community composition, representing a novel form of biotic homogenisation. We ask if breeding and winter bird communities are becoming more similar over time. If so, is homogenisation occurring more rapidly in winter than in the breeding season, and has the presence of individual species changed between seasons?LocationNortheastern United States.Time Period1989–2019.Major Taxa StudiedTwo hundred thirty‐eight bird species.MethodsWe use data from The National Audubon Society's Christmas Bird Count and the North American Breeding Bird Survey to test if winter and breeding bird communities have become more similar (homogenised). We evaluate this change using the Sørensen dissimilarity index, and its components of turnover (species replacement) and nestedness (a subset of a more species rich community) and describe the mechanism in which the seasonal winter and breeding bird communities are changing.ResultsWe found that winter and breeding bird communities are homogenising, driven by significant decrease in turnover and a marginal decrease nestedness. When viewing breeding and wintering communities separately, we observe different trends. Breeding communities are becoming more unique with decreasing turnover and nestedness. Winter communities are becoming more similar to each other, with decreasing turnover and nestedness. More breeding species are declining and species that are typically found in the winter and year‐round residents are the main contributors to the homogenisation between seasons.Main ConclusionsWe show for the first time homogenisation between winter and breeding bird communities over time across the northeastern United States. This insight into how individual species are faring between seasons, and how they impact community structure, can be used when implementing conservation measures for maintaining ecological functioning and integrity.

Field validation of effects of species and flock size on echoes in avian radar surveys

Radar is a powerful technology for surveys of avian movements. Validating the accuracy of radar detection is essential when establishing quantitative criteria for tracking bird trajectories and counting bird flocks. This study clarifies the positional and biological factors influencing the probability of detection (POD) and echo size on X-band marine radar. The bird trajectory for validation was obtained by ornithodolite at the same time as the radar scan. Distance was found to have a negative effect on POD and echo size, while elevation angle positively affected POD. Body mass and flock size positively affected POD and echo size. In predicting detection performance, the survey distance required to achieve 50% POD was 750 m or less for Grey-faced Buzzard, the lightest target species, but up to 1800 m for a pair of Bewick’s Swan. Our study provides survey and analysis procedures that allow for efficient validation using ornithodolites. Then, we identify the range settings that should be considered for target species and contribute to establishing criteria for quantitative radar bird surveys.

Birds as sacred ‘children of god’, beholders of spirit and symbols of twinhood: Human–bird interaction among the Nuer in western Ethiopia

Abstract The deep connection between Indigenous communities and nature plays a pivotal role in biodiversity conservation. Ethiopia, one of Africa's priority countries for bird conservation, harbours 821 bird species and 83 ethnic groups of Indigenous people. However, cultural and spiritual ties between Indigenous peoples and bird species remain largely unexplored. This is particularly true for remote Indigenous communities such as the Nuer. Relying on preexisting bird survey data, we conducted focussed group discussions and semi‐structured interviews with Indigenous Nuer in western Ethiopia to explore human–bird interactions and documented associated traditional ecological knowledge and considered their conservation implications. We found that Nuers have strong ties with birds. In Nuer community, birds are collectively known by three interchangeable terms: ‘gaatkuoth’ to mean sacred children of god, ‘kuoth’ meaning bearers of spirit and ‘diit’ symbols of human twins (since birds nurture multiple offspring, they associate the incidence of twins in human with birds). We identified 71 culturally important bird species that were used in seven different use categories. Among these species, 10 were used as bushmeat, five for traditional medicine, eight as fish indicators, seven as omens (believed to indicate upcoming misfortunes), three as amulets (believed to protect against danger when bird's body parts are used as necklaces and bracelets), three as season indicators and 45 for their scenic beauty. An informant consensus factor for species in all use categories was >90%, except for the scenic value, indicating a high homogeneity of knowledge about species uses. Bird species with multiple uses have significant cultural values among locals, emphasizing the need to understand these values in conservation efforts. Nuer traditional systems regulate the direct use of birds including for bushmeat. Hunting is permitted only by impoverished households during severe food shortages and is prohibited for those with a history of twins in their ancestry. The Nuer people exhibit a profound cultural connection to birds, viewing them as sacred and spiritually valuable beings. This deep‐seated reverence and traditional knowledge highlight the importance of integrating Indigenous perspectives into bird conservation strategies to enhance their effectiveness and respect cultural values. Read the free Plain Language Summary for this article on the Journal blog.

The dual lens of diversity: Seasonal variability of avian community structure in urban hills

Urbanization has significantly increased the environmental intricacy of low mountainous and hilly urban landscapes, exacerbating the need for biodiversity conservation in these ecosystems. This study involved comprehensive bird surveys across four seasons from July 2022 to April 2023 along 64 transects in the low mountainous terrain of Jiangsu Province. Adopting a dual lens of taxonomic and functional dimensions, our research explored seasonal fluctuations and assembly mechanisms governing avian community diversity (both α and β) on these urban hills. The results showed that species richness and functional diversity (FD) were higher in spring and lower in autumn, whereas functional mean pairwise distance (MFD) and mean nearest functional distance (FD.MNTD) were higher in summer and winter. Although the standardized effect sizes for MFD were not significantly different from zero in any of the four periods, those for FD.MNTD were significantly less than zero in summer, autumn, and winter, indicating a propensity for functional trait clustering within avian communities during these seasons. Taxonomic variations were found to be chiefly governed by species turnover, whereas functional dynamics were principally shaped by nestedness. A marked disparity emerged, with functional β-diversity and its turnover components consistently registering lower values than their taxonomic counterparts, accompanied by a higher level of functional nestedness versus taxonomic nestedness. This study underscores the intricate seasonal dynamics of avian communities in urbanized low mountainous regions and provides crucial insights to devise conservation strategies aimed at preserving avian biodiversity within these ecologically complex urban landscapes.

Informative priors can account for location uncertainty in stop-level analyses of the North American Breeding Bird Survey (BBS), allowing fine-scale ecological analyses

Informative priors can account for location uncertainty in stop-level analyses of the North American Breeding Bird Survey (BBS), allowing fine-scale ecological analyses

Bird metacommunities of urban parks in the pampean region, Argentina

Metacommunities are the set of local communities that are linked by the dispersion of potentially interacting species. The study of metacommunities is important to elucidate the relationship between processes that occur at different spatial scales. However, bird metacommunities in urban parks have been little studied. The objectives of this study were: 1) to analyze the relative role of species dispersal, environmental selection, and stochastic processes shaping urban bird metacommunities; and 2) to analyze the structure of the metacommunities of birds in urban parks. Bird surveys were made in 51 parks of six cities in Buenos Aires province, Argentina. To obtain the metacommunity structure, three elements were analyzed: coherence, turnover, and boundary clumping. We found that the metacommunity conforms to a clementsian structure, in which groups of species respond in a similar way to environmental gradients. The environmental and connectivity variables explained a greater proportion of the variance than the spatial variable. The composition of species was related to the location of the cities, the distance to the rural area, the distance to the urban center, the number of cars passing near parks, and habitat diversity. Due to the clementsian structure of metacommunities, they probably were structured under a species sorting and mass effect process. The number of cars and habitat diversity in the parks would be acting as environmental filters for bird species, while the distance to rural areas and the distance to the urban center would affect species dispersal to the parks. These findings emphasize the importance of maintaining and improving park connectivity and habitat diversity for bird species, managing them as cities grow.

Quantifying species biases among multidata sources on illegal wildlife trade and its implications for conservation.

Unsustainable wildlife consumption and illegal wildlife trade (IWT) threaten biodiversity worldwide. Although publicly accessible data sets are increasingly used to generate insights into IWT, little is known about their potential bias. We compared three typical and temporally corresponding data sets (4204 court verdicts, 926 seizure news reports, and 219 bird market surveys) on traded birds native to China and evaluated their possible species biases. Specifically, we evaluated bias and completeness of sampling for species richness, phylogeny, conservation status, spatial distribution, and life-history characteristics among the three data sets when determining patterns of illegal trade. Court verdicts contained the largest species richness. In bird market surveys and seizure news reports, phylogenetic clustering was greater than that in court verdicts, where songbird species (i.e., Passeriformes) were detected in higher proportions in market surveys. The seizure news data set contained the highest proportion of species of high conservation priority but the lowest species coverage. Across the country, all data sets consistently reported relatively high species richness in south and southwest regions, but markets revealed a northern geographic bias. The species composition in court verdicts and markets also exhibited distinct geographical patterns. There was significant ecological trait bias when we modeled whether a bird species is traded in the market. Our regression model suggested that species with small body masses, large geographical ranges, and a preference for anthropogenic habitats and those that are not nationally protected were more likely to be traded illegally. The species biases we found emphasize the need to know the constraints of each data set so that they can optimally inform strategies to combat IWT.

Diversity and Conservation of Wetland Avifauna in Nanjarayan Lake, Tiruppur, Tamil Nadu, India

This paper shares the results from a big bird survey at Nanjarayan Lake in Tamil Nadu. It ran from 2022 to 2024. To check out the bird variety, see how it changes with the seasons and look at how well different bird species are doing there. Over three years, we did lots of field surveys during different times of the year. We used methods like point counts, transect walks, and habitat checks. In total, we found 184 bird species resident birds that live there all year and migrating ones that visit. We even spotted some species that need special attention. This shows how important the lake is for both local birds and those just flying between. When we looked closely at the numbers through the seasons, we found some big changes in how many birds there were. Winter was especially busy, with a lot of different kinds showing up and the migratory birds arriving. The study also identified key threats to avian biodiversity in the lake, such as habitat degradation, water pollution, and human disturbances. Based on these findings, the study recommends urgent conservation measures, including habitat restoration, pollution control, and the implementation of strict regulations to minimize human impact. This survey underscores the importance of Nanjarayan Lake as a vital bird habitat and calls for enhanced conservation efforts to protect its rich avian diversity. The findings provide valuable baseline data for future ecological studies and contribute to the broader understanding of lake ecosystems in Tamil Nadu.

Bird richness at Sítio do Sol in Cabreúva, State of São Paulo, Brazil

The Atlantic Forest biome has suffered great devastation but still possesses a vast biological and endemic richness, making its preservation essential. The Atlantic Forest fragments located in the interior of the state of São Paulo have not been studied as much as other areas, mainly in the municipality of Cabreúva. Therefore, this study aimed to characterize the bird richness of the Sítio do Sol property, in Cabreúva, São Paulo. The study was carried out from August 2021 to September 2022, covering seasonality. The findings revealed that 193 species were registered, distributed among 52 families, and 23 orders, with a predominance of the Passeriformes order and the Tyrannidae family. The most observed trophic guild among species was insectivorous, accounting for 78 (41%) species, followed by omnivorous with 59 (31%) species, carnivorous 18 (9%), frugivorous 16 (8%), granivorous 12 (6%), nectarivorous 8 (4%), and detritivorous species 2 (1%), with lower richness. This study is one of the few bird surveys carried out in the municipality of Cabreúva and indicates that even in small forest fragments, there is a considerable species richness. Developing more fauna surveys and management plans for the species present in the area is important to preserve these birds.

Bayesian integrated species distribution models for hierarchical resource selection by a soaring bird

Migratory birds exhibit seasonal geographic range (hereafter, range) dynamics during the annual cycle. Few studies have examined how migratory birds select their habitats for range occupancy at the species level and space use at the individual level simultaneously. We hypothesized that environmental variables directly related to fitness components would affect the range occupancy probabilities of migrants, whereas environment variables related to movements and flights would affect the space use intensities of migrants. We built Bayesian integrated species distribution models (ISDMs) to evaluate the effects of climate conditions, wind conditions, and landcover compositions on the seasonal range dynamics of American white pelicans Pelecanus erythrorhynchos (hereafter, pelican) during summer and winter. The ISDMs estimated the summer range occupancy probabilities of pelicans with Breeding Bird Survey data, winter range occupancy probabilities with Christmas Bird Count data, and summer and winter space-use intensity rates with eBird data jointly. We evaluated the predictive performance of ISDMs using independent datasets of pelican GPS locations. Integrated species distribution models outperformed the occupancy-only models in the predictive performance of occupancy probabilities. Climate conditions had opposite effects on the range occupancy probabilities between the breeding and non-breeding grounds, whereas landcovers had relatively consistent effects on range occupancy probabilities between the seasons.

New records of birds from Central Vietnam.

There has been a series of bird surveys conducted in Vietnam over the last 20 years. However, most of these studies and surveys have focused on sites in Tonkin, the Red River Delta, Cochinchina (Mekong Delta), the Central Highlands and mountainous areas of Central Annam (Central region of Vietnam). The central coastal plain as well as the mountainous region of North Annam have rarely been comprehensively investigated. As a result of our field surveys in 2023 and 2024, a total of 15 species of birds are recorded for the first time from North, Central and South Annam, comprising one Frigate-Bird species (Fregatidae), one ibis (Threskiornithidae), one reed-warbler (Acrocephalidae), one Treecreeper (Certhiidae), two buntings (Emberizidae), one chat (Muscicapidae), one yuhina (Zosteropidae), two nuthatches (Sittidae), two members of the laughingthrush family (Leiothrichidae) and three bulbuls (Pycnonotidae). In addition to photographs confirming the new records, we provide information on the distribution and conservation status of these newly-recorded bird species from Central Vietnam.