Bird Survey Research Articles

Assessing Threats to Fazao-Malfakassa National Park, Togo, Using Birds as Indicators of Biodiversity Conservation

Protected areas are crucial for the conservation of West Africa’s increasingly imperiled wildlife, but are under unprecedented pressure associated with exponential human population growth in the region. Using birds as biodiversity indicators, we investigated the conservation status of Togo’s Fazao-Malfakassa National Park, which was managed by a private foundation from 1990 to 2015, and since 2015 has been managed by the state. Between 2022 and 2024, we conducted 90 days of bird surveys in the park and documented a total of 240 bird species. Our findings include 34 species new to the park, including the first record of Emin’s Shrike (Lanius gubernator) in Togo, the first sightings of the Great Blue Turaco (Corythaeola cristata) since 1990, and first observations of the Abyssinian Ground-Hornbill (Bucorvus abyssinicus) since 2019. Many such species survive in Togo only in Fazao-Malfakassa National Park, but its exceptional biodiversity has come under increasing assault from illegal activities, including poaching, logging, road construction, charcoal production, cattle grazing, and land clearance to establish agricultural plantations. We were unable to document 91 bird species previously reported for the park during our surveys, suggesting a possible ~31% decline in avian species richness in the park compared to historical records. Apparent extirpations of globally-threatened raptors such as the Critically Endangered White-backed Vulture (Gyps africanus) and Hooded Vulture (Necrosyrtes monachus), and declines of the Endangered Bateleur (Terathopius ecaudatus) and Martial Eagle (Polemaetus bellicosus) further indicate that current conservation strategies are failing to adequately protect wildlife in the park. Togo’s two other historical national parks have already been almost entirely destroyed by human activities, and unless urgent conservation action is taken, there is a high risk that Fazao-Malfakassa National Park will share the same fate. We urgently recommend improving support for law enforcement capacity and park staff, conducting community conservation outreach, and ongoing monitoring of wildlife in the park to assess its conservation success.

Assessing foodborne pathogen survival in bird faeces to co‐manage farms for bird conservation, production, and food safety

Abstract Because birds can carry foodborne pathogens, widespread concern exists that birds impose food‐safety risks to farms. Growers are thus often encouraged to deter birds and forego harvesting crops near bird faeces (e.g., no‐harvest buffers). Developing a holistic understanding of the pathogen spillover process—from individual infection to pathogen persistence on crops—is essential to understand and manage food‐safety risks associated with birds. Here, we coupled field and greenhouse experiments to understand the relative risks associated with different bird species on California farms. We first compared E. coli survival in bird faeces on lettuce, soil, and plastic mulch to identify where pathogens are likely to persist. Next, we quantified pathogen survival in faeces from 10 bird species to identify higher‐risk species. Finally, we combined pathogen survival data with bird surveys and faecal transects to assess food‐safety risks across 29 California lettuce farms. E. coli abundance rapidly declined in bird faeces, but rates varied across substrates. E. coli survival was higher on lettuce compared to soil and plastic mulch, likely because of lettuce's cooler and wetter microclimate. E. coli persistence was also much higher in faeces from larger birds—which produce larger faeces—than small songbirds. Importantly, minimal differences in persistence among species were observed after all faeces were standardized to the same mass. Though bird faeces were common on farms, most birds entering farms, contacting crops, and defecating on crops were small songbirds that defecate small faeces. Coupled with our finding that ~90% of faeces were deposited on soil, these results suggest that most birds on farms present relatively low food‐safety risks. Synthesis and applications. Growers are often encouraged to deter all bird species and forego harvesting crops near all bird faeces, but our work suggests not all birds and faeces pose the same food‐safety risks. If growers ignored small bird faeces on soil, then we estimate that the area of California lettuce farms affected by no‐harvest buffers could decrease from ~10.3% to ~2.7%. More broadly, our results suggest farmers could promote small, insect‐eating birds by erecting nest boxes or preserving habitat without necessarily compromising food safety.

North American avian species that migrate in flocks show greater long-term non-breeding range shift rates.

Many species are exhibiting range shifts associated with anthropogenic change. For migratory species, colonisation of new areas can require novel migratory programmes that facilitate navigation between independently-shifting seasonal ranges. Therefore, in some cases range-shifts may be limited by the capacity for novel migratory programmes to be transferred between generations, which can be genetically and socially mediated. Here we used 50years of North American Breeding Bird Survey and Audubon Christmas Bird Count data to test the prediction that breeding and/or non-breeding range-shifts are more prevalent among flocking migrants, which possess a capacity for rapid social transmission of novel migration routes. Across 122 North American bird species, social migration was a significant positive predictor for the magnitude of non-breeding centre of abundance (COA) shift within our study region (conterminous United States and Southern Canada). Across a subset of 81 species where age-structured flocking was determined, migrating in mixed-age flocks produced the greatest shifts and solo migrants the lowest. Flocking was not a significant predictor of breeding COA shifts, which were better explained by absolute population trends and migration distance. Our results suggest that social grouping may play an important role in facilitating non-breeding distributional responses to climate change in migratory species. We highlight the need to gain a better understanding of migratory programme inheritance, and how this influences spatiotemporal population dynamics under environmental change.

The Effect of Lockdown During the Covid-19 Pandemic on Bird Species Richness at IPB Dramaga Campus

IPB Dramaga Campus in Bogor has been recognized to hold a high diversity of birds, while at the same time is also experiencing disturbance due to human activities. During the covid-19 pandemic in 2020-early 2022, most human activities on campus were decreased. Observations made during lockdown indicated that birds were seen more easily in various habitats on campus. The objective of this study was to describe bird species richness and composition before the period of lockdown and after the pandemic (post-lockdown). Bird surveys were conducted monthly in 2019 and from January to May 2023 to obtain a bird species list. Mist nets were set up monthly for 3 months in 2019 and 2023 to obtain demographic data. Descriptive analysis was conducted by comparing the results with previous data collected by Uni Konservasi Fauna (UKF) and Cikabayan Bird Banding Club (CBC). The number of bird species between the two periods did not differ significantly; there were 66 species in while in 2023 there were 60 species. In both periods bird species composition was dominated by the family of Cuculidae, and the dominant feeding guild was insectivores.

Enhancement of feasibility and opportunities of ecotourism development around Jagdishpur Reservoir, Nepal

The study on Jagdishpur Reservoir, Nepal's largest artificial lake and a key wetland, evaluates its potential as a sustainable ecotourism destination.Situated near the Lumbini World Heritage Site, the reservoir is rich in biodiversity, especially its avian population, with a Simpson diversity index of 0.73519, indicating high species diversity. In addition to bird watching, the area offers scenic lake views, cultural homestays, and proximity to significant historical and cultural sites, including Sagarhawa, Tilaurakot, and the Araurakot Asoka Pillar, enhancing its tourism appeal. Data collection included bird surveys, household and visitor questionnaires, interviews, and mapping tools. Both locals and visitors strongly support ecotourism development, seeing it as a means to improve livelihoods and foster community development. Bird watching emerged as the most preferred activity, followed by lake-related attractions and scenic beauty. Despite its potential, challenges such as inadequate tourism infrastructure, poor marketing, and limited guest management skills among locals pose barriers to growth. The study recommends capacity-building workshops, improved infrastructure, and collaboration with commercial stakeholders to enhance promotion and marketing. These efforts could transform Jagdishpur Reservoir into a sustainable ecotourism hub that benefits local communities and supports conservation initiatives.

Bird Utilisation of Vertical Space in Urban Environments

In an increasingly urbanised world, it is important to understand how species interact with human-modified landscapes across all spatial dimensions. Urban areas, modified for higher density living, are characterised by buildings, airborne vehicles, and other uses of the airspace. These obstructions can alter the available vertical habitat space and hence impact species that rely on the vertical partitioning of resources. Nonetheless, studies in urban areas typically use 2D variables, which are unsuitable as proxies for 3D processes. To address this gap, bird surveys were conducted across three different types of urban environments that reflect a gradient of extensive to intensive within Brisbane, Australia. Bird activity was recorded across a range of heights. While exceptions occurred, we found that urban birds generally interacted with their environment at heights that reflected the taller structures along the urban gradient. Grouping species by urban tolerance (i.e., whether an urban avoider, adapter, or exploiter) and foraging level helped explain why some species could utilise certain height profiles across the urban structural gradient where others could not. A better understanding of how birds use urban vertical spaces can help identify habitat features that facilitate urban biodiversity and support conservation management in urban environments.

The Breeding Bird Survey of the United Kingdom

ABSTRACTMotivationInformation on species' population trends is essential to assess species' conservation status, make informed environmental decisions and ultimately reduce biodiversity loss. Robust population trends require a long‐term monitoring programme, often using citizen scientists, that ideally generates representative and unbiased data from the study area. Here we present the dataset of the Breeding Bird Survey, the main scheme for monitoring the population changes of common and widespread breeding birds in the United Kingdom, which achieves this through a randomised sampling scheme and defined field methodology. We also describe the modelling approach used to calculate the population trends, which are the main output of the survey.Main Types of Variable ContainedThe main published dataset contains 7,070,577 records detailing counts of 217 bird species in 7010 grid cells over 30 years. Data for 78 species that are currently regarded as too sensitive to be released at fine resolution are omitted. As an illustration of the main use of this dataset, we provide population change estimates for 119 bird species.Spatial Location and GrainGrid squares (1 × 1 km) are randomly selected using a stratified sampling scheme throughout the United Kingdom, Isle of Man and Channel Islands. Data in a grid square are collected along two 1‐km‐long transects which are subdivided into 200‐m‐long sections.Time Period and GrainData have been collected every year since 1994, with two major disruptions in 2001 and 2020, when people's movements were nationally restricted. Grid squares are surveyed twice a year during the main breeding season (April to June). Here we present the data collected from 1994 to 2023.Major Taxa Studied and Level of MeasurementBird species.Software FormatData are supplied as comma‐separated text files.

Exploring the driving factors of bird diversity in mangrove natural protected areas in Guangdong Province, China

IntroductionUnder the impacts of high intensity human activities, mangrove natural protected areas are pivotal strategies for biodiversity conservation and play a significant role in preserving bird diversity. Mangrove natural protected areas in Guangdong Province, China, lie along the migratory path of the East Asian-Australasian Flyway, serving as breeding, feeding, and resting grounds for birds. Variations in bird responses to environmental factors are significant.MethodsTo comprehensively understand these variances, redundancy analysis was employed, focusing on bird diversity surveys conducted from March 2022 to February 2023 in natural protected areas of Guangdong to examine how driving factors such as mangrove habitat landscape, community structure, water quality, and soil sedimentation affected the diversity of avian species.ResultsThe findings were as follows: (1) A total of 193 bird species spanning 17 orders and 53 families were documented, including 74 songbirds, 60 wading birds, 27 swimming birds, 17 climbing birds, 10 raptors, and 5 terrestrial birds. (2) Regarding the impact of simple effects on all bird species, aquaculture pond area, mangrove extent, and mudflat area emerged as significant factors driving bird diversity, with explanatory rates of 31.0%, 28.9%, and 20.3%, respectively. Notably, the aquaculture pond area was the main driver of bird diversity, with an explanatory rate of 31.0%. (3) Mangrove extent has emerged as a pivotal factor shaping the songbird diversity, climbing birds, raptors, and terrestrial birds, whereas the aquaculture pond area was pivotal for wading birds, swimming birds, and others.DiscussionTo enhance mangrove bird diversity protection, management agencies overseeing natural mangrove protected areas should adopt science-based approaches when managing mangrove, mudflats, and aquaculture pond areas in mangrove forest protection and restoration plans. This would prevent extensive mangrove planting, which encroaches on non-mangrove habitats. Additionally, the scientific management of aquaculture ponds should accommodate diverse bird habitats through measures, such as water level adjustments.

Protected Areas Do Not Outweigh the Species Richness or Functional Diversity and Traits of Birds in Brazil

Protected areas (PAs) are widely recognized as being essential for maintaining global biodiversity. In this study, I aimed to determine whether PAs support a greater richness of forest bird species than unprotected habitats and whether they exhibit functional diversity indices and traits comparable to those found in protected forests in the eastern Brazilian Semideciduous Atlantic Forest. I conducted bird surveys across 20 forest fragments of varying sizes (43 to 37,000 ha), 12 of which were legally designated as PAs. The results indicated that species richness was not significantly higher in PAs and that there were no significant differences in functional diversity indices and traits between unprotected and protected forests. In eastern Brazil, some forest remnants were designated as PAs merely because they were among the last remaining patches within a heavily fragmented landscape. Therefore, protected areas do not necessarily serve as accurate proxies for well-preserved habitats.

Avian assemblages pattern along forest-tea plantation gradients in the north bank landscape of Eastern Himalaya, Assam, India

Abstract The study explores the patterns of avian communities along forest-tea plantation gradients in the north bank landscape of Eastern Himalayas, India, focusing on the Udalguri district of Assam. The present study aims to identify the impact of transitioning from undisturbed forest to tea plantations on bird diversity and composition. Bird surveys were conducted from August 2022 to June 2023 using point count methods at 16 sampling stations. The results revealed that forests exhibited higher species diversity and functional richness than tea plantations, which showed higher functional evenness and divergence. Additionally, forest edges supported greater species richness and abundance, emphasising their conservation significance. The study also observed significant differences in species composition at varying distances from the forest edge. Key species influencing these differences included the Yellow-footed Green Pigeon (Treron phoenicopterus) and various bulbul species (Pycnonotus spp.), indicating habitat sensitivity and edge effects. These findings suggest that while tea plantations can accommodate certain adaptable species, forests play a crucial role in providing habitats for a wider range of avian species. In addition, the study highlights the importance of conserving forest edges and comprehending avian responses to habitat mosaics for effective biodiversity conservation.

Parasitic survey of birds of prey used for falconry in Poland.

Birds of prey raised in captivity have direct contact with the environment and are fed raw meat various animals, which increases the risk of infections caused by parasites, including endoparasites. The aim of this study was to evaluate the prevalence of endoparasites in predatory birds of the orders Accipitriformes and Falconiformes that are used in falconry in Poland. Fresh feces were sampled from 52 birds, including 16 saker falcons (Falco cherrug), 8 lanner falcons (Falco biarmicus), 7 peregrine falcons (Falco peregrinus), 8 Harris's hawks (Parabuteo unicinctus), 7 Eurasian goshawks (Accipiter gentilis), 3 common kestrels (Falco tinnunculus), 1 Eurasian sparrowhawk (Accipiter nisus), 1 red-tailed hawk (Buteo jamaicensis), and 1 common buzzard (Buteo buteo). Fecal samples were analyzed with the use of Fülleborn's floatation technique and the McMaster method (OPG/EPG). Dispersive forms of parasites were identified in 17 out of 52 fecal samples (32.69%). Protozoa of the genus Avispora and Nematodes of the genera Porrocaecum sp and Capillaria were detected. The predominant parasites were roundworms (Porrocaecum sp) which were identified in 27% of the samples. Polish falconers were surveyed to obtain information about bird rearing conditions, the administered feed, contact with wild fauna, incidence of parasitic infections, and the applied treatments. The survey showed that the housing conditions ensured contact with wild fauna, and the majority of owners (63.6%) feed their birds with part of the game they caught. The majority (81%) of falconers did not notice any clinical signs of infection in their infected birds, indicating the need to examine them regularly. The results of the survey were compared with the findings of the parasitological analysis. This study reports on the prevalence of endoparasites in birds of prey, and the present findings can be used by falconers to optimize the management and welfare of predatory birds.

Effects of farming intensification on avian species richness and abundance within Jos metropolis, Nigeria

With an emphasis on pesticide use and landscape features, this study examines how agricultural development affects the diversity and abundance of farmland bird species. The purpose of the study is to evaluate the effects of many factors on bird populations, including cropping patterns, pesticide frequency, and landscape elements including trees, water bodies, hedgerows, and grass cover. The issue being addressed is the decline in biodiversity brought on by an increase in farming practices and a reliance on pesticides that upset ecosystems. The study uses interviews in addition to line transect surveys over five farmlands to collect data on pesticide use and landscape features. The methodology comprised 200-meter transects separated into 100-meter parts for morning and evening bird surveys. Statistical approaches, including species richness and abundance comparison across farmlands with different pesticide use levels and cropping techniques, were used to analyse the data. The results showed that farmlands without pesticides had better biodiversity, while areas with frequent pesticide usage had significantly lower species richness and abundance. Bird diversity was only slightly increased by mixed cropping systems, grass cover, trees, hedgerows, and adjacent water bodies. The study comes to the conclusion that fostering diverse landscapes and lowering pesticide use can help lessen the loss of biodiversity. To improve agricultural bird conservation, it suggests focused interventions, education initiatives, and policies that support biodiversity.

Formation of the spatial structure of the bird population in High-mountainous Dagestan and the concept of preserving its avifauna

The presented work is the concluding part of a previously published article (Vilkov 2023) and based on a mathematical analysis of the empirical material collected during route bird surveys in 1998–2021 in the High­mountainous Province of Dagestan. Based on the long­term average population density data for 96 birds nesting and likely nesting, a cluster analysis was carried out, during which the identified avifaunal communities were grouped according to the similarity of their abundance. Using correlation analysis, environmental factors were identified that determine the territorial variability of bird population abundance. Based on the estimates of the strengths of connections determined from the Jaccard­Naumov coefficients similarity data matrix, a graph was constructed that reflects the spatial structure of the bird population at the level of selected key areas. When interpreting the spatial structure of the bird population using cluster and correlation analysis data, as well as faunal and ecological ranking data, similarities between the compared avifaunal communities were revealed, and 4 main trends in bird population changes in factor space were identified. Based on the results of assessing the strength and generality of the relationships between structure­forming factors and the territorial variability of the bird population (taking into account the areas of landscapes), the most significant was the impact of afforestation, the area of open spaces and the area of residential landscapes. When interpreting spatial differences taking into account natural and anthropogenic changes, it is possible to create a predictive model of the transformation of avifaunal communities within the study area. Analysis of existing threats that have a negative impact on the number and species diversity of birds allowed developing a population management concept based on 4 strategic directions. 1. Gasification of High­Mountain Dagestan to prevent deforestation and restore the species diversity of forest birds. 2. To preserve the species diversity of meadow birds, redirect cattle grazing to areas of meadows with increased overgrowth of grassy vegetation. 3. Increase the area of fields for sowing grain crops to preserve the species diversity of granivorous birds. 4. To preserve the species diversity of birds of prey, install perches in a mosaic pattern in the fields of grain crops.

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.