Bird Species Richness Research Articles

Estimation and interpretation problems and solutions when using proportion covariates in linear regression models.

Proportion variables, also known as compositional data, are very common in ecology. Unfortunately, few scientists are aware of how compositional data, when used as covariates, can adversely impact statistical analysis. We describe here how proportion covariates result in multicollinearity and parameter identifiability problems. Using simulated data on bird species richness as a function of land use, we show how these problems manifest when fitting a wide range of models in R, both in a frequentist and Bayesian framework. In particular, we show that similar models can often generate substantially different parameter estimates, leading to very different conclusions. Dropping a covariate or the intercept from the model can solve the multicollinearity and parameter identifiability problems. Unfortunately, these solutions do not fix the inherent challenges associated with interpreting parameter estimates. To this end, we propose focusing the interpretation on the difference of slope parameters to avoid the inherent unidentifiability of individual parameters. We also propose conditional plots with two x-axes and marginal plots as visualization techniques that can help users better interpret their modeling results. We illustrate these problems and proposed solutions using empirical data from the North American Breeding Bird Survey. The practical and straightforward approaches suggested in this article will help the fitting of linear models and interpretation of its results when some of the covariates are proportions.

Assessing the Ecotourism Potential in Sarasalai-Kuruvikkadu and Adjacent Areas in the Jaffna Peninsula, Sri Lanka

Ecotourism is environmentally responsible, enlightening travel and visitation to relatively undisturbed natural areas in order to enjoy and appreciate nature (and any accompanying cultural features both past and present) that promotes conservation, has low visitor impact, and provides for beneficially active socio-economic involvement of local populations. Sarasalai Kuruvikkadu and adjacent areas such as Anthanathidal and Kapputhu in the Jaffna District are rich with significant extents of mangroves that are notable for their waterbirds’ diversity. The diversity and abundance of birds and the ecotourism potential of those areas have not been evaluated probably due to the three decades long civil unrest. The objective of the present study was to evaluate the nature-based ecotourism potential of Sarasalai Kuruvikkadu and adjacent areas. Geographic Information System was used as tool for identify the potential status of entire Jaffna District. Suitability analysis was applied and Multi Criteria Decision Method (MCDM) and criteria ranking method were used. Three aspects such as Flamingo sites (13), other birds’ sites (40) and mangroves areas (66) in the district including study areas were considered for suitability analysis. The evaluating process for ecotourism sites were conducted based on criteria viz. species richness (of birds), tourist preferences, proximity to residential areas, proximity to accommodation, distance from roads, scenic beauty and density and distribution. Based on each three analysis, Potentials sites were derived based on priority ranking such high, moderate, and low potential. Through the overall analysis, the study areas, Sarasalai and Anthanathidal come under the high potential areas (> 75%) and Kapputhu represents lower potential (<45%) based on flamingo and other birds aspects but based on mangrove sites’ analysis, both areas represent high potential status and Kapputhu represents lower status. Our recent studies have shown that Sarasalai is home to at least 82 species of waterbirds (Margalef’s Index 6.74) and Anthanathidal represents 47 species (Margalef’s Index 9.23) and Kapputhu 22 species (Margalef’s Index 3.04). In addition to some of mammals, crocodiles and fishes were recorded in the study areas that have a high potential for promoting ecotourism. The areas had a high abundance of flamingos, which are a major Avi-tourist attraction. The study areas have large extents mangroves (896.6 ha) with four true mangrove species, Excoecaria agallocha, Lumnitzera racemosa, Rhizophora mucronate and Aegiceras corniculatum which is a unique ecotone and attraction and sources for ecotourism. Hence these areas have a great nature-based tourism potential. There is also a great potential for the participation of local people for promotion of ecotourism in the Jaffna peninsula, elevating their poverty.
 
 Key words: Sarasalai, Kuruvikadu, Ecotourism potential, Mangroves, Flamingo

Structural and socioeconomic features of cities predict migratory bird species richness

Cities are aggregates of human activities where our decisions shape the environment creating heterogeneity across urban centers that can have significant ecological effects on wildlife. Many bird species are found in cities during the breeding season, which implies they find sufficient resources in cities to support them during this energetically costly time. As populations of many migratory bird species are declining, knowledge of how they are affected by urbanization is needed. Yet, we know little about how the species richness of migratory birds varies across different types of cities. Here we ask if cities' structural and socioeconomic features can predict the species richness of migratory birds that generally select different breeding habitats during the breeding season. We used eBird data from census‐designated urban areas in the US to model the relationship between features of cities (housing density, median income, city age, and commuting time), environmental disturbance (measured by the human footprint index) and species richness by fitting generalized linear models to data. We show that commuting time was the most important factor determining species richness across cities and the rest of the city features were weakly associated with species richness. Overall species were responding to city variation in similar ways. While we expected that cities with more disturbance would have lower species richness, our results indicate that some species are able to tolerate even highly disturbed cities and that cities in certain regions may act as a refuge to birds. This knowledge is important for our general understanding of cities as habitat for birds and how migratory birds respond to across‐city variation during the breeding season.

Climate and biodiversity change constrain the flow of cultural ecosystem services to people: A case study modeling birding across Africa under future climate scenarios

Global change is currently impacting ecosystems and their contributions to people (i.e. ecosystem services). These impacts have consequences for societies and human well-being, especially in Africa. Historically, efforts have focused on assessing global change from a social or biophysical perspective, treating them as separate entities. Yet, our understanding of impacts to social-ecological systems remains limited, particularly in the Global South, due to a lack of data, tools, and approaches accounting for social and ecological aspects of ecosystem services. This is especially relevant for cultural ecosystem services as they are less tangible. We use a simple indicator and important provider of a multitude of cultural ecosystem services, birding, to understand how climate, biodiversity, and land use change will impact cultural ecosystem services across Africa. We explore how emerging tools and data can overcome limitations in mapping and modeling cultural ecosystem services, particularly in analyzing human preferences and behavior at large spatiotemporal scales and in data-poor regions. Leveraging crowdsourced data from eBird and using machine learning techniques we map and model recreational birding to assess the underlying social-ecological relationships and the impact of future climate and environmental change. We show that bird species richness, protected areas, accessibility, and max temperature contribute most to birding suitability across the continent. Further, we show spatial shifts in the suitability of birding under three future climate scenarios (SSP126, 370, and 585). Models suggest climate and biodiversity change will increasingly constrain the flow of birding related cultural ecosystem services across Africa. This has implications for human-nature interactions, development of countries, management of protected areas, and overall human well-being in the future. More generally, we highlight opportunities for crowdsourced datasets and machine learning to integrate non-material ecosystem services in models and thus, enhance the understanding of future impacts to ecosystem services and human well-being.

Species Richness and Composition of Forest Birds in Urban Parks and Reserves of Buenos Aires City, Argentina.

Urbanization is among the main factors of ecosystem transformation and threats to global biodiversity. Urban green spaces provide multiple services, being important for biodiversity and human well-being. However, the relationship between green spaces and forest birds has been scarcely studied in the Global South. In this work, we used citizen science data (eBird) to assess the variation in the species richness and composition of forest birds in two types of public urban green spaces characterized by different vegetation composition and management: parks and reserves. In general, reserves had more native and unmanaged vegetation than parks. We selected parks and reserves located in the coastal area of the Metropolitan Area of Buenos Aires, Argentina. Sampling effort was considered as the number of checklists for each site. The database allowed information to be extracted from 12 sites and 33 species. The most common species were the Green-barred Woodpecker (Colaptes melanochloros), the Narrow-billed Woodcreeper (Lepidocolaptes angustirostris), and the White-crested Tyrannulet (Serpophaga subcristata). Bird species richness was higher in reserves than in parks and was positively related to sampling effort. The forest bird species composition varied according to the type of green area and sampling effort. Species composition showed a significant nestedness, with the least rich sites being a subset of species from the richest sites. Reserves and sites with the highest sampling effort concentrated all species. The results obtained show the importance of urban reserves in the conservation of forest birds.

Unveiling urban ecological integrity: spatially explicit assessment in contrasting environments

Although much attention has been paid to improve the representation of the urban spatial complexity, most efforts have been limited to the inclusion of green cover data to describe the biological component of cities, leaving the measurement of crucial urban ecological properties out of the picture. To tackle this, the Urban Ecosystem Integrity Index (UEII) was recently proposed to spatially represent the interplay between the intensity of urbanization and the biological components of cities, including urban biodiversity. The UEII has shown to be effective in measuring the ecosystem integrity of a Neotropical city; however its generalized applicability remains to be tested. Thus, here we tested the suitability of the UEII when applied in a boreal city and also evaluated if it adds more valuable information than the NDVI (also contrasting it with a UEII previously published for a tropical city), which is often suggested as a proxy of urban greenness and therefore the ecology of cities. We calculated the UEII by considering land surface temperature, built-up cover, and native plants and bird species richness of the city of Lahti, Finland (Palearctic; boreal). The UEII showed to be robust, comparable, and effective in capturing the intra and inter-urban spatial heterogeneity of both cities. Moreover, although the UEII and NDVI values correlated, the variance in such correlation showed the detail that the UEII brings to the quantificaiton of the ecological integrity of the cities, representing a more integral indicator. Thus, our findings indicate that the UEII is a valuable tool to inform on areas requiring ecological enhancement, as well as identifying those that are thriving, in cities ranging from tropical and highly biodiverse to boreal and with considerable less biodiversity.

Bird color and taxonomic diversity are negatively related to human disturbance in urban parks

Abstract. Recently, studies have shown that highly urbanized areas are numerically dominated by birds with grey plumage, probably favoring camouflage with impervious grey surfaces. However, patterns of bird color diversity in urban green areas remain unexplored. In urban parks, sites surrounded by highly urbanized areas may be dominated by grey bird species, whereas urban parks with pedestrians that feed birds may favor commensal birds which also have grey plumage. Thus, we explore the relationship between environmental variables and bird taxonomic and color diversity in urban parks. Bird surveys were conducted twice by fixed points in urban parks of six cities in central Argentina. Bird color diversity was assessed by characterizing bird plumage coloration in different parts of the bird body and the presence of plumage sexual dimorphism, polymorphism, and iridescence. Then, color richness and color diversity (abundance-based) were calculated with species mean pairwise distance. Null models were used to quantify richness-corrected color diversity. Bird species richness and diversity increased with green-area size, and bird diversity decreased with increasing pedestrian traffic. Color richness decreased with increasing car traffic, whereas color diversity was positively related to green-area size and negatively related to car and pedestrian traffic. Richness-corrected color diversity related negatively to car and pedestrian traffic. The abundance of grey birds increased in parks near the urban centers and related positively to pedestrian and car traffic. The abundance of yellow birds increased in parks near rural areas or small cities. Color diversity increased with green-area size, but richness-corrected color diversity ceased to be related to area size. Therefore, the increase in color diversity with area size was mediated by increases in species richness. Color diversity was clustered in parks with the highest human disturbance, favoring the abundance of grey species which probably took advantage of food discarded by humans.

Body size and trophic structure explain global asymmetric response of tetrapod diversity to climate effects.

Although climate-based hypotheses are widely used to explain large-scale diversity patterns, they fall short of explaining the spatial variation among taxonomic groups. Integrating food web and metabolic theories into macroecology is a promising step forward, as they allow including explicit taxon-specific traits that can potentially mediate the relationship between climate and diversity. Our investigation focuses on the role of body size and trophic structure in mediating the influence of contemporary climate and historical climate change on global tetrapods species richness. We used piecewise structural equation modeling to assess the direct effects of contemporary climate and climate instability of species richness and the indirect effects of climate on tetrapod richness mediated by community-wide species traits. We found that birds and mammals are less sensitive to the direct effect of contemporary climate than amphibians and squamates. Contemporary climate and climate instability favored the species richness of mammals and amphibians. However, for birds and squamates, this link is only associated with contemporary climate. Moreover, we showed that community-wide traits are correlated with species richness gradients. However, we highlight that this relationship is dependent upon the specific traits and taxonomic groups. Specifically, bird communities with smaller bodies and bottom-heavy structures support higher species richness. Squamates also tend to be more diverse in communities with prevalence of smaller bodies, while mammals are correlated with top-heavy structures. Moreover, we showed that higher contemporary climate and climate instability reduce the species richness of birds and mammals through community-wide traits and indirectly increase squamate species richness. We also showed that body size and trophic structure are driving a global asymmetric response of tetrapod diversity to climate effects, which highlights the limitation to use the "typical" climate-based hypotheses. Furthermore, by combining multiple theories, our research contributes to a more realistic and mechanistic understanding of diversity patterns across taxonomic groups.

Implication of abandoned post‐quarry sites on avifauna composition for strategic landscape restoration in Ndarugu, Kiambu, Kenya

AbstractAbandoned post‐quarry sites have potentiality to be remodeled into natural‐wilderness areas, a desire especially in rapidly urbanizing and transforming landscapes. However, paucity of ecological information on post‐quarry sites limits nature‐based restoration, especially in the sub‐Saharan tropical landscape. This study investigated avifauna composition of post‐quarry sites in Ndarugu, Kenya, relative to non‐quarried sites for conservation role prioritization. Birds were censused in 166 point count stations using the fixed‐radius distance method. Land use land cover types within each point provided the variables for explaining bird occurrence. Observed bird species were classified into functional guilds, avifaunal composition assessed, and bird data subjected to multivariate analysis. In total 158 species, 128 in post‐quarry and 123 in non‐quarried sites, were recorded. Bush‐ and forest‐related species were dominant, constituting over 55% of total observed birds, in both site categories. Six wetland‐related species were detected only in quarried sampling sites. Mann–Whitney statistical tests returned a significant effect of land use category on bird species richness, abundance, and diversity, all higher in post‐quarried than in non‐quarried sites (p < 0.05). Emergent natural shrubs, quarry cliffs, and cultivated farms were most influential to bird community structuring. Nonmetric multidimensional scaling and cluster analysis revealed four functional groups of birds whose species richness increased with number of post‐quarried sampling sites in a cluster. Unique physical features of post‐quarry sites and emergent vegetation types, can be partially mimicked in nature‐oriented rehabilitation planning for long‐term social and ecological benefits.

Environmental filtering and landscape composition drive multifaceted diversity of bird assemblages in vineyards

Abstract Agricultural landscapes are productive areas with high biodiversity potential, but their conversion to monocultures and intensification of practices are recognised drivers of bird biodiversity loss worldwide. This challenges the compatibility of agricultural land use with bird conservation, as landscape composition affects both the diversity of bird species and traits and the assembly of bird communities. We address the underlying mechanisms of avian community assembly in vineyards at the plot and landscape levels in relation to landscape composition in one of the major wine producing regions of France. We jointly analyse how the taxonomic, functional, and phylogenetic facets of bird alpha and beta diversity respond to a gradient of landscape heterogeneity and test for a non‐random assembly rule. We found that birds tended to avoid vineyard monocultures. There was consistent support for the co‐occurrence of both closely related species and similar functional traits within vineyard plots (namely, phylogenetic and functional clustering, respectively). Landscape composition, both within plots and on a large scale (1000 m), was critical in explaining the occurrence of species and traits within plots. Landscape composition determined a nested pattern of functional and phylogenetic beta diversity from vineyard monoculture to more complex landscapes with increasing seminatural land cover. Synthesis and applications. Landscape composition in seminatural vegetation features significantly influenced both the alpha and beta bird diversity in vineyard‐dominated agricultural landscapes. Interspersed shrubs and woodland can help increase bird abundance and species richness in vineyards, while large‐scale land cover diversity might help promote functional and phylogenetic bird diversity.

Bird species richness and diversity responses to land use change in the Lake Victoria Basin, Kenya

The increasing demand for cultivated lands driven by human population growth, escalating consumption and activities, combined with the vast area of uncultivated land, highlight the pressing need to better understand the biodiversity conservation implications of land use change in Sub-Saharan Africa. Land use change alters natural wildlife habitats with fundamental consequences for biodiversity. Consequently, species richness and diversity typically decline as land use changes from natural to disturbed. We assess how richness and diversity of avian species, grouped into feeding guilds, responded to land use changes, primarily expansion of settlements and cultivation at three sites in the Lake Victoria Basin in western Kenya, following tsetse control interventions. Each site consisted of a matched pair of spatially adjacent natural/semi-natural and settled/cultivated landscapes. Significant changes occurred in bird species richness and diversity in the disturbed relative to the natural landscape. Disturbed areas had fewer guilds and all guilds in disturbed areas also occurred in natural areas. Guilds had significantly more species in natural than in disturbed areas. The insectivore/granivore and insectivore/wax feeder guilds occurred only in natural areas. Whilst species diversity was far lower, a few species of estrildid finches were more common in the disturbed landscapes and were often observed on the scrubby edges of modified habitats. In contrast, the natural and less disturbed wooded areas had relatively fewer estrildid species and were completely devoid of several other species. In aggregate, land use changes significantly reduced bird species richness and diversity on the disturbed landscapes regardless of their breeding range size or foraging style (migratory or non-migratory) and posed greater risks to non-migratory species. Accordingly, land use planning should integrate conservation principles that preserve salient habitat qualities required by different bird species, such as adequate patch size and habitat connectivity, conserve viable bird populations and restore degraded habitats to alleviate adverse impacts of land use change on avian species richness and diversity.

Opposite Responses of Native and Nonnative Birds to Socioeconomics in a Latin American City.

Due to the massive increase of the urban population, a global target is to achieve sustainable cities that are sensitive to nature and environmentally just for urban dwellers. To accomplish this, it is important to understand the responses of native and nonnative birds, identify the environmental variables that promote native species and limit nonnative species, and understand how they vary among socioeconomic groups. Although many cities in the Global South exhibit strong social and environmental segregation, few studies have investigated the relationship between socioeconomics and biodiversity. Therefore, to help promote ecological justice and biodiversity conservation in the developing world, we investigated the influence of socioeconomic level and woody cover on bird species richness and abundance in the city of Santiago de Chile. We also investigated whether bird response changes with species provenance-it is important to understand the response of native birds separately from nonnative birds because they imply opposite management strategies (e.g., conservation vs. species control/eradication). Thus, we surveyed 120 sites located in residential areas of high, medium, and low socioeconomic levels across the city and fit generalized linear (mixed) models that described bird species richness and abundance for total, native, and nonnative birds according to socioeconomic level and woody vegetation cover. We found that both socioeconomic level and woody vegetation cover influenced the bird community, but their effects changed with bird species origin, having opposite effects on native and nonnative birds. Residential areas where wealthier people live supported greater species richness and abundance of native birds than residential areas where people of lower socioeconomic status live. In contrast, residential areas where vulnerable people live had greater bird abundance that was mainly composed of nonnative birds. Therefore, affluent neighborhoods provide more opportunities to encounter native birds and experience nature close to home than poorer neighborhoods. Due to woody cover having positive effects on native birds and a negative influence on nonnative birds, increasing tree and shrub cover will contribute to supporting more native birds in residential areas deprived of woody vegetation, which are commonly low socioeconomic areas. Additional variables that can explain bird response among residential areas of different socioeconomic levels need to be investigated to better understand the factors influencing the distribution of birds in cities and promote a more biodiverse and environmentally just city.

Seasonal patterns of habitat use of resident birds in Białowieża Forest and its links to post-disturbance management

Resident bird species staying in the same area year-round may face very different habitat conditions between seasons in temperate forests. This may cause resident forest birds to use different habitats during winter and spring. Furthermore, habitat use and their seasonal shifts could be additionally affected by large scale forest disturbances (e.g. outbreaks of bark beetles) and post-disturbance management, as they likely affect the availability of crucial resources for reproduction and survival. We investigated the impact of the European spruce bark beetle (Ips typographus) outbreak and post-outbreak management on winter and spring habitat use of 18 resident bird species in Białowieża Forest, Eastern Poland. We showed differences in habitat use of resident birds in winter and spring, at the level of species, community and three foraging guilds (i.e. invertivore bark foragers, invertivore arboreal gleaners and omnivores). First, bird species richness and bird abundance recorded at 111 sites in winter were not related or even showed a negative relationship with richness and abundance in spring, indicating that winter and spring bird diversity hotspots did not spatially overlap. Second, the wintering community as a whole, and the invertivore arboreal gleaners in specific, shifted their density towards more coniferous sites and increased their density at moderately salvage-logged sites, while decreasing their density at strongly salvage-logged sites. The wintering invertivore bark foragers shifted towards more outbreak sites (i.e. both salvage-logged and natural regeneration) and distributed more evenly along the natural regeneration – salvage-logged gradient. The distributions of habitat use were species-specific and there was no single habitat or level of disturbance preferred or avoided by all species or groups in spring or winter. This study highlights the importance of considering habitat use outside of the breeding season, when assessing habitat requirements of resident forest bird communities to evaluate the impact of post-disturbance management. In addition, it shows the significance of maintaining the heterogeneity of forest habitats to the wintering resident bird community, especially when deciding on post-disturbance management actions.

Understanding the drivers of the live bird trade in Brazil

In this work we sought to evaluate the factors that influence the public's interest in wild birds sold as pets in Brazil, and the relationship of those factors with new occurrences of birds outside their natural range. We compiled the richness of bird species traded in Brazil and obtained comparative data of public interest directed to these species through the Google Trend tool. In addition, we gathered data on biological attributes and the sale price of the species in the trade, to analyze which factors would be related to public interest. Then, factors related to public interest were used to assess whether there was a relationship with these new occurrences. The main founds indicated that the public interest is greater for songbirds, omnivores, which live in more open environments and are sold at lower prices. All those factors also showed to be related to the birds that presented new occurrences. The public's preference for birds more generalist and from more open environments are important results, as such factors generally indicate greater environmental tolerance, which may favor the establishment of these birds in new environments. Therefore, it is likely that species releases or escape from captivity, combined with their life history attributes, may favor the establishment of isolates in new environments. Thus, the present results demonstrate that actions aimed at the conservation of commercialized species are essential to reduce the interregional trade of species, and consequently reduce the impact on natural populations and reduce the potential for new biological introductions.

Lack of local genetic representation in one of the regions with the highest bird species richness, the Peruvian Amazonia.

Peru ranks among the three countries with the highest bird species diversity globally and a majority of those species are found in the Peruvian Amazon. However, birds in this area are currently facing serious anthropogenic threats. Genetic and genomic methods are becoming important tools for avian biodiversity monitoring and conservation planning. Comprehensive molecular libraries that are publicly available are key to the effective deployment of these tools. We analyze the information gaps for four molecular markers in the most important genetic sequence databases, Barcode of Life Data Systems (BOLD) and NCBI GenBank, for bird species of the Peruvian Amazonia. We found that 64% of Peruvian Amazonian bird species have gene sequences for COI, 59.5% have CYTB sequences, 16.4% have 12S sequences, and only 0.6% have 18S sequences. However, these numbers decrease drastically to 4.3% for COI sequences when we only consider specimens sampled in Peru. Our data also showed that 43.8% of Peruvian Amazonian endemic species (n = 32) are missing sequences of any screened marker uploaded to GenBank or BOLD. Our results will encourage and guide efforts of the scientific community to complete reference libraries for Peruvian avian species that will be useful for future DNA-based monitoring projects that include birds.

Solar parks can enhance bird diversity in agricultural landscape

Solar photovoltaic power parks are a relatively new anthropogenic habitat that will become more widespread in the future. The greatest potential for solar photovoltaic power production is on arable land and grassland. Knowledge on the impacts of solar parks on biodiversity is scarce and spatially limited. We investigated the impact of ground-mounted solar parks on species richness, abundance, Shannon diversity and composition of bird communities in Slovakia (Central Europe), taking into account pre-construction land cover, elevation and landscape context. We recorded breeding, foraging or perching birds on 32 solar park plots and 32 adjacent control plots (two hectares each) during single breeding season. We found that solar parks supported higher total bird species richness and diversity, and richness and abundance of invertebrate-eaters, and that the abundance of ground-foragers was higher in solar parks developed on grassland than in grassland control plots. Ordination analysis showed that solar parks had a different composition of bird communities and thus increased overall species diversity and beta diversity in the agricultural landscapes studied. Plot type and landscape context accounted for most of the variation in bird community composition. Black redstart, European stonechat, white wagtail and Eurasian tree sparrow were identified as indicator species for solar parks. The observed pattern could be due to the higher structural diversity of solar parks. The solar parks studied were designed and managed exclusively for electricity production. It can therefore be assumed that solar parks designed and managed in synergy with a stronger focus on wildlife would have an even greater positive impact on bird diversity in an agricultural landscape.

Taxon-dependent diversity response along a temperate elevation gradient covered by grassland.

Elevational gradients constitute excellent systems for understanding the mechanisms that generate and maintain global biodiversity patterns. Climatic gradients associated with elevation show strong influence on species distribution in mountains. The study of mountains covered by the same habitat type is an ideal scenario to compare alternatives to the energy hypotheses. Our aim was to investigate how changes in climatic conditions along the elevational gradient drive α- and β-diversity of four taxa in a mountain system located within a grassland biome. We sampled ants, spiders, birds and plants, and measured climatic variables at six elevational bands (with 10 sampling sites each) established between 470 and 1,000 masl on a mountain from the Ventania Mountain System, Argentina. Species richness per site and β-diversity (turnover and nestedness) between the lowest band and upper sites were estimated. For most taxa, species richness declined at high elevations and energy, through temperature, was the major driver of species richness for ants, plants and birds, prevailing over productivity and water availability. The major β-diversity component was turnover for plants, spiders and birds, and nestedness for ants. The unique environmental conditions of the upper bands could favour the occurrence of specialist and endemic species.

Spatiotemporal variations in migratory bird diversity and abundance along the coast of Gochang getbol.

Tidal flats provide critical habitat for migratory waterbird species; however, populations of migratory waterbirds have significantly declined due to tidal flat loss and degradation caused by human activities, particularly in Asia. Gochang getbol is one of tidal flats located on the southwest coast of South Korea and a center of clam production. Using bird monitoring data collected at five zones (zone1 to zone5) established across Gochang getbol and near coastal area, we examined distribution patterns of migratory bird diversity and conservation-related species along the coast of Gochang getbol. The intensity of human activity ‒ mudflat culture (mostly bivalve) and aquaculture was relatively high at zone2 and zone3, occupying > 30% of 2km circular area surrounding most sample points of these zones. Zone1 and particularly zone4 contained more natural/semi-natural habitats (less disturbed mudflats and wetlands) and zone5 had smallest mudflat than others. Shannon diversity, species richness, and abundance of migratory birds differed between zones (Anova test, P ≤ 0.02) except Shannon diversity in winter. In fall, all values were higher at zone4 than zone3 and zone5. In winter, zone1 showed greatest species richness and higher abundance than zone2, zone3, and zone5. In spring, while most differences were found between zone4 and zone5, abundance at zone4 was somewhat higher than zone2. The results from the fourth corner analysis indicated that abundance of species foraging at mudflat level was positively associated with zone1 (winter) but negatively with zone3 (fall). Sandpipers were positively associated with zone4. Abundance distribution maps of conservation-related species, created by inverse distance-weighted interpolation modeling, also showed high abundance of most conservation-related species at zone4 and 1. The findings of our study suggest the importance of natural/semi-natural habitat, and the possible link between human activity and distribution patterns of migratory birds in Gochang getbol. While we need further investigation on direct response of migratory birds to human activity, areas with low human activity with more natural/semi-natural habitat, e.g., zone4 and zone1 may be crucial for the conservation of migratory birds.

Evaluation of an autonomous acoustic surveying technique for grassland bird communities in Nebraska.

Monitoring trends in wildlife communities is integral to making informed land management decisions and applying conservation strategies. Birds inhabit most niches in every environment and because of this they are widely accepted as an indicator species for environmental health. Traditionally, point counts are the common method to survey bird populations, however, passive acoustic monitoring approaches using autonomous recording units have been shown to be cost-effective alternatives to point count surveys. Advancements in automatic acoustic classification technologies, such as BirdNET, can aid in these efforts by quickly processing large volumes of acoustic recordings to identify bird species. While the utility of BirdNET has been demonstrated in several applications, there is little understanding of its effectiveness in surveying declining grassland birds. We conducted a study to evaluate the performance of BirdNET to survey grassland bird communities in Nebraska by comparing this automated approach to point count surveys. We deployed ten autonomous recording units from March through September 2022: five recorders in row-crop fields and five recorders in perennial grassland fields. During this study period, we visited each site three times to conduct point count surveys. We compared focal grassland bird species richness between point count surveys and the autonomous recording units at two different temporal scales and at six different confidence thresholds. Total species richness (focal and non-focal) for both methods was also compared at five different confidence thresholds using species accumulation curves. The results from this study demonstrate the usefulness of BirdNET at estimating long-term grassland bird species richness at default confidence scores, however, obtaining accurate abundance estimates for uncommon bird species may require validation with traditional methods.

Record of Chinese pond-heron Ardeola bacchus from Pokhara, Nepal

Chinese pond-heron (Ardeola bacchus) is a vagrant species in Nepal. We present the first record of Chinese pond-heron from Maidi Lake of Lake Cluster of Pokhara Valley (LCPV), Kaski, Nepal as well as the second record for the species in Nepal itself. Similarly, we recorded 100 bird species around Maidi Lake. We photographed black bittern (Ixobrychus flavicollis) for the first time, an overall second record, for the Pokhara Valley. We monitored the Chinese pond-heron from a vantage point and used a trail around Maidi Lake as a transect for assessing the species richness of birds in the area. Chinese pond-heron was recorded five times in a span of 23 field observation days between 20 May and 11 June 2023. Including this record, Chinese pond-heron is recorded from four districts- Dhanusha, Chitwan, Kaski and Kanchanpur in Nepal.