Bird Abundance Research Articles

Diversity, Abundance, and Distribution of Avifauna in District Jhang, Pakistan

The present study was conducted from March 2021 to February 2022 in the Thal desert and Trimmu barrage of district Jhang located in the Punjab province of Pakistan to find out the diversity, abundance, and distribution of birds. The point count method was used for the Trimmu barrage, and the line transect method was used for the collection of data in the Thal desert area. We recorded 31,696 individuals belonging to 67 species of birds from two distinct types of habitats (Thal desert and Trimmu barrage) of district Jhang. Among these species, 39 species were residents, 18 species were winter visitors, 9 species were summer breeders, and a single species (Terek sandpiper) was a passage migrant. Highly significant differences ( X 2 = 14979.7 , df = 11 , and P < 0.01 ) were observed in the abundance of birds between both habitats on every month. From the Thal desert area, 12,905 individuals belonging to 45 species were identified while 18,791 individuals from 58 bird species were observed in the Trimmu barrage, with 36 bird species among 67 species being common at both habitats. The most dominant species of the Trimmu barrage were the common pochard, little grebe, common coot, cattle egret, gadwall, little egret, red-wattled lapwing, and common teal. On the other hand, the Indian roller, common quail, cattle egret, common myna, and Indian kite were found to be the most common species in the Thal desert. The most notable feature of the present study is the identification of Xenus cinereus (Terek sandpiper) and Ammomanes phoenicura (rufous-tailed lark) in district Jhang as both species had no previous record in the study area. The Trimmu barrage was the more diverse and abundant site compared to the Thal desert as it provides both terrestrial and aquatic habitats for birds. The study determined that more varieties in the habitat and thermal changes affect the diversity, abundance, and distribution of birds.

Estimating mortality of small passerine birds colliding with wind turbines

As demand for renewable energy is rising, wind power development is rapidly growing worldwide. In its wake, conflicts arise over land use changes converting pristine nature into industrial power plants and its associated adverse biodiversity effects, crowned by one of the most obvious and deadly consequences: bird collisions. Most post-construction studies report low levels of avian mortality, but the majority of these studies are conducted primarily on larger birds. However, the diversity and abundance of small passerine birds are rarely reflected in the carcass surveys, although they in numeric proportion to their abundances should be the most numerous. The assumption that surveys find all carcasses seems thus rarely fulfilled and passerine mortality is likely to be grossly underestimated. We therefore designed an experiment with dummy birds to estimate mortality of small-bodied passerines and other small-bodied birds during post-construction surveys, tested in a medium-sized wind farm in western Norway. The wind farm was surveyed weekly during the migration periods by carcass survey teams using trained dogs to find killed birds. The dogs in the carcass surveys were more successful in locating the large than the small dummy birds (60–200 g), where they found 74% of the large dummy birds. Detecting the smaller category (5–24 g) was more demanding and the dogs only found 17% of the small dummy birds. Correcting the post-construction carcass survey outcome with the results from the experiment leads to an almost fourfold increase in estimated mortality rates, largely due to the low detection rate of the smallest category. The detection rates will naturally vary between wind farms, depending on the specific habitat characteristics, the efficiency of the carcass surveys and the search intervals. Thus, implementing a simple experiment with dummy birds to future post-construction surveys will produce more accurate estimates of the wind turbine mortality rates, and thus improve our understanding of the biodiversity effects of conforming to a more sustainable future.

Social information modifies the associations between forest fragmentation and the abundance of a passerine bird

Habitat loss and fragmentation are the main factors driving the occurrence and abundance of species in the landscape. However, the local occurrence and abundance of species may also depend on conspecific and heterospecific social information e.g. clues of animals’ presence or their voices. We investigated the impact of the interaction between different types of social information and forest fragmentation on the abundance of the song thrush, Turdus philomelos, in Central Europe. Three types of social information (attractive, repulsive, and mixed) and procedural control were broadcasted via loudspeakers in 150 forest patches that varied in size and isolation metrics. Repulsive social information (cues of presence of predator) decreased abundance of song thrush. Also, the repulsive social information changed the association between forest patch isolation, size and the abundance. Attractive social information (songs of the studied thrush) had no effect on song thrush abundance. However, the attractive social information reversed the positive correlation between habitat patch size and the abundance. Mixed social information (both repulsive and attractive) had no impact on the abundance nor interacted with habitat fragmentation. The observed effects mostly did not last to the next breeding season. Overall, our findings indicate that lands of fear and social attraction could modify the effect of habitat fragmentation on the species abundance but these effects probably are not long-lasting.

Use of epiphyte by bird communities in IPB Dramaga campus

Epiphytes have a direct or indirect influence on terrestrial ecosystems. The presence of epiphytes can increase habitat complexity vertically and benefit animals, especially birds. The objectives of this study were to identify the species of epiphytes, their host trees, and the birds and to analyze how composition of epiphytes and host trees affects the diversity and abundance of birds. The research was conducted in seven sites within the IPB Dramaga Campus from December 2022 to February 2023. We collected biotic data (the number and type of epiphytes, host trees, and birds) and abiotic data (temperature and humidity) at each site. We used Paleontological Statisctic (PAST) to calculate the diversity index and R software to examine the correlation between birds and epiphytes. We found a significant positive correlation between the species richness of epiphytes, host trees, and birds. The sites with the highest diversity and abundance of trees, epiphytes, and birds were Conservation Park and Campus Forest Park. Sites with more diverse and abundant epiphytes had lower temperatures on average. We observed four bird species that used epiphytes: Pycnonotus aurigaster, Aegithina tiphia, Sitta frontalis, and Dicaeum trochileum. These species foraged for invertebrates on or near the Asplenium sp. epiphytes.

Species composition and ecological groupings of birds of extrazonal transformed landscapes of Yenisei Siberia in the spring and summer period

The article presents the results of a pilot study conducted in May–June 2022 in the places of interpenetration of the Krasnoyarsk forest-steppe and subtaiga, where extrazonal transformed landscapes were formed. An important role in this was played by such factors as the location of the territory on the border of natural zones, the dismembered hilly-rocky terrain, active human economic activity, which also caused the high mosaic of biotopes. As a result, there is an overlap of ranges of typically forest and steppe bird species, as well as their nesting in close proximity to each other, which is explained by their ecological specialization. During this period, 105 species and subspecies of birds belonging to 13 groups were noted. All the diversity is distributed by ecological groups that correspond to the large biotopes identified in the study area: small-leaved birch and mixed forests; forest edges, felling and chopping; coniferous forests; high-stemmed and shrubby floodplain forests; residential landscapes; wetland complex; high-grass and low-grass open areas. Some phenological data, information on the biotopic placement, abundance and nesting of birds collected in the process of route hiking are presented.

Elevational patterns of species richness and community structure of understorey birds in an East African montane forest

AbstractMt. Kasigau is the northeastern most of the Eastern Arc Mountains global hotspot and harbours some endemic and threatened species, but little is known about bird community changes along its elevational gradient. We assessed the relationship between bird biodiversity metrics, season, human disturbance, elevation and temperature using mist‐netting data collected bi‐annually over a 10‐year period. Birds were sampled along the mountain's elevational gradient at four elevation levels (858, 1104, 1321 and 1547 m). Bird richness, diversity and evenness decreased with increasing altitude in both dry and wet seasons. Bird abundance declined with increasing elevation for the lower three elevation levels but peaked at the highest elevation. All diversity metrics were higher in the wet season compared to the dry season across all the years. Elevation had a greater effect on species assemblages than season, disturbance and temperature. Temperature had significant effects on abundance, diversity and richness, while disturbance had significant effects on diversity, evenness and richness. We conclude that bird assemblages in Mt. Kasigau are strongly shaped by elevational changes, while temperature and disturbance constitute important factors influencing bird conservation in the face of global warming. Our study highlights that elevation, disturbance and temperature influence bird assemblages along tropical elevational gradients.

Status of abundant bird species in Lake Qaroun, Egypt.

Status of abundant bird species in Lake Qaroun, Egypt.

Software-dependent biases in the recognition of di- and tri-syllabic bird songs can create false interpretations of bird abundance and singing activity

The use of autonomous recording units (ARUs) for passive acoustic monitoring has recently gained a lot of importance. It is now widely used for scientific purposes and has been increasingly applied in the field of conservation biology. However, while ARUs may greatly increase cost-effectiveness in monitoring, they are not exempt from possible biases. In this study, we compared the performances of three different software in recognizing bi- and tri-syllabic bird songs and tested if their results varied significantly in a real setting. We focused on the interpretation of the relative abundance among habitats and the time of vocal activity, also using different numbers of training records to assess if the results of the software improved. Even with the quality measures of the recognizer being consistent with those of previously published studies, in several cases the results produced significantly different interpretations depending on the software used. While increasing the number of training records slightly improved the overlap in the estimates of activity among the different software, differences in the relative abundance of each song were present even with a fairly solid number of training records. Our results suggest that reliable biological interpretations might only be attained with a large number of training records and very high values of precision, recall, and the F-score. In fact, even with very high precision and F-scores, lower values for recall led not only to statistically significant differences, but also to different interpretations of relative abundance and time of activity between the two best-performing software. Thus, great caution must be taken in interpreting the results of bioacoustics studies that use automated recognition, and standards of minimum quality should be created for recognizers in scientific and technical studies.

The Granular Size Concept in Avian Ecology: A Critical Analysis of eBird Data Bias Using the Bird Rank Abundance Distribution

In previous studies using eBird citizen data, bird abundance rankings followed a power law distribution. Our research delves into the “granular size” concept within these power laws, likening birds to firms. We identified 13 bird species as being the granular size, representing species with significant ecosystem impact, akin to major corporations in an economy. In particular, these species are urban, raising concerns about the eBird database’s sampling bias. Using the economic concept of granular size, we argue that the eBird database may be inherently unreliable.

Association between land use, land cover, plant genera, and pollinator abundance in mixed-use landscapes.

Pollinators are threatened by land-use and land-cover changes, with the magnitude of the threat depending on the pollinating taxa, land-use type and intensity, the amount of natural habitat remaining, and the ecosystem considered. This study aims to determine the effect of land use (protected areas, plantations, pastures), land cover (percentage of forest and open areas within buffers of different sizes), and plant genera on the relative abundance of nectivorous birds (honeyeaters), bees (native and introduced), and beetles in the mixed-use landscape of the Tasman Peninsula (Tasmania, Australia) using mixed-effect models. We found the predictor selected (through model selection based on R2) and the effect of the predictors varied depending on the pollinating taxa. The land-use predictors were selected for only the honeyeater abundance model with protected areas and plantations having substantive positive effects. Land-cover predictors were selected for the honeyeater and native bee abundance models with open land cover within 1500 m and 250 m buffers having substantive negative and positive effects on honeyeaters and native bees respectively. Bees and beetles were observed on 24 plant genera of which only native plants (and not invasive/naturalised) were positively associated with pollinating insects. Pultenaea and Leucopogon were positively associated with native bees while Leucopogon, Lissanthe, Pimelea, and Pomaderris were positively associated with introduced bees. Leptospermum was the only plant genus positively associated with beetles. Our results highlight that one size does not fit all-that is pollinator responses to different landscape characteristics vary, emphasising the importance of considering multiple habitat factors to manage and support different pollinator taxa.

The hallucinating chatbot ‘ChatGPT’ poorly estimates real bird commonness

Recent advances in artificial intelligence have led to the development of increasingly sophisticated chatbot technologies, with ChatGPT, developed by OpenAI, gaining significant popularity. As public awareness of environmental issues has grown during recent decades, there is an increasing demand for access to information about the environment. ChatGPT which offers free, real-time information via a user-friendly interface, has the potential to fill this gap. However, empirical evaluations of reliability and quality of information provided by chatbots are needed. In this study, the biological information provided by GPT-3.5 is evaluated. The commonness indices of 199 bird species in Poland, estimated by the ChatGPT, are correlated with the real commonness indices obtained during ornithological survey conducted across 700 1 × 1 km squares. Bird commonness indices provided by ChatGPT were generally positively correlated (r ≤ 0.6) with bird abundance and occurrence. However, this correlation was not particularly strong. Correlation was especially poor for less common species (i.e., below 1000 individuals recorded during bird monitoring), and some of rare or very rare species were incorrectly identified by ChatGPT as relatively common. Moreover, ChatGPT seemed confident, realistic and persuasive in providing obviously incorrect responses (possibly due to lack of training data), much like it would for correct responses. Generating such false responses due to data deficiency is commonly referred to as “hallucination” of a chatbot. While chatbots can potentially be powerful tools for delivering environmental information, better control over the training process is necessary.

A novel, post-Soviet fire disturbance regime drives bird diversity and abundance on the Eurasian steppe.

Many grassland ecosystems and their associated biodiversity depend on the interactions between fire and land-use, both of which are shaped by socioeconomic conditions. The Eurasian steppe biome, much of it situated in Kazakhstan, contains 10% of the world's remaining grasslands. The break-up of the Soviet Union in 1991, widespread land abandonment and massive declines in wild and domestic ungulates led to biomass accumulation over millions of hectares. This rapid fuel increase made the steppes a global fire hotspot, with major changes in vegetation structure. Yet, the response of steppe biodiversity to these changes remains unexplored. We utilized a unique bird abundance dataset covering the entire Kazakh steppe and semi-desert regions together with the MODIS burned area product. We modeled the response of bird species richness and abundance as a function of fire disturbance variables-fire extent, cumulative burned area, fire frequency-at varying grazing intensity. Bird species richness was impacted negatively by large fire extent, cumulative burned area, and high fire frequency in moderately grazed and ungrazed steppe. Similarly, overall bird abundance was impacted negatively by large fire extent, cumulative burned area and higher fire frequency in the moderately grazed steppe, ungrazed steppe, and ungrazed semi-deserts. At the species level, the effect of high fire disturbance was negative for more species than positive. There were considerable fire legacy effects, detectable for at least 8 years. We conclude that the increase in fire disturbance across the post-Soviet Eurasian steppe has led to strong declines in bird abundance and pronounced changes in community assembly. To gain back control over wildfires and prevent further biodiversity loss, restoration of wild herbivore populations and traditional domestic ungulate grazing systems seems much needed.

Normalized Difference Vegetation Index as a Proxy of Urban Bird Species Presence and Distribution at Different Spatial Scales

Birds are important features of the urban landscape, offering valuable ecosystem services, such as physiological and psychological stress reduction, aesthetic pleasure, and education. Knowing the populations of bird species in cities is important for their successful conservation. The normalized difference vegetation index (NDVI) is a remotely sensed metric used as a green cover proxy. We estimated the abundance of 15 bird species in the urban green spaces of Kavala, Greece, and calculated the NDVI at 19 survey stations with three different spatial scales: 50 m, 200 m, and 500 m circular buffers. NDVI was shown to significantly affect the abundance of 13 species. The 50 m buffer best predicted the abundance of 4 species, the 200 m buffer predicted 7 species, and the 500 m buffer predicted 4 species. Abundance decreased with NDVI for 9 species (urban dwellers) and increased for 6 species (urban utilizers). These findings suggest that NDVI is a reliable predictor of the abundance of bird species in urban areas. More importantly, bird abundance and NDVI associations can be better described if determined at various spatial scales. These findings could be used for the prediction and monitoring of urban bird species populations and incorporated into urban conservation management plans.

Wind farms and Griffon Vultures: Evidence that under certain conditions history is not-always turbulent

Since the early stages of wind energy development, there has been concern about the potential impact of wind farms on wildlife, particularly birds and bats. However, the lack of long-term studies has hindered the assessment of the real effect of wind farms on mortality and disturbances. We show a case study in which we researched during the nestling rearing period the long-term effects of a wind farm located in southern Spain on the abundance, displacement, and mortality of the Griffon Vulture, a raptor considered very sensitive to collisions. After 13 years of operation, observation and abundance rates increased significantly during the study period. Griffon Vultures avoided flights between wind turbines by flying at the ends of the rows or through the existing corridor between alignments of wind turbines. Our results are in line with the theory that birds may become habituated to the presence of wind farms suggesting that, under certain conditions, it could be possible to reconcile the presence of wind farms with raptor conservation. Environmental agencies should not only require robust pre-construction surveys, but also that wind energy developers monitor bird abundance and behaviours throughout the lifetime of a wind farm. Since not all wind farms are associated with high mortality rates, such an initiative could be key to gaining more knowledge on the association between wind-farm location, design and risk to birds.

Role of vernal pools in activity and diversity of bats and birds linked with the emergence of flying insects

Vernal pools are small temporary wetlands occurring in shallow depressions usually filled with precipitation in autumn and winter. They will dry seasonally, which makes them fishless ponds devoid of large aquatic predators. These ephemeral ponds are less studied compared to other freshwater ecosystems, such as lakes, although they are considered biodiversity hotspots. The aim was to study the use of vernal pools by birds and bats and compare this to permanent wetlands. We expected higher bat activity and bird abundance in vernal pools than permanent wetlands, and that is related to the spatial and temporal fluctuations of the emerging flying insects. However, no difference in bird abundance, diversity or community was found between the habitats. Regarding bats, the activity of Myotis spp was generally higher at lakes than vernal pools, while the activity of Eptesicus nilssonii increased during the study period regardless of habitat type. No relationship was found between the emergence of insects and the occurrence of bird and bats. Although, vernal pools were not more attractive habitats compared to lakes, they still form an important, largely neglected, diverse habitat type within the boreal landscape.

Linking avian malaria parasitemia estimates from quantitative PCR and microscopy reveals new infection patterns in Hawai'i

Plasmodium parasites infect thousands of species and provide an exceptional system for studying host-pathogen dynamics, especially for multi-host pathogens. However, understanding these interactions requires an accurate assay of infection. Assessing Plasmodium infections using microscopy on blood smears often misses infections with low parasitemias (the fractions of cells infected), and biases in malaria prevalence estimates will differ among hosts that differ in mean parasitemias. We examined Plasmodium relictum infection and parasitemia using both microscopy of blood smears and quantitative polymerase chain reaction (qPCR) on 299 samples from multiple bird species in Hawai'i and fit models to predict parasitemias from qPCR cycle threshold (Ct) values. We used these models to quantify the extent to which microscopy underestimated infection prevalence and to more accurately estimate infection patterns for each species for a large historical study done by microscopy. We found that most qPCR-positive wild-caught birds in Hawaii had low parasitemias (Ct scores ≥35), which were rarely detected by microscopy. The fraction of infections missed by microscopy differed substantially among eight species due to differences in species’ parasitemia levels. Infection prevalence was likely 4–5-fold higher than previous microscopy estimates for three introduced species, including Zosterops japonicus, Hawaii’s most abundant forest bird, which had low average parasitemias. In contrast, prevalence was likely only 1.5–2.3-fold higher than previous estimates for Himatione sanguinea and Chlorodrepanis virens, two native species with high average parasitemias. Our results indicate that relative patterns of infection among species differ substantially from those observed in previous microscopy studies, and that differences depend on variation in parasitemias among species. Although microscopy of blood smears is useful for estimating the frequency of different Plasmodium stages and host attributes, more sensitive quantitative methods, including qPCR, are needed to accurately estimate and compare infection prevalence among host species.

Impact of the urban environment on habitat selection of wild avifauna: Center to boundary ecological assessment

Urban structures and anthropogenic activities are changing birds' behavior globally. This research work focused on the analysis of avifauna abundance, distribution, and behavior in the Kamoke area (northeastern Punjab, ~20 km2) by anthropogenic activities, novel manmade structures, urban landscape, and spatial distribution patterns. Bird abundance, diversity, and behavior were observed by the point count method and spatial distribution pattern by GIS in the study area including housing, markets, roads, and urban structures. Ecological analysis of urban habitat patches as hotspots indicated a species richness of 36, an abundance of 1994, an evenness of 0.533, and a Shannon-Wiener index value of 1.910. The most dominant species included House sparrow (~586 population), House crow (~452 population), and Red vented bulbul (~277 population). The species which were observed to be lowest in numbers are White throated kingfisher, Wire tailed swallow, and Mourning dove. The spatial distribution pattern in the urban environment of bird species seems to have a relationship with habitats such as urban-specific, park-specific, and urban settlement boundaries specific as indicated by the principal component analysis (PCA). Bird abundance is noted to be higher in the center of the city and gradually decreases towards the boundary of the city. Also, there is a trend in the diversity of birds which increases around the boundary of the city and decreases towards the center. A predictable availability of anthropogenic food items from sources such as waste dumps, marketplaces, public parks, shrines, and rice mills impacts the bird feeding behavior of both resident and migratory species. This study is significant in highlighting the abundance and diversity of native trees which are extremely vital to support the urban ecosystem for avifauna and other species. Environmental planners, authorities, and policymakers can benefit from this study to monitor avifauna diversity in the urban ecosystem.

Optimization of wetland water replenishment process based on the response of waterbirds in a semi-arid and cold region

Emergency ecological water replenishment(EEWR) has become a major strategy for recovering degraded wetland ecosystems worldwide. However, the actual replenishment process mainly depended on the tradeoff and experience between the managers of Taoer River and Xianghai Wetland, which is very random and lacks theoretical guidance. Thus, there is urge to assessing water replenishment effect on wetland and help to optimize the process. With contrasting results as different ecosystem elements respond differently, the optimization of water replenishment process should be based on the improvement of the ecosystem as whole rather than its separate elements. However, the dynamic monitoring of biotic and abiotic factors to reveal the complex relationships underlying their response can be challenging. Based on 6 years’ series data of migratory birds and environmental factors of Xianghai Wetland, which started emergency ecological water replenishment since 2004 and occurred frequently since 2011, the broader ecosystem response to water replenishment was analyzed using a multiple paths regression model and proposed an optimized scheme. The results showed that bird diversity was positively influenced by the increase in water area and vegetation was induced by ecological water replenishment. While the response of bird abundance to water replenishment varied with time, adequate open water in March was found to have a positive relationship with abundance by promoting vegetation germination and the reproduction of benthic organisms. High flow levels in the wet season (June–August) can negatively affect waterbird abundance by rapidly increasing water levels and inhibiting plant respiration, which leads to the reduction in feeding efficiency of waterbirds and biomass accumulation. Therefore, the existing ecological water replenishment time (May–September) is not suitable for bird abundance and should be advanced to spring (March–April). Given the antagonistic effect of flow on diversity and abundance, the total replenished water should be approximately 100 million m3. To avoid the negative influence of high water in the wet season, the allocation of water could be 0.3, 0.3, 0.2, and 0.2 million m3 in April, May, September, and October, respectively. These results scientifically support wetland protection and management.

Bird species richness and abundance in remnant eucalypt forest on the Southern Tablelands of New South Wales: A removal experiment

ABSTRACT Birds were removed after counting numbers along a creek reserve established when old growth eucalypt forest on the Southern Tablelands of New South Wales was cleared for pine plantations. Removal ceased after the number of individuals collected exceeded the number estimated by census to be present. Removal was followed by rapid recolonization probably from a large area of uncleared forest continuous with the reserve. This is similar to results obtained in removal experiments in North America which found the bird community contained ‘surplus’ or ‘floating’ individuals that immediately occupied vacant habitat. The large number of ‘floaters’ we identified by collection on the creek reserve assists in explaining the rapid recolonization by birds of habitats affected by wildfires and has significant conservation benefits.

Factors shaping insectivorous farmland bird abundance in intensively cultivated arable fields: Insights through the former Iron Curtain

The decline of farmland bird populations is a well-documented phenomenon that has primarily been attributed to agricultural intensification. However, the specific mechanisms that make intensively used farmland unsuitable for breeding birds have not yet been satisfactorily elucidated, particularly for insectivorous ground-nesting species. To bridge this knowledge gap, we studied the breeding abundance, invertebrate food supply and habitat characteristics of the Yellow Wagtail (Motacilla flava) in arable fields in the lowlands of south-western Slovakia. This region is characterized by the largest field sizes in the European Union, with conditions that are typical for high-intensity farmland areas in parts of Central and Eastern Europe where farmland underwent collectivization. Since Central and Eastern European farmland is considered one of the strongholds of the Yellow Wagtail in Europe, we tested the capacity of winter wheat, rapeseed and maize to support its local population. The Yellow Wagtail abundance was best predicted by habitat characteristics: birds chose fields without woody plants in their surroundings and with suitable crop height and coverage, while the effect of invertebrate food supply was insignificant. Focussing on individual crops, we found that the birds did not prefer the maize and rapeseed fields despite these having a richer food supply, likely because these crops had an unsuitable vegetation structure. The low overall abundance of the studied species indicates that farmland consisting of large fields creates unsuitable conditions for breeding. Therefore, agricultural policy instruments leading to a reduction of field size or the creation of herbaceous field edges should be supported.