Bird Species Abundance Research Articles

Assessing Southern Gulf of Mexico Resilience: Least Tern Nesting Failure During the COVID-19 Pandemic

The COVID-19 lockdown opened an opportunity to assess the response of animal populations to diminished human activities. As coastal dunes face many disturbances caused by increasing human activities, we assessed the effect of reduced human mobility on coastal bird diversity and abundance and on the Least Tern nest failure rate on an island in the southern Gulf of Mexico before, during, and after the lockdown to test the hypothesis that diminished tourism and recreational activities can contribute to the conservation of coastal ecosystems by increasing species richness and abundance and decreasing the nest failure rate. We used data from 2016 to 2021 to estimate nesting failure probabilities using Bernard’s cumulative distribution function, Kaplan‒Meier tests, and Cox regression for hazard rates. Bird species richness and abundance were compared using Kruskal‒Wallis rank tests. Factors related to breeding site preference were assessed using the BIOENV method. The lockdown did not affect species richness, but bird abundance was inversely related to pedestrian traffic (rho = − 0.908, p < 0.0001, n = 48). Nest failure decreased during the lockdown in 2020 (p < 0.0001) due to reduced presence of people, which allowed occupancy of sites never used before. During the lockdown, the proportion of nest failure was lower than that in the other sampling years (p < 0.0001, φ range = − 0.445 to − 0.278). Accordingly, diminished pedestrian traffic can increase nest survival (log-rank p < 0.0001). Policies to reduce beach pedestrian traffic will help strengthen wildlife conservation and building coastal resilience.

Species traits and latitude mediate bird responses to forest edges globally

ContextAlthough local studies comparing species abundance between forest edges and interiors are common, general patterns in the response of different species to edges are still to be determined. There is little consensus on the impacts of forest edge effects on the abundance of individual bird species, probably because the species traits affecting edge responses have rarely been synthesized.ObjectiveWe aimed to identify how different species’ traits, as well as extrinsic (environmental) factors, mediate the responses of birds to forest edges globally.MethodsWe collected global information from bibliographic databases from 59 studies with 63 different datasets that compared bird abundance between forest edges and interiors. For each species, we compiled six traits (diet, habitat preference, territoriality, body mass, hand-wing index, and foraging stratum). Using Linear Mixed-effects Models, we evaluated how species traits, latitude, edge contrast, and sampling method affected bird responses to edges.ResultsBased on 2981 responses of 1414 bird species, we found that plant/seedeaters birds responded positively to edges. The strength of habitat preferences on edge responses was also mediated by latitude. Open-area species from tropics exhibited a positive response, diminishing as latitude increases. Conversely, forest species tend to exhibit a somewhat more negative response in tropical zones. Edge effects were more negative for soft (low-contrast) edges.ConclusionsSpecies traits, in particular diet and habitat preferences interacting with latitude, mediate the impacts of edge effects on different bird species. These species traits and latitudinal gradients must be explicitly considered in models attempting to explain variability in edge responses among species, as well as in conservation actions in fragmented landscapes.

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 &lt; 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.

Assessment of diversity, abundance, and seasonal variations of bird species in Bengaluru District, India during COVID-19 lockdown

The study investigates bird population dynamics in Bengaluru, India, post-lockdown, focusing on occurrence, seasonal abundance, species diversity, richness, dominance, and evenness. It covers 55 bird species across 52 genera, grouped into 32 families within 13 orders, with a notable peak in winter. Various indices, including Shannon Wiener, Margalef’s, Pielou’s, and Simpson’s, reveal significant seasonal differences in bird population characteristics. The Rock Pigeon Columba livia dominates, while the Black-headed Ibis Threskiornis melanocephalus is less prevalent. The study identifies Near Threatened species like Black-headed Ibis and Oriental Darter Anhinga melanogaster, along with Least Concern species per the IUCN Red List. Common species include Rock Pigeon, Large-billed Crow Corvus macrorhynchos, House Crow Corvus splendens, Black Drongo Dicrurus macrocercus, Brown Shrike Lanius cristatus, Common Myna Acridotheres tristis, Jungle Myna Acridotheres fuscus, Red-whiskered Bulbul Pycnonotus jocosus, and Streak-throated Swallow Petrochelidon fluvicola. The study aims to inform improved management and conservation strategies for Bengaluru’s diverse bird species.

Roosting and Breeding Ecology of Birds in Shola Sky Island Forests: A Systematic Review and Analysis

The Shola Sky Island forests, located in the Western Ghats of India, are unique ecosystems renowned for their high elevation, isolated patches of evergreen forests, and rich avian biodiversity. Understanding the roosting and breeding ecology of birds in these forests is essential for their conservation and management. However, a comprehensive synthesis of the existing literature on this topic is lacking. This systematic review aims to fill this knowledge gap by analyzing and summarizing the available research on the roosting and breeding ecology of birds in the Shola Sky Island forests. The review focuses on various aspects of bird ecology, including roosting site selection, roosting strategies, breeding phenology, nest site selection, nesting behaviors, and factors influencing non-roosting and breeding behaviors. The literature search encompasses studies conducted in the Shola Sky Island forests, covering a wide range of bird species and their ecological requirements. Findings from the review highlight the importance of specific habitat characteristics, such as vegetation structure, microclimate, and resource availability, in influencing bird roosting and breeding behaviors. The availability of suitable roosting sites and nesting habitats within the forest plays a crucial role in determining the distribution and abundance of bird species. Factors such as food availability, altitudinal movements, social interactions, and territoriality also impact non-roosting and breeding behaviors in these forests. Furthermore, the review emphasizes the challenges posed by habitat fragmentation, climate change, and human activities to the roosting and breeding ecology of birds in the Shola Sky Island forests. Understanding these threats and their implications for bird populations is essential for effective conservation and management strategies.

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.

Diversity and Distribution of Avifauna in the Northeast of Addis Ababa, Central Ethiopia.

Exploring avian species diversity and distribution patterns is vigorous for conservation efforts in biodiversity-rich countries such as Ethiopia. Compared to other species, birds are relatively well-known and easily observed, making them great markers of productivity or biodiversity. Although bird species are found all across the world, their survival and range have been negatively impacted by habitat loss, fragmentation, and destruction. Thus, the goal of this study is to provide baseline data on avifaunal diversity in the Northeast of Addis Ababa, including species richness, distribution, and relative abundance in various habitats conducted from January 2023 to September 2023 using a stratified sampling design into three habitat types: settlement, farmland, and abattoir. A fixed-width line transect sampling method was used at the farmland and settlement, and a point transect was employed at the abattoir site to collect the bird data. The data were compared using Mann-Whitney and Kruskal-Wallis statistical tests in both seasons and habitat types. A total of 42 bird species belonging to twenty-three families, and nine orders were recorded during the study period. Of these, blue-winged goose and wattled ibis are endemic to Ethiopia. Hooded vultures and White-backed vultures are critically endangered species. The mean abundance of bird species significantly varied in the three habitat types (χ2 = 13.6, df = 2, p=0.001). The abundance of bird species was nonsignificant difference between wet and dry seasons (U = -0.874, p=0.381). The highest diversity (H' = 2.74) was recorded at settlement, and the lowest diversity index (H' = 1.09) was recorded at the abattoir in the dry season. In the wet season, the highest diversity (H' = 2.66) was recorded in the farmland, and the lowest (H' = 1.08) was recorded at the abattoir. The highest evenness (J = 0.94 and J = 0.93) was recorded on the farmland in the wet and dry seasons, respectively. In the study area, urbanization is extremely impacting the environment and altering ecosystem services upon which human civilization depends. Most of the avian species observed in the study area are capable and tolerant of human-induced habitats in the city. Therefore, city planners must consider conserving urban bird species' habitats and feeding sites.

Assessment of Avifauna and Flora Diversity in Degraded Mangrove Ecosystems on Eagle Island, Niger-Delta Rivers state, Nigeria

The study investigated the impact of degradation on the ecological richness and composition of both avian and plant communities in this specific coastal environment of Eagle Island in the Niger-Delta. The Line Transects method was employed for gathering data on the diversity and abundance of bird species in the designated research area. A total of 20 transect lines, each measuring 1000 meters, were randomly positioned. The ecological survey for the floristic investigation took place in March 2022 as documented In this research, a total of 20 study plots, each measuring approximately 25 m × 25 m (500 sq m), were established. The PAST model was employed to assess species diversity, while quantitative and qualitative indices were utilized to measure floristic composition and similarity. The results revealed that though the study area is degraded was able to support bird species diversity. In all a total of 174 bird species belonging to forty two families were recorded a and 55 plant species belonging to 33 families were recorded in the study area see appendix 1and 2. Shannon diversity in the study area indicates that it was higher in the dry season 5.017 than wet season 5.01. The result of the Pyto-sociological Parameters of tree species study area shown that Ceiba pentandra has the highest DBH and MT (139 and 27), this followed Diallum guineese (117 and 26) ,why Rhizophora mangle has the highest frequency of 13.

The Importance of Wetlands for the Conservation of Birds in Tigray National Regional State (Northern Ethiopia)

Many birds use wetland habitats for all or part of their lives. This study was conducted to investigate the significance of wetlands and associated habitats for bird conservation in the central zone of Tigray, northern Ethiopia, from June 2022 to May 2023. The point count method was used to study the bird assemblage structure and diversity. The Shannon–Wiener diversity index and ANOVA were used to analyze the wetland bird community structure. A total of 4337 individual birds belonging to 120 species, 15 orders, and 41 families were recorded. Among the identified bird species, the Abyssinian catbird, white‐winged cliff chat, Abyssinian longclaw, wattled ibis, and black‐winged lovebird are endemic and near‐endemic species, which are found only in Ethiopia and Eritrea. The Passeriformes order had the greatest number of species (n = 68), followed by the Columbiformes order (n = 9). The​ Mai‐Shigurti Wetland had the greatest abundance of birds (N = 2472), while the Hatsebo Wetland had the least (N = 936). A high abundance of birds was recorded during the wet season (N = 2805), and a low abundance was recorded during the dry season (N = 1532). A significant difference in the abundance of bird species was observed among wetlands and seasons (p &lt; 0.05). The highest species diversity (H′ = 4.13) was recorded in Mai‐Shigurti during the wet season, whereas the lowest was recorded in Hatsebo during the dry season (H′ = 3.2). The highest species evenness was recorded in Hatsebo (E = 0.82) during the dry season, and the lowest was recorded in Mai‐Shigurti (E = 0.72) during the wet season. The results show that wetlands support a high diversity of birds; however, they are highly threatened by anthropogenic threats, including solid waste disposal, erosion, agricultural expansion, human settlement, livestock overgrazing, military camping, and eucalyptus cultivation. Therefore, community‐based conservation initiatives should be implemented to mitigate these threats. Moreover, wetland management policies should be established to safeguard wetlands and their biological resources.

Socio-Cultural Impact of Avian Diversity in the Himalayan Region: A Comprehensive Study of Bird Species in Huddu Village, Chopta, and Deoriatal

The study employed a random visualization method to count and describe bird species in the Huddu Village, Chopta, and Deoriatal regions of the Himalayas. The data, collected through global positioning system (GPS) recordings between March and April, revealed 48 bird species across these areas, belonging to 20 different families and varying orders. The observations included 33 bird species in the Huddu region, 10 in Chopta, and 9 in Deoriatal, each displaying different elevations and geographical coordinates. Aside from birds, the fieldwork documented various flora and fauna species. The research detailed the relative abundance, distribution, and feeding habitats of bird species through recorded tables. Notable high-abundance species in Huddu Village included the streaked laughing thrush, common myna, various drongo species, grey treepie, and yellow or red-vented bulbul. Conversely, low-abundance species like alpine chough, Asian koel, scarlet minivet, and fire-breasted flowerpecker were rare, with their occurrences graphically depicted in the results. The identification of bird species utilized diverse methods, including internet resources and field guides. The study contributes valuable insights into the avian biodiversity of the Himalayan regions, emphasizing the importance of random visualization techniques and recording detailed ecological characteristics.

Wintering Waterbirds in the Wetlands of the Azov-Black Sea Region of Ukraine at the Beginning of the 21st Century — Species Composition, Abundance, Distribution and Tendencies

Data collection on wintering waterbirds in the wetlands of the Azov-Black Sea region of Ukraine began in the late 1980s, mainly thanks to the International Waterbird Census (IWC), which has become more extensive and regular since about 2005. This article is devoted to generalization of data on species composition, abundance of birds and their spatial distribution in that region based on the results of the winter census 2005–2022. The long-term dynamics of the waterbirds number and the peculiarities of the species distribution are mostly analyzed for abundant bird species. General information about common and rare species is also given.

Pine plantations and native forest fragments adjacent to intact forests provide surrogate habitats for birds in an Afrotropical forest landscape

AbstractTropical forests harbour 72% of the world's bird species. The changing land uses have fragmented natural forests or replaced them with plantation forests. This sets in an argument as to whether forest fragments and plantations can support birds. We assessed birds in a plantation, fragment and an intact (continuous) Budongo forest, Uganda. We compared bird species composition, diversity and functional traits between the forests and examined their response to habitat characteristics. We sampled birds using 135 point counts along nine transects and assessed habitat characteristics in 90 plots in the fragment and intact forest. We classified bird species according to habitat preference and feeding guild. Bird species composition differed between forests. Bird abundance and richness in plantation and fragment were lower than in intact forest. Forest specialists and insectivores dominated the intact forest. Most birds in the fragment were forest generalists and frugivores. Forest visitors and granivores dominated in the plantation. Trachyphorus purpuratus, Andropadus latirostris and A. curvirostris preferred sites with greater tree height, diameter and many snags, respectively. Bird species abundance and richness declined with increasing tree diameter and increased with snags. Forest specialists preferred sites without climbers. Thus, plantations and fragments close to intact forests provide surrogate habitats for bird conservation.

Who’s a pretty bird? Predicting the traded abundance of bird species in Australian online pet trade

Who’s a pretty bird? Predicting the traded abundance of bird species in Australian online pet trade

Dynamics of the Abundance of Bird Species during Succession of Oak Forests in Southwestern Belarus

Dynamics of the Abundance of Bird Species during Succession of Oak Forests in Southwestern Belarus

Status of abundant bird species in Lake Qaroun, Egypt.

Status of abundant bird species in Lake Qaroun, Egypt.

Managing Grass Height for Birds and Livestock: Insights from the Río de la Plata Grasslands

Success in conserving biodiversity in rangelands depends on effectively managing the systems to achieve positive economic outcomes while preserving biodiversity. In the native grasslands of the Río de la Plata region, livestock production often falls below its potential due to low forage availability. Cattle management strategies that promote taller grass height can increase forage mass without replacing native vegetation, enhancing cattle dry matter intake and potentially boosting production. Nonetheless, the impact of such changes on grassland bird populations remains unclear. In this study, we implemented management changes to increase grass height across six ranches and evaluated the responses of grassland bird specialists. Initially, the average grass height was 6 cm, but after the management changes, it increased to an average of 12 cm. This also increased grass heterogeneity, which is desirable for supporting a higher richness of grassland birds. We found that both the abundances of individual grassland bird species and richness did not vary after the management changes. Moreover, threatened grassland bird species that rely strictly on taller grasses did not colonize the paddocks following the alterations. Therefore, we conclude that maintaining the abundance of seven grassland bird specialists and potentially increasing livestock production is feasible, as the attained grass height coincided with levels known to maximize cattle dry matter intake rate. However, achieved average grass height was not sufficiently tall to support endangered tall grass specialists. It is possible that longer time frames allow tussocks to grow taller and provide such habitat conditions. Most previous research on rangelands biodiversity has focused on assessing faunal responses in either ungrazed or heavily grazed areas. Therefore, our findings contribute to a better understanding of faunal responses within this spectrum and align with a win-win production-conservation approach, which can aid in safeguarding biodiversity across large geographic scales.

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.

Impact of Urban Landscape on Relative Abundance of Invasive Bird Species

Impact of Urban Landscape on Relative Abundance of Invasive Bird Species

How Are Urban Birds Affected by Surrounding Forests and Agricultural Landscapes?

The main objective of this study was to assess the influence of surrounding forest and agricultural landscapes on the bird communities within cities. Using the point count method, we collected data and analyzed the species richness and relative abundance of breeding birds. We found differences in the species richness and relative abundance of breeding birds between urbanized areas surrounded by forests and agricultural landscapes. However, both types of landscapes significantly differed in terms of bird community structure. The highest relative abundances of bird species were observed in city forest parks and cities surrounded by forest landscapes, while the lowest abundances were detected in highly urbanized areas. Cities surrounded by forests exhibited an additional nine species compared to other areas. The ecological grouping of species revealed that cities surrounded by forests had higher relative abundances of typical forest species, such as the Great Tit (Parus major), Eurasian Blue Tit (Cyanistes caeruleus), Common Chaffinch (Fringilla coelebs), and European Pied Flycatcher (Ficedula hypoleuca), whereas cities surrounded by agricultural landscapes were characterized by bird communities adapted to open or semi-open landscapes with specific feeding and nesting behaviors. The presence of specialist forest species in the composition of urban bird communities enhances biological diversity, which is crucial for the stability of both urban ecosystems and bird communities.