Bird Abundance Research Articles

WATER INHABITING BIRDS OF MAIGANGA POST COAL MINING PONDS AND ARTIFICIAL WETLAND

Wetlands play a significant role in bird conservation and generally support biological diversity. Historically, bird community assessment has been employed in monitoring and identifying areas for conservation actions. In this study, we examined two post mining ponds and one artificial wetland in Maiganga Coal Mine, Gombe State for wetland avifauna. We focused on water birds (i.e. bird species that depend wholly or partially on water and wetland ecosystems for their survival). Survey was conducted during the onset of dry season in October 2021 to September 2022. Point count technique was used for the survey. A total of 626 individuals of 23 species from 19 genera, 10 families and 6 bird Order were recorded. The White-faced whistling duck was the most abundant bird species and was restricted to the active-mine pond (AMP). AMP was the most diverse of the three water bodies surveyed. However, some species were exclusive to either of the three sites. Similarly, AMP was the most abundant site with 426 individuals from 16 bird species, followed closely by the sedimentation pond with 147 individuals drawn from 15 bird species. The results suggest that water depth, age of establishment and surrounding vegetation structure could be a major determinant of bird species composition and abundance in the study area. The study highlights the importance of restorative actions aimed at recovering modified landscapes, through tree planting and creation of wetlands. This is evident in the presence of waterbirds in Maiganga, a location that was previously devoid of perennial water bodies and...

The Neotropical Biodiversity Mapping Initiative: Transforming Venezuelan biodiversity monitoring and capacity building

Tropical Latin America is home to an enormous share of the world's biodiversity. Despite its immense natural wealth, the region faces a significant deficit of reliable biodiversity data and lacks the local capacity necessary to collect such data. The Neotropical Biodiversity Mapping Initiative (NeoMaps or NeoMapas) is a long-term biodiversity monitoring program. NeoMaps has not only addressed these gaps in biodiversity data in one of the megadiverse tropical countries, Venezuela, but has also emerged as a model for efficiently surveying biodiversity while strengthening the local capacity needed to conduct these surveys. After three nationwide systematic surveys and international field courses in 2006, 2009, and 2010, NeoMaps assembled an invertebrate collection and biodiversity database with over 170,000 records of occurrence and abundance for birds, dung beetles, and butterflies. NeoMaps activities lead to direct outcomes by reducing biodiversity knowledge gaps for three taxonomic groups and training more than 60 conservationists from Venezuela, Colombia, Mexico, Peru, Bolivia, Brazil, Uruguay, and Spain. NeoMaps had a broader impact on national capacity building programs, and made important contributions for improving, sharing and applying national biodiversity knowledge.

Urban refuges in winter: the role of habitat characteristics and supplementary feeding in shaping bird occupancy and abundance

Urban refuges in winter: the role of habitat characteristics and supplementary feeding in shaping bird occupancy and abundance

Improving bird abundance estimates in harvested forests with retention by limiting detection radius through sound truncation

Abstract An inherent challenge with acoustically surveying birds is that the distance at which they can be detected depends on how far their song can be heard. We developed a distance-based sound detection space truncation method to correct for variable sampling radii due to surveying in forested or open conditions. The method was pivotal in evaluating bird responses to retention patches; without this methodological advancement, the impact of retention patches on songbird abundance was vastly underestimated. In the boreal forest, these patches of live trees are retained in regenerating harvested forests to provide ecological services for species adapted to natural disturbances. Although we did not verify our a priori assumption with ground observations, our findings suggest that limited-distance sampling better captures the effects of retention patches on bird use of harvested forests. When evaluated using unlimited distance surveys, retained trees had a negligible effect on bird abundance, whereas applying detection distance truncation highlighted the importance of retention on forest birds. We found that early to mid-seral forest songbirds benefited from retention patches, with notable increases in abundance after 10 years of regeneration. The size of retention patches, ranging from 0.1 to 1.2 hectares, did not have a linear relationship with bird abundance. Instead, edge effects stemming from the configuration of these patches emerged as key determinants of abundance for the majority of the species studied. Retention patches that were nearest to unharvested forests were used the most, compared to further into harvest areas. Our research not only highlights the underestimated impact of small-scale live tree retention on forest songbirds but also introduces a significant methodological innovation in the field of acoustic monitoring.

Seasonal Dynamics and Avian Diversity along the Adyar Riverbank: Insights from a Year-Long Survey

The avian survey conducted along the Adyar Riverbank (Manapakkam) from January 2023 to December 2023 documented a total of 3120 individual birds across 75 species from 16 avian orders, highlighting the significant biodiversity within this urban ecosystem. This study aimed to assess seasonal variations in bird diversity and abundance, emphasizing the river’s role as an important habitat. The highest diversity was observed during winter, specifically in February 2023, with a diversity index of 296.80 and a Simpson’s index of 0.22. A total of 36 species and 636 individuals were recorded. In contrast, the lowest diversity was observed in summer, particularly in July 2023, with a diversity index of 29.29 and a Simpson’s index of 0.05, corresponding to 18 species and 114 individuals. The monsoon and post-monsoon periods exhibited a prominent increase in diversity due to the arrival of migratory species and improved habitat conditions. Important species recorded throughout the year included the Paddy Field Pipit, House Crow, and Rufous Treepie, while conservation-significant species such as the Black-headed Ibis and Spot-billed Pelican were also observed. Thus, the present study underscores the Adyar River’s ecological importance and highlights the need for continuous monitoring and targeted conservation efforts to maintain avian biodiversity in urban river ecosystems.

Ptačí diverzita v historickém zámeckém parku – implikace pro ochranu biodiverzity v hospodářských lesích

Long-term trends of abundance and diversity of forest birds have been very stable over past decades in European managed forests. It can be caused by high heterogeneity on habitat scale. In European cultural landscapes, there is another habitat very similar to managed forests, and that is a historic manor park. The parks can even show higher bird diversity than managed forests. However, there is an evident knowledge gap related to long-term changes of bird abundance and diversity in the habitats of manor parks. In this study we observed long-term changes of bird community in the historic manor park Čechy pod Kosířem (Czech Republic) using comparison of bird territory mapping in 2022–2023 with older bird studies in this locality. We gained an overview of bird community changes in the manor park for the period of 1997–2023. Results show that the bird community in historic manor park was remarkably unvarying in abundance and diversity. Historic manor parks can be considered as important refuges for forest bird diversity in cultural landscapes. We discuss the research implications for conserving bird diversity in managed forests especially in connection with large old trees preservation providing heterogeneity of nest habitats.

Habitat structure and an introduced predator limit the abundance of an endangered ground-nesting bird.

Understanding the factors that limit the abundance of threatened species is critical for the development of effective conservation strategies. However, gaining such knowledge from monitoring programs and using it to inform decision-making for rare species can be difficult due to methodological issues posed by the problems of distinguishing true absences from false absences and the analysis of datasets dominated by zero counts. The plains-wanderer (Pedionomus torquatus) is a critically endangered ground-nesting bird that occurs in grasslands of southeastern Australia. Decline of the plains-wanderer has been attributed to habitat modification but little emphasis has been placed on the role of introduced predators, such as the red fox (Vulpes vulpes), which have had a devastating effect on small ground-dwelling vertebrates in dryland regions of Australia. Here, we use a 9-year time series of spotlight counts to investigate the impact of vegetation structure and fox presence on plains-wanderer occupancy and abundance. We used distance sampling to determine the effective strip width for sighting plains-wanderers during spotlight surveys. We then used a hurdle model approach whereby binomial generalized additive models were fitted to presence/absence data within the effective strip-width across all sites and negative-binomial models were fitted to an index of abundance at sites where plains-wanderers were observed. Plains-wanderer occupancy and abundance fluctuated markedly through time. Where foxes were absent, occupancy (but not abundance) of plains-wanderers showed a humped relationship with grass height with an optimal height between 50 and 150 mm. Where foxes were present however, this relationship broke down and plains-wanderers were rarely recorded. Our results suggest that plains-wanderers should benefit from management strategies that maintain grass height at optimal levels and exclude foxes or effectively suppress their populations. A key message from this study is that if statistical analyses of data generated by monitoring programs for rare species are intended to inform management decisions by identifying relationships between threatened species and drivers of their abundance, there should be consideration of analytic approaches that account for true and false zeroes, high prevalence of zeroes, and the possibility of nonlinear responses.

Contributions of Urban Woodlands to Bird Diversity and Abundance in The Anatolian Side of Istanbul

Aim of study: The study aimed to assess the impact of urban woodlands on bird species diversity and abundance in the Anatolian side of Istanbul, focusing on species typically absent from urban centers but found within urban environments. The findings are intended to contribute to the development of future conservation and habitat management strategies. Area of study: The study was conducted in five areas in Üsküdar and Beykoz, including an urban center, three urban woodlands (Fethipaşa, Hidiv, and Beykoz Abrahampaşa) and a natural area in Istanbul's northern region. Material and methods: Data on bird species and their abundances were collected and tabulated through 900 point counts from April 2022 to March 2023. The data was analyzed using abundance values, species richness and diversity, identifying distribution and evenness through rank abundance distribution and curves. Similarity analysis was performed using the clustering method and species composition was compared using a Venn diagram. Main results: Seventy-two bird species were identified across the study areas. A decrease in urbanization density enhances bird species richness, diversity and evenness, with the natural area recording the highest values. Urban woodlands harbor species absent from more urbanized locations. Distinctions in species distribution and bird diversity between the areas were revealed. Research highlights: Urban woodlands are crucial areas for wildlife in metropolises, providing significance from both ecological and sociocultural perspectives. Although they may not match natural areas in species diversity, these woodlands significantly contribute to bird diversity within the urban environments. Further research is needed to explore the unique characteristics of each woodland and their contributions to urban ecosystems.

Sacred sites provide urban green spaces that maintain bird diversity in the megacity of Tokyo, Japan

Green spaces in cities are thought to play an important role in maintaining urban biodiversity. However, it is difficult to create large new areas of green space in big cities. Therefore, existing green spaces need to be conserved and properly managed to conserve urban biodiversity. In big Japanese cities, sacred sites such as shrines, temples, and historic parks are some of the common types of green space. In addition to their role as religious spaces, they may also play an important role in urban biodiversity conservation because of their function as long-term reserves of natural vegetation. In this study, we examined the function of shrines, temples, and historic parks in Bunkyo ward, Tokyo, in maintaining bird diversity by comparing them with urban parks. In addition, a vegetation survey was conducted to identify environmental factors that affect bird diversity, and differences in the bird species observed in each type of green space are discussed. The heterogeneity of bird species composition between study sites was higher among shrines and temples than among urban parks.Forest bird abundance was higher during the breeding season and bird species richness was higher in winter at shrines and temples and historic parks than in urban parks. Bird diversity was positively affected by the abundance of shrubs and evergreen trees. We found that sacred sites were more important than urban parks for maintaining bird diversity. The results also suggested that differences in vegetation structure are a cause of this pattern, and small green spaces in the grounds of sacred sites are managed in a way that is more suitable for maintaining bird diversity.However, shrines and temples, despite their strong historical and cultural value, are threatened by recent urbanization. It is necessary to maintain and properly manage these green spaces as part of urban ecosystems.

Crumb bums? Context dependence in ecosystem services supplied by common urban animals

AbstractBolstering the supply of animal‐mediated ecosystem services is an emerging priority in human‐altered landscapes. Such services are driven not only by environmental factors that shape communities of species that provide the service but also by the ecological context that affects the behavior of these species. In this study, we used a field experiment to investigate an ecosystem service that depends on resource use behavior—the removal of littered food waste by birds and squirrels in urban green spaces. We first explore how landscape‐scale urbanization affects the composition of the litter‐removing species community. We then examine two facets of waste removal provisioning—the amount of food removed and the speed of removal—and how they vary across ecological contexts represented by green space type (picnic areas, urban parks, and forest preserves), bird and squirrel abundance, number of people, amount of existing litter, and weather conditions. We found that although landscape‐scale urbanization affected the composition of species within green spaces, service provisioning was context‐dependent. Littered food removal services were provided at higher rates in park and picnic sites than in forest preserves and the abundance of eastern gray squirrels (Sciurus carolinensis) was a main driver of littered food removal services. Where squirrels were abundant, more food was removed, and food removal began and was completed more quickly. When squirrel abundance is accounted for, removal from picnic areas is higher than park sites, indicating context dependence in this service is likely driven by squirrel behavioral responses to ambient food waste levels in these habitats. This study highlights the role of common urban species in providing a valuable ecosystem service and the importance of ecological context in its supply. Efforts to account for animal‐mediated ecosystem services in human‐altered landscapes should address the potential for services to be driven by a single species and context‐dependent factors that influence behavior.

Updates to the wild bird abundance and movement models for the early warning system for avian influenza in the EU

Abstract Highly pathogenic avian influenza (HPAI) viruses pose a significant threat to both poultry and wild bird populations. Migratory wild birds play a key role in the intercontinental spread of avian influenza (AI), introducing the virus into poultry populations. In response to frequent AI outbreaks in Europe, the European Food Safety Authority (EFSA), at the request of the European Commission (EC), produces quarterly and annual epidemiological reports to monitor and analyse AI trends. A key component of this surveillance includes the integration of outbreak data from Member States and contributions from non‐governmental ornithological organisations like the European Bird Census Council (EBCC) and the European Union for Bird Ringing (EURING) together in a predictive spatio‐temporal risk assessment model. Previous data integration and modelling efforts led to the development of an early warning system for predicting HPAI outbreaks accessible through a publicly available online user interface: the Bird Flu Radar. This report presents an improvement of the system by expanding the species coverage and refining the existing base models behind the epidemiological model. Specifically, this report details the exploration to incorporate 12 additional wild bird species into the models, and the changes made to the base models predicting the distribution and movements of wild birds. We demonstrate the improvements respecting the existing base models while at the same time enhancing the effectiveness in predicting HPAI outbreaks and possibly mitigating negative effects in Europe by providing more accurate predictions to different stakeholders.

Temporal and spatial variability in availability bias has consequences for marine bird abundance estimates during the non‐breeding season

Abstract To effectively monitor how marine ecosystems are being reshaped by anthropogenic pressures, we require understanding of species abundances and distributions. Due to their socio‐economic and ecological value, predatory species are often at the forefront of survey efforts. However, survey data are only valuable if they can reliably be converted into estimates of underlying distributions. We consider at‐sea surveys of marine predators that often inform ecological impact assessments of offshore windfarms. These surveys are subject to a form of detection bias called ‘availability bias’ whereby individuals which are submerged below the surface are consequently ‘unavailable’ for detection. Although correction factors are commonly used in these surveys, they are currently based on limited data that may not be species‐, time‐, or area‐specific. Here, we use time‐depth‐recorder data to investigate variation in marine bird availability bias. We found that the proportion of diving marine birds submerged below the sea surface during daylight hours, and therefore unavailable to be counted during surveys, varied by species, month, and area. For three of our focal species wintering around northwest Europe (Atlantic puffin, common guillemot, razorbill), our results were different to comparable values previously used to correct for the availability bias, whereas no correction factors are regularly used for the fourth species (red‐throated diver). We now present availability bias correction factors that are species‐ and month‐specific to the areas the study populations use during their non‐breeding seasons: the North Sea, the north and west coasts of the UK, the Baltic Sea, and Icelandic coastal waters. Practical implication: Variation in the proportion of daylight hours that marine birds spent submerged lead to differences in availability bias correction factors, thereby impacting estimations of their abundances. We encourage use of correction factors that use data from the species, marine area, and month during which surveys are conducted to provide more accurate abundance estimates. Using more relevant correction factors will result in increasingly accurate abundance and distribution estimates of diving marine birds, with relevance for a range of applications including planning for offshore windfarm developments, the designation and monitoring of protected areas, and understanding environmental change.

Diversity and abundance of birds devastating rice-growing in the town of Daloa and its outskirts (Centre-West, Cote d'Ivoire)

Rice devastating birds are responsible for many losses in rice fields around the world. In Cote d'Ivoire, data on birds in inland are almost non-existent. A study on these birds was carried out from November to December 2019 in three rice fields (Zepreguhe, Abattoir and Kennedy) in the town of Daloa and its outskirts. The study aimed to know the population of those birds in this area. The main method used was the fixed-point, time-dependent counts or point-in-time abundance index (PIA) method. It was possible to count 2368 individuals of 41 species belonging to 14 families of eight orders. The Shannon-Wiever diversity (H'); equitability (E); dominance (IDO) and IPA indices of rice devastating birds in this zone are 3.03, 0.82, 24.79 and 135 respectively. The best-represented family is the Ploceidae with 12 species and 882 individuals. The Village Weaver Ploceus cucullatus and the Northern Grey-headed Sparrow Passer griseus represent the two most abundant species with numbers of 368 and 219 individuals respectively. Of the three study sites, the Zepreguhe site is the most important in terms of specific richness (38 species), relative abundance (37.54%) and PIA (PIA = 155). Further studies are planned to monitor the diversity and population dynamics of these birds over the long term and to determine the extent of their impact on rice production in this area.

Effects of spatial and temporal crop changes on bird diversity in peri‑urban agricultural lands

Numerous studies have investigated bird diversity-environment relationships in agricultural landscapes. While many studies have emphasized the importance of natural/semi-natural elements and their diversity within or surrounding farmlands, it remains unclear how crop diversity impacts birds. There is also a significant gap in our knowledge regarding the effects of temporal changes in crop composition on bird diversity. Using small farmlands in a sub-tropical city of China, we examined how spatial and temporal variation of crops and other local farmland features was linked to species diversity of birds and their traits. In small peri‑urban agricultural areas of Guangzhou, we collected bird and crop/non-crop data approximately bimonthly from December 2021 to October 2022. Overall crop diversity and seasonal crop changes were indexed by alpha diversity (Shannon-Wiener index) and beta diversity, respectively. Both alpha and beta crop diversities were positively associated with Shannon-Wiener diversity of birds. Alpha crop diversity also tended to have a positive impact on species richness. Percent cover of woody vegetation showed a positive effect on all three bird diversity indices, i.e., species richness, Shannon-Wiener diversity, and evenness. Percent cover of rice affected species richness positively and evenness negatively, whereas the effects of percent cover of corn were the opposite. In a fourth-corner analysis, the abundance of plant/seed-eating birds was negatively associated with alpha crop diversity, whereas the abundance of ground-foraging birds was positively associated with beta crop diversity. These patterns indicate that seasonally dynamic crop changes as well as local crop diversity can influence bird diversity and traits in small farmlands. They also suggest that natural/semi-natural woody vegetation, such as trees and shrubs, play a critical role in enhancing species diversity of birds in farmlands dominated by herbaceous edible crops.

Temporal dynamics of acoustic diversity in managed forests

IntroductionIn production forests, management can have cascading effects on biodiversity and ecosystem services. Acoustic diversity reflects the diversity of vocalizing animals and has also considerable recreational value for human well-being, but the relationship between acoustic diversity and forest management remains largely unexploredMethodWe recorded acoustic diversity on forest plots along a gradient of silvicultural management intensity (SMI) in three regions of Germany. We explored the diurnal and seasonal temporal dynamics in acoustic diversity index (ADI) from March to July using generalized additive mixed models (GAMMs). We further investigated the interrelation between acoustic diversity and silvicultural management intensity, forest structural diversity, as well as tree diversity, bird species richness and abundance using structural equation modeling (SEM).ResultsSilvicultural management intensity had significant effects on the temporal dynamics of ADI in May and June from dawn till dusk, but variance explained by SMI was low. We confirmed our hypothesis that ADI was reduced by SMI due to its cascading effects on forest structural diversity and bird species richness and abundance.DiscussionAcoustic diversity indices can provide valuable insights into how forest management affects the acoustic activity of soniferous communities. We discuss how this can indicate both changes in species diversity as well as their vocal activity. We further address potential implications for forest management.

Survey effort and targeted landbird community metrics at Indiana lowland forest restoration sites.

Many sampling and analytical methods can estimate the abundance, distributions, and diversity of birds and other wildlife. However, challenges with sample size and analytical capacity can make these methods difficult to implement for resource-limited monitoring programs. To apprise efficient and attainable sampling designs for landbird monitoring programs with limited observational data, we used breeding season bird point survey data collected in 2016 at four forest restoration sites in Indiana, USA. We evaluated three subsets of observed species richness, total possibly breeding landbirds, Partners in Flight Regional Conservation Concern (PIF RCC) landbirds, and interior forest specialists (IFSs). Simulated surveys based on field data were used to conduct Bayesian Michaelis-Menten curve analyses estimating observed species as a function of sampling effort. On comparing simulated survey sets with multiple habitat types versus those with one habitat, we found that those with multiple habitat types had estimated 39%-83% greater observed PIF RCC species richness and required 41%-55% fewer visits per point to observe an equivalent proportion of PIF RCC species. Even with multiple habitats in a survey set, the number of visits per point required to detect 50% of observable species was 30% higher for PIF RCC species than for total breeding landbird species. Low detection rates of IFS species at two field sites made precise estimation of required effort to observe these species difficult. However, qualitatively, we found that only sites containing mature forest fragments had detections of several bird species designated as high-confidence IFS species. Our results suggest that deriving specialized species diversity metrics from point survey data can add value when interpreting those data. Additionally, designing studies to collect these metrics may require explicitly planning to visit multiple habitat types at a monitoring site and increasing the number of visits per survey point. Integr Environ Assess Manag 2024;20:1954-1968. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Microhabitat coverage influences avian species composition more than habitat heterogeneity in Hong Kong urban parks

The relationship between habitat heterogeneity and diversity can underpin design of urban spaces for biodiversity conservation. The area-heterogeneity trade-off hypothesis predicts that higher habitat heterogeneity should result in an increase in species richness but only up to a point, beyond which habitat micro-fragmentation leads to decreases in species diversity. However, the strength of area-heterogeneity trade-offs at small spatial scales is not well studied. We studied the relationship between avian diversity and habitat heterogeneity in 16 small urban parks across Hong Kong during the winter dry season across 2016 and 2017 (ten repeated surveys in total for each park). Habitat heterogeneity was assessed by measuring the evenness of microhabitat coverage of seven habitats as well as vertical canopy cover. In total, 12,973 individuals of 73 bird species were recorded in the study. Habitat heterogeneity had a small but negligible effect on total bird species richness or abundance. However, water coverage was positively related to total, intermediately rare and habitat specialist bird species richness, and shrub coverage was positively related to total and common bird species richness. These results demonstrate that environmental heterogeneity had little effect on avian species richness in urban green spaces at small spatial scales. We also found that microhabitat coverage can affect avian diversity and abundance, and these effects are specific to certain groups of bird species. When managing urban green spaces for biodiversity conservation in densely urbanized cities, a decrease in management disturbance (e.g. tree topping or pesticide application) will likely benefit avian species. Together with the fact that some locally uncommon species were observed throughout the study, capacity exists for environmental enhancement of these small urban parks to contribute to local avian conservation.

Assessment of bird diversity and abundance in Mai-Nigus artificial reservoir and surrounding semi-forest in Tigray Region, Northern Ethiopia

BackgroundArtificial reservoirs are alternative habitats for bird diversity, and knowledge of the diversity and abundance of bird species contribute to the management of the ecosystem. This study was conducted to investigate the species diversity and abundance of birds in Mai-Nigus reservoir and its surrounding semi-forest from July 2022 to March 2023. Point count method with a total of fifteen count stations at an interval of 50 m radius was used to study the diversity and abundance of bird species in the semi-forest habitat while total count employed on the reservoir.ResultsA total of 123 bird species comprising endemic and globally threatened species were identified. Order Passeriformes had the highest number of species followed by Charadriiformes and Pelecaniformes. Family Scolopacidae was the most abundant followed by Ardeidae, Ploceidae and Anatidae. Bird species richness and abundance were not significantly varied across seasons and habitats (P > 0.05). The highest species diversity (H´=3.96) were recorded in the Semi-forest during the wet season, whereas the least was recorded from reservoir during the dry season (H´=2.66). The highest and lowest species evenness of birds was recorded in Semi-forest (E = 0.725) and reservoir (E = 0.448) during the dry season, respectively. Most birds that inhabited the area had frequent relative abundance followed by uncommon and common species.ConclusionMai-Nigus reservoir and surrounding habitat host high bird diversity and this requires critical conservation concerns for the long-term survival of birds.

Patch shape, connectivity and functional groups moderate the responses of bird diversity to agricultural diversification — A meta-analysis

Agricultural expansion and intensification pose significant threats to global biodiversity. However, the conservation of agricultural biodiversity is essential for harmonizing agricultural production with ecological sustainability. Agricultural diversification can mitigate the negative impacts of agriculture on ecosystem functioning and biodiversity. Characteristics of the broader landscape may also play an important moderating role in diversified agricultural landscapes, but are not fully solved. To bridge this gap, we conducted a meta-analysis of peer-reviewed studies to compare bird abundance and species richness in diversified agricultural landscapes compared to those in simplified farmlands and natural landscapes. We also explored the moderating role of species functional groups and 11 metrics of landscape composition, configuration and heterogeneity. We found a generally positive effect of perimeter-to-area ratio of farmland patches, connectivity within farmland patches, and connectivity within patches of natural and semi-natural habitats on bird abundance and species richness. Responses to other landscape metrics were less consistent. For pollinators, the abundance was higher in diversified agricultural landscapes compared to control groups, and particularly when compared to natural landscapes. For natural enemies, the species richness was significantly lower in diversified agricultural landscapes than in natural landscapes, while their abundance was not. The overall abundance and species richness of granivores and frugivores in diversified agricultural landscapes were comparable to those in control landscapes. These results indicated landscape type of control groups, species functional groups, and their interactions had consistent impacts on the responses of bird diversity. We found a vital role of farmland patch shape and connectivity within farmland and habitat patches for bird conservation in diversified agricultural landscapes, which has been rarely reported in previous studies. These insights underscore the need for policymakers and managers to develop farmland management and planning strategies at multiple scales to fulfill growing human demands while achieving biodiversity conservation objectives.

The role of conservation agriculture in enhancing biodiversity and common beans productivity

Conservation of biodiversity in agricultural landscapes is vital for maintaining ecosystem stability and resilience. Conservation agriculture, a sustainable farming approach that involves minimum tillage and reduced use of synthetic pesticides, herbicides, and growth promoters, has gained attention as a potential strategy to enhance biodiversity and reduce production costs. This study investigated the role of conservation agriculture in enhancing biodiversity and common bean productivity in Tanzania. The study compared plots practicing conservation agriculture (minimum tillage and reduced agrochemical use) with those using conventional farming methods. Biodiversity metrics, that is, earthworm populations, bird species richness, bird nest abundance, bird species diversity, bee visitation rates, and bean yield were assessed. The results showed significant positive effects of conservation agriculture on biodiversity, emphasizing its potential role in promoting sustainable agriculture, biodiversity conservation, and household improvement due to reduced production costs and increased yield per unit area. Earthworms per meter square observed to increase from 12 in the non-conservation plots to 34 in the conservation plots, which is likely to improve nutrient cycling and productivity. Furthermore, conservation plots had a higher number of bird species flying around (36−76) compared with 14–32 in non-conservation plots (4000 m2) at 50 % bean flowering. The number of bird nests observed in the two plots during bean harvesting varied significantly (P<0.05), where the number of bird nests observed in 4000 m2 of non-conservation plots ranged from 14 to 36, compared to 12–62 in conservation plots. High bird nest numbers in conservation plots indicated higher bird habitat quality in conservation plots than in non-conservation plots. Bees as chief pollinators, bees visiting conservation plots during 50 % flowering per square meter ranged from 5 to 11, compared to 2–6 in non-conservation plots. Bee visitation to bean flowers has a significant influence on productivity, as it influences pollen transfer and fertilization. Common beans yield among plots ranged 0.9 tons/ha to 1.4 tons/ha in conservation plots compared to 0.35–1.01 tons/ha, in non-conservation plots. Land use conservation contributes considerably to economic growth through increased productivity and reduced production costs, where the production cost is reduced by 50 % in conservation plots compared with non-conservation plots. However, the present study was conducted in a single location with smallholder farmers; hence, further experiments over larger areas and longer time periods are needed for a more robust conclusion.