This research took place at the Nothern Aldabasin Bridge, Khartoum Sudan it located on the White Nile upstream of the New White Nile Bridge linking Khartoum with Omdurman ( Photo 1 ). The Aldabasin White Nile Bridge is expected a vital transportation link connecting the neighborhoods of Aldabasin and Khartoum North. This bridge will play a crucial role in facilitating travel and commerce across the White Nile, contributing to the region’s infrastructure and connectivity.

The research site encompasses a variety of plant species, shrubs, and small trees, surrounded by traditional crop-filled agricultural fields. Scattered palm trees and fruit orchards, each hosting unique bird habitats, complement the diverse landscape. Bordered on one side by the Nile River, this location is situated amidst alongside primary agricultural irrigation canals, featuring thick clusters of greenery, undergrowth, and various tree species. The study area is regarded as an important habitat for birds due to its surrounding vegetation and wetlands, which provide suitable environments for avian species.

Khartoum is situated at a geographical crossroad, with coordinates ranging from 15˚N to 16˚N latitude and 31.5˚E to 34˚E longitude. The city experiences a pronounced climate: summers are typically rainy, while winters are cool and dry. Temperatures in the summer months, particularly from April to June, can soar between 25˚C and 40˚C. In contrast, from July to October, they generally fluctuate between 20˚C and 35˚C. This vibrant city lies at the convergence of the Blue and White Nile rivers, with Omdurman to the west and Khartoum North to the north, creating a significant urban area in Sudan ( Ali, 2017 ).

Throughout the study, a comprehensive record of 80 bird species was documented, totaling 3708 individuals. These species belonged to 41 families and 17 orders See ( Figure 1 ) showcasing varied abundances in the North Aldabasin Bridge area. The distribution within orders is as follows 1 species belongs to the Psittaciformes order, another to Cuculiformes, 1 to Suliformes, 2 species are classified under Anseriformes, and 1 additional species is included in Caprimulgiformes, 1 species in Gruiformes, 1 species in Coliiformes, 1 species in Recurvirostridae, 2 species in Accipitriformes, 10 species in Pelecaniformes, 2 species in Apodiformes, 16 species in Charadriiformes, 3 species in Columbiformes, 2 species in Bucerotiformes, 30 species in Passeriformes, 5 species in Coraciiformes, and 2 species in Ciconiiformes, See ( Figure 2 ) and ( Figures 3-20 ).

The variety of bird orders found in Eastern Al Dabasin Bridge demonstrates a rich tapestry of ecological roles, indicative of the area’s capacity to support a wide array of avian niches. Passeriformes, with its large number of species, highlights a typical pattern in which more adaptable and generalist groups dominate diverse landscapes furthermore presence of Pelecaniformes, which rely on aquatic habitats, underlines the significant influence of the nearby Nile River, supporting niche differentiation and resource partitioning among water-dependent species ( Brown, 1984 ). Specialized orders like Psittaciformes and Caprimulgiformes appear in smaller numbers, suggesting limited or higher dependency on specific resources, the diverse orders observed indicate a balanced ecosystem, where competition is minimized through varying levels of specialization and habitat preferences.

The most abundant family had stood out as the most abundant and species-rich, indicating its diversity in the Eastern Al Dabasin Bridge, is the “Ardeidae”, Subsequently “Scolopacidae”, “Estrildidae”, “Muscicapidae” and “Columbidae”, all of which were notably well-represented across the study study area, In contrast, families such as “Platystriridae”, “Indicataridae”, “Glaredidae”, “Psitadidae”, and “Coraciidae” were observed in lower numbers and contained fewer species; Additionally, families like the “Ciconiidae”, “Caprimulgidae”, and “Recurvirostridae”, Ciconiidae, Coliidae, Coraciidae, Cuculidae, Hirundinidae, Jacanidae, Leiothrichidae, Passeridae, Phalacrocoracidae, Pluvianidae, Psittaculidae, Pycnonotidae, Rallidae, Sturnidae, Sylviidae and Upupidae ( Figure 21 ).

The study documented 3708 individual birds belonging to 41 families and 80 species, highlighting the remarkable richness of avian diversity within the region. This diversity is probable attributed to area’s abundant food sources, the presence of diverse flora around the North Aldabasin Bridge, and the presence of water. The peak number of birds recorded in July and December and lowest number was during September, the data on monthly bird observations throughout the study period can be found in ( Figure 22 ) and ( Appendix 1 ). The area encompasses various agricultural schemes, offering a diverse array of microhabitats that cater to different bird species. The influential role of vegetation cover on avifauna is well-established ( Mills et al., 1989 ). The agricultural schemes offer ample and suitable habitats for bird feeding and resting. Fluctuations in observed Avian throughout the research could be linked to migration behavior, as some migratory Avian may utilize the area for foraging or as a stopover. The notable high diversity of bird species noted in the study area indicates that the habitat is conducive and suitability habitat to avian life. Nevertheless, the escalating human activities pose significant threat for the survival of these species. The population of birds recorded in the study area indicates that ecological succession may play a role, with variations possibly linked to seasonal rainfall causing inundation surrounding the study area, prompting birds to roost in nearby trees.

The seasonal abundance of bird species, peaking in July and December, reflects migratory patterns influenced by environmental conditions and resource availability. This aligns with the optimal foraging theory, which posits that organisms select habitats that maximize energy efficiency relative to food resources and environmental conditions ( Pyke et al., 1977 ). The abundance of birds during these months suggests that the habitat around Eastern Al Dabasin Bridge serves as a key foraging and resting ground during migration, a crucial function in the broader avian migratory network ( Newton, 2008 ).

Additionally, the migration-linked species diversity supports the resource-tracking hypothesis, which theorizes that birds migrate based on predictable resource patterns, such as those provided by seasonal fluctuations in food availability and climate. This predictable seasonality reinforces the site’s ecological importance within larger flyway networks, enable safe migration ( Kirby et al., 2008 ). See Photos 2-6 for examples of avian diversity observed in North Aldabasin Bridge.

The diversity of habitat is shaped by the presence of water features, farmlands, and clusters of shrubs and trees, each contributing to the ecological value for bird populations. Agricultural activities, combined with natural vegetation and water availability, create favorable conditions that support bird feeding, nesting, and resting requirements by offering consistent access to essential resources, bird survey results can be significantly affected by various factors, including the season, time of day, and variations in local habitats, such as changes in elevation ( Davies, 2002 ). Additionally, other influencing factors include weather conditions, the presence of humans, the experience level of the observers, the number of observers, and their individual limitations. In Sudan, the avifauna comprises a total of 1013 species, some of which are classified as migratory and move during the year. Therefore, for a more comprehensive understanding and effective monitoring of habitat biodiversity, it is essential that surveys are conducted across different seasons and under varying conditions.

Among the bird species observed, the House Sparrow had the highest frequency, with a recorded count of 372 individuals, making it the most common across the study site. The Spur-winged Lapwing followed with 221 sightings, while the Greater Blue-eared Starling, Laughing Dove, and Black Kite were also notable, with individual counts of 188, 171, and 170, respectively (refer to Appendix 1 ).

The mixed habitats surrounding Eastern Al Dabasin Bridge provide multiple resources that support high bird diversity, a concept central to the intermediate disturbance hypothesis. This suggests that moderate disturbances foster biodiversity by creating new ecological niches, leading to greater species richness ( Connell, 1978 ). The mosaic of water bodies, vegetation, and agricultural land supports both specialist and generalist species, providing refuge, food, and nesting opportunities. This heterogeneity also allows niche partitioning, whereby species coexist by exploiting different resources or times, reducing interspecies competition and stabilizing the ecosystem ( Schoener, 1974 ).

Taxonomic classification and species identification of the birds documented in this study were carried out following the guidelines of the IUCN Red List of Threatened Species ( IUCN, 2015 ). The conservation status for each species has been detailed in Appendix 2 , While all bird species in this study were of Least Concern (LC) per the IUCN, the rapid urbanization around Eastern Al Dabasin Bridge suggests the need for proactive conservation measures to preserve avian diversity. limiting pollution, and maintaining ecological corridors are essential to support the area’s ecological integrity and reduce edge effects that may disrupt species’ breeding and feeding patterns. Given its location within a migratory corridor, the bridge area’s conservation needs align with the flyway conservation approach, which emphasizes coordinated management across multiple sites for effective protection of migratory species. By maintaining habitat quality and connectivity within this network, regional biodiversity goals can be achieved, ensuring long-term support for both resident and migratory bird populations ( Sutherland et al., 2004 ).

The Eastern Al Dabasin Bridge is home to various bird species whose populations and habitats face challenges due to human activities. These disturbances have disrupted bird diversity and threaten the sustainability of their habitats. During this study, several key human-induced impacts were identified, each of these human-induced factors presents significant, often lasting, consequences for the bird populations and habitat health in the Al Dabasin Bridge. Addressing these issues through comprehensive environmental management and conservation initiatives is essential to safeguard the region’s biodiversity and the survival of its avian species.

1) Nile River Pollution from Sewage and Industrial Waste: Pollution in the Nile River, caused by the release of untreated sewage and industrial waste, poses a major threat near the Al Dabasin Bridge. Chemical and biological contaminants, including heavy metals like lead and mercury, along with organic pollutants such as phosphates and nitrates, degrade water quality and reduce oxygen levels. This contamination harms fish and other aquatic life, which are primary food sources for many bird species. The deteriorating conditions may force birds to migrate to find safer feeding grounds, decreasing local populations. If pollution persists, the long-term biodiversity of the region may be at risk, particularly for species sensitive to water quality ( HCENR Report, 2021 ).

2) Tree Removal and Soil Disruption from Bridge Construction: The construction of the bridge has led to the removal of vegetation and soil displacement, which decreases the availability of nesting sites and feeding areas. This reduction in habitat can force some birds to relocate in search of suitable environments.

3) Tree Burning by Visitors: Some visitors burn trees for cooking or warmth, leading to the destruction of critical vegetation. This practice diminishes natural habitats essential for birds, including nesting sites and food sources, as observed through visual documentation ( Photo 7(a) ).

4) Improper Waste Management: Waste accumulation disrupts the ecological balance, attracting certain bird species like crows but negatively impacting others. Images taken during the study illustrate how waste build-up contributes to soil and water pollution, undermining the habitat quality for various local bird populations ( Photo 7(b) ).

5) Noise Disturbance from Visitor Activity: Human presence and activity generate noise levels that disrupt the area’s bird populations, which are highly sensitive to changes in sound. This noise disturbance drives birds away from nearby areas and can hinder breeding success by interfering with communication and natural behavior patterns.

6) Anticipated Impact of Vehicle Noise After Construction: Once the bridge is completed, regular vehicle traffic is expected to add ongoing noise pollution, which may particularly disturb noise-sensitive bird species. This will likely disrupt their behavior and regular activities within the region.

7) Grazing by Livestock: Grazing activities in the region impact plant life that birds rely on for food and shelter. Documented observations reveal that the reduction of plant cover from cattle grazing exerts pressure on bird species, sometimes causing them to abandon the area ( Photo 8 ).

The researchers would like to extend heartfelt thanks to their colleagues, particularly the enthusiastic young Sudanese birders: Hind, Islam, and Samah, whose enthusiasm and support greatly enriched the final survey of this study. A special acknowledgment is extended to Moneer KhaliL, the Director of Winji Tour Company, for facilitating the provision of equipment and aiding in data collection.