Bird Diversity in Urban Residential Areas: In Supporting Sustainable Agriculture

Being able to live in natural and artificial environments, the bird is the most commonly encountered wild animal in areas with plants. Having vast areal coverage makes this species a vital natural resource (Pei et al., 2018; Tryjanowski et al., 2017) as it serves the function as a parameter of areal metamorphosis (Sekercioglu, 2012; Xu et al., 2018) in ecological system harmony (Chanate et al., 2020; Machar et al., 2021). Perceptible to interaction among ecosystem elements, it is inevitable that birds support the environmental sustainability cycle (Batisteli et al., 2018) by distributing vegetation. Birds for agricultural activities can help control pests and pollinate crops.

A specific locale’s variety of living environments should impinge on its bird diversity (Lešo et al., 2019; Vale et al., 2018). As one fulfills certain birds’ needs for living and breeding (Shah and Sharma, 2022), different characteristics affect the ranges of birds found (Hagen et al., 2017; Xu et al., 2018). It is, therefore, imperative to conserve such areas to protect bird species (Hoek et al., 2017), and the attempt requires data on habitation, similar individual assemblage, and local situation.

Physical and human resource development has been underway in the capital of Riau province, Pekanbaru. Specifically, in the Umban Sari District of the Rumbai Region, more land has been opened for plantations, business spots, and residences, involving more people. The activity must be effective toward birds’ existence as less and less vegetation remains in their habitats. Birds (and other species of animals) subsist with sufficient food and dwellings (Benedetti et al., 2022), and their decrease in number and variety is often caused by ecological disturbance due to area function changes (Callaghan et al., 2018).

When plants are in their landscapes, residential areas can serve as bird dwellings in addition to homes for humans (Hagen et al., 2017). Notably, plant diversity supports more bird species (Vijay et al., 2016). Birds also play an essential role in agricultural activities, such as controlling pests and helping pollinate plants. Land cover changes in Riau Province from 2012 to 2020 were dominated by oil palm plantations and plantation forests, which tended to be homogeneous at 60.79 %, and there was a continuing upward trend (Forestry, 2021). This condition has an impact on bird habitat, which continues to decrease (Aronson et al., 2014). This is thought to affect the diversity of bird species. The presence of diverse birds can help reduce the need for pesticides and increase plant regeneration. Therefore, identifying plant diversity, bird diversity, and bird evenness levels based on vegetation to support sustainable agriculture in residential areas is appointed as the purpose of this study.

Conducted in Rumbai Region, Pekanbaru, Riau Province, Indonesia (101o 25’ 12.41’’ E and 0o 34’ 42.61’’ N), the research started in March 2023 and concluded in October 2023. Employing a tally sheet and the map of Pekanbaru to determine habitat types, birds in the area had been observed. Equipment covered a pair of binoculars (Arsson XB821PP 500 X 25, China), camera (Canon EOS 100D DS126191, Taiwan), GPS tracker (Garmin eTrex 10 SEA, Swiss), audio recorder (Sony ICD-PX333, China), timer (Casio G Shock GA 500, Thailand), the guide book of birds (MacKinnon et al., 2010) and stationery.

Operating line transect (Bibby et al., 2000), both direct and indirect information on birds’ activity, time of encounter, variant, quantity, and behavior was recorded while moving down the streets of residential areas. Following prearranged tracks, observation time ranges were 6:30 to 8:30 AM and 4:00 to 6:00 PM. This time is the most active time for birds to do daily activities. Observations are made at least three times a week. The focused data were on the activity, name, and quantity of each bird variant found (Bibby et al., 2000).

Shannon-Wiener diversity index was exercised to assess the bird diversity level as per Equation 1 (Thukral, 2010):

H’ = - ∑ pi ln pi …(1)

Note: H’ = Shannon-Wiener diversity index; pi = (ni/N); ni = number of i variant; N = total individual; ln = natural logarithm.

The result of H’< 1.5 is considered low diversity, while H’ 1.5 to 3.5 average diversity and H’ = > 3.5 “high diversity.

To define the evenness level of a certain bird variant in a community, the Shannon-Wiener evenness index was utilized as per Equation 2 (Thukral, 2010).

E= H’/ln S …(2)

Note: E= evenness index (ranged from 0 to 1), H’= Shannon-Wiener diversity index, S= number of variants, ln= natural logarithm.

The result of 0 < E ≤ 0.4 is considered low evenness, while 0.4 < E ≤ 0.6 is average evenness, and 0.6 < E ≤ 1 is high evenness.

To calculate the variety level, the Margalef richness index is applied as per Equation 3 (Thukral, 2010):

Note: R= Margalef richness index, S= number of variants, N= total individual, ln= natural logarithm.

While R < 2.5 means a low richness level, 2.5 ≤ R < 4 shows an average richness level, and R ≥ 4 represents a high level.

To establish the dominant, subdominant, and rare bird composition, the relative density was verified in regards to Thukral (2010) as per Equation 4 and Equation 5.

A bird species is dominant when the relative density rate is >5 %, subdominant 2 % to 5 %, and rare if it is < 2 %.

The encounter rate of bird species was revealed as per Equation 6 (Bibby et al., 2000).

The categories are listed in Table 1.

Table 1: Encounter rate of birds as the basis of abundance level determination (Bibby et al., 2000).

Types of plants and parts that become food for birds were recorded for the purpose.

Overall, 1 006 individuals of 20 species belong to 14 families were detected during observation, as listed in Table 2.

Based on Table 2, the quite dominant bird species are Bondol Peking (Lonchura punctulate Linnaeus, 1758) at 19.38 %, Cucak Kutilang (Pycnonotus aurigaster Vieillot, 1818) at 12.43 %, and Burung Gereja (Passer domesticus Linnaeus, 1758) at 11.93 %. Those species are of the communal type that generally do their group activities. Sufficient vegetation for food and shelter in urban residential areas also allows them to breed (Callaghan et al., 2018; Pena et al., 2017) the birds above and others live in coconut, palm, and bamboo trees. Several nectarine family members also benefit from adequate flowering plants in the area. Cucak Kutilang birds, as insect eaters, will help control plant pests, while Bondol Peking and Burung Gereja help disperse plant seeds (Şekercioĝlu et al., 2012). This will support sustainable agricultural activities (Martinez et al., 2021).

Birds in residential landscapes serve as not only protectors of the ecosystem but also indicators of environmental change and assist agricultural activities (Batisteli et al., 2018; Dearborn and Kark, 2010; Lešo et al., 2019). The existence of varied bird species in an urban residential area should be cherished as they contribute to the natural diversity and balance (Hagen et al., 2017; Xie et al., 2020). Grain-eating, fruit-eating, and nectar-eating birds support seeding and pollination processes in plants (Şekercioĝlu et al., 2012) while insect-eating ones help to control human pests and also plant insect. Additionally, birds bring aesthetic value wherever they are. Their feathers come with assorted colors, patterns, and visually enjoyable textures. Their sounds have a calming effect that matches the purpose of a residence. The landscape of a residential area that focuses on the environment is critical to birds’ sustainability and diversity (Beninde et al., 2015). Among points of consideration are food accessibility and additional food (Ciach and Fröhlich, 2017; Tryjanowski et al., 2015), vegetation structure (Droz et al., 2019; Xie et al., 2016), and plant composition (Nooten et al., 2018).

Table 2: Birds of residential area.

Society should recognize and prevent threats to birds’ existence in an urban residential area, such as habitat loss, pollution, and hunting. Environmentally friendly activities like tree planting and pesticide restriction should help conserve birds (Cox et al., 2017, 2018) and maintain urban ecosystem sustainability (Wood et al., 2018).

The data computing results came out with a diversity index (H’) of 2.59, an evenness index (E) of 0.86, and a richness index (R) of 2.75, as detailed in Table 3.

Table 3: Diversity index, evenness index, and richenness index.

The average diversity index shows that the studied residential areas are good enough for birds to live in. The geographical situation, management intensity, and landscape complexity are essential in expanding bird diversity (Dehling et al., 2014; Lešo et al., 2019), and the studied areas can meet the requirements. As bird diversity relies on the environment, particularly shade composition and vegetation size (Callaghan et al., 2018; Vale et al., 2018), shady trees, shrubbery, fruit trees, agricultural plants, decorative plants, and grasses found in the areas support their existence quite satisfactorily.

Residential areas can provide living space for several bird species. Any change in its diversity, particularly in urban/residential areas, is often influenced by urbanization and vegetation coverage (Benedetti et al., 2022; Hagen et al., 2017; Pei et al., 2018). Protecting and developing varied green open spaces (Callaghan et al., 2018; Yang et al., 2020) for a sustainable urban environment (Namood et al., 2021) should mitigate bird diversity decline. Knowing bird species diversity in residential areas opens possibilities to conserve their habitats, keep their ecosystem balance (Nowak and Greenfield, 2012), and ensure their sustainability for the sake of the locale (Hepburn et al., 2021; Żmihorski et al., 2019).

Table 4: Density, dominance, and abundance.

The evenness index is 0.86, meaning the individuals are almost evenly distributed throughout the studied areas. This index informs diversity and ecosystem stability (Tu et al., 2020), essential in prioritizing a conservation program. Foods and predators affect the index as food availability invites birds, and certain predators shape birds’ behavior and activity. Regular observation of bird population change should serve as an early warning towards ecosystem alteration, such as green area reduction and predator overgrowth. Although birds natural fluctuation may be a challenge in interpreting the evenness index, it is a valuable insight for sustainable environmental development.

With a richness index of 2.75, the areas are considered safe for birds on average. Factors supporting bird growth, like varied habitats (trees, shrubbery, water) (Redlich et al., 2018) and a balanced ecological system (Villaseñor et al., 2020), exist. Bird richness can indicate biodiversity and environmental wellness. Therefore, areas with a high richness index should be prioritized in conservation.

Deforestation, urbanization, and land function change often devastate bird richness as they lose their natural habitats (Hepburn et al., 2021; Proppe et al., 2013; Żmihorski et al., 2019), while climate change affects bird distribution and migration. Conserving bird habitats in urban areas is critical to recovering their abundance (Aronson et al., 2014) as it defines the environmental wellness of an area (Luck et al., 2013), so ecosystem restoration is called for when it is damaged. Motivating the society to actively conserve birds and care for the environment along with the government, related organizations, and researchers should prevent birds from extinction.

Table 4 shows the relatively high density, dominance, and abundance rates of Bondol Peking, Cucak Kutilang, and Burung Gereja in the studied areas.

Table 5: Foods, species, and individuals.

Bird density refers to the quantity in an area or habitat over a certain period. Table 5 demonstrates that Bondol Peking has the highest density at 19.50, followed by Cucak Kutilang and Burung Gereja at 12.50 and 12.00, respectively.

Vegetation type, food availability, and dwelling availability determine bird density in an area. Grains, insects, or fruits in a residential area correspond to varied species monitored. Dwellings in trees or buildings are in proportion to bird reproduction and survival. The land function changes in buildings, streets, and parks influence local bird density (Dehling et al., 2014), and residential areas can drive natural habitat fragmentation toward both density and diversity (Lerman et al., 2012). Moreover, noise and air pollution in urban areas can affect birds behavior and health. Parks, gardens, and other green spots in a residential area should affect bird diversity positively as they serve as habitat structures like trees, shrubbery, and open spaces (Lerman et al., 2014).

Bird dominance signifies the proportion of a bird species in the population of a particular area. A highly dominant species tends to excel in quantity and existence. Seven observed species are dominant in the regions studied as they were more frequently seen than the others. Habitat preference, food availability, and dwelling facility determine dominance. Some species are deduced to be dominant when able to adapt to new habitats like gardens or parks and build their nests on trees, stones, or home shades. Bird dominance can be seasonal due to food availability or other environmental factors. Since land management, plant cultivation, and habitat structure changes in a residential area incline bird dominance (Pellissier et al., 2012), regular observation of their population should give further information on population dynamics and species dominance. An ecological study of their behavior and habitat preference should identify dominance factors.

Bird abundance denotes the total quantity of a bird species in a particular habitat. Dominance is closely related to it as the more dominant a species is, the more abundant it likely is. Vegetation diversity affects bird abundance and diversity (Morelli et al., 2017; Zivanovic and Luck, 2016). Issues that may agitate them are communal activities (Cristaldi et al., 2017; Zhou and Chu, 2012), artificial disturbances (Jokimäki et al., 2020; Perillo et al., 2017), and noise (Fröhlich and Ciach, 2018). However, the abundance of Burung Gereja (Passer domesticus Linnaeus, 1758) seems to be unbothered by passers-by (MacGregor et al., 2017), possibly due to habit (Skórka et al., 2016).

Urban residential area management concerning bird needs can preserve biological diversity while benefiting society ecologically and aesthetically. Therefore, social conservation, which contributes to a sustainable ecosystem in such an area, should be encouraged so birds can coexist with humans.

Based on food, insectivores and granivores are the dominant families, at 45 % and 30 %, respectively. Regarding individuals, granivores and insectivores are the dominant ones at 48.01 % and 27.14 %. The detailed observation result is provided in Table 5.

Birds obtain their foods from natural sources based on their biological needs, habitats, and seasons. Knowing the right foods should help ensure the availability and adequacy of their population while preserving their natural habitat (Harisha et al., 2021).

Table 6 lists the plants found in the studied residential areas: forest trees, fruit trees, palms, shrubbery, bamboo, agricultural plants, flowers, and grasses.

Vegetation in urban residential areas provides shelter, food, and dwellings for birds. Trees, shrubbery, and other plants are essential for bird nests (Luck et al., 2013; Zhou and Chu, 2012). Dense, leafy vegetation protects the nest and egg against predators and extreme weather. Most birds need specific vegetation structures for building their nests, such as branches, kindling, and leaves. While a lot of bird species make their nests on tall trees, shrubbery is favored by insect-eating birds. As urbanization and land function change diminish vegetation for bird dwelling (Batáry et al., 2014), retaining vegetation diversity and bird habitat by planting trees should be feasible. Expanding green space should follow as it is relevant to sustainable ecosystem management.

Vegetation and birds are linked in the food chain, so vegetation conservation in a residential area is a way to save birds (Huang et al., 2015; Lepczyk et al., 2017). Plants produce flowers for nectarines, fruit for frugivores, grain for granivores, and insects for insectivores.

Table 6: Vegetation functions for birds.

Furthermore, plants feed other animals. These facts make vegetation in an urban residential area critical for a balanced ecosystem. Invasive plants are a good choice for marginal areas.

Vegetation provides choices of protection for birds (Gillings, 2019). Leafy, shady plants are suitable for hiding from predators and staying away from rain or intense sunlight; some birds can blend with the surrounding plants for their similar colors. Plant reduction makes birds more prone to predation. Conserving vegetation in urban residential areas should support bird survival and benefit humans (Belaire et al., 2015; Cox et al., 2017; Dallimer et al., 2012).

Vegetation, particularly trees and shrubbery, is a mating place for birds (Hadinoto et al., 2023). Tall trees are ideal spots for male birds to perch, interest the females with their chirps, and mark their territories. Perching points play an important role in bird reproduction, which, in the long run, determines an area’s abundance index. If vegetation in a residential area is cut down, bird diversity will drop (Hadinoto and Suhesti, 2017).

The study discovered 1 006 bird individuals of 20 species and 14 families. The most frequently encountered kinds of bird were Bondol Peking (Lonchura punctulate Linnaeus, 1758), Cucak Kutilang (Pycnonotus aurigaster Vieillot, 1818), and Burung Gereja (Passer domesticus Linnaeus, 1758). The diversity index (H’) in Rumbai urban residential areas averages 2.59, while the evenness index (E) is 0.86, and the richness index (R) is 2.75. Food source vegetation includes but is not limited to forest trees, fruit trees, palms, bamboo, shrubbery, agricultural plants, flowers, and grasses.

The authors would like to thank “RP Editage” for providing guidance and assistance in organizing this manuscript.

Previous research (Bashan et al., 2020; Belaire et al., 2015; Hedblom et al., 2014; Lerman et al., 2021) has documented the presence of urban birds. However, previous investigations have only focused on people’s perceptions, attitudes, and appreciation of urban birds. The current research shows something new because it identifies bird species in urban residential landscapes for sustainable agriculture. Furthermore, this research found 20 unique bird species that can be used as recommendations for urban bird conservation.

Hadinoto Hadinoto: Conceptualizing and designing research, outlining the contents of the paper, conducting literature searches, collecting data, analyzing data, formatting the manuscript, preparing the manuscript, and revising the manuscript.

Lili Zalizar, Joko Triwanto, and Ervayenri Ervayenri: Supervised the manuscript’s contents literature search and reviewed the manuscript.

Eni Suhesti, Endang Dwi Purbajanti, Hasni Ruslan and Imran Ullah: Conducted literature search and manuscript review.

All authors have read and approved the final manuscript.

The authors have declared no conflict of interest.