Habitat heterogeneity influences avian feeding guild composition in urban landscapes: evidence from Bhubaneswar, India

Abstract

Background Habitat heterogeneity clearly distinguished in terms of availability of food and habitat resources and landscape features (natural or human-modified) play a crucial role in the avian species composition and population structure. To examine this, a study was carried out in Bhubaneswar, India, to understand the ecological niche distinction in birds based on habitat heterogeneity. Regular sampling was conducted in 30 sampling sites covering six different habitat types in a predominantly urban landscape of Bhubaneswar for understanding the ecological niche in birds. The birds were classified into 11 types of foraging guilds. Results The insectivorous guild had the highest bird species richness (181 species) and the omnivorous guild had the lowest (11 species). The piscivorous guild and wetland habitat had the strongest linkage, followed by the insectivorous guild and agricultural land. The frugivorous guild was significantly correlated with forest habitats (r = 0.386, p < 0.01) and park and garden habitats (r = 0.281, p < 0.01). This urban area hosted a higher number of bird species in certain habitat types, viz., agricultural lands (52%, 115 species) and forest patches (50%, 111 species). Conclusion The present study highlights the importance of agricultural lands, forest patches, parks and gardens, and wetlands inside the cityscape for supporting avifauna. It is therefore suggested that such habitats should be conserved inside an urban area to protect native avifauna. Thus, the city development plan must invariably include strategies for conserving the forest patches inside the urban area. Measures must be taken to restrain the degradation of agricultural lands and reduce their utilization for non-agricultural purposes, which will help in further reducing the bird population decline in the urban landscape.

Tribhuvan University area serves as a greenspace for birds in the Kathmandu Valley, Central Nepal

“…There were similar ecological studies done in the agroforestry industry of Indonesia (Withaningsih and Alham, 2020), the urban landscapes of India (Panda et al, 2021) and Indonesian urban habitats (Pudyatmoko and Nurvianto, 2009) that showed high alpha diversity values. Similarly, bird density in different habitats of the TU was calculated and we found that higher density was observed in the forest habitat.…”

“…The least number of species was observed in the farm habitat. Several bird studies in urban gardens and parks have shown similar results, indicating that forest sections have a high diversity (Pudyatmoko and Nurvianto, 2009;Panda et al, 2021).…”

“…From the perspective of feeding guilds, the most dominant feeding category at TU is insectivorous and the minority of bird species are granivorous. Similar ecological studies at the University of Lampung (Iswandaru et al, 2020), Musanze's urban landscape (Gatesire et al, 2014) and urban landscapes from Bhubaneswar (Panda et al, 2021), revealed that insectivore is the most dominant feeding guild.…”

Feeding guild structure of birds at Keshopur Chhamb wetland, Gurdaspur

“…Feeding is an important activity in the life of the bird which is indispensible for their survival (Panda et al, 2021). Feeding guilds of birds provide insight into the ecology of species and are particularly useful in studies that assess specific ecological drivers of community change.…”

Avian Diversity and Its Feeding Guilds in Respect to the Rural Landscape of District Barnala (Punjab)

“…Members of the carnivorous guild, such as the cattle egret and Red-wattled lapwing, were seen to eat on insects as well and were therefore classified as members of several guilds. Feeding is an important activity in the life of the bird which is indispensable for their survival [31]. Guild categorization among birds emphasizes the functional component of a community in an ecosystem.…”