Nesting material adaptation of native bird species with anthropogenic litter along an urbanization gradient in Pakistan.

Rapid urbanization and associated waste generation have become a mounting ecological concern for wildlife, especially avian communities. Research has primarily focused on investigating the impacts of human activities on marine birds with comparatively less focus on terrestrial species that live in far more anthropized environments and are at significant risk. Our study has explored the abundance and characteristics of anthropogenic litter in 70 nests of four generalist bird species: Bank Myna (Acridotheres ginginianus) , Common Myna (Acridotheres tristis), Black Kite (Milvus migrans) and House Crow (Corvus splendens) , within the city of Lahore (Pakistan) and its surroundings, by determining and following an urbanization gradient. The overall frequency of litter occurrence (FLO%) for all the sampled nests was 89%. Over 80% of the recorded litter items consisted of plastic materials, primarily dominated by sheet-like plastics. There was a strong association between fabric and Black Kite nests, and metal and House Crow nests. Litter incorporation increased across the gradient from rural to urban habitats. The highest FLO% was found in nests sampled from waste dumping sites and urban sites (95%–100%), where anthropogenic influence was more intense. The high level of litter incorporation is potentially indicative of a species' adaptive response to urbanization, associated with the decline in natural nesting material and availability of anthropogenic litter. These findings highlight the need for strengthening the existing global database for terrestrial litter and its effect on wildlife and devising policy actions for better waste management and conservation of natural ecosystem balance. [Display omitted] • The presence of litter in nests is indicative of surplus availability of anthropogenic waste in the surroundings. • The abundance of plastic sheets in cavity nests suggests its use as cushioning material. • High incorporation of fabric and metal in platform nests reflects its use as a structural material. • Frequency of anthropogenic litter incorporation increased along the urbanization gradient. • Nests in urban and waste dumping sites showed the highest variety of anthropogenic litter. [ABSTRACT FROM AUTHOR]