Birds like the greater coucal are not known to be scavengers. Credit: Subhra Priyadarshini
Species that have not previously been known to scavenge are living off human food waste in Indian urban areas, a field study1 has revealed.
Researchers at the Indian Institute of Science Education and Research (IISER) Kolkata found jungle mynas, pied mynas, spotted doves, domestic goats, northern palm squirrels, greater coucals and ducks making use of urban food waste in 15 sites across West Bengal.
While goats and ducks are domesticated, the spotted dove and greater coucal are not typically associated with humans or known to be scavengers in these sites.
The research, which focused on scavengers consuming human-generated food waste, discovered that 17 vertebrate species actively scavenge, including 12 avian species and five mammals.The experiment carried out during the COVID-19 pandemic, involved dumping rice mixed with a vegetarian or non-vegetarian gravy at study sites.
Species approaching and eating the food were then documented across 498 observation sessions.Free-ranging dogs and common myna were the key species in the urban ecosystem. “Dogs take a lion’s share of the food, and the common myna comes in more numbers, stays longer, and overlaps with the other birds, making them key species,” says study co-author Anindita Bhadra.
Analysis showed robust scavenger networks — around 70% — demonstrating that species were not competing but co-feeding at the feeding sites. With increasing urbanisation, conservation must factor in urban biodiversity, the researchers say.
