Ecological impacts of poultry waste on urban raptors: conflicts, diseases, and climate change implications amidst pandemic threats

Abstract

AbstractThe dramatic increase in poultry production and consumption (PPC) over the past decades has raised questions about its impacts on biodiversity, particularly in the Global South. This study focuses on the ecological and environmental impacts of PPC waste metabolism at Asia’s largest livestock wet market, located next to the continent’s largest landfill ofGhazipurin Delhi, which I have been monitoring since 2012.Daily processing of >100,000 poultry-fowls atGhazipurresults in an annual production of ∼27,375 metric tonnes of poultry-waste, attracting massive flocks of Black-eared kites, migratory facultative scavengers that winter in South Asia. Approximately >33,600 kites foraged in the area every day and disposed 8.83% of the total PPC slaughter-remains produced during October-April. However, with their return migration to Central Asia, kite flocks overGhazipurreduced by 90%, leading to a proportional decrease in scavenging services. Absence of kites from the larger, migratory race during May-September did not elicit any compensatory response from the small Indian kite, whose numbers over landfill remained unchanged. This raises vital questions about microclimate impacts by green house gases (GHG) released from massive amounts of routine detritus. Bearing in mind the prevalence of ritual feeding of meat chunks to kites in Delhi, my research indicates how life-history traits (migratory vs. resident) enable exploitation of specific anthropogenic resources, creating distinct kite-niche(s). Other opportunistic scavengers, e.g., dogs, rats, cattle-egrets, several passerines, and livestock (fishes and pigs) also benefited from PPC waste.Public health and ethical concerns, including Avian-influenza outbreaks in 2018-21 and pandemic-lockdowns from 2020-22 - that affected informal meat processing - reduced the flocking of kites atGhazipurby altering spatial dispersion of PPC remains.Waste-biomass driven cross-species associations can exacerbate zoonotic threats by putting humans and animals in close contact. The ecological impacts of waste-based biomass, as well as the aerospace conflicts caused by avian scavengers that cause birdstrikes must factor in the integrated management of city waste. The quantity, type, dispersion, and accessibility of food-waste for opportunistic urban fauna in tropical cities along avian migratory pathways are crucial for public health, and for conservation of (facultative) migratory avian-scavengers like Eurasian Griffons and Steppe Eagles that are facing extinction threats.Lay SummaryThe global trend of increasing consumption of broiler chickens, driven by rising incomes in tropical cities, has significant ecological implications for both native and migratory birds, as well as other commensal species.The resulting large amounts of debris produced by poultry production and consumption have created a “chicken reconfigured biosphere” in cities along migratory paths.To better understand the local and global impacts of poultry production and consumption chains, I conducted a long-term study at Asia’s largest livestock wet market inGhazipur, Delhi.The findings reveal that informal handling of poultry waste and cultural practices have had significant impacts on animals that scavenge on the slaughter remains, particularly during the bird flu and COVID-19 pandemics.The study recommends ways to minimise conflicts and health risks and reduce the potential impacts of rotting garbage on the climate by accommodating animals that have adapted to shared urban environments.