Where Have All the Storks Gone? Impact of Landfill use on White Stork Behaviour and Population Dynamics

The current biodiversity crisis shows that many species struggle to cope with the drastic changes driven by human expansion, yet some thrive in human-altered environments. White Stork (Ciconia ciconia) populations have grown considerably in recent decades, due to their ability to exploit anthropogenic food waste. Thousands of storks now rely on landfills and rubbish dumps year-round, as feeding on anthropogenic subsidies reduces travelling and foraging times, thus lowering overall energetic costs. This steady food supply has altered movement patterns, enabling year-round nest use and influencing home-ranges and affecting breeding and non-breeding behaviours. This shift in the dietary regime has significantly impacted migratory behaviour, with an increasing number of storks wintering in Southern Europe, closer to their breeding grounds, or even abandoning migration entirely. Feeding on landfill waste improves body condition, reproduction and survival, influencing population dynamics and distribution. However, this behaviour may produce contrasting impacts that remain largely unquantified, by significantly increasing the risk of pathogen infections, poisoning and ingestion of foreign bodies, which can affect storks' health and survival. While reducing food waste remains a global challenge, understanding the ecological and evolutionary implications of human-provided food on White Storks is critical for conservation and addressing broader human-wildlife conflicts.