COVID-19 lockdown effects on the foraging strategies of a facultative scavenger

Human activity has profoundly shaped the landscape of resources available to animals. While certain species, such as scavengers, are particularly adapted to exploit resources that fluctuate significantly over space and time, their responses to sudden human-induced changes in resources remain poorly understood. The COVID-19 lockdown offered a natural experiment to study these dynamics, as reduced human mobility abruptly decreased roadkill availability for scavengers. Here, we examined how reductions in roadkill affected the foraging behaviour of an avian facultative scavenger, the red kite (Milvus milvus). We hypothesized that with fewer carcasses available, red kites would decrease their use of roads for scavenging. GPS tracking data from 199 non-breeding individuals confirmed that red kites switched from actively selecting roads before the lockdown (2017-2019) to avoiding them during lockdown (2020), with the trend reversing again afterwards (2021-2023). Selection for areas with higher probability of anthropogenic feeding increased during lockdown and remained elevated afterwards. Our findings highlight that abrupt changes in human activity can drive rapid behavioural shifts in a generalist forager, with certain effects lasting for years after the change.