A diet perspective on the impact of the COVID-19 lockdown on urban bird assemblages

The COVID-19 pandemic, which significantly altered human activities, particularly in urban areas, presented a unique opportunity to explore the dynamics of wildlife–human coexistence. In this study, we conducted bird counts in 36 parks in Poznań, Poland, before (2019) and during (2020) the pandemic lockdown, and assessed the impact of lockdown-induced changes in human activity on the presence of birds with different diet type in the city. We found a notable decrease in the occurrence of granivorous and waste-feeding birds in urban areas during the pandemic, but the presence of birds feeding mainly on other food sources remained relatively unchanged. This study provides initial evidence of a cross-species and diet type-related decline in bird diversity in urban parks during the COVID-19 pandemic.