Changes in the feeding ecology of an opportunistic predator inhabiting urban environments in response to COVID-19 lockdown

12 pages, 4 figures, 3 tables, supplementary material https://doi.org/10.6084/m9.figshare.c.6534041.-- Data accessibility: The raw stable isotope data is provided in the electronic supplementary material. The data are provided in the electronic supplementary material

Urban-dwelling species present feeding and behavioural innovation that enable them to adjust to anthropogenic food subsidies available in cities. In 2020, the SARS-CoV-2 virus outbreak resulted in unprecedented reduction in the human activity worldwide associated with the human lockdown. This situation opened an excellent opportunity to investigate the capability of urban wildlife to cope with this anthropopause event. Here, we investigated the effects of the COVID-19 lockdown on the feeding strategies of the urban yellow-legged gull (Larus michahellis) population inhabiting the highly dense city of Barcelona (NE Spain). We compared the diet of chicks (through stomach content and stable isotope analyses) sampled randomly around the city of Barcelona before (2018 and 2019), during (2020) and after (2021) the COVID-19 lockdown. The results revealed that the anthropopause associated with the lockdown had an effect on the diet of this urban-dwelling predator. The diversity of prey consumed during the lockdown was lower, and consumption of urban birds (pigeons and parakeets) and marine prey (fishery discards and natural prey) decreased during the year of lockdown. Although it was not analysed, these diet changes probably were associated with variations in the availability of these resources due to the decrease in human activity during the lockdown. These results demonstrate the trophic flexibility of urban-dwelling species to cope with the changes in the availability of human-related anthropogenic resources in urban marine ecosystems

This study is a contribution of the ICM-TEF (Trophic Ecology Facility of the Institut de Ciències del Mar—CSIC), of the BCN-Gulls project and the Master's thesis of M.V.-G. M.V.-G. and J.G. were supported by a JAE-Intro grant of CSIC (JAEIntro2020, CSIC) and a contract of the Spanish National Program Juan de la Cierva-Formación (FJC2019-040016-I), respectively. This work acknowledges the accreditation of the ‘Severo Ochoa Center of Excellence’ (CEX2019-000928-S). Open Access funding provided thanks to the CRUE-CSIC agreement with Royal Society

Peer reviewed